x-ray diffraction vibrating: Topics by Science.gov

Sample records for x-ray diffraction vibrating

Coherence Length and Vibrations of the Coherence Beamline I13 at the Diamond Light Source

NASA Astrophysics Data System (ADS)

Wagner, U. H.; Parson, A.; Rau, C.

2017-06-01

I13 is a 250 m long hard x-ray beamline for imaging and coherent diffraction at the Diamond Light Source. The beamline (6 keV to 35 keV) comprises two independent experimental endstations: one for imaging in direct space using x-ray microscopy and one for imaging in reciprocal space using coherent diffraction based imaging techniques [1]. In particular the coherence experiments pose very high demands on the performance on the beamline instrumentation, requiring extensive testing and optimisation of each component, even during the assembly phase. Various aspects like the quality of optical components, the mechanical design concept, vibrations, drifts, thermal influences and the performance of motion systems are of particular importance. In this paper we study the impact of the front-end slit size (FE slit size), which determines the horizontal source size, onto the coherence length and the detrimental impact of monochromator vibrations using in-situ x-ray metrology in conjunction with fringe visibility measurements and vibration measurements, based on centroid tracking of an x-ray pencil beam with a photon-counting detector.
Vibrational spectra, powder X-ray diffractions and physical properties of cyanide complexes with 1-ethylimidazole

NASA Astrophysics Data System (ADS)

Kürkçüoğlu, Güneş Süheyla; Kiraz, Fulya Çetinkaya; Sayın, Elvan

2015-10-01

The heteronuclear tetracyanonickelate(II) complexes of the type [M(etim)Ni(CN)4]n (hereafter, abbreviated as M-Ni-etim, M = Mn(II), Fe(II) or Co(II); etim = 1-ethylimidazole, C5H8N2) were prepared in powder form and characterized by FT-IR and Raman spectroscopy, powder X-ray diffraction (PXRD), thermal (TG; DTG and DTA), and elemental analysis techniques. The structures of these complexes were elucidated using vibrational spectra and powder X-ray diffraction patterns with the peak assignment to provide a better understanding of the structures. It is shown that the spectra are consistent with a proposed crystal structure for these compounds derived from powder X-ray diffraction measurements. Vibrational spectra of the complexes were presented and discussed with respect to the internal modes of both the etim and the cyanide ligands. The C, H and N analyses were carried out for all the complexes. Thermal behaviors of these complexes were followed using TG, DTG and DTA curves in the temperature range 30-700 °C in the static air atmosphere. The FT-IR, Raman spectra, thermal and powder X-ray analyses revealed no significant differences between the single crystal and powder forms. Additionally, electrical and magnetic properties of the complexes were investigated. The FT-IR and Raman spectroscopy, PXRD, thermal and elemental analyses results propose that these complexes are similar in structure to the Hofmann-type complexes.
The effect of the cation substitution on the structural and vibrational properties of Cs2NaGaxSc1-xF6 solid solution

NASA Astrophysics Data System (ADS)

Doriguetto, A. C.; Boschi, T. M.; Pizani, P. S.; Mascarenhas, Y. P.; Ellena, J.

2004-08-01

Raman scattering and x-ray diffration were used to characterize the structural and vibrational properties of the Cs2NaGaxSc1-xF6 solid solutions, for x ranging from 0.0 to 1.0. The Raman spectra, taken at room and low temperature, allow us to follow the phase evolution in detail and indicate the breaking of the local symmetry since low Ga concentration levels. Five compositions were studied by x-ray diffraction: x=0.0, 0.2, 0.5, 0.8, and 1.0. A cubic space group, Fm3¯m, was found to x=0.0 and x=0.2 and a trigonal one was found to x=0.5, 0.8, and 1.0. Details of both phases are presented and the correlation between x-ray diffraction and Raman scattering is discussed.
Characterization of Al-ALLOYS (50xx) by Using Positron Annihilation, X-Ray Diffraction and Vibrating Reed Techniques

NASA Astrophysics Data System (ADS)

Kumar, Uday; Badawi, Emad; Mukhopadhyay, P. K.

A series of Al-Mgx alloys, with x = 0.82, 2.09, 2.28, 2.49 and 4.47 wt.%, respectively were characterized by using positron annihilation lifetime studies (PAL), X-ray diffraction (XRD), and sound velocity and internal friction using a vibrating reed technique (VRT). PAL lifetime values increase linearly as the composition is varied, but texturing or preferential orientation is maximum at an intermediate value of composition (x = 2.49%). The internal friction shows a minimum at the same composition, and the sound velocity changes show the maximum value here too. This means that at this composition the sample is the most ordered and defect free.
Spatial Distortion of Vibration Modes via Magnetic Correlation of Impurities

NASA Astrophysics Data System (ADS)

Krasniqi, F. S.; Zhong, Y.; Epp, S. W.; Foucar, L.; Trigo, M.; Chen, J.; Reis, D. A.; Wang, H. L.; Zhao, J. H.; Lemke, H. T.; Zhu, D.; Chollet, M.; Fritz, D. M.; Hartmann, R.; Englert, L.; Strüder, L.; Schlichting, I.; Ullrich, J.

2018-03-01

Long wavelength vibrational modes in the ferromagnetic semiconductor Ga0.91 Mn0.09 As are investigated using time resolved x-ray diffraction. At room temperature, we measure oscillations in the x-ray diffraction intensity corresponding to coherent vibrational modes with well-defined wavelengths. When the correlation of magnetic impurities sets in, we observe the transition of the lattice into a disordered state that does not support coherent modes at large wavelengths. Our measurements point toward a magnetically induced broadening of long wavelength vibrational modes in momentum space and their quasilocalization in the real space. More specifically, long wavelength vibrational modes cannot be assigned to a single wavelength but rather should be represented as a superposition of plane waves with different wavelengths. Our findings have strong implications for the phonon-related processes, especially carrier-phonon and phonon-phonon scattering, which govern the electrical conductivity and thermal management of semiconductor-based devices.
Time-spliced X-ray diffraction imaging of magnetism dynamics in a NdNiO3 thin film

NASA Astrophysics Data System (ADS)

Beyerlein, Kenneth R.

2018-03-01

Diffraction imaging of nonequilibrium dynamics at atomic resolution is becoming possible with X-ray free-electron lasers. However, there are unresolved problems with applying this method to objects that are confined in only one dimension. Here I show that reliable one-dimensional coherent diffraction imaging is possible by splicing together images recovered from different time delays in an optical pump X-ray probe experiment. The time and space evolution of antiferromagnetic order in a vibrationally excited complex oxide heterostructure is recovered from time-resolved measurements of a resonant soft X-ray diffraction peak. Midinfrared excitation of the substrate is shown to lead to a demagnetization front that propagates at a velocity exceeding the speed of sound, a critical observation for the understanding of driven phase transitions in complex condensed matter.
Time-spliced X-ray diffraction imaging of magnetism dynamics in a NdNiO3 thin film.

PubMed

Beyerlein, Kenneth R

2018-02-27

Diffraction imaging of nonequilibrium dynamics at atomic resolution is becoming possible with X-ray free-electron lasers. However, there are unresolved problems with applying this method to objects that are confined in only one dimension. Here I show that reliable one-dimensional coherent diffraction imaging is possible by splicing together images recovered from different time delays in an optical pump X-ray probe experiment. The time and space evolution of antiferromagnetic order in a vibrationally excited complex oxide heterostructure is recovered from time-resolved measurements of a resonant soft X-ray diffraction peak. Midinfrared excitation of the substrate is shown to lead to a demagnetization front that propagates at a velocity exceeding the speed of sound, a critical observation for the understanding of driven phase transitions in complex condensed matter.
Luminescent properties under X-ray excitation of Ba(1-x)PbxWO4 disordered solid solution

NASA Astrophysics Data System (ADS)

Bakiz, B.; Hallaoui, A.; Taoufyq, A.; Benlhachemi, A.; Guinneton, F.; Villain, S.; Ezahri, M.; Valmalette, J.-C.; Arab, M.; Gavarri, J.-R.

2018-02-01

A series of polycrystalline barium-lead tungstate Ba1-xPbxWO4 with 0 ≤ x ≤ 1 was synthesized using a classical solid-state method with thermal treatment at 1000 °C. These materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier Transform Raman (FT-Raman) spectroscopy. X-ray diffraction profile analyses were performed using Rietveld method. These materials crystallized in the scheelite tetragonal structure and behaved as quasi ideal solid solution. Raman spectroscopy confirmed the formation of the solid solution. Structural distortions were evidenced in X-ray diffraction profiles and in vibration Raman spectra. The scanning electron microscopy experiments showed large and rounded irregular grains. Luminescence experiments were performed under X-ray excitation. The luminescence emission profiles have been interpreted in terms of four Gaussian components, with a major contribution of blue emission. The integrated intensity of luminescence reached a maximum value in the composition range x = 0.3-0.6, in relation with distortions of crystal lattice.
Spatial Distortion of Vibration Modes via Magnetic Correlation of Impurities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krasniqi, Faton S.; Zhong, Yinpeng; Epp, S. W.

Long wavelength vibrational modes in the ferromagnetic semiconductor Ga 0.91M n0.09As are investigated using time resolved x-ray diffraction. At room temperature, we measure oscillations in the x-ray diffraction intensity corresponding to coherent vibrational modes with well-defined wavelengths. When the correlation of magnetic impurities sets in, we observe the transition of the lattice into a disordered state that does not support coherent modes at large wavelengths. Our measurements point toward a magnetically induced broadening of long wavelength vibrational modes in momentum space and their quasilocalization in the real space. More specifically, long wavelength vibrational modes cannot be assigned to a singlemore » wavelength but rather should be represented as a superposition of plane waves with different wavelengths. Lastly, our findings have strong implications for the phonon-related processes, especially carrier-phonon and phonon-phonon scattering, which govern the electrical conductivity and thermal management of semiconductor-based devices.« less
Spatial Distortion of Vibration Modes via Magnetic Correlation of Impurities

DOE PAGES

Krasniqi, Faton S.; Zhong, Yinpeng; Epp, S. W.; ...

2018-03-08

Long wavelength vibrational modes in the ferromagnetic semiconductor Ga 0.91M n0.09As are investigated using time resolved x-ray diffraction. At room temperature, we measure oscillations in the x-ray diffraction intensity corresponding to coherent vibrational modes with well-defined wavelengths. When the correlation of magnetic impurities sets in, we observe the transition of the lattice into a disordered state that does not support coherent modes at large wavelengths. Our measurements point toward a magnetically induced broadening of long wavelength vibrational modes in momentum space and their quasilocalization in the real space. More specifically, long wavelength vibrational modes cannot be assigned to a singlemore » wavelength but rather should be represented as a superposition of plane waves with different wavelengths. Lastly, our findings have strong implications for the phonon-related processes, especially carrier-phonon and phonon-phonon scattering, which govern the electrical conductivity and thermal management of semiconductor-based devices.« less
Raman scattering and X-ray powder diffraction studies of hydrate layered perovskites: dirubidium aquapentafluoromanganate(III) and dipotassium aquapentafluoroferrate(III)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Galicka, Karolina; Slodczyk, Aneta; Ratuszna, Alicja

2004-06-08

The structural and vibrational properties of above mentioned crystals were determined using X-ray powder diffraction and Raman scattering experiments. At room temperature hydrate layered perovskites: Rb{sub 2}MnF{sub 5}{center_dot}H{sub 2}O and K{sub 2}FeF{sub 5}{center_dot}H{sub 2}O exhibit orthorhombic--Cmcm (D{sub 2h}{sup 17}) and monoclinic--C2/c (C{sub 2h}{sup 6}) symmetry. Their structure is built up of MnF{sub 6} or FeF{sub 5}{center_dot}H{sub 2}O octahedra forming trans-linked zig-zag chains or hydrogen bonded zig-zag chains along the major crystallographic direction [0 0 1], respectively. To confirm crystal structures and to describe lattice dynamics of these compounds the vibrational normal modes (in {gamma} point of first Brillouin zone) weremore » calculated on the base of the group theory analysis and compared with the spectra obtained from Raman scattering experiments. A relatively good reliability was obtained for both X-ray powder diffraction and Raman scattering.« less
Development of a Grazing Incidence X-Ray Interferometer

NASA Technical Reports Server (NTRS)

Shipley, Ann; Cash, Webster; Osterman, Steve; Joy, Marshall; Carter, James

1999-01-01

A grazing incidence x-ray interferometer design capable of micro-arcsecond level resolution is discussed. This practical design employs a Michelson Stellar interferometer approach to create x-ray interference fringes without the use of Wolter style optics or diffraction crystals. Design solutions accommodating alignment, vibration, and thermal constraints are reviewed. We present the development and demonstration of a working experiment along with tolerance studies, data analysis, and results.
FT-IR and Zeta potential measurements on TiO nanoparticles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singh, Jaiveer; Rathore, Ravi; Kaurav, Netram, E-mail: netramkaurav@yahoo.co.uk

2016-05-23

In the present investigation, ultrafine TiO particles have been synthesized successfully by thermal decomposition method. The sample was characterized by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. As-synthesized TiO nanoparticles have a cubic structure as characterized by power X-ray diffraction (XRD), which shows that TiO nanoparticles have narrow size distribution with particle size 11.5 nm. FTIR data shows a strong peak at 1300 cm{sup −1}, assignable to the Ti-O stretching vibrations mode.
Synthesis, structural characterization and theoretical studies of a new Schiff base 4-(((3-(tert-Butyl)-(1-phenyl)pyrazol-5-yl) imino)methyl)phenol

NASA Astrophysics Data System (ADS)

Cuenú, Fernando; Londoño-Salazar, Jennifer; Torres, John Eduard; Abonia, Rodrigo; D'Vries, Richard F.

2018-01-01

4-(((3-(tert-Butyl)-(1-phenyl)pyrazol-5-yl)imino)methyl)phenol (4-OHFPz) was synthesized and characterized by FT-IR, MS, NMR, and single-crystal X-ray diffraction. Optimization of molecular geometry, vibrational frequencies, and chemical shifts were calculated by using the methods of density functional theory (DFT) with B3LYP and B3PW91 as functionals and Hartree-Fock with 6-311G++(d,p) as basis set using the GAUSSIAN 09 program package. With the VEDA 4 software, the vibrational frequencies were assigned in terms of the potential energy distribution (PED). The equilibrium geometries calculated by all methods were compared with X-ray diffraction results, indicating that the theoretical results matches well with the experimental ones. The data obtained from the vibrational analysis and the calculated NMR are consistent with the experimental spectra.
Vibrational cross-angles in condensed molecules: a structural tool.

PubMed

Chen, Hailong; Zhang, Yufan; Li, Jiebo; Liu, Hongjun; Jiang, De-En; Zheng, Junrong

2013-09-05

The fluctuations of three-dimensional molecular conformations of a molecule in different environments play critical roles in many important chemical and biological processes. X-ray diffraction (XRD) techniques and nuclear magnetic resonance (NMR) methods are routinely applied to monitor the molecular conformations in condensed phases. However, some special requirements of the methods have prevented them from exploring many molecular phenomena at the current stage. Here, we introduce another method to resolve molecular conformations based on an ultrafast MIR/T-Hz multiple-dimensional vibrational spectroscopic technique. The model molecule (4'-methyl-2'-nitroacetanilide, MNA) is prepared in two of its crystalline forms and liquid samples. Two polarized ultrafast infrared pulses are then used to determine the cross-angles of vibrational transition moment directions by exciting one vibrational band and detecting the induced response on another vibrational band of the molecule. The vibrational cross-angles are then converted into molecular conformations with the aid of calculations. The molecular conformations determined by the method are supported by X-ray diffraction and molecular dynamics simulation results. The experimental results suggest that thermodynamic interactions with solvent molecules are not altering the molecular conformations of MNA in the solutions to control their ultimate conformations in the crystals.
CheMin Instrument Performance and Calibration on Mars

NASA Technical Reports Server (NTRS)

Vaniman, D. T.; Blake, D. F.; Morookian, J. M.; Yen, A. S.; Ming, D. W.; Morris, R. V.; Achilles, C. N.; Bish, D. L.; Chipera, S. J.; Morrison, S. M.;

2013-01-01

The CheMin (Chemistry and Mineralogy) instrument on the Mars Science Laboratory rover Curiosity uses a CCD detector and a Co-anode X-ray tube source to acquire both mineralogy (from the pattern of Co diffraction) and chemical information (from energies of fluoresced X-rays). A key component of the CheMin instrument is the ability to move grains within sample cells during analysis, providing multiple, random grain orientations that disperse diffracted X-ray photons along Debye rings rather than producing discrete Laue spots. This movement is accomplished by piezoelectric vibration of the sample cells. A cryocooler is used to maintain the CCD at a temperature at about -50 C in order to obtain energy resolution better than 250 eV, allowing discrimination of diffracted Co K X-rays from Fe K and other fluorescent X-rays. A detailed description of CheMin is provided in [1]. The CheMin flight model (FM) is mounted within the body of Curiosity and has been operating on Mars since August 6, 2012. An essentially identical sister instrument, the CheMin demonstration model (DM), is operated in a Mars environment chamber at JPL.

Optics for coherent X-ray applications.

PubMed

Yabashi, Makina; Tono, Kensuke; Mimura, Hidekazu; Matsuyama, Satoshi; Yamauchi, Kazuto; Tanaka, Takashi; Tanaka, Hitoshi; Tamasaku, Kenji; Ohashi, Haruhiko; Goto, Shunji; Ishikawa, Tetsuya

2014-09-01

Developments of X-ray optics for full utilization of diffraction-limited storage rings (DLSRs) are presented. The expected performance of DLSRs is introduced using the design parameters of SPring-8 II. To develop optical elements applicable to manipulation of coherent X-rays, advanced technologies on precise processing and metrology were invented. With propagation-based coherent X-rays at the 1 km beamline of SPring-8, a beryllium window fabricated with the physical-vapour-deposition method was found to have ideal speckle-free properties. The elastic emission machining method was utilized for developing reflective mirrors without distortion of the wavefronts. The method was further applied to production of diffraction-limited focusing mirrors generating the smallest spot size in the sub-10 nm regime. To enable production of ultra-intense nanobeams at DLSRs, a low-vibration cooling system for a high-heat-load monochromator and advanced diagnostic systems to characterize X-ray beam properties precisely were developed. Finally, new experimental schemes for combinative nano-analysis and spectroscopy realised with novel X-ray optics are discussed.
Structure and vibrational spectra of melaminium bis(trifluoroacetate) trihydrate: FT-IR, FT-Raman and quantum chemical calculations

NASA Astrophysics Data System (ADS)

Sangeetha, V.; Govindarajan, M.; Kanagathara, N.; Marchewka, M. K.; Gunasekaran, S.; Anbalagan, G.

Melaminium bis(trifluoroacetate) trihydrate (MTFA), an organic material has been synthesized and single crystals of MTFA have been grown by the slow solvent evaporation method at room temperature. X-ray powder diffraction analysis confirms that MTFA crystal belongs to the monoclinic system with space group P2/c. The molecular geometry, vibrational frequencies and intensity of the vibrational bands have been interpreted with the aid of structure optimization based on density functional theory (DFT) B3LYP method with 6-311G(d,p) and 6-311++G(d,p) basis sets. The X-ray diffraction data have been compared with the data of optimized molecular structure. The theoretical results show that the crystal structure can be reproduced by optimized geometry and the vibrational frequencies show good agreement with the experimental values. The nuclear magnetic resonance (NMR) chemical shift of the molecule has been calculated by the gauge independent atomic orbital (GIAO) method and compared with experimental results. HOMO-LUMO, and other related molecular and electronic properties are calculated. The Mulliken and NBO charges have also been calculated and interpreted.
Structural, vibrational and luminescence properties of the (1−x)CaWO{sub 4}−xCdWO{sub 4} system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taoufyq, A.; Laboratoire Matériaux et Environnement LME, Faculté des Sciences, Université Ibn Zohr, BP 8106, Cité Dakhla, Agadir, Maroc; CEA/DEN, Département d’Études des Réacteurs, Laboratoire Dosimétrie Capteurs Instrumentation, CEA Cadarache, 13108, Saint-Paul-lez-Durance

2014-11-15

In the present work, we investigate the structural, microstructural, vibrational and luminescence properties of the system (1−x)CaWO{sub 4}−xCdWO{sub 4} with x ranging between 0 and 1. Polycrystalline samples were elaborated using a coprecipitation technique followed by thermal treatment at 1000 °C. The samples were then characterized using X-ray diffraction, scanning electron microscopy, Raman spectroscopy and luminescence analyses. X-ray diffraction profile analyses using Rietveld method showed that two kinds of solid solutions Ca{sub 1−x}Cd{sub x}WO{sub 4} having scheelite and wolframite structures, with respectively tetragonal and monoclinic crystal cells, were observed, with a biphasic system for compositions x=0.6 and 0.7. The scanningmore » electron microscopy experiments showed a complex evolution of morphologies and crystallite sizes as x increased. The vibration modes of Raman spectra were characteristic of composition-dependent disordered solid solutions with decreasing wavenumbers as x increased. Luminescence experiments were performed under UV-laser light irradiation. The energies of emission bands increased linearly with cadmium composition x. The integrated intensity of luminescence reached a maximum value for the substituted wolframite phase with composition x=0.8. - Graphical abstract: Luminescence on UV excitation (364.5 nm) of (1−x)CaWO{sub 4−x}CdWO{sub 4} system, elaborated from coprecipitation technique at 1000 °C, with 0« less
Synthesis of nanocrystalline CdS thin film by SILAR and their characterization

NASA Astrophysics Data System (ADS)

Mukherjee, A.; Satpati, B.; Bhattacharyya, S. R.; Ghosh, R.; Mitra, P.

2015-01-01

Cadmium sulphide (CdS) thin film was prepared by successive ion layer adsorption and reaction (SILAR) technique using ammonium sulphide as anionic precursor. Characterization techniques of XRD, SEM, TEM, FTIR and EDX were utilized to study the microstructure of the films. Structural characterization by x-ray diffraction reveals the polycrystalline nature of the films. Cubic structure is revealed from X-ray diffraction and selected area diffraction (SAD) patterns. The particle size estimated using X-ray line broadening method is approximately 7 nm. Instrumental broadening was taken into account while particle size estimation. TEM shows CdS nanoparticles in the range 5-15 nm. Elemental mapping using EFTEM reveals good stoichiometric composition of CdS. Characteristic stretching vibration mode of CdS was observed in the absorption band of FTIR spectrum. Optical absorption study exhibits a distinct blue shift in band gap energy value of about 2.56 eV which confirms the size quantization.

Spacer layer thickness dependent structural and magnetic properties of Co/Si multilayers

NASA Astrophysics Data System (ADS)

Roy, Ranjan; Singh, Dushyant; Kumar, M. Senthil

2018-05-01

In this article, the study of high resolution x-ray diffraction and magnetization of sputter deposited Co/Si multilayer is reported. Multilayers are prepared at ambient temperature by dc magnetron sputtering. Structural properties are studied by high resolution x-ray diffraction. Magnetic properties are studied at room temperature by vibrating sample magnetometer. Structural properties show that the Co layer is polycrystalline and the Si layer is amorphous. The magnetization study indicates that the samples are soft ferromagnetic in nature. The study of magnetization also shows that the easy axis of magnetization lies in the plane of the film.
Single-crystal Raman spectroscopy and X-ray crystallography at beamline X26-C of the NSLS

PubMed Central

Stoner-Ma, Deborah; Skinner, John M.; Schneider, Dieter K.; Cowan, Matt; Sweet, Robert M.; Orville, Allen M.

2011-01-01

Three-dimensional structures derived from X-ray diffraction of protein crystals provide a wealth of information. Features and interactions important for the function of macromolecules can be deduced and catalytic mechanisms postulated. Still, many questions can remain, for example regarding metal oxidation states and the interpretation of ‘mystery density’, i.e. ambiguous or unknown features within the electron density maps, especially at ∼2 Å resolutions typical of most macromolecular structures. Beamline X26-C at the National Synchrotron Light Source (NSLS), Brookhaven National Laboratory (BNL), provides researchers with the opportunity to not only determine the atomic structure of their samples but also to explore the electronic and vibrational characteristics of the sample before, during and after X-ray diffraction data collection. When samples are maintained under cryo-conditions, an opportunity to promote and follow photochemical reactions in situ as a function of X-ray exposure is also provided. Plans are in place to further expand the capabilities at beamline X26-C and to develop beamlines at NSLS-II, currently under construction at BNL, which will provide users access to a wide array of complementary spectroscopic methods in addition to high-quality X-ray diffraction data. PMID:21169688
Optics for coherent X-ray applications

PubMed Central

Yabashi, Makina; Tono, Kensuke; Mimura, Hidekazu; Matsuyama, Satoshi; Yamauchi, Kazuto; Tanaka, Takashi; Tanaka, Hitoshi; Tamasaku, Kenji; Ohashi, Haruhiko; Goto, Shunji; Ishikawa, Tetsuya

2014-01-01

Developments of X-ray optics for full utilization of diffraction-limited storage rings (DLSRs) are presented. The expected performance of DLSRs is introduced using the design parameters of SPring-8 II. To develop optical elements applicable to manipulation of coherent X-rays, advanced technologies on precise processing and metrology were invented. With propagation-based coherent X-rays at the 1 km beamline of SPring-8, a beryllium window fabricated with the physical-vapour-deposition method was found to have ideal speckle-free properties. The elastic emission machining method was utilized for developing reflective mirrors without distortion of the wavefronts. The method was further applied to production of diffraction-limited focusing mirrors generating the smallest spot size in the sub-10 nm regime. To enable production of ultra-intense nanobeams at DLSRs, a low-vibration cooling system for a high-heat-load monochromator and advanced diagnostic systems to characterize X-ray beam properties precisely were developed. Finally, new experimental schemes for combinative nano-analysis and spectroscopy realised with novel X-ray optics are discussed. PMID:25177986
Self-referenced coherent diffraction x-ray movie of Ångstrom- and femtosecond-scale atomic motion

DOE PAGES

Glownia, J. M.; Natan, A.; Cryan, J. P.; ...

2016-10-03

Time-resolved femtosecond x-ray diffraction patterns from laser-excited molecular iodine are used to create a movie of intramolecular motion with a temporal and spatial resolution of 30 fs and 0.3 Å. This high fidelity is due to interference between the nonstationary excitation and the stationary initial charge distribution. The initial state is used as the local oscillator for heterodyne amplification of the excited charge distribution to retrieve real-space movies of atomic motion on ångstrom and femtosecond scales. This x-ray interference has not been employed to image internal motion in molecules before. In conclusion, coherent vibrational motion and dispersion, dissociation, and rotationalmore » dephasing are all clearly visible in the data, thereby demonstrating the stunning sensitivity of heterodyne methods.« less
Structural and magnetic properties of nanocrystalline NiFe2O4 thin film prepared by spray pyrolysis technique

NASA Astrophysics Data System (ADS)

Chavan, Apparao R.; Chilwar, R. R.; Shisode, M. V.; Hivrekar, Mahesh M.; Mande, V. K.; Jadhav, K. M.

2018-05-01

The nanocrystalline NiFe2O4 thin film has been prepared using a spray pyrolysis technique on glass substrate. The prepared thin film was characterized by using X-ray diffraction (XRD), Fourier transform Infrared spectroscopy (FTIR), and Field Emission-Scanning Electron Microscopy (FE-SEM) characterization techniques for the structural and microstructural analysis. The magnetic property was measured using vibrating sample magnetometer (VSM) at room temperature. X-ray diffraction studies show the formation of single phase spinel structure of the thin film. The octahedral and tetrahedral vibration in the sample was studied by Fourier transform infrared (FT-IR) spectra. Magnetic hysteresis loop was recorded for thin film at room temperature. At 15 kOe, saturation magnetization (Ms) was found to increase while coercivity (Hc) decreases with thickness of the NiFe2O4 thin film.
Structure and vibrational spectra of melaminium bis(trifluoroacetate) trihydrate: FT-IR, FT-Raman and quantum chemical calculations.

PubMed

Sangeetha, V; Govindarajan, M; Kanagathara, N; Marchewka, M K; Gunasekaran, S; Anbalagan, G

2014-05-05

Melaminium bis(trifluoroacetate) trihydrate (MTFA), an organic material has been synthesized and single crystals of MTFA have been grown by the slow solvent evaporation method at room temperature. X-ray powder diffraction analysis confirms that MTFA crystal belongs to the monoclinic system with space group P2/c. The molecular geometry, vibrational frequencies and intensity of the vibrational bands have been interpreted with the aid of structure optimization based on density functional theory (DFT) B3LYP method with 6-311G(d,p) and 6-311++G(d,p) basis sets. The X-ray diffraction data have been compared with the data of optimized molecular structure. The theoretical results show that the crystal structure can be reproduced by optimized geometry and the vibrational frequencies show good agreement with the experimental values. The nuclear magnetic resonance (NMR) chemical shift of the molecule has been calculated by the gauge independent atomic orbital (GIAO) method and compared with experimental results. HOMO-LUMO, and other related molecular and electronic properties are calculated. The Mulliken and NBO charges have also been calculated and interpreted. Copyright © 2014 Elsevier B.V. All rights reserved.
X-Ray Diffraction Reference Intensity Ratios of Amorphous and Poorly Crystalline Phases: Implications for CheMin on the Mars Science Laboratory

NASA Technical Reports Server (NTRS)

Morris, R. V.; Achilles, C. N.; Chipera, S. J.; Ming, D. W.; Rampe, E. B.

2013-01-01

The CheMin instrument on the Mars Science Laboratory (MSL) rover Curiosity is an X-ray diffraction (XRD) and X-ray fluorescence (XRF) instrument capable of providing the mineralogical and chemical compositions of rocks and soils on the surface of Mars. CheMin uses a microfocus X-ray tube with a Co target, transmission geometry, and an energy-discriminating X-ray sensitive CCD to produce simultaneous 2-D XRD patterns and energy-dispersive X-ray histograms from powdered samples. Piezoelectric vibration of the cell is used to randomize the sample to reduce preferred orientation effects. Instrument details are provided in [1, 2, 3]. Analyses of rock and soil samples by the Mars Exploration Rovers (MER) show nanophase ferric oxide (npOx) is a significant component of the Martian global soil [4] and is thought to be one of the major contributing phases that the Curiosity rover will encounter if a soil sample is analyzed in Gale Crater. Because of the nature of this material, npOx will likely contribute to an X-ray amorphous or short-order component of a XRD pattern measured by the CheMin instrument.
Molecular structure of hybrid imino-chalcone in the solid state: X-ray diffraction, spectroscopy study and third-order nonlinear optical properties

NASA Astrophysics Data System (ADS)

Custodio, J. M. F.; Santos, F. G.; Vaz, W. F.; Cunha, C. E. P.; Silveira, R. G.; Anjos, M. M.; Campos, C. E. M.; Oliveira, G. R.; Martins, F. T.; da Silva, C. C.; Valverde, C.; Baseia, B.; Napolitano, H. B.

2018-04-01

A comprehensive structural study of the compound (2E)-1-((E)-4-(4-methoxybenzylideneamino)phenyl)-3-(4-methoxyphenyl)prop-2-en-1-one was carried out in this work. Single crystal X-ray diffraction (SCXRD), X-ray powder diffraction (XRPD), NMR, Raman and Infrared spectroscopies, and DFT calculations were performed for characterization of this iminochalcone hybrid. Intermolecular interactions were described by Hirshfeld surface analysis derived from crystal structure. Reactivity and intramolecular charge transfer were investigated using the frontier molecular orbitals and molecular electrostatic potential. In addition, we have calculated the Nonlinear Optical Properties at the CAM-B3LYP/6-311+g(d) level of theory in the presence of different solvents (gas-phase, acetone, chloroform, dichloromethane, dimethyl sulfoxide, ethanol, methanol, and water), being found meaningful NLO parameters for our compound. At last, there is a good agreement between calculated and experimental IR spectrum, allowing the assignment of some of normal vibrational modes of the iminochalcone hybrid.
Studies on the growth, structural, spectral and third-order nonlinear optical properties of ammonium 3-carboxy-4-hydroxy benzenesulfonate monohydrate single crystal.

PubMed

Silambarasan, A; Krishna Kumar, M; Thirunavukkarasu, A; Mohan Kumar, R; Umarani, P R

2015-01-25

An organic nonlinear optical bulk single crystal, Ammonium 3-carboxy-4-hydroxy benzenesulfonate monohydrate (ACHBS) was successfully grown by solution growth technique. Single crystal X-ray diffraction study confirms that, the grown crystal belongs to P21/c space group. Powder X-ray diffraction and high resolution X-ray diffraction analyses revealed the crystallinity of the grown crystal. Infrared spectral analysis showed the vibrational behavior of chemical bonds and its functional groups. The thermal stability and decomposition stages of the grown crystal were studied by TG-DTA analysis. UV-Visible transmittance studies showed the transparency region and cut-off wavelength of the grown crystal. The third-order nonlinear optical susceptibility of the grown crystal was estimated by Z-scan technique using He-Ne laser source. The mechanical property of the grown crystal was studied by using Vicker's microhardness test. Copyright © 2014 Elsevier B.V. All rights reserved.
Effect of Cu2+ substitution on the structural, optical and magnetic behaviour ofchemically derived manganese ferrite nanoparticles

NASA Astrophysics Data System (ADS)

Vasuki, G.; Balu, T.

2018-06-01

Mixed spinel copper manganese ferrite (CuXMn1‑XFe2O4, X = 0, 0.25, 0.5, 0.75, 1) nanoparticles were synthesized by chemical co-precipitation technique. From the powder x-ray diffraction analysis the lattice constant, volume of unit cell, x-ray density, hopping lengths, crystallite size, surface area, dislocation density and microstrain were calculated. The substitution of Cu2+ ions shows a considerable reduction in the crystallite size of manganese ferrite from 34 nm to 22 nm. Further a linear fit of Williamson-Hall plot has been drawn to determine the microstrain and crystallite size. The crystallite size and morphology were further observed through high resolution transmission electron microscope and scanning electron microscope. The diffraction rings observed from selected area electron diffraction pattern exhibits the crystalline nature of all the samples. The energy dispersive x-ray analysis shows the composition of all the elements incorporated in the synthesized nanomaterials. FTIR studies reveal the absorption peaks that correspond to the metal-oxygen vibrations in the tetrahedral and octahedral sites. From the UV–vis absorption spectra the band gap energy, refractive index and optical dielectric constant were determined. Magnetic studies carried out using vibrating sample magnetometer shows interesting behaviour in the variation of magnetisation and coercivity. Peculiar magnetic behaviour is observed when Cu2+ ions are substituted in manganese ferrites. All the synthesized materials have very low value of squareness ratio which attributes to the superparamagnetic behaviour.
Structural, Electronic and Vibrational Properties of Nax Si 136(0 < x < 24) Clathrates

NASA Astrophysics Data System (ADS)

Higgins, Craig; Nenghabi, Emmanuel; Myles, Charles; Biswas, Koushik; Beekman, Matt; Nolas, George

2011-03-01

CRAIG HIGGINS, EMMANUEL NENGHA BI† , CHARLES W. MYLES, Texas Tech U.; KOUSHIK BISWAS, Oak Ridge National Lab; MATT BEEKMAN, U. of Oregon; GEORGE S. NOLAS, U. of South Florida - Na x Si 136 is a Type II clathrate with important thermoelectric properties. It's face-centered cubic lattice contains polyhedral ``cages'' of silicon atoms with Na atom ``guests'' in the cages. This material is very interesting because powder X-ray diffraction experiments 1 for differing Na content x have shown that, for increasing x in the range 0
Crystal structure, Raman scattering and magnetic properties of CuCr2-xZrxSe4 and CuCr2-xSnxSe4 selenospinels

NASA Astrophysics Data System (ADS)

Pinto, C.; Galdámez, A.; Barahona, P.; Moris, S.; Peña, O.

2018-06-01

Selenospinels, CuCr2-xMxSe4 (M = Zr and Sn), were synthesized via conventional solid-state reactions. The crystal structure of CuCr1.5Sn0.5Se4, CuCr1.7Sn0.3Se4, CuCr1.5Zr0.5Se4, and CuCr1.8Zr0.2Se4 were determined using single-crystal X-ray diffraction. All the phases crystallized in a cubic spinel-type structure. The chemical compositions of the single-crystals were examined using energy-dispersive X-ray analysis (EDS). Powder X-ray diffraction patterns of CuCr1.3Sn0.7Se4 and CuCr1.7Sn0.3Se4 were consistent with phases belonging to the Fd 3 bar m Space group. An analysis of the vibrational properties on the single-crystals was performed using Raman scattering measurements. The magnetic properties showed a spin glass behavior with increasing Sn content and ferromagnetic order for CuCr1.7Sn0.3Se4.
Compressibility of Cs2SnBr6 by X-ray diffraction and Raman spectroscopy

NASA Astrophysics Data System (ADS)

Yuan, Guan; Huang, Shengxuan; Niu, Jingjing; Qin, Shan; Wu, Xiang; Ding, Hongrui; Lu, Anhuai

2018-07-01

Cs2SnBr6, one promising material applied in perovskite solar cells, has been investigated up to 20 GPa by synchrotron X-ray diffraction and Raman spectroscopy. Both experimental data demonstrate that no phase transition occurs up to 20 GPa. By fitting the third-order Birch-Murnaghan equation of state, we have obtained V0 = 1288 (14) Å3, K0 = 11 (1) GPa and K0‧ = 7 (1). The ultralow value of bulk modulus K0 demonstrates the soft nature of Cs2SnBr6. Combining calculated values with experimental results, we find that x coordinate of Sn (x,0,0) atoms increases and Snsbnd Br bond lengths get shortened on compression. We have assigned vibrational peaks of Cs2SnBr6 in Raman measurements, and all the three Raman bands present nonlinear correlations with pressure.
Structural and magnetic properties of FeCoC system obtained by mechanical alloying

NASA Astrophysics Data System (ADS)

Rincón Soler, A. I.; Rodríguez Jacobo, R. R.; Medina Barreto, M. H.; Cruz-Muñoz, B.

2017-11-01

Fe96-XCoXC4 (x = 0, 10, 20, 30, 40 at. %) alloys were obtained by mechanical alloying of Fe, C and Co powders using high-energy milling. The structural and magnetic properties of the alloy system were analyzed by X-ray diffraction, Scanning Electron Microscopy (SEM), Vibrating Sample Magnetometer (VSM) and Mössbauer Spectrometry at room temperature. The X-ray diffraction patterns showed a BCC-FeCoC structure phase for all samples, as well as a lattice parameter that slightly decreases with Co content. The saturation magnetization and coercive field were analyzed as a function of Co content. The Mössbauer spectra were fitted with a hyperfine magnetic field distribution showing the ferromagnetic behavior and the disordered character of the samples. The mean hyperfine magnetic field remained nearly constant (358 T) with Co content.
CROSS-DISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY: The effect of substrate on magnetic properties of Co/Cu multilayer nanowire arrays

NASA Astrophysics Data System (ADS)

Ren, Yong; Wang, Jian-Bo; Liu, Qing-Fang; Han, Xiang-Hua; Xue, De-Sheng

2009-08-01

Ordered Co/Cu multilayer nanowire arrays have been fabricated into anodic aluminium oxide templates with Ag and Cu substrate by direct current electrodeposition. This paper studies the morphology, structure and magnetic properties by transmission electron microscopy, selective area electron diffraction, x-ray diffraction, and vibrating sample magnetometer. X-ray diffraction patterns reveal that both as-deposited nanowire arrays films exhibit face-centred cubic structure. Magnetic measurements indicate that the easy magnetization direction of Co/Cu multilayer nanowire arrays films on Ag substrate is perpendicular to the long axis of nanowire, whereas the easy magnetization direction of the sample with Cu substrate is parallel to the long axis of nanowire. The change of easy magnetization direction attributed to different substrates, and the magnetic properties of the nanowire arrays are discussed.
Local Structure Determination of Carbon/Nickel Ferrite Composite Nanofibers Probed by X-ray Absorption Spectroscopy.

PubMed

Nilmoung, Sukunya; Kidkhunthod, Pinit; Maensiri, Santi

2015-11-01

Carbon/NiFe2O4 composite nanofibers have been successfully prepared by electrospinning method using a various concentration solution of Ni and Fe nitrates dispersed into polyacrylonitride (PAN) solution in N,N' dimethylformamide. The phase and mophology of PAN/NiFe2O4 composite samples were characterized and investigated by X-ray diffraction and scanning electron microscopy. The magnetic properties of the prepared samples were measured at ambient temperature by a vibrating sample magnetometer. It is found that all composite samples exhibit ferromagnetism. This could be local-structurally explained by the existed oxidation states of Ni2+ and Fe3+ in the samples. Moreover, local environments around Ni and Fe ions could be revealed by X-ray absorption spectroscopy (XAS) measurement including X-ray absorption near edge structure (XANES) and Extended X-ray absorption fine structure (EXAFS).
The Influence of Various Vibration Frequency on Barium Sulfate Scale Formation Of Vibrated Piping System In The Presence Citric Acid

NASA Astrophysics Data System (ADS)

Karaman, N.; Mangestiyono, W.; Muryanto, S.; Jamari, J.; Bayuseno, A. P.

2018-01-01

In this paper, the influence of vibrated piping system for BaSO4 scale formation was investigated. The vibration frequency and presence of citric acid were independent variables determining the kinetics, mass deposit and polymorph of the crystals. Correspondingly, induction time and mass of scale were obtained during the experiments. The crystalline scale was observed by scanning electron microscopy (SEM) and X-Ray Diffraction (XRD) to investigate the morphology and the phase mineral deposits, respectively. This effect indicated that the increase in vibration frequency promoted the increased deposition rate, while the pure barite with a plate-like morphology was produced in the experiments.
High-pressure studies with x-rays using diamond anvil cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shen, Guoyin; Mao, Ho Kwang

2016-11-22

Pressure profoundly alters all states of matter. The symbiotic development of ultrahigh-pressure diamond anvil cells, to compress samples to sustainable multi-megabar pressures; and synchrotron x-ray techniques, to probe materials' properties in situ, has enabled the exploration of rich high-pressure (HP) science. In this article, we first introduce the essential concept of diamond anvil cell technology, together with recent developments and its integration with other extreme environments. We then provide an overview of the latest developments in HP synchrotron techniques, their applications, and current problems, followed by a discussion of HP scientific studies using x-rays in the key multidisciplinary fields. Thesemore » HP studies include: HP x-ray emission spectroscopy, which provides information on the filled electronic states of HP samples; HP x-ray Raman spectroscopy, which probes the HP chemical bonding changes of light elements; HP electronic inelastic x-ray scattering spectroscopy, which accesses high energy electronic phenomena, including electronic band structure, Fermi surface, excitons, plasmons, and their dispersions; HP resonant inelastic x-ray scattering spectroscopy, which probes shallow core excitations, multiplet structures, and spin-resolved electronic structure; HP nuclear resonant x-ray spectroscopy, which provides phonon densities of state and time-resolved Mössbauer information; HP x-ray imaging, which provides information on hierarchical structures, dynamic processes, and internal strains; HP x-ray diffraction, which determines the fundamental structures and densities of single-crystal, polycrystalline, nanocrystalline, and non-crystalline materials; and HP radial x-ray diffraction, which yields deviatoric, elastic and rheological information. Integrating these tools with hydrostatic or uniaxial pressure media, laser and resistive heating, and cryogenic cooling, has enabled investigations of the structural, vibrational, electronic, and magnetic properties of materials over a wide range of pressure-temperature conditions.« less
High-pressure studies with x-rays using diamond anvil cells

NASA Astrophysics Data System (ADS)

Shen, Guoyin; Mao, Ho Kwang

2017-01-01

Pressure profoundly alters all states of matter. The symbiotic development of ultrahigh-pressure diamond anvil cells, to compress samples to sustainable multi-megabar pressures; and synchrotron x-ray techniques, to probe materials’ properties in situ, has enabled the exploration of rich high-pressure (HP) science. In this article, we first introduce the essential concept of diamond anvil cell technology, together with recent developments and its integration with other extreme environments. We then provide an overview of the latest developments in HP synchrotron techniques, their applications, and current problems, followed by a discussion of HP scientific studies using x-rays in the key multidisciplinary fields. These HP studies include: HP x-ray emission spectroscopy, which provides information on the filled electronic states of HP samples; HP x-ray Raman spectroscopy, which probes the HP chemical bonding changes of light elements; HP electronic inelastic x-ray scattering spectroscopy, which accesses high energy electronic phenomena, including electronic band structure, Fermi surface, excitons, plasmons, and their dispersions; HP resonant inelastic x-ray scattering spectroscopy, which probes shallow core excitations, multiplet structures, and spin-resolved electronic structure; HP nuclear resonant x-ray spectroscopy, which provides phonon densities of state and time-resolved Mössbauer information; HP x-ray imaging, which provides information on hierarchical structures, dynamic processes, and internal strains; HP x-ray diffraction, which determines the fundamental structures and densities of single-crystal, polycrystalline, nanocrystalline, and non-crystalline materials; and HP radial x-ray diffraction, which yields deviatoric, elastic and rheological information. Integrating these tools with hydrostatic or uniaxial pressure media, laser and resistive heating, and cryogenic cooling, has enabled investigations of the structural, vibrational, electronic, and magnetic properties of materials over a wide range of pressure-temperature conditions.
Magnetic and topographical modifications of amorphous Co-Fe thin films induced by high energy Ag7+ ion irradiation

NASA Astrophysics Data System (ADS)

Pookat, G.; Hysen, T.; Al-Harthi, S. H.; Al-Omari, I. A.; Lisha, R.; Avasthi, D. K.; Anantharaman, M. R.

2013-09-01

We have investigated the effects of swift heavy ion irradiation on thermally evaporated 44 nm thick, amorphous Co77Fe23 thin films on silicon substrates using 100 MeV Ag7+ ions fluences of 1 × 1011 ions/cm2, 1 × 1012 ions/cm2, 1 × 1013 ions/cm2, and 3 × 1013 ions/cm2. The structural modifications upon swift heavy irradiation were investigated using glancing angle X-ray diffraction. The surface morphological evolution of thin film with irradiation was studied using Atomic Force Microscopy. Power spectral density analysis was used to correlate the roughness variation with structural modifications investigated using X-ray diffraction. Magnetic measurements were carried out using vibrating sample magnetometry and the observed variation in coercivity of the irradiated films is explained on the basis of stress relaxation. Magnetic force microscopy images are subjected to analysis using the scanning probe image processor software. These results are in agreement with the results obtained using vibrating sample magnetometry. The magnetic and structural properties are correlated.

Ion beam modification of the structure and properties of hexagonal boron nitride: An infrared and X-ray diffraction study

NASA Astrophysics Data System (ADS)

Aradi, E.; Naidoo, S. R.; Billing, D. G.; Wamwangi, D.; Motochi, I.; Derry, T. E.

2014-07-01

The vibrational mode for the cubic symmetry of boron nitride (BN) has been produced by boron ion implantation of hexagonal boron nitride (h-BN). The optimum fluence at 150 keV was found to be 5 × 1014 ions/cm2. The presence of the c-BN phase was inferred using glancing incidence XRD (GIXRD) and Fourier Transform Infrared Spectroscopy (FTIR). After implantation, Fourier Transform Infrared Spectroscopy indicated a peak at 1092 cm-1 which corresponds to the vibrational mode for nanocrystalline BN (nc-BN). The glancing angle XRD pattern after implantation exhibited c-BN diffraction peaks relative to the implantation depth of 0.4 μm.
Bond compressibility and bond Grüneisen parameters of CdTe

NASA Astrophysics Data System (ADS)

Fornasini, P.; Grisenti, R.; Irifune, T.; Shinmei, T.; Mathon, O.; Pascarelli, S.; Rosa, A. D.

2018-06-01

Extended x-ray absorption fine structure (EXAFS) at the Cd K edge and diffraction patterns have been measured on CdTe as a function of pressure from 100 kPa (1 bar) to 5 GPa using a cell with nano-polycrystalline diamond anvils and an x-ray focussing scanning spectrometer. Three phases—zincblende (ZB), mixed cinnabar-ZB and rocksalt (RS)—are well distinguished in different pressure intervals. The bond compressibility measured by EXAFS in the ZB phase is slightly smaller than the one measured by diffraction and decreases significantly faster when the pressure increases; the difference is attributed to the effect of relative vibrations perpendicular to the Cd–Te bond. The parallel mean square relative displacement (MSRD) decreases, the perpendicular MSRD increases when the pressure increases, leading to an increasing anisotropy of relative atomic vibrations. A constant-temperature bond Grüneisen parameter (GP) has been evaluated for the ZB phase and compared with the constant-pressure bond GP measured in a previous experiment; an attempt is made to connect the bond GPs measured by EXAFS and the more familiar thermodynamic GP and mode GPs; the comparisons suggest the inadequacy of the quasi-harmonic approximation to deal with the local vibrational properties sampled by EXAFS.
Structural, vibrational, thermal and optical studies of organic single crystal: Benzotriazolium p-toluene sulfonate (BTPTS)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumar, R. Ramesh; Sathya, P.; Gopalakrishnan, R., E-mail: krgkrishnan@yahoo.com

Benzotriazolium p-toluene sulfonate (BTPTS) was grown by solution growth technique. The powder X-ray diffraction analysis was carried out to evaluate crystal system of the compound. LeBail Profile fitting analysis was performed to extract the individual peak intensities. FTIR spectrum analysis was recorded to study vibration frequencies of the prepared organic salt. Thermal studies were carried out using TG-DSC analysis. Optical absorption and energy band gap of the title compound was evaluated by UV-Vis spectral study.
The Composition of Intermediate Products of the Thermal Decomposition of (NH4)2ZrF6 to ZrO2 from Vibrational-Spectroscopy Data

NASA Astrophysics Data System (ADS)

Voit, E. I.; Didenko, N. A.; Gaivoronskaya, K. A.

2018-03-01

Thermal decomposition of (NH4)2ZrF6 resulting in ZrO2 formation within the temperature range of 20°-750°C has been investigated by means of thermal and X-ray diffraction analysis and IR and Raman spectroscopy. It has been established that thermolysis proceeds in six stages. The vibrational-spectroscopy data for the intermediate products of thermal decomposition have been obtained, systematized, and summarized.
Solid-state amorphization of rebamipide and investigation on solubility and stability of the amorphous form.

PubMed

Xiong, Xinnuo; Xu, Kailin; Li, Shanshan; Tang, Peixiao; Xiao, Ying; Li, Hui

2017-02-01

Solid-state amorphization of crystalline rebamipide (RBM) was realized by ball milling and spray drying. The amorphous content of samples milled for various time was quantified using X-ray powder diffraction. Crystalline RBM and three amorphous RBM obtained by milling and spray drying were characterized by morphological analysis, X-ray diffraction, thermal analysis and vibrational spectroscopy. The crystal structure of RBM was first determined by single-crystal X-ray diffraction. In addition, the solubility and dissolution rate of the RBM samples were investigated in different media. Results indicated that the solubility and the dissolution rates of spray-dried RBM-PVP in different media were highly improved compared with crystalline RBM. The physical stabilities of the three amorphous RBM were systematically investigated, and the stability orders under different storage temperatures and levels of relative humidity (RH) were both as follows: spray dried RBM < milled RBM < spray dried RBM-PVP. A direct glass-to-crystal transformation was induced under high RH, and the transformation rate rose with increasing RH. However, amorphous RBM could stay stable at RH levels lower than 57.6% (25 °C).
The Effect of a Rapid Heating Rate, Mechanical Vibration and Surfactant Chemistry on the Structure–Property Relationships of Epoxy/Clay Nanocomposites

PubMed Central

Nuhiji, Betime; Attard, Darren; Thorogood, Gordon; Hanley, Tracey; Magniez, Kevin; Bungur, Jenny; Fox, Bronwyn

2013-01-01

The role of processing conditions and intercalant chemistry in montmorillonite clays on the dispersion, morphology and mechanical properties of two epoxy/clay nanocomposite systems was investigated in this paper. This work highlights the importance of employing complementary techniques (X-ray diffraction, small angle X-ray scattering, optical microscopy and transmission electron microscopy) to correlate nanomorphology to macroscale properties. Materials were prepared using an out of autoclave manufacturing process equipped to generate rapid heating rates and mechanical vibration. The results suggested that the quaternary ammonium surfactant on C30B clay reacted with the epoxy during cure, while the primary ammonium surfactant (I.30E) catalysed the polymerisation reaction. These effects led to important differences in nanocomposite clay morphologies. The use of mechanical vibration at 4 Hz prior to matrix gelation was found to facilitate clay dispersion and to reduce the area fraction of I.30E clay agglomerates in addition to increasing flexural strength by over 40%. PMID:28811457
Synthesis, spectroscopic and theoretical studies of ethyl (2E)-3-amino-2-({[(4-benzoyl-1,5-diphenyl-1H-pyrazol-3-yl)carbonyl]amino}carbonothioyl)but-2-enoate butanol solvate

NASA Astrophysics Data System (ADS)

Koca, İrfan; Sert, Yusuf; Gümüş, Mehmet; Kani, İbrahim; Çırak, Çağrı

2014-01-01

We have synthesized ethyl (2E)-3-amino-2-({[(4-benzoyl-1,5-diphenyl-1H-pyrazol-3-yl)carbonyl]amino}carbonothioyl)but-2-enoate (2) by the reaction of 4-benzoyl-1,5-diphenyl-1H-pyrazole-3-carbonyl chloride (1), ammonium thiocyanate and ethyl 3-aminobut-2-enoate and then characterized by elemental analyses, IR, Raman, 1H NMR, 13C NMR and X-ray diffraction methods. The experimental and theoretical vibrational spectra of 2 were investigated. The experimental FT-IR (4000-400 cm-1) and Laser-Raman spectra (4000-100 cm-1) of the molecule in the solid phase were recorded. Theoretical vibrational frequencies and geometric parameters (bond lengths, bond angles) were calculated using Ab Initio Hartree Fock (HF), Density Functional Theory (B3LYP) methods with 6-311++G(d,p) basis set by Gaussian 09W program. The computed values of frequencies are scaled using a suitable scale factor to yield good coherence with the observed values. The assignments of the vibrational frequencies were performed by potential energy distribution (PED) analysis by using VEDA 4 program. The theoretical optimized geometric parameters and vibrational frequencies were compared with the corresponding experimental X-ray diffraction data, and they were seen to be in a good agreement with each other. Also, the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energies were calculated.
Vibrational, DFT, and thermal analysis of 2,4,6-triamino-1,3,5-triazin-1-ium 3-(prop-2-enoyloxy) propanoate acrylic acid monosolvate monohydrate

NASA Astrophysics Data System (ADS)

Sangeetha, V.; Govindarajan, M.; Kanagathara, N.; Marchewka, M. K.; Drozd, M.; Anbalagan, G.

2013-12-01

New organic crystals of 2,4,6-triamino-1,3,5-triazin-1-ium 3-(prop-2-enoyloxy) propanoate acrylic acid monosolvate monohydrate (MAC) have been obtained from aqueous solution by the slow solvent evaporation method at room temperature. Single crystal X-ray diffraction analysis reveals that the compound crystallises in the triclinic system with centrosymmetric space group P-1. FT-IR and FT-Raman spectra of MAC have been recorded and analyzed. The molecular geometry and vibrational frequencies and intensity of the vibrational bands are interpreted with the aid of structure optimization based on density functional theory (DFT) B3LYP method with 6-31G(d,p) basis set. The results of the optimized molecular structure are presented and compared with the experimental X-ray diffraction data. The theoretical results show that the optimized geometry can well reproduce the crystal structure, and the calculated vibrational frequency values show good agreement with experimental values. A study of the electronic properties, such as HOMO and LUMO energies and Molecular electrostatic potential (MEP) were performed. Mulliken charges and NBO charges of the title molecule were also calculated and interpreted. Thermogravimetric analysis has been done to study the thermal behaviour of MAC. The 13C and 1H nuclear magnetic resonance (NMR) chemical shifts of the molecule are calculated by the gauge independent atomic orbital (GIAO) method and compared with experimental results.
Theoretical and experimental studies on vibrational and nonlinear optic properties of guanidinium 3-nitrobenzoate. Differences and similarity between guanidinium 3-nitrobenzoate and guanidinium 4-nitrobenzoate complexes

NASA Astrophysics Data System (ADS)

Drozd, Marek

2018-03-01

According to literature data two structures of guanidine with nitrobenzoic acids are known. For guanidinium 4-nitrobenzoate the detailed studies of X-ray structure, vibrational and theoretical properties were performed. This compound was classified as second harmonic generator with efficiency of 3.3 times that KDP, standard crystal. On the contrary to mentioned above results for the guanidinium 3-nitrobenzoate the basic X-ray diffraction study was performed, only. On the basis of established crystallographic results, the detailed investigation of geometry and vibrational properties were made on the basis of theoretical calculation. According to this data the equilibrium geometry of investigated molecule was established. On the basis of this calculation the detailed computational studies of vibrational properties were performed. The theoretical IR and Raman frequencies, intensities and PED analysis are presented. Additionally, the NBO charges, HOMO and LUMO shapes and NLO properties of titled crystal were calculated. On the basis of these results the crystal was classified as second order generator in NLO but with bigger efficiency that guanidinium 4-nitorobenzoate compound. The obtained data are compared with experimental crystallographic and vibrational results for real crystal of guanidinium 3-nitrobenzoate. Additionally, the theoretical vibrational spectra are compared with literature calculations of guanidinium 4-nitrobenzoate compound.
X-ray diffraction of solid tin to 1.2 TPa

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lazicki, A.; Rygg, J. R.; Coppari, F.

2015-08-12

In this study, we report direct in situ measurements of the crystal structure of tin between 0.12 and 1.2 TPa, the highest stress at which a crystal structure has ever been observed. Using angle-dispersive powder x-ray diffraction, we find that dynamically compressed Sn transforms to the body-centered-cubic (bcc) structure previously identified by ambient-temperature quasistatic-compression studies and by zero-kelvin density-functional theory predictions between 0.06 and 0.16 TPa. However, we observe no evidence for the hexagonal close-packed (hcp) phase found by those studies to be stable above 0.16 TPa. Instead, our results are consistent with bcc up to 1.2 TPa. We conjecturemore » that at high temperature bcc is stabilized relative to hcp due to differences in vibrational free energy.« less
Structural, dielectric and impedance spectroscopic studies of Ni0.5Zn0.5-xLixFe2O4 nanocrystalline ferrites

NASA Astrophysics Data System (ADS)

Venkatesh, Davuluri; Ramesh, K. V.

2017-09-01

Nanocrystalline lithium substituted Ni-Zn ferrites with composition Ni0.5Zn0.5-xLixFe2O4 (x = 0.00-0.25 in steps of 0.05) were synthesized by the citrate gel auto-combustion method and were sintered at 1000∘C for 4 h in air atmosphere. The structural, dielectric, impedance spectroscopic and magnetic properties were studied by using X-ray diffraction, impedance analyzer and vibrating sample magnetometer respectively. The X-ray diffraction patterns confirm that all samples exhibit a single phase cubic spinel structure. Suitable cation distribution for all compositions has been proposed by using the X-ray diffraction line intensity calculations and the theoretical lattice parameter for each composition was observed in close agreement with the experimental ones and thereby supporting the proposed distribution. An increase in the saturation magnetization was observed up to x = 0.10 level of Li+ substitution and thereafter magnetization reduced for higher concentrations to the highest level of Li+ substitution. The dielectric constant and the DC resistivity of Ni-Zn-Li ferrites were noticed to decrease with increase in the Li+ ion concentration. The impedance spectroscopic studies by using the Cole-Cole plots were studied in order to obtain the relaxation time, grain resistance and grain capacitance. AC conductivity initially remained almost independent of frequency for lower frequencies and thereafter for higher frequencies the AC conductivity increased with increase of Lithium concentration.
Effect of Phosphine-Free Selenium Precursor Reactivity on The Optical and Vibrational properties of Colloidal CdSe Nanocrystals

NASA Astrophysics Data System (ADS)

Thi, L. A.; Lieu, N. T. T.; Hoa, N. M.; Tran, N.; Binh, N. T.; Quang, V. X.; Nghia, N. X.

2018-03-01

Phosphine-free selenium precursor solutions have been prepared by heating at temperatures ranging from 160 °C to 240 °C and studied by means of infrared absorption spectroscopy. The colloidal CdSe nanocrystals (NCs) synthesized from all those solutions by the wet chemical method. The influence of heating temperature on the chemical reactivity of selenium precursor and its role on the optical and vibrational properties of CdSe NCs are discussed in details. Their morphology, particle size, structural, optical and vibrational properties were investigated using transmission electron microscopy, X-ray diffraction, UV-Vis, fluorescence and Raman spectroscopy, respectively.
Structural, optical and vibrational properties of Cr2O3 with ferromagnetic and antiferromagnetic order: A combined experimental and density functional theory study

NASA Astrophysics Data System (ADS)

Larbi, T.; Ouni, B.; Gantassi, A.; Doll, K.; Amlouk, M.; Manoubi, T.

2017-12-01

Chromium oxide (Cr2O3) thin films have been synthesized on glass substrates by the spray pyrolysis technique. The structural, morphological and optical properties of the sample have been studied by X-ray diffraction (XRD), Raman spectroscopy, FTIR spectroscopy, scanning probe microscopy and UV-vis spectroscopy respectively. X-ray diffraction results reveal that as deposited film is polycrystalline with a rhombohedral corundum structure and a preferential orientation of the crystallites along the (1 0 4) direction. IR and Raman spectra were recorded in the 100-900 cm-1 range and the observed modes were analysed and assigned to different normal modes of vibration. The direct optical band gap energy value calculated from the transmittance spectra of as-deposited thin film is about 3.38 eV. We employ first principles calculations based on density functional theory (DFT) with the B3LYP hybrid functional and a coupled perturbed Hartree-Fock/Kohn-Sham approach (CPHF/KS). We study the electronic structure, optimum geometry, and IR and Raman spectra of ferromagnetically and antiferromagnetically ordered Cr2O3. The computed results are consistent with the experimental measurements, and provide complete vibrational assignment, for the characterization of Cr2O3 thin film materials which can be used in photocatalysis and gas sensors.
[Does carbonate originate from carbonate-calcium crystal component of the human urinary calculus?].

PubMed

Yuzawa, Masayuki; Nakano, Kazuhiko; Kumamaru, Takatoshi; Nukui, Akinori; Ikeda, Hitoshi; Suzuki, Kazumi; Kobayashi, Minoru; Sugaya, Yasuhiro; Morita, Tatsuo

2008-09-01

It gives important information in selecting the appropriate treatment for urolithiasis to confirm the component of urinary calculus. Presently component analysis of the urinary calculus is generally performed by infrared spectroscopy which is employed by companies providing laboratory testing services in Japan. The infrared spectroscopy determines the molecular components from the absorption spectra in consequence of atomic vibrations. It has the drawback that an accurate crystal structure cannot be analyzed compared with the X-ray diffraction method which analyzes the crystal constituent based on the diffraction of X-rays on crystal lattice. The components of the urinary calculus including carbonate are carbonate apatite and calcium carbonate such as calcite. Although the latter is reported to be very rare component in human urinary calculus, the results by infrared spectroscopy often show that calcium carbonate is included in calculus. The infrared spectroscopy can confirm the existence of carbonate but cannot determine whether carbonate is originated from carbonate apatite or calcium carbonate. Thus, it is not clear whether calcium carbonate is included in human urinary calculus component in Japan. In this study, we examined human urinary calculus including carbonate by use of X-ray structural analysis in order to elucidate the origin of carbonate in human urinary calculus. We examined 17 human calculi which were reported to contain calcium carbonate by infrared spectroscopy performed in the clinical laboratory. Fifteen calculi were obtained from urinary tract, and two were from gall bladder. The stones were analyzed by X-ray powder method after crushed finely. The reports from the clinical laboratory showed that all urinary culculi consisted of calcium carbonate and calcium phosphate, while the gallstones consisted of calcium carbonate. But the components of all urinary calculi were revealed to be carbonate apatite by X-ray diffraction. The components of gallstones were shown to be calcium carbonate (one calcite and the other aragonite) not only by infrared spectroscopy but by X-ray diffraction. It was shown that component analysis of the calculus could be more accurately performed by adding X-ray diffraction method to infrared spectroscopy. It was shown that calcium carbonate existed in a gallstone. As for the carbonate in human urinary calculi, present study showed that it was not calcium carbonate origin but carbonate apatite origin.
Magnetic Properties of Copper Doped Nickel Ferrite Nanoparticles Synthesized by Co Precipitation Method

NASA Astrophysics Data System (ADS)

Anjana, V.; John, Sara; Prakash, Pooja; Nair, Amritha M.; Nair, Aravind R.; Sambhudevan, Sreedha; Shankar, Balakrishnan

2018-02-01

Nickel ferrite nanoparticles with copper atoms as dopant have been prepared using co-precipitation method with general formula Ni1-xCuxFe2O4 (x=0.2, 0.4, 0.6, 0.8 and 1) and are sintered at quite ambient temperature. Structural and magnetic properties were examined using Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction method (XRD) and Vibrating Sample Magnetometer (VSM) to study the influence of copper doping in nickel ferrite magnetic nanoparticles. X-ray studies proves that the particles are possessing single phase spinel structure with an average particle size calculated using Debye Scherer formula. Magnetic measurements reveal that saturation magnetization value (Ms) decreases while magnetic coercivity (Hc) increases upon doping.
Structural, antimicrobial and computational characterization of 1-benzoyl-3-(5-chloro-2-hydroxyphenyl)thiourea.

PubMed

Atiş, Murat; Karipcin, Fatma; Sarıboğa, Bahtiyar; Taş, Murat; Çelik, Hasan

2012-12-01

A new thiourea derivative, 1-benzoyl-3-(5-chloro-2-hydroxyphenyl)thiourea (bcht) has been synthesized from the reaction of 2-amino-4-chlorophenol with benzoyl isothiocyanate. The title compound has been characterized by elemental analyses, FT-IR, (13)C, (1)H NMR spectroscopy and the single crystal X-ray diffraction analysis. The structure of bcht derived from X-ray diffraction of a single crystal has been presented. The structural and spectroscopic data of the molecule in the ground state were calculated by using density functional method using 6-311++G(d,p) basis set. The complete assignments of all vibrational modes were performed on the basis of the total energy distributions (TED). Isotropic chemical shifts ((13)C NMR and (1)H NMR) were calculated using the gauge-invariant atomic orbital (GIAO) method. Theoretical calculations of bond parameters, harmonic vibration frequencies and nuclear magnetic resonance are in good agreement with experimental results. The UV absorption spectra of the compound that dissolved in ACN and MeOH were recorded. Bcht was also screened for antimicrobial activity against pathogenic bacteria and fungi. Copyright © 2012 Elsevier B.V. All rights reserved.
X-ray diffraction, vibrational and quantum chemical investigations of 2-methyl-4-nitroanilinium trichloroacetate trichloroacetic acid

NASA Astrophysics Data System (ADS)

Arjunan, V.; Marchewka, Mariusz K.; Pietraszko, A.; Kalaivani, M.

2012-11-01

The structural investigations of the molecular complex of 2-methyl-4-nitroaniline with trichloroacetic acid, namely 2-methyl-4-nitroanilinium trichloroacetate trichloroacetic acid (C11H10Cl6N2O6) have been performed by means of single crystal and powder X-ray diffraction method. The complex was formed with accompanying proton transfer from trichloroacetic acid molecule to 2-methyl-4-nitroaniline. The studied crystal is built up of singly protonated 2-methyl-4-nitroanilinium cations, trichloroacetate anions and neutral trichloroacetic acid molecules. The crystals are monoclinic, space group P21/c, with a = 14.947 Å, b = 6.432 Å, c = 19.609 Å and Z = 4. The vibrational assignments and analysis of 2-methyl-4-nitroanilinium trichloroacetate trichloroacetic acid have also been performed by FTIR, FT-Raman and far-infrared spectral studies. More support on the experimental findings were added from the quantum chemical studies performed with DFT (B3LYP) method using 6-31G**, cc-pVDZ, 6-31G and 6-31++G basis sets. The structural parameters, energies, thermodynamic parameters and the NBO charges of 2M4NATCA were also determined by the DFT methods.
Diffraction leveraged modulation of X-ray pulses using MEMS-based X-ray optics

DOEpatents

Lopez, Daniel; Shenoy, Gopal; Wang, Jin; Walko, Donald A.; Jung, Il-Woong; Mukhopadhyay, Deepkishore

2016-08-09

A method and apparatus are provided for implementing Bragg-diffraction leveraged modulation of X-ray pulses using MicroElectroMechanical systems (MEMS) based diffractive optics. An oscillating crystalline MEMS device generates a controllable time-window for diffraction of the incident X-ray radiation. The Bragg-diffraction leveraged modulation of X-ray pulses includes isolating a particular pulse, spatially separating individual pulses, and spreading a single pulse from an X-ray pulse-train.
High Ms Fe16N2 thin film with Ag under layer on GaAs substrate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Allard Jr, Lawrence Frederick

2016-01-01

(001) textured Fe16N2 thin film with Ag under layer is successfully grown on GaAs substrate using a facing target sputtering (FTS) system. After post annealing, chemically ordered Fe16N2 phase is formed and detected by X-ray diffraction (XRD). High saturation magnetization (Ms) is measured by a vibrating sample magnetometer (VSM). In comparison with Fe16N2 with Ag under layer on MgO substrate and Fe16N2 with Fe under layer on GaAs substrate, the current layer structure shows a higher Ms value, with a magnetically softer feature in contrast to the above cases. In addition, X-ray photoelectron spectroscopy (XPS) is performed to characterize themore » binding energy of N atoms. To verify the role of strain that the FeN layer experiences in the above three structures, Grazing Incidence X-ray Diffraction (GIXRD) is conducted to reveal a large in-plane lattice constant due to the in-plane biaxial tensile strain. INTRODUCTION« less
Experimental (13C NMR, 1H NMR, FT-IR, single-crystal X-ray diffraction) and DFT studies on 3,4-bis(isoproylamino)cyclobut-3-ene-1,2-dione.

PubMed

Süleymanoğlu, Nevin; Ustabaş, Reşat; Alpaslan, Yelda Bingöl; Eyduran, Fatih; Ozyürek, Cengiz; Iskeleli, Nazan Ocak

2011-12-01

In this work, 3,4-bis(isoproylamino)cyclobut-3-ene-1,2-dione C(10)H(16)N(2)O(2) (I), was synthesized and characterized by (13)C NMR, (1)H NMR, FT-IR, UV-vis spectroscopy and single-crystal X-ray diffraction. DFT method with 6-31G(d,p) basis set has been used to calculate the optimized geometrical parameters, atomic charges, vibrational frequencies and chemical shift values. The calculated vibrational frequencies and chemical shift values are compared with experimental FT-IR and NMR spectra. The results of the calculation shows good agreement between experimental and calculated values of the compound I. The existence of N-H⋯O type intermolecular ve C-H⋯O type intramolecular hydrogen bonds can be deduced from differences between experimental and calculated results of FT-IR and NMR. In addition, the molecular electrostatic potential map and frontier molecular orbitals and electronic absorption spectra were performed at B3LYP/6-31G(d,p) level of theory. HOMO-LUMO electronic transition of 4.90 eV are derived from the contribution of the bands π→π* and n→π* The spectral results obtained from FT-IR, NMR and X-ray of I revealed that the compound I is in predominantly enamine tautomeric form, which was supported by DFT calculations. Copyright © 2011 Elsevier B.V. All rights reserved.

Growth, crystalline perfection, spectral, thermal and theoretical studies on imidazolium L-tartrate crystals.

PubMed

Meena, K; Muthu, K; Meenatchi, V; Rajasekar, M; Bhagavannarayana, G; Meenakshisundaram, S P

2014-04-24

Transparent optical quality single crystals of imidazolium L-tartrate (IMLT) were grown by conventional slow evaporation solution growth technique. Crystal structure of the as-grown IMLT was determined by single crystal X-ray diffraction analysis. Thermal analysis reveals the purity of the crystal and the sample is stable up to the melting point. Good transmittance in the visible region is observed and the band gap energy is estimated using diffuse reflectance data by the application of Kubelka-Munk algorithm. The powder X-ray diffraction study reveals the crystallinity of the as-grown crystal and it is compared with that of the experimental one. An additional peak in high resolution X-ray diffraction (HRXRD) indicates the presence of an internal structural low angle boundary. Second harmonic generation (SHG) activity of IMLT is significant as estimated by Kurtz and Perry powder technique. HOMO-LUMO energies and first-order molecular hyperpolarizability of IMLT have been evaluated using density functional theory (DFT) employing B3LYP functional and 6-31G(d,p) basis set. The optimized geometry closely resembles the ORTEP. The vibrational patterns present in the molecule are confirmed by FT-IR coinciding with theoretical patterns. Copyright © 2014 Elsevier B.V. All rights reserved.
1-Amino-4-hydroxy-9,10-anthraquinone - An analogue of anthracycline anticancer drugs, interacts with DNA and induces apoptosis in human MDA-MB-231 breast adinocarcinoma cells: Evaluation of structure-activity relationship using computational, spectroscopic and biochemical studies.

PubMed

Mondal, Palash; Roy, Sanjay; Loganathan, Gayathri; Mandal, Bitapi; Dharumadurai, Dhanasekaran; Akbarsha, Mohammad A; Sengupta, Partha Sarathi; Chattopadhyay, Shouvik; Guin, Partha Sarathi

2015-12-01

The X-ray diffraction and spectroscopic properties of 1-amino-4-hydroxy-9,10-anthraquinone (1-AHAQ), a simple analogue of anthracycline chemotherapeutic drugs were studied by adopting experimental and computational methods. The optimized geometrical parameters obtained from computational methods were compared with the results of X-ray diffraction analysis and the two were found to be in reasonably good agreement. X-ray diffraction study, Density Functional Theory (DFT) and natural bond orbital (NBO) analysis indicated two types of hydrogen bonds in the molecule. The IR spectra of 1-AHAQ were studied by Vibrational Energy Distribution Analysis (VEDA) using potential energy distribution (PED) analysis. The electronic spectra were studied by TDDFT computation and compared with the experimental results. Experimental and theoretical results corroborated each other to a fair extent. To understand the biological efficacy of 1-AHAQ, it was allowed to interact with calf thymus DNA and human breast adino-carcinoma cell MDA-MB-231. It was found that the molecule induces apoptosis in this adinocarcinoma cell, with little, if any, cytotoxic effect in HBL-100 normal breast epithelial cell.
In situ Raman and X-ray diffraction studies on the high pressure and temperature stability of methane hydrate up to 55 GPa.

PubMed

Kadobayashi, Hirokazu; Hirai, Hisako; Ohfuji, Hiroaki; Ohtake, Michika; Yamamoto, Yoshitaka

2018-04-28

High-temperature and high-pressure experiments were performed under 2-55 GPa and 298-653 K using in situ Raman spectroscopy and X-ray diffraction combined with externally heated diamond anvil cells to investigate the stability of methane hydrate. Prior to in situ experiments, the typical C-H vibration modes of methane hydrate and their pressure dependence were measured at room temperature using Raman spectroscopy to make a clear discrimination between methane hydrate and solid methane which forms through the decomposition of methane hydrate at high temperature. The sequential in situ Raman spectroscopy and X-ray diffraction revealed that methane hydrate survives up to 633 K and 40.3 GPa and then decomposes into solid methane and ice VII above the conditions. The decomposition curve of methane hydrate estimated by the present experiments is >200 K lower than the melting curves of solid methane and ice VII, and moderately increases with increasing pressure. Our result suggests that although methane hydrate may be an important candidate for major constituents of cool exoplanets and other icy bodies, it is unlikely to be present in the ice mantle of Neptune and Uranus, where the temperature is expected to be far beyond the decomposition temperatures.
In situ Raman and X-ray diffraction studies on the high pressure and temperature stability of methane hydrate up to 55 GPa

NASA Astrophysics Data System (ADS)

Kadobayashi, Hirokazu; Hirai, Hisako; Ohfuji, Hiroaki; Ohtake, Michika; Yamamoto, Yoshitaka

2018-04-01

High-temperature and high-pressure experiments were performed under 2-55 GPa and 298-653 K using in situ Raman spectroscopy and X-ray diffraction combined with externally heated diamond anvil cells to investigate the stability of methane hydrate. Prior to in situ experiments, the typical C-H vibration modes of methane hydrate and their pressure dependence were measured at room temperature using Raman spectroscopy to make a clear discrimination between methane hydrate and solid methane which forms through the decomposition of methane hydrate at high temperature. The sequential in situ Raman spectroscopy and X-ray diffraction revealed that methane hydrate survives up to 633 K and 40.3 GPa and then decomposes into solid methane and ice VII above the conditions. The decomposition curve of methane hydrate estimated by the present experiments is >200 K lower than the melting curves of solid methane and ice VII, and moderately increases with increasing pressure. Our result suggests that although methane hydrate may be an important candidate for major constituents of cool exoplanets and other icy bodies, it is unlikely to be present in the ice mantle of Neptune and Uranus, where the temperature is expected to be far beyond the decomposition temperatures.
Synthesis, characterization, and DFT studies of a new chiral ionic liquid from (S)-1-phenylethylamine

NASA Astrophysics Data System (ADS)

Cui, Shuya; Wang, Tao; Hu, Xiaoli

2014-12-01

A new chiral ionic liquid was synthesized from (S)-1-phenylethylamine and it was studied by IR, Raman, polarimetry, NMR and X-ray crystal diffraction. Its vibrational spectral bands are precisely ascribed to the studied structure with the aid of DFT theoretical calculations. The optimized geometries and calculated vibrational frequencies are evaluated via comparison with experimental values. The vibrational spectral data obtained from IR and Raman spectra are assigned based on the results of the theoretical calculations by the DFT-B3LYP method at 6-311G(d,p) level. The computed vibrational frequencies were scaled by scale factors to yield a good agreement with observed experimental vibrational frequencies. The vibrational modes assignments were performed by using the animation option of GaussView5.0 graphical interface for Gaussian program.
Molecular and crystal structure of 2-{( E)-[(4-Methylphenyl)imino]methyl}-4-nitrophenol: A redetermination

NASA Astrophysics Data System (ADS)

Kaynar, Nihal Kan; Tanak, Hasan; Şahin, Songul; Dege, Necmi; Ağar, Erbil; Yavuz, Metin

2016-03-01

The crystal structure of the title compound, C14H12N2O3, was recently determined as a mixture of its neutral (OH containing) and zwitterionic (NH containing) forms, in a 0.60 (4): 0.40 (4) ratio using the X-ray determination. In this study, the title compound has been characterized by FT-IR and X-ray diffraction. The redetermination showed that the title compound has only enol (OH) form because of lack of the NH stretching vibration in FT-IR spectrum. In addition, the molecular structure and tautomerism of the title compound have been discussed.
Molecular and crystal structure of 2-((E)-[(4-Methylphenyl)imino]methyl)-4-nitrophenol: A redetermination

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaynar, Nihal Kan, E-mail: nihal-kan84@windowslive.com; Tanak, Hasan; Şahin, Songul

The crystal structure of the title compound, C{sub 14}H{sub 12}N{sub 2}O{sub 3}, was recently determined as a mixture of its neutral (OH containing) and zwitterionic (NH containing) forms, in a 0.60 (4): 0.40 (4) ratio using the X-ray determination. In this study, the title compound has been characterized by FT-IR and X-ray diffraction. The redetermination showed that the title compound has only enol (OH) form because of lack of the NH stretching vibration in FT-IR spectrum. In addition, the molecular structure and tautomerism of the title compound have been discussed.
Synthesis, spectroscopic and theoretical studies of ethyl (2E)-3-amino-2-({[(4-benzoyl-1,5-diphenyl-1H-pyrazol-3-yl)carbonyl]amino}carbonothioyl)but-2-enoate butanol solvate.

PubMed

Koca, İrfan; Sert, Yusuf; Gümüş, Mehmet; Kani, İbrahim; Çırak, Çağrı

2014-01-24

We have synthesized ethyl (2E)-3-amino-2-({[(4-benzoyl-1,5-diphenyl-1H-pyrazol-3-yl)carbonyl]amino}carbonothioyl)but-2-enoate (2) by the reaction of 4-benzoyl-1,5-diphenyl-1H-pyrazole-3-carbonyl chloride (1), ammonium thiocyanate and ethyl 3-aminobut-2-enoate and then characterized by elemental analyses, IR, Raman, (1)H NMR, (13)C NMR and X-ray diffraction methods. The experimental and theoretical vibrational spectra of 2 were investigated. The experimental FT-IR (4000-400 cm(-1)) and Laser-Raman spectra (4000-100 cm(-1)) of the molecule in the solid phase were recorded. Theoretical vibrational frequencies and geometric parameters (bond lengths, bond angles) were calculated using Ab Initio Hartree Fock (HF), Density Functional Theory (B3LYP) methods with 6-311++G(d,p) basis set by Gaussian 09W program. The computed values of frequencies are scaled using a suitable scale factor to yield good coherence with the observed values. The assignments of the vibrational frequencies were performed by potential energy distribution (PED) analysis by using VEDA 4 program. The theoretical optimized geometric parameters and vibrational frequencies were compared with the corresponding experimental X-ray diffraction data, and they were seen to be in a good agreement with each other. Also, the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energies were calculated. Copyright © 2013 Elsevier B.V. All rights reserved.
Structure of dimethylphenyl betaine hydrochloride studied by X-ray diffraction, DFT calculation, NMR and FTIR spectra

NASA Astrophysics Data System (ADS)

Szafran, M.; Katrusiak, A.; Dega-Szafran, Z.; Kowalczyk, I.

2013-01-01

The structure of dimethylphenyl betaine hydrochloride (1) has been studied by X-ray diffraction, DFT calculations, NMR and FTIR spectra. The crystals are monoclinic, space group P21/c. In the crystal, the Cl- anion is connected with protonated betaine through the O-H⋯Cl- hydrogen bond of 2.943(2) Å. The structures in the gas phase (2) and water solution (3) have been optimized by the B3LYP/6-311++G(d,p) approach and the geometrical results have been compared with the X-ray data of 1. The FTIR spectrum of the solid compound is consistent with the X-ray results. The probable assignments of the anharmonic experimental vibrational frequencies of the investigated chloride (1) based on the calculated harmonic frequencies in water solution (3) are proposed. The correlations between the experimental 1H and 13C NMR chemical shifts (δexp) of 1 in D2O and the magnetic isotropic shielding constants (σcalc) calculated by the GIAO/B3LYP/6-311G++(d,p) approach, using the screening solvation model (COSMO), δexp = a + b σcalc, for optimized molecule 3 in water solution are linear and correctly reproduce the experimental chemical shifts.
Comparative study of structural and magnetic properties of nano-crystalline Li 0.5Fe 2.5O 4 prepared by various methods

NASA Astrophysics Data System (ADS)

Verma, Vivek; Pandey, Vibhav; Singh, Sukhveer; Aloysius, R. P.; Annapoorni, S.; Kotanala, R. K.

2009-08-01

Lithium ferrite has been considered as one of the highly strategic magnetic material. Nano-crystalline Li 0.5Fe 2.5O 4 was prepared by four different techniques and characterized by X-ray diffraction, vibrating sample magnetometer (VSM), transmission electron microscope (TEM) and Fourier transform infrareds (FTIR). The effect of annealing temperature (700, 900 and 1050 °C) on microstructure has been correlated to the magnetic properties. From X-ray diffraction patterns, it is confirmed that the pure phase of lithium ferrite began to form at 900 °C annealing. The particle size of as-prepared lithium ferrite was observed around 40, 31, 22 and 93 nm prepared by flash combustion, sol-gel, citrate precursor and standard ceramic technique, respectively. Lithium ferrite prepared by citrate precursor method shows a maximum saturation magnetization 67.6 emu/g at 5 KOe.
Characterization of cubic ceria?zirconia powders by X-ray diffraction and vibrational and electronic spectroscopy

NASA Astrophysics Data System (ADS)

Sánchez Escribano, Vicente; Fernández López, Enrique; Panizza, Marta; Resini, Carlo; Gallardo Amores, José Manuel; Busca, Guido

2003-10-01

The X-ray diffraction (XRD) patterns and the Infrared, Raman and UV-visible spectra of CeO 2ZrO 2 powders prepared by co-precipitation are presented. Raman spectra provide evidence for the largely predominant cubic structure of the powders with CeO 2 molar composition higher than 25%. Also skeletal IR spectra allow to distinguish cubic from tetragonal phases which are instead not easily distinguished on the basis of the XRD patterns. All mixed oxides including pure ceria are strong UV absorbers although also absorb in the violet visible region. By carefully selecting their composition and treatment temperature, the onset of the radiation that they cut off can be chosen in the 425-475 nm interval. Although they are likely metastable, the cubic phases are still pure even after heating at 1173 K for 4 h.
Single-crystal X-ray diffraction study of SrGeO3 high-pressure perovskite phase at 100 K

NASA Astrophysics Data System (ADS)

Nakatsuka, Akihiko; Arima, Hiroshi; Ohtaka, Osamu; Fujiwara, Keiko; Yoshiasa, Akira

2017-10-01

Single-crystal X-ray diffraction study of SrGeO3 perovskite (cubic; space group Pmɜ¯m) synthesized at 6 GPa and 1223 K was conducted at a low temperature of 100 K. The residual electron density revealed the presence of the bonding electron at the center of the Ge-O bond, in accordance with our previous conclusion that the Ge-O bond is strongly covalent. From comparison with our previous structure-refinement result at 296 K, the mean square displacement (MSD) of the O atom in the direction of the Ge-O bond is suggested to exhibit no significant temperature dependence, in contrast to that in the direction perpendicular to the bond. Thus, the strong covalency of the Ge-O bond can have a large influence on the temperature dependence of thermal vibration of the O atom.
Phase transitions in heated Sr{sub 2}MgTeO{sub 6} double perovskite oxide probed by X-ray diffraction and Raman spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Manoun, Bouchaib, E-mail: manounb@gmail.com; Tamraoui, Y.; Lazor, P.

2013-12-23

Double-perovskite oxide Sr{sub 2}MgTeO{sub 6} has been synthetized, and its crystal structure was probed by the technique of X-ray diffraction at room temperature. The structure is monoclinic, space group I2/m. Temperature-induced phase transitions in this compound were investigated by Raman spectroscopy up to 550 °C. Two low-wavenumber modes corresponding to external lattice vibrations merge at temperature of around 100 °C, indicating a phase transition from the monoclinic (I2/m) to the tetragonal (I4/m) structure. At 300 °C, changes in the slopes of temperature dependencies of external and O–Te–O bending modes are detected and interpreted as a second phase transition from the tetragonal (I4/m) tomore » the cubic (Fm-3m) structure.« less
Application of vibrational spectroscopy, thermal analyses and X-ray diffraction in the rapid evaluation of the stability in solid-state of ranitidine, famotidine and cimetidine.

PubMed

Jamrógiewicz, Marzena; Ciesielski, Aleksander

2015-03-25

This paper reports the study on applicability of Fourier transform infrared (FTIR), near-infrared (NIR) and Raman spectroscopy, differential scanning calorimetry (DSC) and X-ray diffraction (XRD) for the estimation of the chemical stability and photostability of histamine H2-receptor antagonist substances. Ranitidine hydrochloride (RAN), famotidine (FAM) and cimetidine (CIM) were tested and differences in sensitivity were measured via soft independence modeling of class analogies (Simca) model. The low values of variations for FAM and CIM and high variations obtained for RAN using FTIR and NIR techniques indicated that these methods were suitable and applicable to classify the degradation of RAN. Examined methods are recommendable in the first technological stage of drug production, and the preclinical and clinical development of pharmaceuticals or their quality control. Copyright © 2015 Elsevier B.V. All rights reserved.
Yes, one can obtain better quality structures from routine X-ray data collection.

PubMed

Sanjuan-Szklarz, W Fabiola; Hoser, Anna A; Gutmann, Matthias; Madsen, Anders Østergaard; Woźniak, Krzysztof

2016-01-01

Single-crystal X-ray diffraction structural results for benzidine dihydrochloride, hydrated and protonated N,N,N,N-peri(dimethylamino)naphthalene chloride, triptycene, dichlorodimethyltriptycene and decamethylferrocene have been analysed. A critical discussion of the dependence of structural and thermal parameters on resolution for these compounds is presented. Results of refinements against X-ray data, cut off to different resolutions from the high-resolution data files, are compared to structural models derived from neutron diffraction experiments. The Independent Atom Model (IAM) and the Transferable Aspherical Atom Model (TAAM) are tested. The average differences between the X-ray and neutron structural parameters (with the exception of valence angles defined by H atoms) decrease with the increasing 2θmax angle. The scale of differences between X-ray and neutron geometrical parameters can be significantly reduced when data are collected to the higher, than commonly used, 2θmax diffraction angles (for Mo Kα 2θmax > 65°). The final structural and thermal parameters obtained for the studied compounds using TAAM refinement are in better agreement with the neutron values than the IAM results for all resolutions and all compounds. By using TAAM, it is still possible to obtain accurate results even from low-resolution X-ray data. This is particularly important as TAAM is easy to apply and can routinely be used to improve the quality of structural investigations [Dominiak (2015 ▸). LSDB from UBDB. University of Buffalo, USA]. We can recommend that, in order to obtain more adequate (more accurate and precise) structural and displacement parameters during the IAM model refinement, data should be collected up to the larger diffraction angles, at least, for Mo Kα radiation to 2θmax = 65° (sin θmax/λ < 0.75 Å(-1)). The TAAM approach is a very good option to obtain more adequate results even using data collected to the lower 2θmax angles. Also the results of translation-libration-screw (TLS) analysis and vibrational entropy values are more reliable for 2θmax > 65°.
Modeling and measurements of XRD spectra of extended solids under high pressure

NASA Astrophysics Data System (ADS)

Batyrev, I. G.; Coleman, S. P.; Stavrou, E.; Zaug, J. M.; Ciezak-Jenkins, J. A.

2017-06-01

We present results of evolutionary simulations based on density functional calculations of various extended solids: N-Si and N-H using variable and fixed concentration methods of USPEX. Predicted from the evolutionary simulations structures were analyzed in terms of thermo-dynamical stability and agreement with experimental X-ray diffraction spectra. Stability of the predicted system was estimated from convex-hull plots. X-ray diffraction spectra were calculated using a virtual diffraction algorithm which computes kinematic diffraction intensity in three-dimensional reciprocal space before being reduced to a two-theta line profile. Calculations of thousands of XRD spectra were used to search for a structure of extended solids at certain pressures with best fits to experimental data according to experimental XRD peak position, peak intensity and theoretically calculated enthalpy. Comparison of Raman and IR spectra calculated for best fitted structures with available experimental data shows reasonable agreement for certain vibration modes. Part of this work was performed by LLNL, Contract DE-AC52-07NA27344. We thank the Joint DoD / DOE Munitions Technology Development Program, the HE C-II research program at LLNL and Advanced Light Source, supported by BES DOE, Contract No. DE-AC02-05CH112.
Synthesis, characterization, and DFT studies of a new chiral ionic liquid from (S)-1-phenylethylamine.

PubMed

Cui, Shuya; Wang, Tao; Hu, Xiaoli

2014-12-10

A new chiral ionic liquid was synthesized from (S)-1-phenylethylamine and it was studied by IR, Raman, polarimetry, NMR and X-ray crystal diffraction. Its vibrational spectral bands are precisely ascribed to the studied structure with the aid of DFT theoretical calculations. The optimized geometries and calculated vibrational frequencies are evaluated via comparison with experimental values. The vibrational spectral data obtained from IR and Raman spectra are assigned based on the results of the theoretical calculations by the DFT-B3LYP method at 6-311G(d,p) level. The computed vibrational frequencies were scaled by scale factors to yield a good agreement with observed experimental vibrational frequencies.The vibrational modes assignments were performed by using the animation option of GaussView5.0 graphical interface for Gaussian program. Copyright © 2014 Elsevier B.V. All rights reserved.
Micro X-ray diffraction analysis of thin films using grazing-exit conditions.

PubMed

Noma, T; Iida, A

1998-05-01

An X-ray diffraction technique using a hard X-ray microbeam for thin-film analysis has been developed. To optimize the spatial resolution and the surface sensitivity, the X-ray microbeam strikes the sample surface at a large glancing angle while the diffracted X-ray signal is detected with a small (grazing) exit angle. Kirkpatrick-Baez optics developed at the Photon Factory were used, in combination with a multilayer monochromator, for focusing X-rays. The focused beam size was about 10 x 10 micro m. X-ray diffraction patterns of Pd, Pt and their layered structure were measured. Using a small exit angle, the signal-to-background ratio was improved due to a shallow escape depth. Under the grazing-exit condition, the refraction effect of diffracted X-rays was observed, indicating the possibility of surface sensitivity.
The molecular structure and vibrational spectra of N-(2,2-diphenylacetyl)- N'-(naphthalen-1yl)-thiourea by Hartree-Fock and density functional methods

NASA Astrophysics Data System (ADS)

Arslan, Hakan; Mansuroglu, Demet Sezgin; VanDerveer, Don; Binzet, Gun

2009-04-01

N-(2,2-Diphenylacetyl)- N'-(naphthalen-1yl)-thiourea (PANT) has been synthesized and characterized by elemental analysis, IR spectroscopy and 1H NMR spectroscopy. The crystal and molecular structure of the title compound has been determined from single crystal X-ray diffraction data. It crystallizes in the triclinic space group P-1, Z = 2 with a = 10.284(2) Å, b = 10.790(2) Å, c = 11.305(2) Å, α = 64.92(3)°, β = 89.88(3)°, γ = 62.99(3)°, V = 983.7(3) Å 3 and Dcalc = 1.339 Mg/m 3. The molecular structure, vibrational frequencies and infrared intensities of PANT were calculated by the Hartree-Fock and density functional theory methods (BLYP and B3LYP) using the 6-31G* basis set. The calculated geometric parameters were compared to the corresponding X-ray structure of the title compound. We obtained 22 stable conformers for the title compound; however Conformer 1 is approximately 9.53 kcal/mol more stable than Conformer 22. The comparison of the theoretical and experimental geometry of the title compound shows that the X-ray parameters fairly well reproduce the geometry of Conformer 17. The harmonic vibrations computed for this compound by the B3LYP/6-31G* method are in good agreement with the observed IR spectral data. Theoretical vibrational spectra of the title compound were interpreted by means of PEDs using the VEDA 4 program. A general better performance of the investigated methods was calculated by PAVF 1.0 program.
Ultrafast large-amplitude relocation of electronic charge in ionic crystals

PubMed Central

Zamponi, Flavio; Rothhardt, Philip; Stingl, Johannes; Woerner, Michael; Elsaesser, Thomas

2012-01-01

The interplay of vibrational motion and electronic charge relocation in an ionic hydrogen-bonded crystal is mapped by X-ray powder diffraction with a 100 fs time resolution. Photoexcitation of the prototype material KH2PO4 induces coherent low-frequency motions of the PO4 tetrahedra in the electronically excited state of the crystal while the average atomic positions remain unchanged. Time-dependent maps of electron density derived from the diffraction data demonstrate an oscillatory relocation of electronic charge with a spatial amplitude two orders of magnitude larger than the underlying vibrational lattice motions. Coherent longitudinal optical and tranverse optical phonon motions that dephase on a time scale of several picoseconds, drive the charge relocation, similar to a soft (transverse optical) mode driven phase transition between the ferro- and paraelectric phase of KH2PO4. PMID:22431621

Hydrogen bonded nonlinear optical γ-glycine: Crystal growth and characterization

NASA Astrophysics Data System (ADS)

Narayana Moolya, B.; Jayarama, A.; Sureshkumar, M. R.; Dharmaprakash, S. M.

2005-07-01

Single crystals of γ-glycine(GG) were grown by solvent evaporation technique from a mixture of aqueous solutions of glycine and ammonium nitrate at ambient temperature. X-ray diffraction, thermogravimetric/differential thermal analysis, Fourier transform infrared spectral techniques were employed to characterize the crystal. The lattice parameters were calculated and they agree well with the reported values. GG exists as dipolar ions in which the carboxyl group is present as a carboxylate ion and the amino group as an ammonium ion. Due to this dipolar nature, glycine has a high decomposition temperature. The UV cutoff of GG is below 300 nm and has a wide transparency window, which is suitable for second harmonic generation of laser in the blue region. Nonlinear optical characteristics of GG were studied using Q switched Nd:YAG laser ( λ=1064 nm). The second harmonic generation conversion efficiency of GG is 1.5 times that of potassium dihydrogen phosphate . The X-ray diffraction and Fourier transform infrared spectral studies show the presence of strong hydrogen bonds which create and stabilize the crystal structure in GG. The main contributions to the nonlinear optical properties in GG results from the presence of the hydrogen bond and from the vibrational part due to very intense infrared bands of the hydrogen bond vibrations. GG is thermally stable up to 441 K.
X-ray diffraction, vibrational and quantum chemical investigations of 2-methyl-4-nitroanilinium trichloroacetate trichloroacetic acid.

PubMed

Arjunan, V; Marchewka, Mariusz K; Pietraszko, A; Kalaivani, M

2012-11-01

The structural investigations of the molecular complex of 2-methyl-4-nitroaniline with trichloroacetic acid, namely 2-methyl-4-nitroanilinium trichloroacetate trichloroacetic acid (C(11)H(10)Cl(6)N(2)O(6)) have been performed by means of single crystal and powder X-ray diffraction method. The complex was formed with accompanying proton transfer from trichloroacetic acid molecule to 2-methyl-4-nitroaniline. The studied crystal is built up of singly protonated 2-methyl-4-nitroanilinium cations, trichloroacetate anions and neutral trichloroacetic acid molecules. The crystals are monoclinic, space group P2(1)/c, with a=14.947Å, b=6.432Å, c=19.609Å and Z=4. The vibrational assignments and analysis of 2-methyl-4-nitroanilinium trichloroacetate trichloroacetic acid have also been performed by FTIR, FT-Raman and far-infrared spectral studies. More support on the experimental findings were added from the quantum chemical studies performed with DFT (B3LYP) method using 6-31G, cc-pVDZ, 6-31G and 6-31++G basis sets. The structural parameters, energies, thermodynamic parameters and the NBO charges of 2M4NATCA were also determined by the DFT methods. Copyright © 2012 Elsevier B.V. All rights reserved.
Shear induced weakening of the hydrogen bonding lattice of the energetic material 5,5'-Hydrazinebistetrazole at high-pressure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ciezak-Jenkins, Jennifer A.; Jenkins, Timothy A.

5,5'-Hydrazinebistetrazole (HBTA) has been studied by in-situ x-ray diffraction and vibrational spectroscopy to pressures near 25 GPa at room temperature. Analysis of the x-ray diffraction pattern of HBTA collected at ambient pressure and temperature revealed a monoclinic structure consistent with that previously reported. Under compression, the x-ray diffraction reveals little evidence of a phase transition over the pressure range studied. Slight anisotropy in response to compression was noted and the β angle decreased moderately, suggesting geometry modifications occur in the hydrogen bonding lattice and between neighboring HBTA molecules as a result of compression along the c axis. Blue shifts inmore » the Infrared active N-H stretching modes were observed, implying a weakening of the hydrogen bond with compression. The weakening of the hydrogen bonding lattice with pressure may lead to an increase in the bending angle of the C-N=N-C bridge between the tetrazole rings and an increased overlap between the π-bonding orbitals. The Raman spectra showed a number of modes associated with H-N=N-H motions of the bridge become more prominent in the spectra under compression. Additionally, the possibility that the increased bend in the angle of the C-N=N-C bridge results from a shearing deformation is discussed.« less
Optical and magnetic properties of Co-doped CuO flower/plates/particles-like nanostructures.

PubMed

Basith, N Mohamed; Vijaya, J Judith; Kennedy, L John; Bououdina, M; Hussain, Shamima

2014-03-01

In this study, pure and Co-doped CuO nanostructures (0.5, 1.0, 1.5, and 2.0 at wt% of Co) were synthesized by microwave combustion method. The prepared samples were characterized by X-ray diffraction (XRD), high resolution scanning electron microscopy (HR-SEM), energy dispersive X-ray analysis (EDX), diffuse reflectance spectroscopy (DRS), photoluminescence (PL) spectroscopy and vibrating sample magnetometry (VSM). Powder X-ray diffraction patterns refined by the Rietveld method indicated the formation of single-phase monoclinic structure. The surface morphology and elemental analysis of Co-doped CuO nanostructures were studied by using HR-SEM and EDX. Interestingly, the morphology was found to change considerably from nanoflowers to nanoplates then to nanoparticles with the variation of Co concentration. The optical band gap calculated using DRS was found to be 2.1 eV for pure CuO and increases up to 3.4 eV with increasing cobalt content. Photoluminescence measurements also confirm these results. The magnetic measurements indicated that the obtained nanostructures were ferromagnetic at room temperature with an optimum value of saturation magnetization at 1.0 wt.% of Co-doped CuO, i.e., 970 micro emu/g.
Structure, optical and phonon properties of bulk and nanocrystalline Al2-xScx(WO4)3 solid solutions doped with Cr3+

NASA Astrophysics Data System (ADS)

Mączka, M.; Hermanowicz, K.; Pietraszko, A.; Yordanova, A.; Koseva, I.

2014-01-01

Pure and Cr3+ doped nanosized Al2-xScx(WO4)3 solid solutions were prepared by co-precipitation method as well as Al2-xScx(WO4)3 single crystals were grown by high-temperature flux method. The obtained samples were characterized by X-ray, Raman, IR, absorption and luminescence methods. Single crystal X-ray diffraction showed that AlSc(WO4)3 is orthorhombic at room temperature with space group Pnca and trivalent cations are statistically distributed. Raman and IR studies showed that Al2-xScx(WO4)3 solid solutions show "two mode" behavior. They also showed that vibrational properties of nanosized samples have been weakly modified in comparison with the bulk materials. The luminescence and absorption spectra revealed that chromium ions occupy two sites of weak and strong crystal field strength.
Phase stability and lattice thermal conductivity reduction in CoSb{sub 3} skutterudites, doped with chalcogen atoms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Battabyal, M., E-mail: manjusha.battabyal@project.arci.res.in; Priyadarshini, B.; Gopalan, R.

We report a significant reduction in the lattice thermal conductivity of the CoSb{sub 3} skuttertudites, doped with chalcogen atoms. Te/Se chalcogen atoms doped CoSb{sub 3} skutterudite samples (Te{sub 0.1}Co{sub 4}Sb{sub 12}, Se{sub 0.1}Co{sub 4}Sb{sub 12}, Te{sub 0.05}Se{sub 0.05}Co{sub 4}Sb{sub 12}) are processed by ball milling and spark plasma sintering. X-ray diffraction data combined with energy dispersive X-ray spectra indicate the doping of Te/Se chalcogen atoms in the skutterudite. The temperature dependent X-ray diffraction confirms the stability of the Te/Se doped CoSb{sub 3} skutterudite phase and absence of any secondary phase in the temperature range starting from 300 K to 773more » K. The Raman spectroscopy reveals that different chalcogen dopant atoms cause different resonant optical vibrational modes between the dopant atom and the host CoSb{sub 3} skutterudite lattice. These optical vibrational modes do scatter heat carrying acoustic phonons in a different spectral range. It was found that among the Te/Se chalcogen atoms, Te atoms alter the host CoSb{sub 3} skutterudite lattice vibrations to a larger extent than Se atoms, and can potentially scatter more Sb related acoustic phonons. The Debye model of lattice thermal conductivity confirms that the resonant phonon scattering has important contributions to the reduction of lattice thermal conductivity in CoSb{sub 3} skutterudites doped with Te/Se chalcogen atoms. Lattice thermal conductivity ∼ 0.9 W/mK at 773 K is achieved in Te{sub 0.1}Co{sub 4}Sb{sub 12} skutterudites, which is the lowest value reported so far in CoSb{sub 3} skutterudites, doped with single Te chalcogen atom.« less
Crystalline structure analysis of cellulose treated with sodium hydroxide and carbon dioxide by means of X-ray diffraction and FTIR spectroscopy.

PubMed

Oh, Sang Youn; Yoo, Dong Il; Shin, Younsook; Kim, Hwan Chul; Kim, Hak Yong; Chung, Yong Sik; Park, Won Ho; Youk, Ji Ho

2005-10-31

Crystalline structures of cellulose (named as Cell 1), NaOH-treated cellulose (Cell 2), and subsequent CO2-treated cellulose (Cell 2-C) were analyzed by wide-angle X-ray diffraction and FTIR spectroscopy. Transformation from cellulose I to cellulose II was observed by X-ray diffraction for Cell 2 treated with 15-20 wt% NaOH. Subsequent treatment with CO2 also transformed the Cell 2-C treated with 5-10 wt% NaOH. Many of the FTIR bands including 2901, 1431, 1282, 1236, 1202, 1165, 1032, and 897 cm(-1) were shifted to higher wave number (by 2-13 cm(-1)). However, the bands at 3352, 1373, and 983 cm(-1) were shifted to lower wave number (by 3-95 cm(-1)). In contrast to the bands at 1337, 1114, and 1058 cm(-1), the absorbances measured at 1263, 993, 897, and 668 cm(-1) were increased. The FTIR spectra of hydrogen-bonded OH stretching vibrations at around 3352 cm(-1) were resolved into three bands for cellulose I and four bands for cellulose II, assuming that all the vibration modes follow Gaussian distribution. The bands of 1 (3518 cm(-1)), 2 (3349 cm(-1)), and 3 (3195 cm(-1)) were related to the sum of valence vibration of an H-bonded OH group and an intramolecular hydrogen bond of 2-OH ...O-6, intramolecular hydrogen bond of 3-OH...O-5 and the intermolecular hydrogen bond of 6-O...HO-3', respectively. Compared with the bands of cellulose I, a new band of 4 (3115 cm(-1)) related to intermolecular hydrogen bond of 2-OH...O-2' and/or intermolecular hydrogen bond of 6-OH...O-2' in cellulose II appeared. The crystallinity index (CI) was obtained by X-ray diffraction [CI(XD)] and FTIR spectroscopy [CI(IR)]. Including absorbance ratios such as A1431,1419/A897,894 and A1263/A1202,1200, the CI(IR) was evaluated by the absorbance ratios using all the characteristic absorbances of cellulose. The CI(XD) was calculated by the method of Jayme and Knolle. In addition, X-ray diffraction curves, with and without amorphous halo correction, were resolved into portions of cellulose I and cellulose II lattice. From the ratio of the peak area, that is, peak area of cellulose I (or cellulose II)/total peak area, CI(XD) were divided into CI(XD-CI) for cellulose I and CI(XD-CII) for cellulose II. The correlation between CI(XD-CI) (or CI(XD-CII)) and CI(IR) was evaluated, and the bands at 2901 (2802), 1373 (1376), 897 (894), 1263, 668 cm(-1) were good for the internal standard (or denominator) of CI(IR), which increased the correlation coefficient. Both fraction of the absorbances showing peak shift were assigned as the alternate components of CI(IR). The crystallite size was decreased to constant value for Cell 2 treated at >or= 15 wt% NaOH. The crystallite size of Cell 2-C (cellulose II) was smaller than that of Cell 2 (cellulose I) treated at 5-10 wt% NaOH. But the crystallite size of Cell 2-C (cellulose II) was larger than that of Cell 2 (cellulose II) treated at 15-20 wt% NaOH.
Synthesis, structural, dielectric and magnetic properties of CuFe2O4/MnO2 nanocomposites

NASA Astrophysics Data System (ADS)

Ali, Kashif; Bahadur, Ali; Jabbar, Abdul; Iqbal, Shahid; Ahmad, Ijaz; Bashir, Muhammad Imran

2017-07-01

Novel nanocomposite of (1-x)CuFe2O4/xMnO2 [x=10% to 50 wt%] has been synthesized by two step wet chemical route without impurity. The x-ray diffraction analysis shows the formation of both phases with crystallite size 40-100 nm which is consist ant with estimated size of SEM.The FTIR spectra confirms the characteristics vibration of ferrites atoms at tetrahedral and octahedral sites along with Mn-O vibration mode, which also confirms the coexistence of both phases. The dielectric properties studied by LCR meter in frequency range of 1 K Hz to 2 MHz.The dielectric constant and tangent loss shows same dispersion of ferrites while a.c. conductivity decreases with increase in MnO2 contents. The real and imaginary part of impedance also calculated which shows decreasing trend at higher frequency. The magnetic characterization performed by vibrating sample magnetometer (VSM) at room temperature, which shows normal ferromagnetic behavior of ferrites but saturation magnetization and coercivity decreases with incorporation of MnO2 contents.
Low-loss Ca{sub 5-x}Sr{sub x}A{sub 2}TiO{sub 12} [A=Nb,Ta] ceramics: Microwave dielectric properties and vibrational spectroscopic analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bijumon, Pazhoor Varghese; Sebastian, Mailadil Thomas; Dias, Anderson

2005-05-15

Complex perovskite-type Ca{sub 5-x}Sr{sub x}A{sub 2}TiO{sub 12} [A=Nb,Ta] (0{<=}x{<=}5) ceramics were prepared by conventional solid-state ceramic route. The crystal structure, microwave dielectric properties, and vibrational spectroscopic characteristics of these materials are reported. The structure and microstructure were investigated by x-ray diffraction and scanning electron microscopy techniques. The microwave dielectric properties were measured in the 3-5-GHz frequency range by the resonance method. Structural evolutions from orthorhombic to an averaged pseudocubic phase, with associated changes in dielectric properties, were observed as a function of composition. The structure-property relationships in these ceramics were established using Raman and Fourier transform infrared spectroscopic techniques. Ramanmore » analysis showed characteristic bands of ordered perovskite materials, with variation in both intensity and frequency as a function of composition.« less
X-ray diffraction from shock-loaded polycrystals.

PubMed

Swift, Damian C

2008-01-01

X-ray diffraction was demonstrated from shock-compressed polycrystalline metals on nanosecond time scales. Laser ablation was used to induce shock waves in polycrystalline foils of Be, 25-125 microm thick. A second laser pulse was used to generate a plasma x-ray source by irradiation of a Ti foil. The x-ray source was collimated to produce a beam of controllable diameter, which was directed at the Be sample. X-rays were diffracted from the sample, and detected using films and x-ray streak cameras. The diffraction angle was observed to change with shock pressure. The diffraction angles were consistent with the uniaxial (elastic) and isotropic (plastic) compressions expected for the loading conditions used. Polycrystalline diffraction will be used to measure the response of the crystal lattice to high shock pressures and through phase changes.
Synthesis, X-ray diffraction method, spectroscopic characterization (FT-IR, 1H and 13C NMR), antimicrobial activity, Hirshfeld surface analysis and DFT computations of novel sulfonamide derivatives

NASA Astrophysics Data System (ADS)

Demircioğlu, Zeynep; Özdemir, Fethi Ahmet; Dayan, Osman; Şerbetçi, Zafer; Özdemir, Namık

2018-06-01

Synthesized compounds of N-(2-aminophenyl)benzenesulfonamide 1 and (Z)-N-(2-((2-nitrobenzylidene)amino)phenyl)benzenesulfonamide 2 were characterized by antimicrobial activity, FT-IR, 1H and 13C NMR. Two new Schiff base ligands containing aromatic sulfonamide fragment of (Z)-N-(2-((3-nitrobenzylidene)amino)phenyl)benzenesulfonamide 3 and (Z)-N-(2-((4-nitrobenzylidene)amino)phenyl)benzenesulfonamide 4 were synthesized and investigated by spectroscopic techniques including 1H and 13C NMR, FT-IR, single crystal X-ray diffraction, Hirshfeld surface, theoretical method analyses and by antimicrobial activity. The molecular geometry obtained from the X-ray structure determination was optimized Density Functional Theory (DFT/B3LYP) method with the 6-311++G(d,p) basis set in ground state. From the optimized geometry of the molecules of 3 and 4, the geometric parameters, vibrational wavenumbers and chemical shifts were computed. The optimized geometry results, which were well represented the X-ray data, were shown that the chosen of DFT/B3LYP 6-311G++(d,p) was a successful choice. After a successful optimization, frontier molecular orbitals, chemical activity, non-linear optical properties (NLO), molecular electrostatic mep (MEP), Mulliken population method, natural population analysis (NPA) and natural bond orbital analysis (NBO), which cannot be obtained experimentally, were calculated and investigated.
Single-pulse x-ray diffraction using polycapillary optics for in situ dynamic diffraction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maddox, B. R., E-mail: maddox3@llnl.gov; Akin, M. C., E-mail: akin1@llnl.gov; Teruya, A.

2016-08-15

Diagnostic use of single-pulse x-ray diffraction (XRD) at pulsed power facilities can be challenging due to factors such as the high flux and brightness requirements for diffraction and the geometric constraints of experimental platforms. By necessity, the x-ray source is usually positioned very close, within a few inches of the sample. On dynamic compression platforms, this puts the x-ray source in the debris field. We coupled x-ray polycapillary optics to a single-shot needle-and-washer x-ray diode source using a laser-based alignment scheme to obtain high-quality x-ray diffraction using a single 16 ns x-ray pulse with the source >1 m from themore » sample. The system was tested on a Mo sample in reflection geometry using 17 keV x-rays from a Mo anode. We also identified an anode conditioning effect that increased the x-ray intensity by 180%. Quantitative measurements of the x-ray focal spot produced by the polycapillary yielded a total x-ray flux on the sample of 3.3 ± 0.5 × 10{sup 7} molybdenum Kα photons.« less
Vibrational spectroscopy of synthetic archerite (K,NH4)HPO4- and in comparison with the natural cave mineral

NASA Astrophysics Data System (ADS)

Frost, Ray L.; Xi, Yunfei; Palmer, Sara J.; Tan, Keqin; Millar, Graeme J.

2012-03-01

In order to mimic the formation of archerite in cave minerals, the mineral analogue has been synthesised. The cave mineral is formed by the reaction of the chemicals in bat guano with calcite substrates. X-ray diffraction proves that the synthesised archerite analogue was pure and more pure than the natural cave mineral. The vibrational spectra of the synthesised mineral are compared with that of the natural cave mineral from the Murra-el-elevyn Cave, Eucla, Western Australia. Raman and infrared bands are assigned to HPO4-, OH and NH stretching and bending vibrations. The Raman band at 917 cm-1 is assigned to the HOP stretching vibration of HPO4- units. Bands in the 1200-1800 cm-1 region are associated with NH4+ bending modes. Vibrational spectroscopy enables the molecular structure of archerite analogue to be analysed.
X-Ray Diffraction Apparatus

NASA Technical Reports Server (NTRS)

Blake, David F. (Inventor); Bryson, Charles (Inventor); Freund, Friedmann (Inventor)

1996-01-01

An x-ray diffraction apparatus for use in analyzing the x-ray diffraction pattern of a sample is introduced. The apparatus includes a beam source for generating a collimated x-ray beam having one or more discrete x-ray energies, a holder for holding the sample to be analyzed in the path of the beam, and a charge-coupled device having an array of pixels for detecting, in one or more selected photon energy ranges, x-ray diffraction photons produced by irradiating such a sample with said beam. The CCD is coupled to an output unit which receives input information relating to the energies of photons striking each pixel in the CCD, and constructs the diffraction pattern of photons within a selected energy range striking the CCD.
Synthesis, spectroscopic characterization, X-ray structure and DFT studies on 2,6-bis(1-benzyl-1H-benzo[d]imidazol-2-yl)pyridine

NASA Astrophysics Data System (ADS)

İnkaya, Ersin; Günnaz, Salih; Özdemir, Namık; Dayan, Osman; Dinçer, Muharrem; Çetinkaya, Bekir

2013-02-01

The title molecule, 2,6-bis(1-benzyl-1H-benzo[d]imidazol-2-yl)pyridine (C33H25N5), was synthesized and characterized by elemental analysis, FT-IR spectroscopy, one- and two-dimensional NMR spectroscopies, and single-crystal X-ray diffraction. In addition, the molecular geometry, vibrational frequencies and gauge-independent atomic orbital (GIAO) 1H and 13C NMR chemical shift values of the title compound in the ground state have been calculated using the density functional theory at the B3LYP/6-311G(d,p) level, and compared with the experimental data. The complete assignments of all vibrational modes were performed by potential energy distributions using VEDA 4 program. The geometrical parameters of the optimized structure are in good agreement with the X-ray crystallographic data, and the theoretical vibrational frequencies and GIAO 1H and 13C NMR chemical shifts show good agreement with experimental values. Besides, molecular electrostatic potential (MEP) distribution, frontier molecular orbitals (FMO) and non-linear optical properties of the title compound were investigated by theoretical calculations at the B3LYP/6-311G(d,p) level. The linear polarizabilities and first hyper polarizabilities of the molecule indicate that the compound is a good candidate of nonlinear optical materials. The thermodynamic properties of the compound at different temperatures were calculated, revealing the correlations between standard heat capacity, standard entropy, standard enthalpy changes and temperatures.
Three-dimensional magnetophotonic crystals based on artificial opals

NASA Astrophysics Data System (ADS)

Baryshev, A. V.; Kodama, T.; Nishimura, K.; Uchida, H.; Inoue, M.

2004-06-01

We fabricated and experimentally investigated three-dimensional magnetophotonic crystals (3D MPCs) based on artificial opals. Opal samples with three-dimensional dielectric lattices were impregnated with different types of magnetic material. Magnetic and structural properties of 3D MPCs were studied by field emission scanning electron microscopy, x-ray diffraction analysis, and vibrating sample magnetometer. We have shown that magnetic materials synthesized in voids of opal lattices and the composites obtained have typical magnetic properties.
Spinel NixZn1-xFe2O4 (0.0 ≤ x ≤ 1.0) nano-photocatalysts: Synthesis, characterization and photocatalytic degradation of methylene blue dye

NASA Astrophysics Data System (ADS)

Padmapriya, G.; Manikandan, A.; Krishnasamy, V.; Jaganathan, Saravana Kumar; Antony, S. Arul

2016-09-01

Spinel NixZn1-xFe2O4 (x = 0.0 to 1.0) nanoparticles were successfully synthesized by a simple microwave combustion method (MCM) using metal nitrates as raw materials and glycine as the fuel. The structural, morphological and opto-magnetic properties of the spinel NixZn1-xFe2O4 ferrites were determined by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), high resolution scanning electron microscopy (HR-SEM), energy dispersive X-ray (EDX) spectroscopy, high resolution transmission electron microscopy (HR-TEM), selected area electron diffraction (SAED) pattern, UV-Visible diffuse reflectance spectroscopy (DRS), photoluminescence (PL) spectroscopy and vibrating sample magnetometer (VSM). Powder XRD, and EDX analysis was confirmed the formation of pure phase of spinel ferrites. HR-SEM and HR-TEM analysis was confirmed the formation of sphere like-particle morphology of the samples with smaller agglomeration. VSM analysis clearly showed the superparamagnetic and ferromagnetic nature of the samples. The Ms value is 3.851 emu/g for undoped ZnFe2O4 sample and it increased with increase in Ni content. Photo-catalytic degradation (PCD) of methylene blue (MB) dye using the samples were carried out and observed good PCD results.
Same Precursor, Two Different Products: Comparing the Structural Evolution of In–Ga–O “Gel-Derived” Powders and Solution-Cast Films Using Pair Distribution Function Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wood, Suzannah R.; Woods, Keenan N.; Plassmeyer, Paul N.

Amorphous metal oxides are central to a variety of technological applications. In particular, indium gallium oxide has garnered attention as a thin-film transistor channel layer material. In this work we examine the structural evolution of indium gallium oxide gel-derived powders and thin films using infrared vibrational spectroscopy, X-ray diffraction, and pair distribution function (PDF) analysis of X-ray total scattering from standard and normal incidence thin-film geometries (tfPDF). We find that the gel-derived powders and films from the same aqueous precursor evolve differently with temperature, forming mixtures of Ga-substituted In2O3 and In-substituted β-Ga2O3 with different degrees of substitution. X-ray total scatteringmore » and PDF analysis indicate that the majority phase for both the powders and films is an amorphous/nanocrystalline β-Ga2O3 phase, with a minor constituent of In2O3 with significantly larger coherence lengths. This amorphous β-Ga2O3 phase could not be identified using the conventional Bragg diffraction techniques traditionally used to study crystalline metal oxide thin films. The combination of Bragg diffraction and tfPDF provides a much more complete description of film composition and structure, which can be used to detail the effect of processing conditions and structure–property relationships. This study also demonstrates how structural features of amorphous materials, traditionally difficult to characterize by standard diffraction, can be elucidated using tfPDF.« less
Real-time X-ray Diffraction: Applications to Materials Characterization

NASA Technical Reports Server (NTRS)

Rosemeier, R. G.

1984-01-01

With the high speed growth of materials it becomes necessary to develop measuring systems which also have the capabilities of characterizing these materials at high speeds. One of the conventional techniques of characterizing materials was X-ray diffraction. Film, which is the oldest method of recording the X-ray diffraction phenomenon, is not quite adequate in most circumstances to record fast changing events. Even though conventional proportional counters and scintillation counters can provide the speed necessary to record these changing events, they lack the ability to provide image information which may be important in some types of experiment or production arrangements. A selected number of novel applications of using X-ray diffraction to characterize materials in real-time are discussed. Also, device characteristics of some X-ray intensifiers useful in instantaneous X-ray diffraction applications briefly presented. Real-time X-ray diffraction experiments with the incorporation of image X-ray intensification add a new dimension in the characterization of materials. The uses of real-time image intensification in laboratory and production arrangements are quite unlimited and their application depends more upon the ingenuity of the scientist or engineer.
Synthesis, structural, spectroscopic and optical studies of charge transfer complex salts.

PubMed

Manikandan, Maruthappan; Mahalingam, Thaiyan; Hayakawa, Yasuhiro; Ravi, Ganesan

2013-01-15

New charge transfer molecular complex adducts of picric acid (C6H3N3O7) with triethylamine (C6H15N) and dimethylformamide (HCON(CH3)2) were synthesized successfully for the first time. Chemical composition and stoichiometry of the synthesized complex salts were verified by CHN elemental analysis. Solubility of the complex salts have been determined by gravimetric method and single crystals of two new salts were grown by low temperature solution growth technique. Crystal system, crystalline nature and cell parameters of the grown crystals were determined by single crystal X-ray diffraction (SXRD) and powder X-ray diffraction (PXRD) analyses. The formations of the charge-transfer complex, functional groups and the modes of vibrations have been confirmed by Fourier transform infrared (FTIR) spectroscopy. In order to know the linear and nonlinear optical suitability for device fabrication, UV-Vis (UV) spectral analysis and relative second harmonic generation (SHG) efficiency test were performed for the grown crystals. Copyright © 2012 Elsevier B.V. All rights reserved.

Characterization of food additive-potato starch complexes by FTIR and X-ray diffraction.

PubMed

Dankar, Iman; Haddarah, Amira; Omar, Fawaz E L; Pujolà, Montserrat; Sepulcre, Francesc

2018-09-15

Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) techniques were used to study the effect of four food additives, agar, alginate, lecithin and glycerol, at three different concentrations, 0.5, 1 and 1.5%, on the molecular structure of potato puree prepared from commercial potato powder. Vibrational spectra revealed that the amylose-amylopectin skeleton present in the raw potato starch was missing in the potato powder but could be fully recovered upon water addition when the potato puree was prepared. FTIR peaks corresponding to water were clearly present in the potato powder, indicating the important structural role of water molecules in the recovery of the initial molecular conformation. None of the studied puree samples presented a crystalline structure or strong internal order. A comparison of the FTIR and XRD results revealed that the additives exerted some effects, mainly on the long-range order of the starch structure via interacting with and changing -OH and hydrogen bond interactions. Copyright © 2018 Elsevier Ltd. All rights reserved.
Synthesis, structural, spectroscopic and optical studies of charge transfer complex salts

NASA Astrophysics Data System (ADS)

Manikandan, Maruthappan; Mahalingam, Thaiyan; Hayakawa, Yasuhiro; Ravi, Ganesan

2013-01-01

New charge transfer molecular complex adducts of picric acid (C6H3N3O7) with triethylamine (C6H15N) and dimethylformamide (HCON(CH3)2) were synthesized successfully for the first time. Chemical composition and stoichiometry of the synthesized complex salts were verified by CHN elemental analysis. Solubility of the complex salts have been determined by gravimetric method and single crystals of two new salts were grown by low temperature solution growth technique. Crystal system, crystalline nature and cell parameters of the grown crystals were determined by single crystal X-ray diffraction (SXRD) and powder X-ray diffraction (PXRD) analyses. The formations of the charge-transfer complex, functional groups and the modes of vibrations have been confirmed by Fourier transform infrared (FTIR) spectroscopy. In order to know the linear and nonlinear optical suitability for device fabrication, UV-Vis (UV) spectral analysis and relative second harmonic generation (SHG) efficiency test were performed for the grown crystals.
Radiation damage free ghost diffraction with atomic resolution

DOE PAGES

Li, Zheng; Medvedev, Nikita; Chapman, Henry N.; ...

2017-12-21

The x-ray free electron lasers can enable diffractive structural determination of protein nanocrystals and single molecules that are too small and radiation-sensitive for conventional x-ray diffraction. However the electronic form factor may be modified during the ultrashort x-ray pulse due to photoionization and electron cascade caused by the intense x-ray pulse. For general x-ray imaging techniques, the minimization of the effects of radiation damage is of major concern to ensure reliable reconstruction of molecular structure. Here in this paper, we show that radiation damage free diffraction can be achieved with atomic spatial resolution by using x-ray parametric down-conversion and ghostmore » diffraction with entangled photons of x-ray and optical frequencies. We show that the formation of the diffraction patterns satisfies a condition analogous to the Bragg equation, with a resolution that can be as fine as the crystal lattice length scale of several Ångstrom. Since the samples are illuminated by low energy optical photons, they can be free of radiation damage.« less
Radiation damage free ghost diffraction with atomic resolution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Zheng; Medvedev, Nikita; Chapman, Henry N.

The x-ray free electron lasers can enable diffractive structural determination of protein nanocrystals and single molecules that are too small and radiation-sensitive for conventional x-ray diffraction. However the electronic form factor may be modified during the ultrashort x-ray pulse due to photoionization and electron cascade caused by the intense x-ray pulse. For general x-ray imaging techniques, the minimization of the effects of radiation damage is of major concern to ensure reliable reconstruction of molecular structure. Here in this paper, we show that radiation damage free diffraction can be achieved with atomic spatial resolution by using x-ray parametric down-conversion and ghostmore » diffraction with entangled photons of x-ray and optical frequencies. We show that the formation of the diffraction patterns satisfies a condition analogous to the Bragg equation, with a resolution that can be as fine as the crystal lattice length scale of several Ångstrom. Since the samples are illuminated by low energy optical photons, they can be free of radiation damage.« less
Synchrotron Radiation X-ray Diffraction Techniques Applied to Insect Flight Muscle.

PubMed

Iwamoto, Hiroyuki

2018-06-13

X-ray fiber diffraction is a powerful tool used for investigating the molecular structure of muscle and its dynamics during contraction. This technique has been successfully applied not only to skeletal and cardiac muscles of vertebrates but also to insect flight muscle. Generally, insect flight muscle has a highly ordered structure and is often capable of high-frequency oscillations. The X-ray diffraction studies on muscle have been accelerated by the advent of 3rd-generation synchrotron radiation facilities, which can generate brilliant and highly oriented X-ray beams. This review focuses on some of the novel experiments done on insect flight muscle by using synchrotron radiation X-rays. These include diffraction recordings from single myofibrils within a flight muscle fiber by using X-ray microbeams and high-speed diffraction recordings from the flight muscle during the wing-beat of live insects. These experiments have provided information about the molecular structure and dynamic function of flight muscle in unprecedented detail. Future directions of X-ray diffraction studies on muscle are also discussed.
Synthesis, crystal structure, vibrational spectroscopy and photoluminescence of new hybrid compound containing chlorate anions of stanate (II)

NASA Astrophysics Data System (ADS)

Lassoued, Mohamed Saber; Abdelbaky, Mohammed S. M.; Lassoued, Abdelmajid; Meroño, Rafael Mendoza; Gadri, Abdellatif; Ammar, Salah; Ben Salah, Abdelhamid; García-Granda, Santiago

2017-08-01

The present work aimed at studying a new organic-inorganic bis (4-amino quinolinium) hexachloro stanate (II) dihydrate compound. It was prepared and characterized by single crystal X-ray diffraction, X-ray powder, Hirshfeld surface, Spectroscopy measurement, thermal study and photoluminescence properties. It was found to crystallize in the monoclinic system (P21/c space group) with the following lattice parameters: a = 7.2558(6) Å, b = 13.4876(5) Å, c = 17.2107(13) Å, β = 102.028 (12)°. Its crystal structure was determined and refined down to an R value of 0.06 and a wR value of 0.087. The structure consisted of two different alternating organic-inorganic layers. The crystal packing was stabilized by Nsbnd H⋯Cl and Osbnd H⋯Cl hydrogen bonds and π-π interactions. Hirshfeld surface analysis was used to investigate intermolecular interactions, as well 2D finger plots were conducted to reveal the contribution of these interactions in the crystal structure quantitatively. The X-ray powder is in agreement with the X-ray structure. Scanning electronic microscopy (SEM) was carried out. Furthermore, the room temperature Infra Red (IR) spectrum of the title compound was analyzed on the basis of data found in the literature. Solid state 13C NMR spectrum shows ten signals, confirming the solid state structure determined by X-ray diffraction. Thermal analysis shows two anomalies at 380 and 610 °C. The optical properties of the crystal were studied using optical absorption UV-visible and photoluminescence (PL) spectroscopy, which were investigated at room temperature.
Transmission Grating and Optics Technology Development for the Arcus Explorer Mission

NASA Astrophysics Data System (ADS)

Heilmann, Ralf; Arcus Team

2018-01-01

Arcus is a high-resolution x-ray spectroscopy MIDEX mission selected for a Phase A concept study. It is designed to explore structure formation through measurements of hot baryon distributions, feedback from black holes, and the formation and evolution of stars, disks, and exoplanet atmospheres. The design provides unprecedented sensitivity in the 1.2-5 nm wavelength band with effective area above 450 sqcm and spectral resolution R > 2500. The Arcus technology is based on 12 m-focal length silicon pore optics (SPO) developed for the European Athena mission, and critical-angle transmission (CAT) x-ray diffraction gratings and x-ray CCDs developed at MIT. The modular design consists of four parallel channels, each channel holding an optics petal, followed by a grating petal. CAT gratings are lightweight, alignment insensitive, high-efficiency x-ray transmission gratings that blaze into high diffraction orders, leading to high spectral resolution. Each optics petal represents an azimuthal sub-aperture of a full Wolter optic. The sub-aperturing effect increases spectral resolving power further. Two CCD readout strips receive photons from each channel, including higher-energy photons in 0th order. Each optics petal holds 34 SPO modules. Each grating petal holds 34 grating windows, and each window holds 4-6 grating facets. A grating facet consists of a silicon grating membrane, bonded to a flexure frame that interfaces with the grating window. We report on a sequence of tests with increasing complexity that systematically increase the Technology Readiness Level (TRL) for the combination of CAT gratings and SPOs towards TLR 6. CAT gratings have been evaluated in x rays for diffraction efficiency (> 30% at 2.5 nm) and for resolving power (R> 10,000). A CAT grating/SPO combination was measured at R ~ 3100 at blaze angles smaller than design values, exceeding Arcus requirements. Efficiency and resolving power were not impacted by vibration and thermal testing of gratings. A pair of large (32 mm x 32 mm) gratings was aligned using laser metrology, and alignment was verified under x rays. We present results on simultaneous illumination of the aligned grating pair, and describe our progress towards further tests.
New Phases of YBaCuGeO Superconductors Identified from X-ray Diffraction and Infra-red Absorption Measurements

NASA Astrophysics Data System (ADS)

Abo-Arais, Ahmed; Dawoud, Mohamad Ahmad Taher

2005-01-01

X-ray powder diffraction patterns and infra-red absorption spectra have been evaluated and analysed for the Y1 Ba2 Cu3 O7-d - Gex compound samples prepared by the solid state reaction with x values ranging from 0.0 to 1.13. All samples show bulk superconductivity above liquid nitrogen temperature using the levitation test (Meissner effect). Samples with Ge content up to x = 0.2 have offset Tc between 83K and 92K while the sample with x = 1.13 shows semiconducting behavior above 100K. As a result of the solid state interaction between YBCO and Ge, new phases are observed and determined, mainly three phases are concluded from X-ray powder diffraction analysis: (i) Ba2GeO4 (ii) Y2BaCuO5 (iii) BaCO3. The unit cell parameters a, b and c of the orthorhombic superconducting phase are calculated for all the prepared samples. The anisotropy factor is evaluated and related to the new structural phases in YBCO-Ge composite system. The I-R absorption spectra for the samples with orthorhombic symmetry have been determined. The phonon modes between ~ 400 cm-1 and 630 cm-1 are attributed to the Cu - O octahedron and pyramid vibrations for the CuO2 -planes and CuO-chains, while the peaks in the range from ~ 700 cm-1 to ~ 860 cm-1 may be due to defects such as the new phase Ba2GeO4 and the green phase Y2BaCuO5. The obtained results are discussed according to the superconductor - semi-conductor composite model and with the phonon-mediated charge transfer between CuO2 -planes and CuO- chains through apex oxygen (BaO).
Combining experiment and optical simulation in coherent X-ray nanobeam characterization of Si/SiGe semiconductor heterostructures

DOE PAGES

Tilka, J. A.; Park, J.; Ahn, Y.; ...

2016-07-06

Here, the highly coherent and tightly focused x-ray beams produced by hard x-ray light sources enable the nanoscale characterization of the structure of electronic materials but are accompanied by significant challenges in the interpretation of diffraction and scattering patterns. X-ray nanobeams exhibit optical coherence combined with a large angular divergence introduced by the x-ray focusing optics. The scattering of nanofocused x-ray beams from intricate semiconductor heterostructures produces a complex distribution of scattered intensity. We report here an extension of coherent xray optical simulations of convergent x-ray beam diffraction patterns to arbitrary x-ray incident angles to allow the nanobeam diffraction patternsmore » of complex heterostructures to be simulated faithfully. These methods are used to extract the misorientation of lattice planes and the strain of individual layers from synchrotron x-ray nanobeam diffraction patterns of Si/SiGe heterostructures relevant to applications in quantum electronic devices. The systematic interpretation of nanobeam diffraction patterns from semiconductor heterostructures presents a new opportunity in characterizing and ultimately designing electronic materials.« less
High-pressure polymorphism of the electrochemically active organic molecule tetrahydroxy-p-benzoquinone

DOE PAGES

Ciezak-Jenkins, Jennifer A.

2016-04-22

We have studied the structural and chemical response of tetrahydroxy-p-benzoquinone to isothermal compression to near 20 GPa using powder x-ray diffraction and vibrational spectroscopy. Compression beyond 11.5 GPa resulted in the appearance of several new peaks in the x-ray patterns, changes in the peak distribution and intensities, as well as the disappearance of features observed at lower pressures, which when coupled with concomitant changes in the infrared spectrum are indicative of a phase transition. Further analysis of the infrared spectra suggest this phase transition results in an increase in the anharmonicity of the system. Finally, Raman spectroscopic experiments indicate themore » high-pressure phase to be highly photosensitive and easily polymerized.« less
Fabrication and testing of a newly designed slit system for depth-resolved X-ray diffraction measurements

DOE PAGES

Sinsheimer, John; Bouet, Nathalie; Ghose, Sanjit; ...

2016-10-06

A new system of slits called `spiderweb slits' have been developed for depth-resolved powder or polycrystalline X-ray diffraction measurements. The slits act on diffracted X-rays to select a particular gauge volume of sample, while absorbing diffracted X-rays from outside of this volume. Although the slit geometry is to some extent similar to that of previously developed conical slits or spiral slits, this new design has advantages over the previous ones in use for complex heterogeneous materials and in situ and operando diffraction measurements. For example, the slits can measure a majority of any diffraction cone for any polycrystalline material, overmore » a continuous range of diffraction angles, and work for X-ray energies of tens to hundreds of kiloelectronvolts. In addition, the design is generated and optimized using ray-tracing simulations, and fabricated through laser micromachining. The first prototype was successfully tested at the X17A beamline at the National Synchrotron Light Source, and shows similar performance to simulations, demonstrating gauge volume selection for standard powders, for all diffraction peaks over angles of 2–10°. A similar, but improved, design will be implemented at the X-ray Powder Diffraction beamline at the National Synchrotron Light Source II.« less
Zr doping dependence of structural and magnetic properties of cobalt ferrite synthesized by sol-gel based Pechini method

NASA Astrophysics Data System (ADS)

Motavallian, Pourya; Abasht, Behzad; Abdollah-Pour, Hassan

2018-04-01

Nanocrystalline CoZrxFe2-xO4 (0 ≤ x ≤ 0.3 in a step of 0.05) powders were synthesized by Pechini sol-gel method. The dry gel was grinded and calcined at 700 °C in a static air atmosphere for 1 h. Some tests such as thermo gravimetric analysis (TGA) combined with differential analysis (DTA), fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and vibrating sample magnetometer (VSM) were carried out to investigate the thermal behaviour, structural bonds identification, crystallographic properties, morphology and magnetic properties of the obtained powders. X-ray diffraction revealed a single-phase cubic spinel structure for all samples, where the crystallite size decreases; the lattice parameter simultaneously increases with substitution of Zr. The results of FE-SEM showed that the particle size is in the 20-70 nm range. The magnetic properties such as saturation magnetization (Ms), remanent magnetization (Mr) and coercivity (Hc) were measured from the hysteresis loops. The greatest amount of saturation magnetization for CoZr0.05Fe1.95O4 sample was 67.9 emu·g-1.
Dynamical scattering in coherent hard x-ray nanobeam Bragg diffraction

NASA Astrophysics Data System (ADS)

Pateras, A.; Park, J.; Ahn, Y.; Tilka, J. A.; Holt, M. V.; Kim, H.; Mawst, L. J.; Evans, P. G.

2018-06-01

Unique intensity features arising from dynamical diffraction arise in coherent x-ray nanobeam diffraction patterns of crystals having thicknesses larger than the x-ray extinction depth or exhibiting combinations of nanoscale and mesoscale features. We demonstrate that dynamical scattering effects can be accurately predicted using an optical model combined with the Darwin theory of dynamical x-ray diffraction. The model includes the highly divergent coherent x-ray nanobeams produced by Fresnel zone plate focusing optics and accounts for primary extinction, multiple scattering, and absorption. The simulation accurately reproduces the dynamical scattering features of experimental diffraction patterns acquired from a GaAs/AlGaAs epitaxial heterostructure on a GaAs (001) substrate.
Coherent x-ray diffraction imaging with nanofocused illumination.

PubMed

Schroer, C G; Boye, P; Feldkamp, J M; Patommel, J; Schropp, A; Schwab, A; Stephan, S; Burghammer, M; Schöder, S; Riekel, C

2008-08-29

Coherent x-ray diffraction imaging is an x-ray microscopy technique with the potential of reaching spatial resolutions well beyond the diffraction limits of x-ray microscopes based on optics. However, the available coherent dose at modern x-ray sources is limited, setting practical bounds on the spatial resolution of the technique. By focusing the available coherent flux onto the sample, the spatial resolution can be improved for radiation-hard specimens. A small gold particle (size <100 nm) was illuminated with a hard x-ray nanobeam (E=15.25 keV, beam dimensions approximately 100 x 100 nm2) and is reconstructed from its coherent diffraction pattern. A resolution of about 5 nm is achieved in 600 s exposure time.
High pressure Raman and single crystal X-ray diffraction of the alkali/calcium carbonate, shortite

NASA Astrophysics Data System (ADS)

Williams, Q. C.; Vennari, C.; O'Bannon, E. F., III

2015-12-01

Raman and synchrotron-based single crystal x-ray diffraction data have been collected on shortite (Na2Ca2(CO3)3) up to 10 GPa at 300 K. Shortite is of geological importance due to its presence in the ground-mass of kimberlites, and the alkaline-/carbon-rich character of kimberlitic eruptions. This investigation focuses on shortite's high pressure behavior and is relevant to the behavior of alkali-carbonate systems within Earth's upper mantle. X-ray data demonstrate that shortite's symmetry remains stable at high pressures—retaining orthorhombic C crystal system (Amm2) up to 10 GPa; diffraction data show a 12% volume decrease from room pressure, and a bulk modulus of 71.0(3) GPa. These also demonstrate that the c-axis is twice as compressible as the a- and b-axes. This anisotropic compression is likely due to the orientation of the relatively stiff carbonate groups, a third of which are oriented close to the plane of the a- and b-axes, c axis compression primarily involves the compaction of the 9-fold coordinate sodium and calcium polyhedral. The two distinct carbonate sites within the unit cell give rise to two Raman symmetric stretching modes of the symmetric stretch; the carbonate group stretching vibration which is close to in plane with the a- and b-axes shifts at 3.75 cm-1/GPa as opposed to the carbonate groups which is closer to in plane with the b- and c-axes which shift at 4.25 cm-1/GPa. This furthers evidence for anisotropic compression observed using x-ray diffraction--as the carbonate in plane with the a- and b-axes is compressed, the strength of oxygen bonds along the c-axis with the cations increases, thus decreasing the pressure shift of the mode. The out of plane bending vibration shifts at -0.48 cm-1/GPa, indicating an enhanced interaction of the oxygens with the cations. The multiple in plane bending modes all shift positively, as do at the low frequency lattice modes, indicating that major changes in bonding do not occur up to 10 GPa. The data collected indicates that this phase is stable at 300 K to 10 GPa. The anisotropic compaction of this alkali-rich carbonate appears to be governed by the orientation of the sodium sites, thus the behavior of alkali-rich carbonates within the kimberlitic systems is likely dependent on the bonding and local geometry of alkali cations.
DynAMITe: a prototype large area CMOS APS for breast cancer diagnosis using x-ray diffraction measurements

NASA Astrophysics Data System (ADS)

Konstantinidis, A.; Anaxagoras, T.; Esposito, M.; Allinson, N.; Speller, R.

2012-03-01

X-ray diffraction studies are used to identify specific materials. Several laboratory-based x-ray diffraction studies were made for breast cancer diagnosis. Ideally a large area, low noise, linear and wide dynamic range digital x-ray detector is required to perform x-ray diffraction measurements. Recently, digital detectors based on Complementary Metal-Oxide- Semiconductor (CMOS) Active Pixel Sensor (APS) technology have been used in x-ray diffraction studies. Two APS detectors, namely Vanilla and Large Area Sensor (LAS), were developed by the Multidimensional Integrated Intelligent Imaging (MI-3) consortium to cover a range of scientific applications including x-ray diffraction. The MI-3 Plus consortium developed a novel large area APS, named as Dynamically Adjustable Medical Imaging Technology (DynAMITe), to combine the key characteristics of Vanilla and LAS with a number of extra features. The active area (12.8 × 13.1 cm2) of DynaMITe offers the ability of angle dispersive x-ray diffraction (ADXRD). The current study demonstrates the feasibility of using DynaMITe for breast cancer diagnosis by identifying six breast-equivalent plastics. Further work will be done to optimize the system in order to perform ADXRD for identification of suspicious areas of breast tissue following a conventional mammogram taken with the same sensor.
Resolution enhancement in coherent x-ray diffraction imaging by overcoming instrumental noise.

PubMed

Kim, Chan; Kim, Yoonhee; Song, Changyong; Kim, Sang Soo; Kim, Sunam; Kang, Hyon Chol; Hwu, Yeukuang; Tsuei, Ku-Ding; Liang, Keng San; Noh, Do Young

2014-11-17

We report that reference objects, strong scatterers neighboring weak phase objects, enhance the phase retrieval and spatial resolution in coherent x-ray diffraction imaging (CDI). A CDI experiment with Au nano-particles exhibited that the reference objects amplified the signal-to-noise ratio in the diffraction intensity at large diffraction angles, which significantly enhanced the image resolution. The interference between the diffracted x-ray from reference objects and a specimen also improved the retrieval of the phase of the diffraction signal. The enhancement was applied to image NiO nano-particles and a mitochondrion and confirmed in a simulation with a bacteria phantom. We expect that the proposed method will be of great help in imaging weakly scattering soft matters using coherent x-ray sources including x-ray free electron lasers.
Mean-Square Amplitudes of Vibration and Anisotropic Motion of Metal Atoms in Iron Organometallics

NASA Astrophysics Data System (ADS)

Herber, Rolfe H.; Nowik, Israel

2002-12-01

Mössbauer recoil-free fraction (f) data for ferrocene [(η5-(C5H5)2Fe] over the temperature range 90≤T≤370 K have been used to calculate the mean-square-amplitude-of-vibration (msav) of the iron atom, and these data have been compared to the thermal factors (U ij ) extracted from X-ray diffraction data reported in the literature. The agreement between these two independent data sets is taken as a validation of the interpretation of the Mössbauer data in terms of the mean-square-amplitude-of-vibration of the metal atom in iron organometallic solids. The contribution of three low-frequency IR active modes of ferrocene (ω11, ω21, and ω22) to the f(T) parameter is discussed in detail.
Growth and luminescent properties of Yb:YAG and Ca co-doped Yb:YAG ultrafast scintillation crystals

NASA Astrophysics Data System (ADS)

Zhu, Maodong; Qi, Hongji; Pan, Mingyan; Hou, Qing; Jiang, Benxue; Jin, Yaxue; Han, Hetong; Song, Zhaohui; Zhang, Hui

2018-05-01

In this work, Yb-doped Y3Al5O12 [yttrium aluminum garnet (YAG)] crystals and Ca co-doped Yb:YAG crystals were grown by the Czochralski (CZ) method. The chemical formulas of the two crystals are (Yb0.1Y0.9)3Al5O12 and (Ca0.001Yb0.1Y0.899)3Al5O12, respectively. The structural, optical and luminescent properties of the Yb:YAG and Ca, Yb:YAG crystals were investigated by X-ray rocking curve, X-ray diffraction, Raman spectra, UV-Visble-NIR absorption spectra and X-ray fluorescence. X-ray fluorescence spectrum with two emission peaks at 330 nm and 490 nm were observed in the two kinds of crystals, which would increase slightly after the annealing. Comparing to the Yb:YAG crystal, Ca co-doped Yb:YAG crystal behaved the better luminescent intensity without changing the crystal structure and vibrational modes. This indicates that by doping Ca2+ in Yb:YAG crystal may be an appropriate way to enhance the luminescent property of the scintillation crystal.
Investigation of magnetic and structural properties of Ni-Zr co-doped M-type Sr-La hexaferrites

NASA Astrophysics Data System (ADS)

Yang, Yujie; Wang, Fanhou; Shao, Juxiang; Huang, Duohui; Tang, Jin; Rehman, Khalid Mehmood Ur

2018-02-01

In this research, Ni2+ and Zr4+ co-doped Sr-La hexaferrites Sr0.7La0.3Fe12.0-2 x (NiZr) x O19 (0.0 ≤ x ≤ 0.5) were synthesized by the standard ceramic method. The phase identification of the hexaferrites was confirmed by X-ray diffraction analysis. X-ray diffraction analysis showed that all the samples were in single phase M-type hexagonal structure and no impurity phase was observed. Lattice parameters ( c and a) increased with increasing NiZr content ( x) from 0.0 to 0.5. The morphology of the hexaferrites was analyzed by a field emission scanning electron microscopy (FE-SEM). FE-SEM micrographs showed that the grains exhibited hexagonal shape in a plate-like structure with clear grain boundaries. Magnetization properties of the hexaferrites were carried out at room temperature using a physical property measurement system-vibrating sample magnetometer. The values of saturation magnetization ( M s), remanent magnetization ( M r) and coercivity ( H c) were calculated from magnetic hysteresis ( M- H) loops. M s and H c decreased with increasing NiZr content ( x) from 0.0 to 0.5. M r and M r/ M s ratio first increased with increasing NiZr content ( x) from 0.0 to 0.1, and then decreased when NiZr content ( x) ≥ 0.1.

Fabrication and testing of a newly designed slit system for depth-resolved X-ray diffraction measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sinsheimer, John; Bouet, Nathalie; Ghose, Sanjit

2016-10-06

A new system of slits called `spiderweb slits' have been developed for depth-resolved powder or polycrystalline X-ray diffraction measurements. The slits act on diffracted X-rays to select a particular gauge volume of sample, while absorbing diffracted X-rays from outside of this volume. Although the slit geometry is to some extent similar to that of previously developed conical slits or spiral slits, this new design has advantages over the previous ones in use for complex heterogeneous materials andin situandoperandodiffraction measurements. For example, the slits can measure a majority of any diffraction cone for any polycrystalline material, over a continuous range ofmore » diffraction angles, and work for X-ray energies of tens to hundreds of kiloelectronvolts. The design is generated and optimized using ray-tracing simulations, and fabricated through laser micromachining. The first prototype was successfully tested at the X17A beamline at the National Synchrotron Light Source, and shows similar performance to simulations, demonstrating gauge volume selection for standard powders, for all diffraction peaks over angles of 2–10°. A similar, but improved, design will be implemented at the X-ray Powder Diffraction beamline at the National Synchrotron Light Source II.« less
Ultrafast molecular processes mapped by femtosecond x-ray diffraction

NASA Astrophysics Data System (ADS)

Elsaesser, Thomas

2012-02-01

X-ray diffraction with a femtosecond time resolution allows for mapping photoinduced structural dynamics on the length scale of a chemical bond and in the time domain of atomic and molecular motion. In a pump-probe approach, a femtosecond excitation pulse induces structural changes which are probed by diffracting a femtosecond hard x-ray pulse from the excited sample. The transient angular positions and intensities of diffraction peaks give insight into the momentary atomic or molecular positions and into the distribution of electronic charge density. The simultaneous measurement of changes on different diffraction peaks is essential for determining atom positions and charge density maps with high accuracy. Recent progress in the generation of ultrashort hard x-ray pulses (Cu Kα, wavelength λ=0.154 nm) in laser-driven plasma sources has led to the implementation of the powder diffraction and the rotating crystal method with a time resolution of 100 fs. In this contribution, we report new results from powder diffraction studies of molecular materials. A first series of experiments gives evidence of a so far unknown concerted transfer of electrons and protons in ammonium sulfate [(NH4)2SO4], a centrosymmetric structure. Charge transfer from the sulfate groups results in the sub-100 fs generation of a confined electron channel along the c-axis of the unit cell which is stabilized by transferring protons from the adjacent ammonium groups into the channel. Time-dependent charge density maps display a periodic modulation of the channel's charge density by low-frequency lattice motions with a concerted electron and proton motion between the channel and the initial proton binding site. A second study addresses atomic rearrangements and charge dislocations in the non-centrosymmetric potassium dihydrogen phosphate [KH2PO4, KDP]. Photoexcitation generates coherent low-frequency motions along the LO and TO phonon coordinates, leaving the average atomic positions unchanged. The time-dependent maps of electron density demonstrate a concomitant oscillatory relocation of electronic charge with a spatial amplitude of the order of a chemical bond length, two orders of magnitude larger than the vibrational amplitudes. The coherent phonon motions drive the charge relocation, similar to a soft mode driven phase transition between the ferro- and paraelectric phase of KDP.
Local terahertz field enhancement for time-resolved x-ray diffraction

DOE PAGES

Kozina, M.; Pancaldi, M.; Bernhard, C.; ...

2017-02-20

We report local field strength enhancement of single-cycle terahertz (THz) pulses in an ultrafast time-resolved x-ray diffraction experiment. We show that patterning the sample with gold microstructures increases the THz field without changing the THz pulse shape or drastically affecting the quality of the x-ray diffraction pattern. Lastly, we find a five-fold increase in THz-induced x-ray diffraction intensity change in the presence of microstructures on a SrTiO 3 thin-film sample.
Local terahertz field enhancement for time-resolved x-ray diffraction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kozina, M.; Pancaldi, M.; Bernhard, C.

We report local field strength enhancement of single-cycle terahertz (THz) pulses in an ultrafast time-resolved x-ray diffraction experiment. We show that patterning the sample with gold microstructures increases the THz field without changing the THz pulse shape or drastically affecting the quality of the x-ray diffraction pattern. Lastly, we find a five-fold increase in THz-induced x-ray diffraction intensity change in the presence of microstructures on a SrTiO 3 thin-film sample.
Structural, microstructural and vibrational analyses of the monoclinic tungstate BiLuWO{sub 6}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ait Ahsaine, H.; Taoufyq, A.; Institut Matériaux Microélectronique et Nanosciences de Provence, IM2NP, UMR CNRS 7334, Université de Toulon, BP 20132, 83957 La Garde Cedex

2014-10-15

The bismuth lutetium tungstate phase BiLuWO{sub 6} has been prepared using a solid state route with stoichiometric mixtures of oxide precursors. The obtained polycrystalline phase has been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectroscopy. In the first step, the crystal structure has been refined using Rietveld method: the crystal cell was resolved using monoclinic system (parameters a, b, c, β) with space group A2/m. SEM images showed the presence of large crystallites with a constant local nominal composition (BiLuW). TEM analyses showed that the actual local structure could be better representedmore » by a superlattice (a, 2b, c, β) associated with space groups P2 or P2/m. The Raman spectroscopy showed the presence of vibrational bands similar to those observed in the compounds BiREWO{sub 6} with RE=Y, Gd, Nd. However, these vibrational bands were characterized by large full width at half maximum, probably resulting from the long range Bi/Lu disorder and local WO{sub 6} octahedron distortions in the structure. - Graphical abstract: The average structure of BiLuWO{sub 6} determined from X-ray diffraction data can be represented by A2/m space group. Experimental Electron Diffraction patterns along the [0vw] zone axes of the monoclinic structure and associated simulated patterns show the existence of a monoclinic superstructure with space group P2 or P2/m. - Highlights: • A new monoclinic BiLuWO{sub 6} phase has been elaborated from solid-state reaction. • The space group of the monoclinic disordered average structure should be A2/m. • Transmission electron microscopy leads to a superlattice with P2/m space group. • Raman spectroscopy suggests existence of local disorder.« less
Bragg Coherent Diffractive Imaging of Zinc Oxide Acoustic Phonons at Picosecond Timescales

DOE PAGES

Ulvestad, A.; Cherukara, M. J.; Harder, R.; ...

2017-08-29

Mesoscale thermal transport is of fundamental interest and practical importance in materials such as thermoelectrics. Coherent lattice vibrations (acoustic phonons) govern thermal transport in crystalline solids and are affected by the shape, size, and defect density in nanoscale materials. The advent of hard x-ray free electron lasers (XFELs) capable of producing ultrafast x-ray pulses has significantly impacted the understanding of acoustic phonons by enabling their direct study with x-rays. However, previous studies have reported ensemble-averaged results that cannot distinguish the impact of mesoscale heterogeneity on the phonon dynamics. Here we use Bragg coherent diffractive imaging (BCDI) to resolve the 4Dmore » evolution of the acoustic phonons in a single zinc oxide rod with a spatial resolution of 50 nm and a temporal resolution of 25 picoseconds. We observe homogeneous (lattice breathing/rotation) and inhomogeneous (shear) acoustic phonon modes, which are compared to finite element simulations. We investigate the possibility of changing phonon dynamics by altering the crystal through acid etching. Lastly, we find that the acid heterogeneously dissolves the crystal volume, which will significantly impact the phonon dynamics. In general, our results represent the first step towards understanding the effect of structural properties at the individual crystal level on phonon dynamics.« less
A 2D Metal-Organic Framework with a Flexible Cyclohexane-1,2,5,6-tetracarboxylic Acid Ligand: Synthesis, Characterization and Photoluminescent Property

PubMed Central

Wang, Rongming; Zhang, Jian; Li, Lijuan

2009-01-01

A novel metal-organic framework, [Zn2(OH)(Hcht)(4,4′-bpy)]n·4nH2O (1) (H4cht = cyclohexane-1,2,4,5-tetracarboxylic acid and 4,4′-bpy = 4,4′-bipyridine), was synthesized by the hydrothermal reaction of Zn(NO3)2.6H2O, 4,4′-bipyridine, and cyclohexane-1,2,4,5-tetracarboxylic acid in the presence of sodium carbonate. The complex was obtained by controlling the ratio of the starting materials and a reaction temperature at 120°C and was characterized by IR, X-ray powder diffraction, thermogravimetric analysis, fluorescent spectrum, and single crystal X-ray diffraction. Single-crystal X-ray investigation reveals that the structure features a two-dimensional framework with novel coordination mode of Hcht ligand and all Hcht ligands exclusively convert to a sole conformation in the complex. IR spectrum reveals the characteristic absorption peaks of asymmetric stretching vibrations that result from the protonated and deprotonated carboxyl groups,. Thermogravimetric analysis shows four clear courses of weight loss, which corresponds to the decomposition of different ligands. Fluorescent spectrum displays that complex 1 is a potential blue-luminescent material. PMID:20383315
Bragg Coherent Diffractive Imaging of Zinc Oxide Acoustic Phonons at Picosecond Timescales

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ulvestad, A.; Cherukara, M. J.; Harder, R.

Mesoscale thermal transport is of fundamental interest and practical importance in materials such as thermoelectrics. Coherent lattice vibrations (acoustic phonons) govern thermal transport in crystalline solids and are affected by the shape, size, and defect density in nanoscale materials. The advent of hard x-ray free electron lasers (XFELs) capable of producing ultrafast x-ray pulses has significantly impacted the understanding of acoustic phonons by enabling their direct study with x-rays. However, previous studies have reported ensemble-averaged results that cannot distinguish the impact of mesoscale heterogeneity on the phonon dynamics. Here we use Bragg coherent diffractive imaging (BCDI) to resolve the 4Dmore » evolution of the acoustic phonons in a single zinc oxide rod with a spatial resolution of 50 nm and a temporal resolution of 25 picoseconds. We observe homogeneous (lattice breathing/rotation) and inhomogeneous (shear) acoustic phonon modes, which are compared to finite element simulations. We investigate the possibility of changing phonon dynamics by altering the crystal through acid etching. Lastly, we find that the acid heterogeneously dissolves the crystal volume, which will significantly impact the phonon dynamics. In general, our results represent the first step towards understanding the effect of structural properties at the individual crystal level on phonon dynamics.« less
Synthesis, structural and vibrational studies on mixed alkali metal gadolinium double tungstate, K1-xNaxGd(WO4)2

NASA Astrophysics Data System (ADS)

Durairajan, A.; Thangaraju, D.; Moorthy Babu, S.

2013-02-01

Mixed alkali double tungstates K1-xNaxGd(WO4)2 (KNGW) (0 ⩽ x ⩽ 1) were synthesized by solid state reaction using sodium doped monoclinic KGd(WO4)2 (KGW). Synthesized KNGW powders were characterized using powder X-ray diffraction (XRD), differential thermal analysis (DTA), scanning electron microscopy (SEM) and Raman analysis. DTA analysis confirms that the melting point of the KGW matrix increases from 1063 °C to 1255 °C with increasing sodium content. The Powder XRD analyses reveal that mixed phases were observed up to 40 wt.% of Na in the KGW matrix above that percentage there is domination of scheelite structure in the synthesized powder. Polyhedral type, bi-pyramidal shape and spheroid shape morphology was observed for KGW, NKGW and NGW powders respectively. The Raman analysis was carried out to understand the vibrational characteristic changes with mixing of sodium ions in the KGW matrix.
Structural analysis and ferroelectric properties of Fe doped BaTiO{sub 3}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mishra, Ashutosh, E-mail: a.mansuri14@gmail.com, E-mail: amishra1960@yahoo.co.in; Mansuri, Amantulla, E-mail: a.mansuri14@gmail.com, E-mail: amishra1960@yahoo.co.in; Dwivedi, J. P.

2016-05-23

The polycrystalline samples of Fe doped BaTiO{sub 3} (BTO) with compositional formula BaTi{sub 1-x}Fe{sub x}O{sub 3} (x = 0, 0.03, 0.04 and 0.05) were prepared by solid-state reaction route. The influence of the Fe content on the structural, vibrational and electric properties of BaTiO{sub 3} was investigated using X-ray powder diffraction (XRD), Raman spectroscopy and Polarization techniques. XRD analysis indicates the formation of single-phase tetragonal structure for all the prepared samples. Tetragonal cubic structure with space group P4mm of all samples is further approved by Rietveld refinement. Room temperature Raman spectra of pure BaTiO{sub 3} show four active modes ofmore » vibration whose intensity decreases with increasing Fe doping. Small shift in Raman modes and increment in the line width has been observed with the doping ions. The hysteresis loop is very well performed with regular sharp characteristic of ferroelectric materials.« less
Thermal x-ray diffraction and near-field phase contrast imaging

NASA Astrophysics Data System (ADS)

Li, Zheng; Classen, Anton; Peng, Tao; Medvedev, Nikita; Wang, Fenglin; Chapman, Henry N.; Shih, Yanhua

2017-10-01

Using higher-order coherence of thermal light sources, the resolution power of standard x-ray imaging techniques can be enhanced. In this work, we applied the higher-order measurement to far-field x-ray diffraction and near-field phase contrast imaging (PCI), in order to achieve superresolution in x-ray diffraction and obtain enhanced intensity contrast in PCI. The cost of implementing such schemes is minimal compared to the methods that achieve similar effects by using entangled x-ray photon pairs.
Thermal x-ray diffraction and near-field phase contrast imaging

DOE PAGES

Li, Zheng; Classen, Anton; Peng, Tao; ...

2017-12-27

Using higher-order coherence of thermal light sources, the resolution power of standard x-ray imaging techniques can be enhanced. Here in this work, we applied the higher-order measurement to far-field x-ray diffraction and near-field phase contrast imaging (PCI), in order to achieve superresolution in x-ray diffraction and obtain enhanced intensity contrast in PCI. The cost of implementing such schemes is minimal compared to the methods that achieve similar effects by using entangled x-ray photon pairs.
An image focusing means by using an opaque object to diffract x-rays

DOEpatents

Sommargren, Gary E.; Weaver, H. Joseph

1991-01-01

The invention provides a method and apparatus for focusing and imaging x-rays. An opaque sphere is used as a diffractive imaging element to diffract x-rays from an object so that the divergent x-ray wavefronts are transformed into convergent wavefronts and are brought to focus to form an image of the object with a large depth of field.
Soft X-Ray Diffraction Microscopy of a Frozen Hydrated Yeast Cell

DOE PAGES

Huang, Xiaojing; Nelson, Johanna; Kirz, Janos; ...

2009-11-01

We report the first image of an intact, frozen hydrated eukaryotic cell using x-ray diffraction microscopy, or coherent x-ray diffraction imaging. By plunge freezing the specimen in liquid ethane and maintaining it below -170 °C, artifacts due to dehydration, ice crystallization, and radiation damage are greatly reduced. In this example, coherent diffraction data using 520 eV x rays were recorded and reconstructed to reveal a budding yeast cell at a resolution better than 25 nm. This demonstration represents an important step towards high resolution imaging of cells in their natural, hydrated state, without limitations imposed by x-ray optics.
Application of focused-beam flat-sample method to synchrotron powder X-ray diffraction with anomalous scattering effect

NASA Astrophysics Data System (ADS)

Tanaka, M.; Katsuya, Y.; Matsushita, Y.

2013-03-01

The focused-beam flat-sample method (FFM), which is a method for high-resolution and rapid synchrotron X-ray powder diffraction measurements by combination of beam focusing optics, a flat shape sample and an area detector, was applied for diffraction experiments with anomalous scattering effect. The advantages of FFM for anomalous diffraction were absorption correction without approximation, rapid data collection by an area detector and good signal-to-noise ratio data by focusing optics. In the X-ray diffraction experiments of CoFe2O4 and Fe3O4 (By FFM) using X-rays near the Fe K absorption edge, the anomalous scattering effect between Fe/Co or Fe2+/Fe3+ can be clearly detected, due to the change of diffraction intensity. The change of observed diffraction intensity as the incident X-ray energy was consistent with the calculation. The FFM is expected to be a method for anomalous powder diffraction.
Rietveld analysis using powder diffraction data with anomalous scattering effect obtained by focused beam flat sample method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tanaka, Masahiko, E-mail: masahiko@spring8.or.jp; Katsuya, Yoshio, E-mail: katsuya@spring8.or.jp; Sakata, Osami, E-mail: SAKATA.Osami@nims.go.jp

2016-07-27

Focused-beam flat-sample method (FFM) is a new trial for synchrotron powder diffraction method, which is a combination of beam focusing optics, flat shape powder sample and area detectors. The method has advantages for X-ray diffraction experiments applying anomalous scattering effect (anomalous diffraction), because of 1. Absorption correction without approximation, 2. High intensity X-rays of focused incident beams and high signal noise ratio of diffracted X-rays 3. Rapid data collection with area detectors. We applied the FFM to anomalous diffraction experiments and collected synchrotron X-ray powder diffraction data of CoFe{sub 2}O{sub 4} (inverse spinel structure) using X-rays near Fe K absorptionmore » edge, which can distinguish Co and Fe by anomalous scattering effect. We conducted Rietveld analyses with the obtained powder diffraction data and successfully determined the distribution of Co and Fe ions in CoFe{sub 2}O{sub 4} crystal structure.« less
A study on magneto-optic properties of CoxMg1-xFe2O4 nanoferrofluids

NASA Astrophysics Data System (ADS)

Karthick, R.; Ramachandran, K.; Srinivasan, R.

2018-04-01

Nanoparticles of CoxMg1-xFe2O4 (x = 0.1, 0.5, 0.9) were synthesized using chemical co-precipitation method. Characterization by X-ray diffraction technique confirmed the formation of cubic crystalline structure and the crystallite size of the samples obtained using Debye-Scherrer approximation were found to increase with increasing cobalt substitution. Surface morphology and the Chemical composition of the samples were visualized using scanning electron microscope (SEM) with energy dispersive analysis of X-rays (EDAX). Room temperature magnetic parameters of the nanoparticles by vibrating sample magnetometer (VSM) revealed the magnetic properties such as Saturation magnetization (Ms), Remanent magnetization (Mr) and Coercive field (Hc) found to increase with increasing cobalt substitution. Faraday rotation measurements on CoxMg1-xFe2O4 ferrofluids exhibited increase in rotation with cobalt substitution. Further, there is an increase in Faraday rotation with increasing magnetic field for all the samples.
Synthesis, crystal structure investigation, spectroscopic characterizations and DFT computations on a novel 1-(2-chloro-4-phenylquinolin-3-yl)ethanone

NASA Astrophysics Data System (ADS)

Murugavel, S.; Stephen, C. S. Jacob Prasanna; Subashini, R.; Reddy, H. Raveendranatha; AnanthaKrishnan, Dhanabalan

2016-10-01

The title compound 1-(2-chloro-4-phenylquinolin-3-yl)ethanone (CPQE) was synthesised effectively by chlorination of 3-acetyl-4-phenylquinolin-2(1H)-one (APQ) using POCl3 reagent. Structural and vibrational spectroscopic studies were performed by utilizing single crystal X-ray diffraction, FTIR and NMR spectral analysis along with DFT method utilizing GAUSSIAN‧ 03 software. Veda program has been employed to perform a detailed interpretation of vibrational spectra. Mulliken population analyses on atomic charges, MEP, HOMO-LUMO, NBO, Global chemical reactivity descriptors and thermodynamic properties have been examined by (DFT/B3LYP) method with the 6-311G(d,p) basis set level.
Vibrational spectroscopic analysis of taranakite (K,NH 4)Al 3(PO 4) 3(OH)·9(H 2O) from the Jenolan Caves, Australia

NASA Astrophysics Data System (ADS)

Frost, Ray L.; Xi, Yunfei; Palmer, Sara J.; Pogson, Ross E.

2011-12-01

Many phosphate containing minerals are found in the Jenolan Caves. Such minerals are formed by the reaction of bat guano and clays from the caves. Among these cave minerals is the mineral taranakite (K,NH 4)Al 3(PO 4) 3(OH)·9(H 2O) which has been identified by X-ray diffraction. Jenolan Caves taranakite has been characterised by Raman spectroscopy. Raman and infrared bands are assigned to H 2PO 4, OH and NH stretching vibrations. By using a combination of XRD and Raman spectroscopy, the existence of taranakite in the caves has been proven.
Synthesis, spectroscopic characterization, X-ray structure and DFT studies on 2,6-bis(1-benzyl-1H-benzo[d]imidazol-2-yl)pyridine.

PubMed

İnkaya, Ersin; Günnaz, Salih; Özdemir, Namık; Dayan, Osman; Dinçer, Muharrem; Çetinkaya, Bekir

2013-02-15

The title molecule, 2,6-bis(1-benzyl-1H-benzo[d]imidazol-2-yl)pyridine (C(33)H(25)N(5)), was synthesized and characterized by elemental analysis, FT-IR spectroscopy, one- and two-dimensional NMR spectroscopies, and single-crystal X-ray diffraction. In addition, the molecular geometry, vibrational frequencies and gauge-independent atomic orbital (GIAO) (1)H and (13)C NMR chemical shift values of the title compound in the ground state have been calculated using the density functional theory at the B3LYP/6-311G(d,p) level, and compared with the experimental data. The complete assignments of all vibrational modes were performed by potential energy distributions using VEDA 4 program. The geometrical parameters of the optimized structure are in good agreement with the X-ray crystallographic data, and the theoretical vibrational frequencies and GIAO (1)H and (13)C NMR chemical shifts show good agreement with experimental values. Besides, molecular electrostatic potential (MEP) distribution, frontier molecular orbitals (FMO) and non-linear optical properties of the title compound were investigated by theoretical calculations at the B3LYP/6-311G(d,p) level. The linear polarizabilities and first hyper polarizabilities of the molecule indicate that the compound is a good candidate of nonlinear optical materials. The thermodynamic properties of the compound at different temperatures were calculated, revealing the correlations between standard heat capacity, standard entropy, standard enthalpy changes and temperatures. Copyright © 2012 Elsevier B.V. All rights reserved.

Uncommon and Emissive {[Au2(C3H6NS2)2][Au(C3H6NS2)2]2(PF6)2} Mixed Au+ and Au3+ Pseudotetranuclear Crystalline Compound: Synthesis, Structural Characterization, and Optical Properties.

PubMed

Langaro, Ana P; Souza, Ana K R; Morassuti, Claudio Y; Lima, Sandro M; Casagrande, Gleison A; Deflon, Victor M; Nunes, Luiz A O; Da Cunha Andrade, Luis H

2016-11-23

An uncommon emissive pseudotetranuclear compound, {[Au 2 (C 3 H 6 NS 2 ) 2 ][Au(C 3 H 6 NS 2 ) 2 ] 2 (PF 6 ) 2 }, was synthesized and characterized in terms of its structure and optical properties. The synthesis produced a crystalline compound composed of four gold atoms with two different oxidation states (Au + and Au 3+ ) in the same crystalline structure. The title complex belonged to a triclinic crystalline system involving the centrosymmetric P1̅ space group. X-ray diffractometry and vibrational spectroscopy (infrared, Raman, and SERS) were used for structural characterization of the new crystal. The vibrational spectroscopy techniques supported the X-ray diffraction results and confirmed the presence of bonds including Au-Au and Au-S. Optical characterization performed using UV-vis spectroscopy showed that under ultraviolet excitation, the emissive crystalline complex presented characteristic broad luminescent bands centered at 420 and 670 nm.
Dynamical effects in Bragg coherent x-ray diffraction imaging of finite crystals

NASA Astrophysics Data System (ADS)

Shabalin, A. G.; Yefanov, O. M.; Nosik, V. L.; Bushuev, V. A.; Vartanyants, I. A.

2017-08-01

We present simulations of Bragg coherent x-ray diffractive imaging (CXDI) data from finite crystals in the frame of the dynamical theory of x-ray diffraction. The developed approach is based on a numerical solution of modified Takagi-Taupin equations and can be applied for modeling of a broad range of x-ray diffraction experiments with finite three-dimensional crystals of arbitrary shape also in the presence of strain. We performed simulations for nanocrystals of a cubic and hemispherical shape of different sizes and provided a detailed analysis of artifacts in the Bragg CXDI reconstructions introduced by the dynamical diffraction. Based on our theoretical analysis we developed an analytical procedure to treat effects of refraction and absorption in the reconstruction. Our results elucidate limitations for the kinematical approach in the Bragg CXDI and suggest a natural criterion to distinguish between kinematical and dynamical cases in coherent x-ray diffraction on a finite crystal.
A facile one-pot solvothermal method for synthesis of magnetically recoverable Pd-Fe3O4 hybrid nanocatalysts for the Mizoroki-Heck reaction

NASA Astrophysics Data System (ADS)

Zhen, Fangchen; Ran, Maofei; Chu, Wei; Jiang, Chengfa; Sun, Wenjing

2018-03-01

Pd-Fe3O4 hybrid nanostructures were prepared using a simple one-pot hydrothermal method. The prepared materials were characterized by Fourier transform-infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, inductively coupled plasma, N2 adsorption-desorption, and vibrating sample magnetometry. This self-assembled nanosystem acted as an efficient magnetically recyclable noble metal-based multi-functional nanocatalyst. It showed excellent catalytic activity and stability for the Heck reaction of iodobenzene and styrene under mild conditions. The methods used to prepare the Pd-Fe3O4 catalysts were simple and low-cost, which will be useful for the large-scale development and application of a magnetically recoverable Pd catalyst.
Size dependence of magnetorheological properties of cobalt ferrite ferrofluid

DOE Office of Scientific and Technical Information (OSTI.GOV)

Radhika, B.; Sahoo, Rasmita; Srinath, S., E-mail: srinath@uohyd.ac.in

2015-06-24

Cobalt Ferrite nanoparticles were synthesized using co-precipitation method at reaction temperatures of 40°C and 80°C. X-Ray diffraction studies confirm cubic phase formation. The average crystallite sizes were found to be ∼30nm and ∼48nm for 40°C sample and 80°C sample respectively. Magnetic properties measured using vibrating sample magnetometer show higher coercivety and magnetization for sample prepared at 80°C. Magnetorheological properties of CoFe2O4 ferrofluids were measured and studied.
Cooperative use of VCD and XRD for the determination of tetrahydrobenzoisoquinolines absolute configuration: a reliable proof of memory of chirality and retention of configuration in enediyne rearrangements.

PubMed

Mondal, Shovan; Naubron, Jean-Valère; Campolo, Damien; Giorgi, Michel; Bertrand, Michéle P; Nechab, Malek

2013-12-01

The absolute configurations (AC) of azaheterocylic compounds resulting from the cascade rearrangement of enediynes involving only light atoms were unambiguously assigned by the joint use of vibrational circular dichroism (VCD) and copper radiation single crystal X-ray diffraction (XRD). These AC determinations proved that the rearrangements of enediynes proceeded with memory of chirality and retention of configuration. © 2013 Wiley Periodicals, Inc.
Synthesis, X-ray crystallography characterization, vibrational spectroscopic, molecular electrostatic potential maps, thermodynamic properties studies of N,N'-di(p-thiazole)formamidine.

PubMed

Rofouei, M K; Fereyduni, E; Sohrabi, N; Shamsipur, M; Attar Gharamaleki, J; Sundaraganesan, N

2011-01-01

In this work, we will report a combined experimental and theoretical study on molecular and vibrational structure of N,N'-di(p-thiazole)formamidine (DpTF). DpTF has been synthesized and characterized by elemental analysis, FT-IR, FT-Raman, 1H NMR, 13C NMR spectroscopy and X-ray single crystal diffraction. The FT-IR and FT-Raman spectra of DpTF were recorded in the solid phase. The optimized geometry was calculated by HF and B3LYP methods using 6-31G(d) basis set. The FT-IR and FT-Raman spectra of DpTF was calculated at the HF/B3LYP/6-31G(d) level and were interpreted in terms of potential energy distribution (PED) analysis. The scaled theoretical wavenumber showed very good agreement with the experimental values. A detailed interpretation of the infrared and Raman spectra of DpTF was reported. On the basis of vibrational analyses, the thermodynamic properties of the title compound at different temperatures have been calculated, revealing the correlations between Cp,m°, Sm°, Hm° and temperatures. Furthermore, molecular electrostatic potential maps (MESP) and total dipole moment properties of the compound have been calculated. Copyright © 2010 Elsevier B.V. All rights reserved.
Instrument and method for X-ray diffraction, fluorescence, and crystal texture analysis without sample preparation

NASA Technical Reports Server (NTRS)

Gendreau, Keith (Inventor); Martins, Jose Vanderlei (Inventor); Arzoumanian, Zaven (Inventor)

2010-01-01

An X-ray diffraction and X-ray fluorescence instrument for analyzing samples having no sample preparation includes a X-ray source configured to output a collimated X-ray beam comprising a continuum spectrum of X-rays to a predetermined coordinate and a photon-counting X-ray imaging spectrometer disposed to receive X-rays output from an unprepared sample disposed at the predetermined coordinate upon exposure of the unprepared sample to the collimated X-ray beam. The X-ray source and the photon-counting X-ray imaging spectrometer are arranged in a reflection geometry relative to the predetermined coordinate.
Structural, vibrational and dielectric studies of (0.95)Pb(Zr{sub x}Ti{sub 1−x})O{sub 3}-(0.05)BiFeO{sub 3} nanoceramics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sharma, Subhash, E-mail: rk.dwivedi@jiit.ac.in; Singh, Vikash, E-mail: rk.dwivedi@jiit.ac.in; Dwivedi, R. K., E-mail: rk.dwivedi@jiit.ac.in

2014-04-24

(0.95)Pb(Zr{sub x}Ti{sub 1−x})O{sub 3}-(0.05)BiFeO{sub 3} nanoceramics with x=0.51, 0.53 and 0.55 were synthesized by sol-gel route. Rietveld refined X-ray powder diffraction pattern of the samples confirm the single phase formation of compounds with tetragonal structure (P4mm). FT-IR studies revealed that slight shift of phonon modes towards the lower wave number and increase in the bond length with increasing Zr{sup 4+} concentration. Room temperature dielectric properties of system revealed that relaxor characteristics of these samples. Ferroelectric hysteresis curve shows the decrease in polarization values with Zr concentration.
Effect of chromium doping on the structural and vibrational properties of Mn-Zn ferrites

NASA Astrophysics Data System (ADS)

Saleem, M.; Varshney, Dinesh

2018-05-01

The synthesis of Mn0.5Zn0.5-xCrxFe2O4 (x = 0.0, 0.1, 0.2 and 0.5) via sol-gel Auto-combustion technique is reported. The x-ray diffraction spectra analysis revealed the cubic spinel structure for all the prepared spinel ferrite samples with the space group Fd3m. The structural studies identify the decrease of lattice parameter however the crystallite size decreases on increasing the Cr concentration. The Raman spectrum reveals five active phonon modes at room temperature and shifting of modes toward the higher frequency side on moving from Mn-ZnFe2O4 to Mn-CrFe2O4.
Simulation of X-ray transient absorption for following vibrations in coherently ionized F2 molecules

NASA Astrophysics Data System (ADS)

Dutoi, Anthony D.; Leone, Stephen R.

2017-01-01

Femtosecond and attosecond X-ray transient absorption experiments are becoming increasingly sophisticated tools for probing nuclear dynamics. In this work, we explore and develop theoretical tools needed for interpretation of such spectra,in order to characterize the vibrational coherences that result from ionizing a molecule in a strong IR field. Ab initio data for F2 is combined with simulations of nuclear dynamics, in order to simulate time-resolved X-ray absorption spectra for vibrational wavepackets after coherent ionization at 0 K and at finite temperature. Dihalogens pose rather difficult electronic structure problems, and the issues encountered in this work will be reflective of those encountered with any core-valence excitation simulation when a bond is breaking. The simulations reveal a strong dependence of the X-ray absorption maximum on the locations of the vibrational wave packets. A Fourier transform of the simulated signal shows features at the overtone frequencies of both the neutral and the cation, which reflect spatial interferences of the vibrational eigenstates. This provides a direct path for implementing ultrafast X-ray spectroscopic methods to visualize coherent nuclear dynamics.
Philip A. Parilla | NREL

Science.gov Websites

atomic layer deposition for applications. He also manages the majority of X-ray characterization equipment at NREL, specifically X-ray diffraction and X-ray fluorescence instrumentation. Additionally, he for EERE's Hydrogen Storage program. He is also an expert in X-ray diffraction and X-ray fluorescence
Dislocation, crystallite size distribution and lattice strain of magnesium oxide nanoparticles

NASA Astrophysics Data System (ADS)

Sutapa, I. W.; Wahid Wahab, Abdul; Taba, P.; Nafie, N. L.

2018-03-01

The oxide of magnesium nanoparticles synthesized using sol-gel method and analysis of the structural properties was conducted. The functional groups of nanoparticles has been analysed by Fourier Transform Infrared Spectroscopy (FT-IR). Dislocations, average size of crystal, strain, stress, the energy density of crystal, crystallite size distribution and morphologies of the crystals were determined based on X-ray diffraction profile analysis. The morphological of the crystal was analysed based on the image resulted from SEM analysis. The crystallite size distribution was calculated with the contention that the particle size has a normal logarithmic form. The most orientations of crystal were determined based on the textural crystal from diffraction data of X-ray diffraction profile analysis. FT-IR results showed the stretching vibration mode of the Mg-O-Mg in the range of 400.11-525 cm-1 as a broad band. The average size crystal of nanoparticles resulted is 9.21 mm with dislocation value of crystal is 0.012 nm-2. The strains, stress, the energy density of crystal are 1.5 x 10-4 37.31 MPa; 0.72 MPa respectively. The highest texture coefficient value of the crystal is 0.98. This result is supported by morphological analysis using SEM which shows most of the regular cubic-shaped crystals. The synthesis method is suitable for simple and cost-effective synthesis model of MgO nanoparticles.
Simulations of X-ray diffraction of shock-compressed single-crystal tantalum with synchrotron undulator sources.

PubMed

Tang, M X; Zhang, Y Y; E, J C; Luo, S N

2018-05-01

Polychromatic synchrotron undulator X-ray sources are useful for ultrafast single-crystal diffraction under shock compression. Here, simulations of X-ray diffraction of shock-compressed single-crystal tantalum with realistic undulator sources are reported, based on large-scale molecular dynamics simulations. Purely elastic deformation, elastic-plastic two-wave structure, and severe plastic deformation under different impact velocities are explored, as well as an edge release case. Transmission-mode diffraction simulations consider crystallographic orientation, loading direction, incident beam direction, X-ray spectrum bandwidth and realistic detector size. Diffraction patterns and reciprocal space nodes are obtained from atomic configurations for different loading (elastic and plastic) and detection conditions, and interpretation of the diffraction patterns is discussed.
Simulations of X-ray diffraction of shock-compressed single-crystal tantalum with synchrotron undulator sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tang, M. X.; Zhang, Y. Y.; E, J. C.

Polychromatic synchrotron undulator X-ray sources are useful for ultrafast single-crystal diffraction under shock compression. Here, simulations of X-ray diffraction of shock-compressed single-crystal tantalum with realistic undulator sources are reported, based on large-scale molecular dynamics simulations. Purely elastic deformation, elastic–plastic two-wave structure, and severe plastic deformation under different impact velocities are explored, as well as an edge release case. Transmission-mode diffraction simulations consider crystallographic orientation, loading direction, incident beam direction, X-ray spectrum bandwidth and realistic detector size. Diffraction patterns and reciprocal space nodes are obtained from atomic configurations for different loading (elastic and plastic) and detection conditions, and interpretation of themore » diffraction patterns is discussed.« less
Coherent X-ray diffraction imaging of nanoengineered polymeric capsules

NASA Astrophysics Data System (ADS)

Erokhina, S.; Pastorino, L.; Di Lisa, D.; Kiiamov, A. G.; Faizullina, A. R.; Tayurskii, D. A.; Iannotta, S.; Erokhin, V.

2017-10-01

For the first time, nanoengineered polymeric capsules and their architecture have been studied with coherent X-ray diffraction imaging technique. The use of coherent X-ray diffraction imaging technique allowed us to analyze the samples immersed in a liquid. We report about the significant difference between polymeric capsule architectures under dry and liquid conditions.
A high-transparency, micro-patternable chip for X-ray diffraction analysis of microcrystals under native growth conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Murray, Thomas D.; Johns Hopkins University School of Medicine, Baltimore, MD 21205; Lyubimov, Artem Y.

A highly X-ray-transparent, silicon nitride-based device has been designed and fabricated to harvest protein microcrystals for high-resolution X-ray diffraction data collection using microfocus beamlines and XFELs. Microcrystals present a significant impediment to the determination of macromolecular structures by X-ray diffraction methods. Although microfocus synchrotron beamlines and X-ray free-electron lasers (XFELs) can enable the collection of interpretable diffraction data from microcrystals, there is a need for efficient methods of harvesting small volumes (<2 µl) of microcrystals grown under common laboratory formats and delivering them to an X-ray beam source under native growth conditions. One approach that shows promise in overcoming themore » challenges intrinsic to microcrystal analysis is to pair so-called ‘fixed-target’ sample-delivery devices with microbeam-based X-ray diffraction methods. However, to record weak diffraction patterns it is necessary to fabricate devices from X-ray-transparent materials that minimize background scattering. Presented here is the design of a new micro-diffraction device consisting of three layers fabricated from silicon nitride, photoresist and polyimide film. The chip features low X-ray scattering and X-ray absorption properties, and uses a customizable blend of hydrophobic and hydrophilic surface patterns to help localize microcrystals to defined regions. Microcrystals in their native growth conditions can be loaded into the chips with a standard pipette, allowing data collection at room temperature. Diffraction data collected from hen egg-white lysozyme microcrystals (10–15 µm) loaded into the chips yielded a complete, high-resolution (<1.6 Å) data set sufficient to determine a high-quality structure by molecular replacement. The features of the chip allow the rapid and user-friendly analysis of microcrystals grown under virtually any laboratory format at microfocus synchrotron beamlines and XFELs.« less
Thermal analyses, spectral characterization and structural interpretation of Nd3+/Er3+ ions co-doped TeO2-ZnCl2 glasses system

NASA Astrophysics Data System (ADS)

Ahmed, Kasim F.; Ibrahim, Saeed O.; Sahar, Md. R.; Mawlud, Saman Q.; Khizir, Hersh A.

2017-09-01

The Nd3+/Er3+ ions co-doped in the system of zinc-tellurite with the composition of (70-2x)TeO2-30ZnCl2-xNd2O3-xEr2O3 concentration from 1.0 to 3.0 mol% (x=1, 2 and 3) glasses were prepared by using conventional melt-quenching technique. The amorphous nature of the glass been confirmed by using X-RAY Diffraction Spectroscopy. Thermal characteristic were determined using a DTA. The obtained results discussed in terms of the glass structure. The glass structure studied by means of FTIR. Seven significant vibrational peaks around 471, 687, 742, 768, 1632, 2833 and 3378 cm-1 which correspond to the structural bonding of the glass are observed in a range of 400-4000cm-1. The peaks observed are consistent with the stretching and bending vibrations of the Te-O, TeO4 trigonal bipyramids, TeO3 trigonal pyramids, Te-O-Te and OH linkages respectively.
X-Ray Structure determination of the Glycine Cleavage System Protein H of Mycobacterium tuberculosis Using An Inverse Compton Synchrotron X-Ray Source

PubMed Central

Abendroth, Jan; McCormick, Michael S.; Edwards, Thomas E.; Staker, Bart; Loewen, Roderick; Gifford, Martin; Rifkin, Jeff; Mayer, Chad; Guo, Wenjin; Zhang, Yang; Myler, Peter; Kelley, Angela; Analau, Erwin; Hewitt, Stephen Nakazawa; Napuli, Alberto J.; Kuhn, Peter; Ruth, Ronald D.; Stewart, Lance J.

2010-01-01

Structural genomics discovery projects require ready access to both X-ray and NMR instrumentation which support the collection of experimental data needed to solve large numbers of novel protein structures. The most productive X-ray crystal structure determination laboratories make extensive frequent use of tunable synchrotron X-ray light to solve novel structures by anomalous diffraction methods. This requires that frozen cryo-protected crystals be shipped to large government-run synchrotron facilities for data collection. In an effort to eliminate the need to ship crystals for data collection, we have developed the first laboratory-scale synchrotron light source capable of performing many of the state-of-the-art synchrotron applications in X-ray science. This Compact Light Source is a first-in-class device that uses inverse Compton scattering to generate X-rays of sufficient flux, tunable wavelength and beam size to allow high-resolution X-ray diffraction data collection from protein crystals. We report on benchmarking tests of X-ray diffraction data collection with hen egg white lysozyme, and the successful high-resolution X-ray structure determination of the Glycine cleavage system protein H from Mycobacterium tuberculosis using diffraction data collected with the Compact Light Source X-ray beam. PMID:20364333
Structural and Spectral Characterization of Co2+- and Ni2+-DOPED CdO Powder Prepared From Solution at Room Temperature

NASA Astrophysics Data System (ADS)

Reddy, C. V.; Rao, L. V. Krishna; Satish, D. V.; Shim, J.; Ravikumar, R. V. S. S. N.

2015-11-01

The mild and simple solution method was used for the synthesis of Co2+- and Ni2+-doped CdO powders at room temperature. The prepared powders were characterized using powder X-ray diffraction, scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), optical absorption, and Fourier transform infrared spectroscopy (FTIR). From the powder X-ray diffraction patterns, it has been observed that the prepared Co2+ and Ni2+ ion-doped CdO powders belong to the cubic phase, and the evaluated average crystalline sizes of the powders are 20 and 14 nm, respectively. The SEM images and the EDS spectra show that the prepared powders are distributed over different sizes in the grain boundaries. Optical absorption studies allow determination of site symmetry of the metal ion with its ligands. The crystal field (Dq) and inter-electronic repulsion (B and C) parameters have been evaluated from the optical absorption spectra. The FTIR spectra show the characteristic fundamental vibrations of the metal oxide and CdO.
Preparation and characterization of hydroxyapatite-coated iron oxide particles by spray-drying technique.

PubMed

Donadel, Karina; Felisberto, Marcos D V; Laranjeira, Mauro C M

2009-06-01

Magnetic particles of iron oxide have been increasingly used in medical diagnosis by magnetic resonance imaging and in cancer therapies involving targeted drug delivery and magnetic hyperthermia. In this study we report the preparation and characterization of iron oxide particles coated with bioceramic hydroxyapatite by spray-drying. The iron oxide magnetic particles (IOMP) were coated with hydroxyapatite (HAp) by spray-drying using two IOMP/HAp ratios (0.7 and 3.2). The magnetic particles were characterized by way of scanning electronic microscopy, energy dispersive X-ray, X-ray diffraction, Fourier transformed infrared spectroscopy, flame atomic absorption spectrometry,vibrating sample magnetometry and particle size distribution (laser diffraction). The surface morphology of the coated samples is different from that of the iron oxide due to formation of hydroxyapatite coating. From an EDX analysis, it was verified that the surface of the coated magnetic particles is composed only of HAp, while the interior containsiron oxide and a few layers of HAp as expected. The results showed that spray-drying technique is an efficient and relatively inexpensive method for forming spherical particles with a core/shell structure.

X-ray diffraction, spectroscopic and mechanical studies on potential organic NLO materials of metaNitroaniline and N-3-Nitrophenyl Acetamide single crystals

NASA Astrophysics Data System (ADS)

Senthil, S.; Madhavan, J.

2015-02-01

In the present paper, attempts were made to grow good quality metaNitroaniline (mNA) and N-3-Nitrophenyl (3-NAA) single crystals. The lattice parameter values from the Powder X-ray diffraction pattern confirms that mNA belongs to orthorhombic crystal system with the unit cell parameter values of a = 6.501 Å, b = 19.330 Å and c = 5.082 Å with space group Pbc21. Similarly the powder XRD data indicates that 3-NAA crystal retained its monoclinic structure with lattice parameter values a = 9.762 Å, b =13.287 Å, c =13.226 Å, and β = 102.99°. Investigation has been carried out to assign the vibrational frequencies of the grown crystals by Fourier Transform infrared spectroscopy technique. The SHG efficiency of mNA and 3NAA was determined by Kurtz and Perry powder technique. The Optical absorption study confirms the suitability of the crystals for device applications. The mechanical properties of the grown crystals have been studied using Vickers microhardness tester.
FTIR spectroscopic, thermal and XRD characterization of hydroxyapatite from new natural sources

NASA Astrophysics Data System (ADS)

Shaltout, Abdallah A.; Allam, Moussa A.; Moharram, Mohamed A.

2011-12-01

The inorganic constituents of 5 different plants (leaves and stalks) were investigated by using Fourier transformer infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermal analysis including thermal gravimetric analysis (TGA), derivative thermogravimetry (DTG) and differential scanning calorimetry (DSC). These plants are Catha edulis (Khat), basil, mint, green tea and trifolium. The absorption bands of carbonate ions CO 32- was exhibited at 1446 cm -1, and the phosphate ions PO 43- was assigned at 1105 and 1035 cm -1. At high temperatures (600, 700 and 600 °C) further absorption bands of the phosphate ions PO 43- was assigned at the frequencies 572, 617, 962, 1043 and 1110 cm -1 and the vibrational absorption band of the carbonate ions CO 32- was assigned at 871, 1416 and 1461 cm -1. X-ray diffraction and thermal analysis confirm the obtained results of FITR. Results showed that the main inorganic constituents of C. edulis and basil leaves are hydroxyapatite whereas the hydroxyapatite content in the other plant samples is less than that in case of C. edulis and basil plant leaves.
Optical, Magnetic and Photocatalytic Activity Studies of Li, Mg and Sr Doped and Undoped Zinc Oxide Nanoparticles.

PubMed

Shanthi, S I; Poovaragan, S; Arularasu, M V; Nithya, S; Sundaram, R; Magdalane, C Maria; Kaviyarasu, K; Maaza, M

2018-08-01

Nanoparticles of Li, Mg and Sr doped and undoped zinc oxide was prepared by simple precipitation method. The structural, optical, and magnetic properties of the samples were investigated by the Powder X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM), Fourier Transform Infrared (FTIR) spectroscopy, Ultra-violet Visible spectroscopy (UV-vis) spectra, Photoluminescence (PL) and Vibrational Sample Magnetometer (VSM). The Powder X-ray diffraction data confirm the formation of hexagonal wurtzite structure of all doped and undoped ZnO. The SEM photograph reveals that the pores availability and particles size in the range of 10 nm-50 nm. FTIR and UV-Visible spectra results confirm the incorporation of the dopant into the ZnO lattice nanostructure. The UV-Visible spectra indicate that the shift of blue region (lower wavelength) due to bandgap widening. Photoluminescence intensity varies with doping due to the increase of oxygen vacancies in prepared ZnO. The pure ZnO exist paramagnetic while doped (Li, Mg and Sr) ZnO exist ferromagnetic property. The photocatalytic activity of the prepared sample also carried out in detail.
Crystal growth, structural, optical, spectral and thermal studies of tris( L-phenylalanine) L-phenylalaninium nitrate: A new organic nonlinear optical material

NASA Astrophysics Data System (ADS)

Prakash, M.; Geetha, D.; Lydia Caroline, M.

2011-10-01

Tris( L-phenylalanine) L-phenylalaninium nitrate, C 9H 12NO 2+·NO 3-·3C 9H 11NO 2 (TPLPN), a new organic nonlinear optical material was grown from aqueous solution by slow evaporation solution growth at room temperature. The grown crystals were subjected to powder X-ray diffraction and single crystal X-ray diffraction studies to confirm the crystalline nature and crystal structure. The modes of vibration of different molecular groups present in TPLPN have been identified by FTIR spectral analysis. The presence of hydrogen and carbon in the grown crystal were confirmed by using proton and carbon nuclear magnetic resonance (NMR) spectral analyses. The optical transmission spectral study establishes good transmitting ability of the crystal in the entire visible region. The thermogravimetric (TG) and differential thermal analyses (DTA) were carried out to understand the thermal stability of the sample. The nonlinear optical property of the compound observed using Kurtz powder second harmonic generation test assets the suitability of the grown material for the frequency conversion of laser radiation of Nd:YAG.
Functional biocompatible magnetite-cellulose nanocomposite fibrous networks: Characterization by fourier transformed infrared spectroscopy, X-ray powder diffraction and field emission scanning electron microscopy analysis.

PubMed

Habibi, Neda

2015-02-05

The preparation and characterization of functional biocompatible magnetite-cellulose nano-composite fibrous material is described. Magnetite-cellulose nano-composite was prepared by a combination of the solution-based formation of magnetic nano-particles and subsequent coating with amino celluloses. Characterization was accomplished using X-ray powder diffraction (XRD), fourier transformed infrared (FTIR) and field emission scanning electron microscopy (FESEM) analysis. The peaks of Fe3O4 in the XRD pattern of nanocomposite confirm existence of the nanoparticles in the amino cellulose matrix. Magnetite-cellulose particles exhibit an average diameter of roughly 33nm as demonstrated by field emission scanning electron microscopy. Magnetite nanoparticles were irregular spheres dispersed in the cellulose matrix. The vibration corresponding to the NCH3 functional group about 2850cm(-1) is assigned in the FTIR spectra. Functionalized magnetite-cellulose nano-composite polymers have a potential range of application as targeted drug delivery system in biomedical field. Copyright © 2014 Elsevier B.V. All rights reserved.
Anti-contamination device for cryogenic soft X-ray diffraction microscopy

DOE PAGES

Huang, Xiaojing; Miao, Huijie; Nelson, Johanna; ...

2011-05-01

Cryogenic microscopy allows one to view frozen hydrated biological and soft matter specimens with good structural preservation and a high degree of stability against radiation damage. We describe a liquid nitrogen-cooled anti-contamination device for cryogenic X-ray diffraction microscopy. The anti-contaminator greatly reduces the buildup of ice layers on the specimen due to condensation of residual water vapor in the experimental vacuum chamber. We show by coherent X-ray diffraction measurements that this leads to fivefold reduction of background scattering, which is important for far-field X-ray diffraction microscopy of biological specimens.
Observation of electromigration in a Cu thin line by in situ coherent x-ray diffraction microscopy

NASA Astrophysics Data System (ADS)

Takahashi, Yukio; Nishino, Yoshinori; Furukawa, Hayato; Kubo, Hideto; Yamauchi, Kazuto; Ishikawa, Tetsuya; Matsubara, Eiichiro

2009-06-01

Electromigration (EM) in a 1-μm-thick Cu thin line was investigated by in situ coherent x-ray diffraction microscopy (CXDM). Characteristic x-ray speckle patterns due to both EM-induced voids and thermal deformation in the thin line were observed in the coherent x-ray diffraction patterns. Both parts of the voids and the deformation were successfully visualized in the images reconstructed from the diffraction patterns. This result not only represents the first demonstration of the visualization of structural changes in metallic materials by in situ CXDM but is also an important step toward studying the structural dynamics of nanomaterials using x-ray free-electron lasers in the near future.
Investigation of structural, optical, magnetic and electrical properties of tungsten doped Nisbnd Zn nano-ferrites

NASA Astrophysics Data System (ADS)

Pathania, Abhilash; Bhardwaj, Sanjay; Thakur, Shyam Singh; Mattei, Jean-Luc; Queffelec, Patrick; Panina, Larissa V.; Thakur, Preeti; Thakur, Atul

2018-02-01

Tungsten substituted nickel-zinc ferrite nanoparticles with chemical composition of Ni0.5Zn0.5WxFe2-xO4 (x = 0.0, 0.2, 0.4, 0.6, 0.8 & 1.0) were successfully synthesized by a chemical co-precipitation method. The prepared ferrites were pre sintered at 850 °C and then annealed at 1000 °C in a muffle furnace for 3 h each. This sintered powder was inspected by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and vibrating sample magnetometer (VSM) to study the structural, optical, and magnetic properties. XRD measurement revealed the phase purity of all the nanoferrite samples with cubic spinel structure. The estimated crystallite size by X-ray line broadening is found in the range of 49-62 nm. FTIR spectra of all the samples have observed two prominent absorption bands in the range 400-700 cm-1 arising due to tetrahedral and octahedral stretching vibrations. Vibrating sample magnetometer experiments showed that the saturation magnetizations (MS) decreased with an increase in non-magnetic tungsten ion doping. The electrical resistivity of tungsten doped Nisbnd Zn nano ferrites were examined extensively as a function of temperature. With an increase in tungsten composition, resistivity was found to decrease from 2.2 × 105 Ω cm to 1.9 × 105 Ω cm which indicates the semiconducting behavior of the ferrite samples. The activation energy also decreased from 0.0264 to 0.0221 eV at x = 0.0 to x = 1.0. These low coercive field tungsten doped Nisbnd Zn ferrites are suitable for hyperthermia and sensor applications. These observations are explained in detail on the basis of various models and theories.
Note: application of a pixel-array area detector to simultaneous single crystal X-ray diffraction and X-ray absorption spectroscopy measurements.

PubMed

Sun, Cheng-Jun; Zhang, Bangmin; Brewe, Dale L; Chen, Jing-Sheng; Chow, G M; Venkatesan, T; Heald, Steve M

2014-04-01

X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS) are two main x-ray techniques in synchrotron radiation facilities. In this Note, we present an experimental setup capable of performing simultaneous XRD and XAS measurements by the application of a pixel-array area detector. For XRD, the momentum transfer in specular diffraction was measured by scanning the X-ray energy with fixed incoming and outgoing x-ray angles. By selecting a small fixed region of the detector to collect the XRD signal, the rest of the area was available for collecting the x-ray fluorescence for XAS measurements. The simultaneous measurement of XRD and X-ray absorption near edge structure for Pr0.67Sr0.33MnO3 film was demonstrated as a proof of principle for future time-resolved pump-probe measurements. A static sample makes it easy to maintain an accurate overlap of the X-ray spot and laser pump beam.
X-Ray Diffraction Wafer Mapping Method for Rhombohedral Super-Hetero-Epitaxy

NASA Technical Reports Server (NTRS)

Park, Yoonjoon; Choi, Sang Hyouk; King, Glen C.; Elliott, James R.; Dimarcantonio, Albert L.

2010-01-01

A new X-ray diffraction (XRD) method is provided to acquire XY mapping of the distribution of single crystals, poly-crystals, and twin defects across an entire wafer of rhombohedral super-hetero-epitaxial semiconductor material. In one embodiment, the method is performed with a point or line X-ray source with an X-ray incidence angle approximating a normal angle close to 90 deg, and in which the beam mask is preferably replaced with a crossed slit. While the wafer moves in the X and Y direction, a narrowly defined X-ray source illuminates the sample and the diffracted X-ray beam is monitored by the detector at a predefined angle. Preferably, the untilted, asymmetric scans are of {440} peaks, for twin defect characterization.
Diffraction based method to reconstruct the spectrum of the Thomson scattering x-ray source

NASA Astrophysics Data System (ADS)

Chi, Zhijun; Yan, Lixin; Zhang, Zhen; Zhou, Zheng; Zheng, Lianmin; Wang, Dong; Tian, Qili; Wang, Wei; Nie, Zan; Zhang, Jie; Du, Yingchao; Hua, Jianfei; Shi, Jiaru; Pai, Chihao; Lu, Wei; Huang, Wenhui; Chen, Huaibi; Tang, Chuanxiang

2017-04-01

As Thomson scattering x-ray sources based on the collision of intense laser and relativistic electrons have drawn much attention in various scientific fields, there is an increasing demand for the effective methods to reconstruct the spectrum information of the ultra-short and high-intensity x-ray pulses. In this paper, a precise spectrum measurement method for the Thomson scattering x-ray sources was proposed with the diffraction of a Highly Oriented Pyrolytic Graphite (HOPG) crystal and was demonstrated at the Tsinghua Thomson scattering X-ray source. The x-ray pulse is diffracted by a 15 mm (L) ×15 mm (H)× 1 mm (D) HOPG crystal with 1° mosaic spread. By analyzing the diffraction pattern, both x-ray peak energies and energy spectral bandwidths at different polar angles can be reconstructed, which agree well with the theoretical value and simulation. The higher integral reflectivity of the HOPG crystal makes this method possible for single-shot measurement.
Diffraction based method to reconstruct the spectrum of the Thomson scattering x-ray source.

PubMed

Chi, Zhijun; Yan, Lixin; Zhang, Zhen; Zhou, Zheng; Zheng, Lianmin; Wang, Dong; Tian, Qili; Wang, Wei; Nie, Zan; Zhang, Jie; Du, Yingchao; Hua, Jianfei; Shi, Jiaru; Pai, Chihao; Lu, Wei; Huang, Wenhui; Chen, Huaibi; Tang, Chuanxiang

2017-04-01

As Thomson scattering x-ray sources based on the collision of intense laser and relativistic electrons have drawn much attention in various scientific fields, there is an increasing demand for the effective methods to reconstruct the spectrum information of the ultra-short and high-intensity x-ray pulses. In this paper, a precise spectrum measurement method for the Thomson scattering x-ray sources was proposed with the diffraction of a Highly Oriented Pyrolytic Graphite (HOPG) crystal and was demonstrated at the Tsinghua Thomson scattering X-ray source. The x-ray pulse is diffracted by a 15 mm (L) ×15 mm (H)× 1 mm (D) HOPG crystal with 1° mosaic spread. By analyzing the diffraction pattern, both x-ray peak energies and energy spectral bandwidths at different polar angles can be reconstructed, which agree well with the theoretical value and simulation. The higher integral reflectivity of the HOPG crystal makes this method possible for single-shot measurement.
Gas gun shock experiments with single-pulse x-ray phase contrast imaging and diffraction at the Advanced Photon Source

NASA Astrophysics Data System (ADS)

Luo, S. N.; Jensen, B. J.; Hooks, D. E.; Fezzaa, K.; Ramos, K. J.; Yeager, J. D.; Kwiatkowski, K.; Shimada, T.

2012-07-01

The highly transient nature of shock loading and pronounced microstructure effects on dynamic materials response call for in situ, temporally and spatially resolved, x-ray-based diagnostics. Third-generation synchrotron x-ray sources are advantageous for x-ray phase contrast imaging (PCI) and diffraction under dynamic loading, due to their high photon fluxes, high coherency, and high pulse repetition rates. The feasibility of bulk-scale gas gun shock experiments with dynamic x-ray PCI and diffraction measurements was investigated at the beamline 32ID-B of the Advanced Photon Source. The x-ray beam characteristics, experimental setup, x-ray diagnostics, and static and dynamic test results are described. We demonstrate ultrafast, multiframe, single-pulse PCI measurements with unprecedented temporal (<100 ps) and spatial (˜2 μm) resolutions for bulk-scale shock experiments, as well as single-pulse dynamic Laue diffraction. The results not only substantiate the potential of synchrotron-based experiments for addressing a variety of shock physics problems, but also allow us to identify the technical challenges related to image detection, x-ray source, and dynamic loading.
X-ray and neutron diffraction studies of crystallinity in hydroxyapatite coatings.

PubMed

Girardin, E; Millet, P; Lodini, A

2000-02-01

To standardize industrial implant production and make comparisons between different experimental results, we have to be able to quantify the crystallinity of hydroxyapatite. Methods of measuring crystallinity ratio were developed for various HA samples before and after plasma spraying. The first series of methods uses X-ray diffraction. The advantage of these methods is that X-ray diffraction equipment is used widely in science and industry. In the second series, a neutron diffraction method is developed and the results recorded are similar to those obtained by the modified X-ray diffraction methods. The advantage of neutron diffraction is the ability to obtain measurements deep inside a component. It is a nondestructive method, owing to the very low absorption of neutrons in most materials. Copyright 2000 John Wiley & Sons, Inc.
X-ray Diffraction Gratings for Astrophysics

NASA Astrophysics Data System (ADS)

Paerels, Frits

2010-12-01

Over the past year, we have celebrated the tenth anniversary of the Chandra and XMM-Newton X-ray observatories. Both carry powerful, novel diffraction grating spectrometers, which have opened true X-ray spectroscopy for astrophysics. I will describe the design and operation of these instruments, as the background to some of the beautiful results they have produced. But these designs do not exhaust the versatility and essential simplicity of diffraction grating spectrometers, and I will discuss applications for the International X-ray Observatory IXO.
Amorphous boron gasket in diamond anvil cell research

NASA Astrophysics Data System (ADS)

Lin, Jung-Fu; Shu, Jinfu; Mao, Ho-kwang; Hemley, Russell J.; Shen, Guoyin

2003-11-01

Recent advances in high-pressure diamond anvil cell experiments include high-energy synchrotron x-ray techniques as well as new cell designs and gasketing procedures. The success of high-pressure experiments usually depends on a well-prepared sample, in which the gasket plays an important role. Various gasket materials such as diamond, beryllium, rhenium, and stainless steel have been used. Here we introduce amorphous boron as another gasket material in high-pressure diamond anvil cell experiments. We have applied the boron gasket for laser-heating x-ray diffraction, radial x-ray diffraction, nuclear resonant inelastic x-ray scattering, and inelastic x-ray scattering. The high shear strength of the amorphous boron maximizes the thickness of the sample chamber and increases the pressure homogeneity, improving the quality of high-pressure data. Use of amorphous boron avoids unwanted x-ray diffraction peaks and reduces the absorption of incident and x rays exiting the gasket material. The high quality of the diffraction patterns makes it possible to refine the cell parameters with powder x-ray diffraction data under high pressure and high temperature. The reactivity of boron prevents its use at high temperatures, however. When heated, boron may also react with the specimen to produce unwanted phases. The relatively porous boron starting material at ambient conditions also poses some challenges for sample preparation.
Synthesis and characterization of Cu3Se2 nanofilms by an underpotential deposition based electrochemical codeposition technique

NASA Astrophysics Data System (ADS)

Aydın, Zehra Yazar; Abacı, Serdar

2017-12-01

The Cu3Se2 nanofilms were synthesized with underpotential deposition based electrochemical codeposition technique for the first time in the literature. The electrochemical behaviors of copper and selenium were investigated in 0.1 M H2SO4 on Au electrode. The effects of concentration and scan rate on the electrochemical behavior of selenium were studied. The electrochemical behaviors in underpotential deposition and bulk regions of the Cu-Se system were investigated in acidic solution by cyclic voltammetry and electrolysis techniques. X-ray photoelectron spectroscopy, scanning electron microscopy, atomic force microscopy, X-ray diffraction, Raman spectroscopy, and ultraviolet and visible absorption spectroscopy techniques were used for characterization of synthesized films. According to the X-ray photoelectron spectroscopy spectrum, Cu/Se ratio was determined to be approximately 3/2. Copper selenide nanofilms are two phases and polycrystalline according to X-ray diffraction. The films mainly formed tetragonal Cu3Se2 (umangite mineral structure) structure and the particle size was approximately 45.95 nm. Scanning electron microscopy images showed that Cu3Se2 nanofilms consisted of uniform, nano-sizes and two-dimensional. It was found through AFM that the surface roughness of the film was 6.173 nm, with a mean particle size of around 50 nm. Depending on the deposition time, the band gaps of the Cu3Se2 films were in the range of 2.86-3.20 eV. Three characteristic vibrational modes belonging to Cu3Se2 nanofilms were recorded in the Raman spectrum.
New supramolecular cocrystal of 2-amino-5-chloropyridine with 3-methylbenzoic acids: Syntheses, structural characterization, Hirshfeld surfaces and quantum chemical investigations

NASA Astrophysics Data System (ADS)

Thanigaimani, Kaliyaperumal; Khalib, Nuridayanti Che; Temel, Ersin; Arshad, Suhana; Razak, Ibrahim Abdul

2015-11-01

2-amino-5-chloropyridine: 3-methylbenzoic acid [(2A5CP) (3MBA)] (I) cocrystal was synthesized and its single crystal was grown by slow evaporation technique. The structure of the grown crystal was elucidated by using single crystal X-ray diffraction technique. The cocrystal belongs to the monoclinic crystallographic system with space group P21/c, Z = 4, and a = 13.3155 (5) Å, b = 5.5980 (2) Å, c = 18.3787 (7) Å, β = 110.045 (2)°. The crystal structure is stabilized by Npyridine-H•••Odbnd C, Cdbnd O-H•••Npyridine and C-H⋯O type hydrogen bonding interactions. The presence of unionized -COOH functional group in the cocrystal was identified both by spectral methods and X-ray structural analysis. The experimental studies obtained by using the methods of single crystal X-ray analysis, powder X-ray diffraction (PXRD) analysis, FTIR, 1H NMR and 13C NMR spectroscopies confirmed the predicted cocrystal. The supramolecular assembly of the cocrystal was analyzed and discussed. The molecular geometry, vibrational frequencies of the compound in the ground state were calculated by using the density functional theory (DFT) method with 6-311++G (d,p) basis set and were compared with the experimental data. Additionally, HOMO-LUMO energy gap, natural bond orbital (NBO) analysis and nonlinear optical (NLO) properties of the compound were performed at B3LYP/6-311++G (d,p) level. Hirshfeld surfaces were used to confirm the existence of inter-molecular interactions in the compound.
X-Ray Sum Frequency Diffraction for Direct Imaging of Ultrafast Electron Dynamics

NASA Astrophysics Data System (ADS)

Rouxel, Jérémy R.; Kowalewski, Markus; Bennett, Kochise; Mukamel, Shaul

2018-06-01

X-ray diffraction from molecules in the ground state produces an image of their charge density, and time-resolved x-ray diffraction can thus monitor the motion of the nuclei. However, the density change of excited valence electrons upon optical excitation can barely be monitored with regular diffraction techniques due to the overwhelming background contribution of the core electrons. We present a nonlinear x-ray technique made possible by novel free electron laser sources, which provides a spatial electron density image of valence electron excitations. The technique, sum frequency generation carried out with a visible pump and a broadband x-ray diffraction pulse, yields snapshots of the transition charge densities, which represent the electron density variations upon optical excitation. The technique is illustrated by ab initio simulations of transition charge density imaging for the optically induced electronic dynamics in a donor or acceptor substituted stilbene.
DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaus, Noor Haida Mohd., E-mail: noorhaida@usm.my; Collins, A. M.; Mann, S.

In this paper, we present a facile method for production stable aqueous dispersion of ferrocene (FO) nanoparticles. Ferrocene compounds were employed to achieve stable nanodispersions, stabilized with three different biopolymers namely, alginate, CM-dextran and chitosan. The nanoparticles produce are spherical, less than 10 nm in mean diameter and highly stable without any sedimentation. Fourier infrared transform (FTIR) and X-ray diffraction (XRD) studies confirmed the purity of ferrocene nanoparticles there is no modifications occur during the preparation route. FTIR spectra results were consistent with the presence of absorption band of cyclopentadienyl ring (C{sub 5}H{sub 5}{sup −} ion) which assigned to ν(C-C)more » vibrations (1409 cm-1), δ(C-H) stretching at 1001 cm{sup −1} and π(C-H) vibrations at 812 cm{sup −1}. Furthermore, all functional group for biopolymers such as CO from carboxyl group of CM-dextran and sodium alginate appears at 1712 cm{sup −1} and 1709 cm{sup −1} respectively, indicating there are steric repulsion interactions for particles stabilization. Powder X-ray diffraction patterns of sedimented samples of the biopolymers-stabilized ferrocene (FO) showed all reflections which were indexed respectively to the (−110), (001), (−201), (−111), (200), (−211), (210), (120) and (111) according to the monoclinic phase ferrocene. This confirmed that the products obtained were of high purity of Fe and EDAX analysis also suggests that the presence of the Fe element in the colloidal dispersion.« less

Growth, structure, and magnetic properties of γ-Fe2O3 epitaxial films on MgO

NASA Astrophysics Data System (ADS)

Gao, Y.; Kim, Y. J.; Thevuthasan, S.; Chambers, S. A.; Lubitz, P.

1997-04-01

Single-crystal epitaxial thin films of γ-Fe2O3(001) have been grown on MgO(001) using oxygen-plasma-assisted molecular beam epitaxy. The structure and magnetic properties of these films have been characterized by a variety of techniques, including reflection high-energy electron diffraction (RHEED), low-energy electron diffraction (LEED), x-ray photoelectron spectroscopy and x-ray photoelectron/Auger electron diffraction (XPD/AED), vibrating sample magnetometry, and ferromagnetic resonance. Real-time RHEED reveals that the film growth occurs in a layer-by-layer fashion. The γ-Fe2O3(001) film surface exhibits a (1×1) LEED pattern. The growth of γ-Fe2Ooverflow="scroll">3 films at 450 °C is accompanied by significant Mg outdiffusion. AED of Mg KLL Auger emission reveals that Mg substitutionally incorporates in the γ-Fe2O3 lattice, occupying the octahedral sites. Magnetic moments are ˜2300 G and ˜4500 G for γ-Fe2O3 films grown at 250 °C and 450 °C, respectively. The high magnetic moment for the films grown at 450 °C could be attributed to the high degree of structural order of the films and Mg substitution at octahedral sites.
Infrared spectrometric study of acid-degradable glasses.

PubMed

De Maeyer, E A P; Verbeeck, R M H; Vercruysse, C W J

2002-08-01

The composition of glasses used in glass-ionomer cements affects their leaching behavior and hence the properties of the cement. The aim of this study was to correlate the composition and leaching behavior of these glasses with their infrared absorption characteristics. The wavenumber of the absorption band of the Si-O asymmetric stretching vibration shifts to a higher value with decreasing content of mono- and bivalent cations in the glass. This effect can be ascribed to the influence of these extraneous ions on the glass network order and connectivity. Preferential leaching of these ions induces an increase of asymmetric stretching vibration and a general modification of the band profile. The results can be correlated with the x-ray diffraction characteristics of the glass.
Studies on nickel-tungsten oxide thin films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Usha, K. S.; Sivakumar, R., E-mail: krsivakumar1979@yahoo.com; Sanjeeviraja, C.

2014-10-15

Nickel-Tungsten oxide (95:5) thin films were prepared by rf sputtering at 200W rf power with various substrate temperatures. X-ray diffraction study reveals the amorphous nature of films. The substrate temperature induced decrease in energy band gap with a maximum transmittance of 71%1 was observed. The Micro-Raman study shows broad peaks at 560 cm{sup −1} and 1100 cm{sup −1} correspond to Ni-O vibration and the peak at 860 cm{sup −1} can be assigned to the vibration of W-O-W bond. Photoluminescence spectra show two peaks centered on 420 nm and 485 nm corresponding to the band edge emission and vacancies created duemore » to the addition of tungsten, respectively.« less
Development of an adaptable coherent x-ray diffraction microscope with the emphasis on imaging hydrated specimens.

PubMed

Nam, Daewoong; Park, Jaehyun; Gallagher-Jones, Marcus; Shimada, Hiroki; Kim, Sangsoo; Kim, Sunam; Kohmura, Yoshiki; Ishikawa, Tetsuya; Song, Changyong

2013-11-01

This paper describes the development of a versatile coherent x-ray diffraction microscope capable of imaging biological specimens in solution. The microscope is a flexible platform accommodating various conditions, from low vacuum (10(-2) Pa) to helium gas filled ambient pressure. This flexibility greatly expands the application area, from in situ materials science to biology systems in their native state, by significantly relaxing restrictions to the sample environment. The coherent diffraction microscope has been used successfully to image a yeast cell immersed in buffer solution. We believe that the design of this coherent diffraction microscope can be directly adapted to various platforms such as table top soft x-ray laser, synchrotron x-ray sources, and x-ray free electron laser with minor relevant adjustments.
Development of an adaptable coherent x-ray diffraction microscope with the emphasis on imaging hydrated specimens

NASA Astrophysics Data System (ADS)

Nam, Daewoong; Park, Jaehyun; Gallagher-Jones, Marcus; Shimada, Hiroki; Kim, Sangsoo; Kim, Sunam; Kohmura, Yoshiki; Ishikawa, Tetsuya; Song, Changyong

2013-11-01

This paper describes the development of a versatile coherent x-ray diffraction microscope capable of imaging biological specimens in solution. The microscope is a flexible platform accommodating various conditions, from low vacuum (10-2 Pa) to helium gas filled ambient pressure. This flexibility greatly expands the application area, from in situ materials science to biology systems in their native state, by significantly relaxing restrictions to the sample environment. The coherent diffraction microscope has been used successfully to image a yeast cell immersed in buffer solution. We believe that the design of this coherent diffraction microscope can be directly adapted to various platforms such as table top soft x-ray laser, synchrotron x-ray sources, and x-ray free electron laser with minor relevant adjustments.
Thin Film Research. Volume 1

DTIC Science & Technology

1985-05-30

Order (FECO) ......... 23 3. X -Ray Diffraction ............................... 26 4. Transmission Electron Microscopy (TEM) ............... 26 5...remained amorphous after bombardment, as evidenced by X - ray diffraction, and showed no other changes. 0 (2) For Sb203, the crystallite size was reduced...main effect on MgF2 was the reduction in crystallite size. The films were too thir. for meaningful x - ray diffraction analysis. Durability and
X-Ray Diffraction and the Discovery of the Structure of DNA

ERIC Educational Resources Information Center

Crouse, David T.

2007-01-01

A method is described for teaching the analysis of X-ray diffraction of DNA through a series of steps utilizing the original methods used by James Watson, Francis Crick, Maurice Wilkins and Rosalind Franklin. The X-ray diffraction pattern led to the conclusion of the basic helical structure of DNA and its dimensions while basic chemical principles…
High Resolution X-Ray Diffraction of Macromolecules with Synchrotron Radiation

NASA Technical Reports Server (NTRS)

Stojanoff, Vivian; Boggon, Titus; Helliwell, John R.; Judge, Russell; Olczak, Alex; Snell, Edward H.; Siddons, D. Peter; Rose, M. Franklin (Technical Monitor)

2000-01-01

We recently combined synchrotron-based monochromatic X-ray diffraction topography methods with triple axis diffractometry and rocking curve measurements: high resolution X-ray diffraction imaging techniques, to better understand the quality of protein crystals. We discuss these methods in the light of results obtained on crystals grown under different conditions. These non destructive techniques are powerful tools in the characterization of the protein crystals and ultimately will allow to improve, develop, and understand protein crystal growth. High resolution X-ray diffraction imaging methods will be discussed in detail in light of recent results obtained on Hen Egg White Lysozyme crystals and other proteins.
Hard X-ray polarizer to enable simultaneous three-dimensional nanoscale imaging of magnetic structure and lattice strain

DOE PAGES

Logan, Jonathan; Harder, Ross; Li, Luxi; ...

2016-01-01

Recent progress in the development of dichroic Bragg coherent diffractive imaging, a new technique for simultaneous three-dimensional imaging of strain and magnetization at the nanoscale, is reported. This progress includes the installation of a diamond X-ray phase retarder at beamline 34-ID-C of the Advanced Photon Source. Here, the performance of the phase retarder for tuning X-ray polarization is demonstrated with temperature-dependent X-ray magnetic circular dichroism measurements on a gadolinium foil in transmission and on a Gd 5Si 2Ge 2crystal in diffraction geometry with a partially coherent, focused X-ray beam. Feasibility tests for dichroic Bragg coherent diffractive imaging are presented. Thesemore » tests include (1) using conventional Bragg coherent diffractive imaging to determine whether the phase retarder introduces aberrations using a nonmagnetic gold nanocrystal as a control sample, and (2) collecting coherent diffraction patterns of a magnetic Gd 5Si 2Ge 2nanocrystal with left- and right-circularly polarized X-rays. Future applications of dichroic Bragg coherent diffractive imaging for the correlation of strain and lattice defects with magnetic ordering and inhomogeneities are considered.« less
Three Dimensional Variable-Wavelength X-Ray Bragg Coherent Diffraction Imaging

DOE PAGES

Cha, W.; Ulvestad, A.; Allain, M.; ...

2016-11-23

Here, we present and demonstrate a formalism by which three-dimensional (3D) Bragg x-ray coherent diffraction imaging (BCDI) can be implemented without moving the sample by scanning the energy of the incident x-ray beam. This capability is made possible by introducing a 3D Fourier transform that accounts for x-ray wavelength variability. We also demonstrate the approach by inverting coherent Bragg diffraction patterns from a gold nanocrystal measured with an x-ray energy scan. Furthermore, variable-wavelength BCDI will expand the breadth of feasible in situ 3D strain imaging experiments towards more diverse materials environments, especially where sample manipulation is difficult.
Synchrotron X-Ray Diffraction Analysis of Meteorites in Thin Section: Preliminary Results

NASA Technical Reports Server (NTRS)

Treiman, A. H.; Lanzirotti, A.; Xirouchakis, D.

2004-01-01

X-ray diffraction is the pre-eminent technique for mineral identification and structure determination, but is difficult to apply to grains in thin section, the standard meteorite preparation. Bright focused X-ray beams from synchrotrons have been used extensively in mineralogy and have been applied to extraterrestrial particles. The intensity and small spot size achievable in synchrotron X-ray beams makes them useful for study of materials in thin sections. Here, we describe Synchrotron X-ray Diffraction (SXRD) in thin section as done at the National Synchrotron Light Source, and cite examples of its value for studies of meteorites in thin section.
Three Dimensional Variable-Wavelength X-Ray Bragg Coherent Diffraction Imaging

NASA Astrophysics Data System (ADS)

Cha, W.; Ulvestad, A.; Allain, M.; Chamard, V.; Harder, R.; Leake, S. J.; Maser, J.; Fuoss, P. H.; Hruszkewycz, S. O.

2016-11-01

We present and demonstrate a formalism by which three-dimensional (3D) Bragg x-ray coherent diffraction imaging (BCDI) can be implemented without moving the sample by scanning the energy of the incident x-ray beam. This capability is made possible by introducing a 3D Fourier transform that accounts for x-ray wavelength variability. We demonstrate the approach by inverting coherent Bragg diffraction patterns from a gold nanocrystal measured with an x-ray energy scan. Variable-wavelength BCDI will expand the breadth of feasible in situ 3D strain imaging experiments towards more diverse materials environments, especially where sample manipulation is difficult.
Three Dimensional Variable-Wavelength X-Ray Bragg Coherent Diffraction Imaging.

PubMed

Cha, W; Ulvestad, A; Allain, M; Chamard, V; Harder, R; Leake, S J; Maser, J; Fuoss, P H; Hruszkewycz, S O

2016-11-25

We present and demonstrate a formalism by which three-dimensional (3D) Bragg x-ray coherent diffraction imaging (BCDI) can be implemented without moving the sample by scanning the energy of the incident x-ray beam. This capability is made possible by introducing a 3D Fourier transform that accounts for x-ray wavelength variability. We demonstrate the approach by inverting coherent Bragg diffraction patterns from a gold nanocrystal measured with an x-ray energy scan. Variable-wavelength BCDI will expand the breadth of feasible in situ 3D strain imaging experiments towards more diverse materials environments, especially where sample manipulation is difficult.
[Study on the vibrational spectra and XRD characters of Huanglong jade from Longling County, Yunnan Province].

PubMed

Pei, Jing-cheng; Fan, Lu-wei; Xie, Hao

2014-12-01

Based on the conventional test methods, the infrared absorption spectrum, Raman spectrum and X-ray diffraction (XRD) were employed to study the characters of the vibration spectrum and mineral composition of Huanglong jade. The testing results show that Huanglong jade shows typical vibrational spectrum characteristics of quartziferous jade. The main infrared absorption bands at 1162, 1076, 800, 779, 691, 530 and 466 cm(-1) were induced by the asymmetric stretching vibration, symmetrical stretching vibration and bending vibration of Si-O-Si separately. Especially the absorption band near 800 cm(-1) is split, which indicates that Huanglong jade has good crystallinity. In Raman spectrum, the main strong vibration bands at 463 and 355 cm(-1) were attributed to bending vibration of Si-O-Si. XRD test confirmed that Quartz is main mineral composition of Huanglong jade and there is a small amount of hematite in red color samples which induced the red color of Huanglong jade. This is the first report on the infrared, Raman and XRD spectra feature of Huanglong jade. It will provide a scientific basis for the identification, naming and other research for huanglong jade.
In-situ X-ray diffraction system using sources and detectors at fixed angular positions

DOEpatents

Gibson, David M [Voorheesville, NY; Gibson, Walter M [Voorheesville, NY; Huang, Huapeng [Latham, NY

2007-06-26

An x-ray diffraction technique for measuring a known characteristic of a sample of a material in an in-situ state. The technique includes using an x-ray source for emitting substantially divergent x-ray radiation--with a collimating optic disposed with respect to the fixed source for producing a substantially parallel beam of x-ray radiation by receiving and redirecting the divergent paths of the divergent x-ray radiation. A first x-ray detector collects radiation diffracted from the sample; wherein the source and detector are fixed, during operation thereof, in position relative to each other and in at least one dimension relative to the sample according to a-priori knowledge about the known characteristic of the sample. A second x-ray detector may be fixed relative to the first x-ray detector according to the a-priori knowledge about the known characteristic of the sample, especially in a phase monitoring embodiment of the present invention.
Magnetic cellulose/Ag as a novel eco-friendly nanobiocomposite to catalyze synthesis of chromene-linked nicotinonitriles.

PubMed

Maleki, Ali; Movahed, Hamed; Ravaghi, Parisa

2017-01-20

In this work, design, preparation and performance of magnetic cellulose/Ag nanobiocomposite as a recyclable and highly efficient heterogeneous nanocatalyst is described. Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) pattern, vibrating sample magnetometer (VSM) curve, field-emission scanning electron microscopy (FE-SEM) image, energy dispersive X-ray (EDX) analysis and thermogravimetric analysis/differential thermal analysis (TGA/DTA) were used for the characterization. Then, its activity was investigated in the synthesis of 2-amino-6-(2-oxo-2H-chromen-3-yl)-4-phenylnicotinonitrile derivatives. The main advantages of the reaction are high yields and short reaction times. The remarkable magnetic property of the nanobiocomposite catalyst provides easy separation from the reaction mixture by an external magnet without considerable loss of its catalytic activity. Copyright © 2016 Elsevier Ltd. All rights reserved.
Synthesis of MnFe2O4 magnetic nano hollow spheres by a facile solvothermal route and its characterization

NASA Astrophysics Data System (ADS)

Dey, Chaitali; Chaudhuri, Arka; Goswami, Madhuri Mandal

2018-04-01

Herein, we report the synthesis of manganese ferrite (MnFe2O4) magnetic nano hollow sphere (NHS) by a solvothermal route. Crystalline phase was confirmed by X-ray diffraction (XRD), energy dispersive x-ray (EDX). Magnetic measurements were done in vibrating sample magnetometer (VSM) and morphological structure was analyzed by field emission high resolution scanning electron microscope (FESEM) and structural characterization was confirmed by Fourier transform infrared spectroscopy (FTIR), thermal analysis was performed by thermo-gravimetric analysis-differential thermal analysis (TGA-DTA). The size of the NHS was around 470 nm, this large size may show a potential applicability in industrial application, like dye adsorption, catalysis etc. In addition, because of its ferromagnetic character at room temperature, it can be easily separated by external magnetic field after the application is done.
The effect of exit beam phase aberrations on parallel beam coherent x-ray reconstructions

NASA Astrophysics Data System (ADS)

Hruszkewycz, S. O.; Harder, R.; Xiao, X.; Fuoss, P. H.

2010-12-01

Diffraction artifacts from imperfect x-ray windows near the sample are an important consideration in the design of coherent x-ray diffraction measurements. In this study, we used simulated and experimental diffraction patterns in two and three dimensions to explore the effect of phase imperfections in a beryllium window (such as a void or inclusion) on the convergence behavior of phasing algorithms and on the ultimate reconstruction. A predictive relationship between beam wavelength, sample size, and window position was derived to explain the dependence of reconstruction quality on beryllium defect size. Defects corresponding to this prediction cause the most damage to the sample exit wave and induce signature error oscillations during phasing that can be used as a fingerprint of experimental x-ray window artifacts. The relationship between x-ray window imperfection size and coherent x-ray diffractive imaging reconstruction quality explored in this work can play an important role in designing high-resolution in situ coherent imaging instrumentation and will help interpret the phasing behavior of coherent diffraction measured in these in situ environments.
The effect of exit beam phase aberrations on parallel beam coherent x-ray reconstructions.

PubMed

Hruszkewycz, S O; Harder, R; Xiao, X; Fuoss, P H

2010-12-01

Diffraction artifacts from imperfect x-ray windows near the sample are an important consideration in the design of coherent x-ray diffraction measurements. In this study, we used simulated and experimental diffraction patterns in two and three dimensions to explore the effect of phase imperfections in a beryllium window (such as a void or inclusion) on the convergence behavior of phasing algorithms and on the ultimate reconstruction. A predictive relationship between beam wavelength, sample size, and window position was derived to explain the dependence of reconstruction quality on beryllium defect size. Defects corresponding to this prediction cause the most damage to the sample exit wave and induce signature error oscillations during phasing that can be used as a fingerprint of experimental x-ray window artifacts. The relationship between x-ray window imperfection size and coherent x-ray diffractive imaging reconstruction quality explored in this work can play an important role in designing high-resolution in situ coherent imaging instrumentation and will help interpret the phasing behavior of coherent diffraction measured in these in situ environments.
Femtosecond X-ray Diffraction From Two-Dimensional Protein Crystals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frank, Matthias; Carlson, David B.; Hunter, Mark

2014-02-28

Here we present femtosecond x-ray diffraction patterns from two-dimensional (2-D) protein crystals using an x-ray free electron laser (XFEL). To date it has not been possible to acquire x-ray diffraction from individual 2-D protein crystals due to radiation damage. However, the intense and ultrafast pulses generated by an XFEL permits a new method of collecting diffraction data before the sample is destroyed. Utilizing a diffract-before-destroy methodology at the Linac Coherent Light Source, we observed Bragg diffraction to better than 8.5 Å resolution for two different 2-D protein crystal samples that were maintained at room temperature. These proof-of-principle results show promisemore » for structural analysis of both soluble and membrane proteins arranged as 2-D crystals without requiring cryogenic conditions or the formation of three-dimensional crystals.« less

Influence of gamma ray irradiation on stoichiometry of hydrothermally synthesized bismuth telluride nanoparticles

NASA Astrophysics Data System (ADS)

Abishek, N. S.; Naik, K. Gopalakrishna

2018-05-01

Bismuth telluride (Bi2Te3) nanoparticles were synthesized by the hydrothermal method at 200 °C for 24 h. The synthesized Bi2Te3 nanoparticles were irradiated with gamma rays at doses of 50 kGy and 100 kGy. The structural characterization of the pre-irradiated and post-irradiated samples was carried out by X-ray diffraction technique and was found to have rhombohedral phase having R3 ¯m (166) space group. The X-ray diffraction peaks were found to shift towards lower diffraction angle with gamma ray irradiation. The morphologies and compositions of the grown Bi2Te3 nanoparticles were studied using Field Emission Scanning Electron Microscope and X-ray energy dispersive analysis, respectively. The possible cause for the shift in the X-ray diffraction peaks with gamma ray irradiation has been discussed in the present work.
High Power Optical Coatings by Atomic Layer Deposition and Signatures of Laser-Induced Damage

DTIC Science & Technology

2012-08-28

diffraction angle 0 into crystal lattice spacing d by the Bragg condition, mX = 2d sin 0. Here X is the x - ray wavelength... angle x - ray diffraction (GAXRD) measurements, which were made at a fixed shallow incidence angle of 0.5°. Detector scans were done to measure the...was finished with 200 hafnia cycles m the fmal half period rather than 400. Crystallinity was measured by x - ray diffraction (XRD) with
Materials identification using a small-scale pixellated x-ray diffraction system

NASA Astrophysics Data System (ADS)

O'Flynn, D.; Crews, C.; Drakos, I.; Christodoulou, C.; Wilson, M. D.; Veale, M. C.; Seller, P.; Speller, R. D.

2016-05-01

A transmission x-ray diffraction system has been developed using a pixellated, energy-resolving detector (HEXITEC) and a small-scale, mains operated x-ray source (Amptek Mini-X). HEXITEC enables diffraction to be measured without the requirement of incident spectrum filtration, or collimation of the scatter from the sample, preserving a large proportion of the useful signal compared with other diffraction techniques. Due to this efficiency, sufficient molecular information for material identification can be obtained within 5 s despite the relatively low x-ray source power. Diffraction data are presented from caffeine, hexamine, paracetamol, plastic explosives and narcotics. The capability to determine molecular information from aspirin tablets inside their packaging is demonstrated. Material selectivity and the potential for a sample classification model is shown with principal component analysis, through which each different material can be clearly resolved.
Dynamic X-ray diffraction sampling for protein crystal positioning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Scarborough, Nicole M.; Godaliyadda, G. M. Dilshan P.; Ye, Dong Hye

A sparse supervised learning approach for dynamic sampling (SLADS) is described for dose reduction in diffraction-based protein crystal positioning. Crystal centering is typically a prerequisite for macromolecular diffraction at synchrotron facilities, with X-ray diffraction mapping growing in popularity as a mechanism for localization. In X-ray raster scanning, diffraction is used to identify the crystal positions based on the detection of Bragg-like peaks in the scattering patterns; however, this additional X-ray exposure may result in detectable damage to the crystal prior to data collection. Dynamic sampling, in which preceding measurements inform the next most information-rich location to probe for image reconstruction,more » significantly reduced the X-ray dose experienced by protein crystals during positioning by diffraction raster scanning. The SLADS algorithm implemented herein is designed for single-pixel measurements and can select a new location to measure. In each step of SLADS, the algorithm selects the pixel, which, when measured, maximizes the expected reduction in distortion given previous measurements. Ground-truth diffraction data were obtained for a 5 µm-diameter beam and SLADS reconstructed the image sampling 31% of the total volume and only 9% of the interior of the crystal greatly reducing the X-ray dosage on the crystal. Furthermore, by usingin situtwo-photon-excited fluorescence microscopy measurements as a surrogate for diffraction imaging with a 1 µm-diameter beam, the SLADS algorithm enabled image reconstruction from a 7% sampling of the total volume and 12% sampling of the interior of the crystal. When implemented into the beamline at Argonne National Laboratory, without ground-truth images, an acceptable reconstruction was obtained with 3% of the image sampled and approximately 5% of the crystal. The incorporation of SLADS into X-ray diffraction acquisitions has the potential to significantly minimize the impact of X-ray exposure on the crystal by limiting the dose and area exposed for image reconstruction and crystal positioning using data collection hardware present in most macromolecular crystallography end-stations.« less
Dynamic X-ray diffraction sampling for protein crystal positioning

DOE PAGES

Scarborough, Nicole M.; Godaliyadda, G. M. Dilshan P.; Ye, Dong Hye; ...

2017-01-01

A sparse supervised learning approach for dynamic sampling (SLADS) is described for dose reduction in diffraction-based protein crystal positioning. Crystal centering is typically a prerequisite for macromolecular diffraction at synchrotron facilities, with X-ray diffraction mapping growing in popularity as a mechanism for localization. In X-ray raster scanning, diffraction is used to identify the crystal positions based on the detection of Bragg-like peaks in the scattering patterns; however, this additional X-ray exposure may result in detectable damage to the crystal prior to data collection. Dynamic sampling, in which preceding measurements inform the next most information-rich location to probe for image reconstruction,more » significantly reduced the X-ray dose experienced by protein crystals during positioning by diffraction raster scanning. The SLADS algorithm implemented herein is designed for single-pixel measurements and can select a new location to measure. In each step of SLADS, the algorithm selects the pixel, which, when measured, maximizes the expected reduction in distortion given previous measurements. Ground-truth diffraction data were obtained for a 5 µm-diameter beam and SLADS reconstructed the image sampling 31% of the total volume and only 9% of the interior of the crystal greatly reducing the X-ray dosage on the crystal. Furthermore, by usingin situtwo-photon-excited fluorescence microscopy measurements as a surrogate for diffraction imaging with a 1 µm-diameter beam, the SLADS algorithm enabled image reconstruction from a 7% sampling of the total volume and 12% sampling of the interior of the crystal. When implemented into the beamline at Argonne National Laboratory, without ground-truth images, an acceptable reconstruction was obtained with 3% of the image sampled and approximately 5% of the crystal. The incorporation of SLADS into X-ray diffraction acquisitions has the potential to significantly minimize the impact of X-ray exposure on the crystal by limiting the dose and area exposed for image reconstruction and crystal positioning using data collection hardware present in most macromolecular crystallography end-stations.« less
Dynamic X-ray diffraction sampling for protein crystal positioning

PubMed Central

Scarborough, Nicole M.; Godaliyadda, G. M. Dilshan P.; Ye, Dong Hye; Kissick, David J.; Zhang, Shijie; Newman, Justin A.; Sheedlo, Michael J.; Chowdhury, Azhad U.; Fischetti, Robert F.; Das, Chittaranjan; Buzzard, Gregery T.; Bouman, Charles A.; Simpson, Garth J.

2017-01-01

A sparse supervised learning approach for dynamic sampling (SLADS) is described for dose reduction in diffraction-based protein crystal positioning. Crystal centering is typically a prerequisite for macromolecular diffraction at synchrotron facilities, with X-ray diffraction mapping growing in popularity as a mechanism for localization. In X-ray raster scanning, diffraction is used to identify the crystal positions based on the detection of Bragg-like peaks in the scattering patterns; however, this additional X-ray exposure may result in detectable damage to the crystal prior to data collection. Dynamic sampling, in which preceding measurements inform the next most information-rich location to probe for image reconstruction, significantly reduced the X-ray dose experienced by protein crystals during positioning by diffraction raster scanning. The SLADS algorithm implemented herein is designed for single-pixel measurements and can select a new location to measure. In each step of SLADS, the algorithm selects the pixel, which, when measured, maximizes the expected reduction in distortion given previous measurements. Ground-truth diffraction data were obtained for a 5 µm-diameter beam and SLADS reconstructed the image sampling 31% of the total volume and only 9% of the interior of the crystal greatly reducing the X-ray dosage on the crystal. Using in situ two-photon-excited fluorescence microscopy measurements as a surrogate for diffraction imaging with a 1 µm-diameter beam, the SLADS algorithm enabled image reconstruction from a 7% sampling of the total volume and 12% sampling of the interior of the crystal. When implemented into the beamline at Argonne National Laboratory, without ground-truth images, an acceptable reconstruction was obtained with 3% of the image sampled and approximately 5% of the crystal. The incorporation of SLADS into X-ray diffraction acquisitions has the potential to significantly minimize the impact of X-ray exposure on the crystal by limiting the dose and area exposed for image reconstruction and crystal positioning using data collection hardware present in most macromolecular crystallography end-stations. PMID:28009558
Dynamic X-ray diffraction sampling for protein crystal positioning.

PubMed

Scarborough, Nicole M; Godaliyadda, G M Dilshan P; Ye, Dong Hye; Kissick, David J; Zhang, Shijie; Newman, Justin A; Sheedlo, Michael J; Chowdhury, Azhad U; Fischetti, Robert F; Das, Chittaranjan; Buzzard, Gregery T; Bouman, Charles A; Simpson, Garth J

2017-01-01

A sparse supervised learning approach for dynamic sampling (SLADS) is described for dose reduction in diffraction-based protein crystal positioning. Crystal centering is typically a prerequisite for macromolecular diffraction at synchrotron facilities, with X-ray diffraction mapping growing in popularity as a mechanism for localization. In X-ray raster scanning, diffraction is used to identify the crystal positions based on the detection of Bragg-like peaks in the scattering patterns; however, this additional X-ray exposure may result in detectable damage to the crystal prior to data collection. Dynamic sampling, in which preceding measurements inform the next most information-rich location to probe for image reconstruction, significantly reduced the X-ray dose experienced by protein crystals during positioning by diffraction raster scanning. The SLADS algorithm implemented herein is designed for single-pixel measurements and can select a new location to measure. In each step of SLADS, the algorithm selects the pixel, which, when measured, maximizes the expected reduction in distortion given previous measurements. Ground-truth diffraction data were obtained for a 5 µm-diameter beam and SLADS reconstructed the image sampling 31% of the total volume and only 9% of the interior of the crystal greatly reducing the X-ray dosage on the crystal. Using in situ two-photon-excited fluorescence microscopy measurements as a surrogate for diffraction imaging with a 1 µm-diameter beam, the SLADS algorithm enabled image reconstruction from a 7% sampling of the total volume and 12% sampling of the interior of the crystal. When implemented into the beamline at Argonne National Laboratory, without ground-truth images, an acceptable reconstruction was obtained with 3% of the image sampled and approximately 5% of the crystal. The incorporation of SLADS into X-ray diffraction acquisitions has the potential to significantly minimize the impact of X-ray exposure on the crystal by limiting the dose and area exposed for image reconstruction and crystal positioning using data collection hardware present in most macromolecular crystallography end-stations.
(2E)-1-(5-Chlorothiophen-2-yl)-3-{4-[(E)-2-phenylethenyl]phenyl}prop-2-en-1-one: Synthesis, XRD, FT-IR, Raman and DFT studies.

PubMed

Parlak, Cemal; Ramasami, Ponnadurai; Kumar, Chandraju Sadolalu Chidan; Tursun, Mahir; Quah, Ching Kheng; Rhyman, Lydia; Bilge, Metin; Fun, Hoong-Kun; Chandraju, Siddegowda

2015-01-01

A novel (2E)-1-(5-chlorothiophen-2-yl)-3-{4-[(E)-2-phenylethenyl]phenyl}prop-2-en-1-one [C21H15ClOS] compound has been synthesized and its structure has been characterized by FT-IR, Raman and single-crystal X-ray diffraction techniques. The conformational isomers, optimized geometric parameters, normal mode frequencies and corresponding vibrational assignments of the compound have been examined by means of HF, MP2, BP86, BLYP, BMK, B3LYP, B3PW91, B3P86 and M06-2X functionals. Reliable vibrational assignments and molecular orbitals have been investigated by the potential energy distribution and natural bonding orbital analyses, respectively. The compound crystallizes in the triclinic space group P-1 with the cis-trans-trans form. There is a good agreement between the experimentally determined structural parameters and vibrational frequencies of the compound and those predicted theoretically using the density functional theory with the BLYP and BP86 functionals. Copyright © 2015 Elsevier B.V. All rights reserved.
Anharmonic vibrational spectroscopy, NBO charges and global chemical reactivity studies on the charge transfer PDCA-.AHMP+ single crystal using DFT calculations

NASA Astrophysics Data System (ADS)

Faizan, Mohd; Afroz, Ziya; Bhat, Sheeraz Ahmad; Alam, Mohamad Jane; Ahmad, Shabbir; Ahmad, Afaq

2018-04-01

The charge transfer (CT) complex of the 2-amino-4-hydroxy-6-methylpyrimidine and 2,3 pyrazinedicarboxylic acid (PDCA-.AHMP+) was synthesized and its single crystal was grown by solution method. The structure of the crystalline complex has been investigated by single crystal X-ray diffraction (SCXRD). The vibrational features of the complex have been studied with the help of FTIR spectra and DFT computation. The anharmonic corrections in vibrational frequencies are made using the GVPT2 method at B3LYP/6-311++G(d,p) level of theory. The frontier molecular orbitals and global chemical reactivity have been calculated to understand the pharmacological aspect of the synthesized crystal. Furthermore, Hirshfeld electrostatic potential (ESP) surface, void space in the crystal structure and natural as well as Mulliken atomic charges are studied.
Terahertz spectra of L-phenylalanine and its monohydrate

NASA Astrophysics Data System (ADS)

Pan, Tingting; Li, Shaoping; Zou, Tao; Yu, Zheng; Zhang, Bo; Wang, Chenyang; Zhang, Jianbing; He, Mingxia; Zhao, Hongwei

2017-05-01

The low-frequency vibrational property of L-phenylalanine (L-Phe) and L-phenylalanine monohydrate (L-Phe·H2O) has been investigated by terahertz time-domain spectroscopy (THz-TDS) at room and low temperature ranging from 0.5 to 4.5 THz. Distinctive THz absorption spectra of the two compounds were observed. Density functional theory (DFT) calculations based on the crystal structures have been performed to simulate the vibrational modes of L-Phe and L-Phe·H2O and the results agree well with the experimental observations. The study indicates that the characterized features of L-Phe mainly originate from the collective vibration of molecules. And the characterized features of L-Phe·H2O mainly come from hydrogen bond interactions between L-Phe and water molecules. L-Phe and L-Phe·H2O were also verified by differential scanning calorimetry and thermogravimetry (DSC-TG) and powder X-ray diffraction (PXRD) examinations.
Crystal structure and vibrational spectra of melaminium arsenate

NASA Astrophysics Data System (ADS)

Anbalagan, G.; Marchewka, M. K.; Pawlus, K.; Kanagathara, N.

2015-01-01

The crystals of the new melaminium arsenate (MAS) [C3H7N6+ṡH2AsO4-] were obtained by the slow evaporation of an aqueous solution at room temperature. Single crystal X-ray diffraction analysis reveals that the crystal belongs to triclinic system with centro symmetric space group P-1. The crystals are built up from single protonated melaminium residues and single dissociated arsenate H2AsO4- anions. The protonated melaminium ring is almost planar. A combination of ionic and donor-acceptor hydrogen-bond interactions linking together the melaminium and arsenate residues forms a three-dimensional network. Vibrational spectroscopic analysis is reported on the basis of FT-IR and FT-Raman spectra recorded at room temperature. Hydrogen bonded network present in the crystal gives notable vibrational effect. DSC has also been performed for the crystal shows no phase transition in the studied temperature range (113-293 K).
Preparation, crystal structure, vibrational spectral and density functional studies of bis (4-nitrophenol)-2,4,6-triamino-1,3,5-triazine monohydrate

NASA Astrophysics Data System (ADS)

Kanagathara, N.; Marchewka, M. K.; Drozd, M.; Renganathan, N. G.; Gunasekaran, S.; Anbalagan, G.

2013-10-01

An organic-organic salt, bis (4-nitrophenol) 2,4,6-triamino 1,3,5-triazine monohydrate (BNPM) has been prepared by slow evaporation technique at room temperature. Single crystal X-ray diffraction analysis reveals that the compound crystallizes in triclinic system with centrosymmetric space group P-1. IR and Raman spectra of BNPM have been recorded and analyzed. The study has been extended to confocal Raman spectral analysis. Band assignments have been made for the melamine and p-nitrophenol molecules. Vibrational spectra have also been discussed on the basis of quantum chemical density functional theory calculations using Firefly (PC GAMESS) Version 7.1 G. Vibrational frequencies are calculated and scaled values are compared with the experimental one. The Mulliken charges, HOMO-LUMO orbital energies are calculated and analyzed. The chemical structure of the compound was established by 1H NMR and 13C NMR spectra.
Fixture for supporting and aligning a sample to be analyzed in an x-ray diffraction apparatus

DOEpatents

Green, L.A.; Heck, J.L. Jr.

1985-04-23

A fixture is provided for supporting and aligning small samples of material on a goniometer for x-ray diffraction analysis. A sample-containing capillary is accurately positioned for rotation in the x-ray beam by selectively adjusting the fixture to position the capillary relative to the x and y axes thereof to prevent wobble and position the sample along the z axis or the axis of rotation. By employing the subject fixture relatively small samples of materials can be analyzed in an x-ray diffraction apparatus previously limited to the analysis of much larger samples.
Fixture for supporting and aligning a sample to be analyzed in an X-ray diffraction apparatus

DOEpatents

Green, Lanny A.; Heck, Jr., Joaquim L.

1987-01-01

A fixture is provided for supporting and aligning small samples of material on a goniometer for X-ray diffraction analysis. A sample-containing capillary is accurately positioned for rotation in the X-ray beam by selectively adjusting the fixture to position the capillary relative to the x and y axes thereof to prevent wobble and position the sample along the z axis or the axis of rotation. By employing the subject fixture relatively small samples of materials can be analyzed in an X-ray diffraction apparatus previously limited to the analysis of much larger samples.
DFT and experimental studies of the structure and vibrational spectra of curcumin

NASA Astrophysics Data System (ADS)

Kolev, Tsonko M.; Velcheva, Evelina A.; Stamboliyska, Bistra A.; Spiteller, Michael

The potential energy surface of curcumin [1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione] was explored with the DFT correlation functional B3LYP method using 6-311G* basis. The single-point calculations were performed at levels up to B3LYP/6-311++G**//B3LYP/6-311G*. All isomers were located and relative energies determined. According to the calculation the planar enol form is more stable than the nonplanar diketo form. The results of the optimized molecular structure are presented and compared with the experimental X-ray diffraction. In addition, harmonic vibrational frequencies of the molecule were evaluated theoretically using B3LYP density functional methods. The computed vibrational frequencies were used to determine the types of molecular motions associated with each of the experimental bands observed. Our vibrational data show that in both the solid state and in all studied solutions curcumin exists in the enol form.
JMFA2—a graphically interactive Java program that fits microfibril angle X-ray diffraction data

Treesearch

Steve P. Verrill; David E. Kretschmann; Victoria L. Herian

2006-01-01

X-ray diffraction techniques have the potential to decrease the time required to determine microfibril angles dramatically. In this paper, we discuss the latest version of a curve-fitting toll that permits us to reduce the time required to evaluate MFA X-ray diffraction patterns. Further, because this tool reflects the underlying physics more accurately than existing...
Lifetime-vibrational interference effects in resonantly excited x-ray emission spectra of CO

DOE Office of Scientific and Technical Information (OSTI.GOV)

Skytt, P.; Glans, P.; Gunnelin, K.

1997-04-01

The parity selection rule for resonant X-ray emission as demonstrated for O{sub 2} and N{sub 2} can be seen as an effect of interference between coherently excited degenerate localized core states. One system where the core state degeneracy is not exact but somewhat lifted was previously studied at ALS, namely the resonant X-ray emission of amino-substituted benzene (aniline). It was shown that the X-ray fluorescence spectrum resulting from excitation of the C1s at the site of the {open_quotes}aminocarbon{close_quotes} could be described in a picture separating the excitation and the emission processes, whereas the spectrum corresponding to the quasi-degenerate carbons couldmore » not. Thus, in this case it was necessary to take interference effects between the quasi-degenerate intermediate core excited states into account in order to obtain agreement between calculations and experiment. The different vibrational levels of core excited states in molecules have energy splittings which are of the same order of magnitude as the natural lifetime broadening of core excitations in the soft X-ray range. Therefore, lifetime-vibrational interference effects are likely to appear and influence the band shapes in resonant X-ray emission spectra. Lifetime-vibrational interference has been studied in non-resonant X-ray emission, and in Auger spectra. In this report the authors discuss results of selectively excited soft X-ray fluorescence spectra of molecules, where they focus on lifetime-interference effects appearing in the band shapes.« less
A high-transparency, micro-patternable chip for X-ray diffraction analysis of microcrystals under native growth conditions

DOE PAGES

Murray, Thomas D.; Lyubimov, Artem Y.; Ogata, Craig M.; ...

2015-08-11

Microcrystals present a significant impediment to the determination of macromolecular structures by X-ray diffraction methods. Although microfocus synchrotron beamlines and X-ray free-electron lasers (XFELs) can enable the collection of interpretable diffraction data from microcrystals, there is a need for efficient methods of harvesting small volumes (<2 µl) of microcrystals grown under common laboratory formats and delivering them to an X-ray beam source under native growth conditions. One approach that shows promise in overcoming the challenges intrinsic to microcrystal analysis is to pair so-called `fixed-target' sample-delivery devices with microbeam-based X-ray diffraction methods. However, to record weak diffraction patterns it is necessarymore » to fabricate devices from X-ray-transparent materials that minimize background scattering. Presented here is the design of a new micro-diffraction device consisting of three layers fabricated from silicon nitride, photoresist and polyimide film. The chip features low X-ray scattering and X-ray absorption properties, and uses a customizable blend of hydrophobic and hydrophilic surface patterns to help localize microcrystals to defined regions. Microcrystals in their native growth conditions can be loaded into the chips with a standard pipette, allowing data collection at room temperature. Diffraction data collected from hen egg-white lysozyme microcrystals (10–15 µm) loaded into the chips yielded a complete, high-resolution (<1.6 Å) data set sufficient to determine a high-quality structure by molecular replacement. In addition, the features of the chip allow the rapid and user-friendly analysis of microcrystals grown under virtually any laboratory format at microfocus synchrotron beamlines and XFELs.« less
A high-transparency, micro-patternable chip for X-ray diffraction analysis of microcrystals under native growth conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Murray, Thomas D.; Lyubimov, Artem Y.; Ogata, Craig M.

Microcrystals present a significant impediment to the determination of macromolecular structures by X-ray diffraction methods. Although microfocus synchrotron beamlines and X-ray free-electron lasers (XFELs) can enable the collection of interpretable diffraction data from microcrystals, there is a need for efficient methods of harvesting small volumes (<2 µl) of microcrystals grown under common laboratory formats and delivering them to an X-ray beam source under native growth conditions. One approach that shows promise in overcoming the challenges intrinsic to microcrystal analysis is to pair so-called `fixed-target' sample-delivery devices with microbeam-based X-ray diffraction methods. However, to record weak diffraction patterns it is necessarymore » to fabricate devices from X-ray-transparent materials that minimize background scattering. Presented here is the design of a new micro-diffraction device consisting of three layers fabricated from silicon nitride, photoresist and polyimide film. The chip features low X-ray scattering and X-ray absorption properties, and uses a customizable blend of hydrophobic and hydrophilic surface patterns to help localize microcrystals to defined regions. Microcrystals in their native growth conditions can be loaded into the chips with a standard pipette, allowing data collection at room temperature. Diffraction data collected from hen egg-white lysozyme microcrystals (10–15 µm) loaded into the chips yielded a complete, high-resolution (<1.6 Å) data set sufficient to determine a high-quality structure by molecular replacement. In addition, the features of the chip allow the rapid and user-friendly analysis of microcrystals grown under virtually any laboratory format at microfocus synchrotron beamlines and XFELs.« less
A high-transparency, micro-patternable chip for X-ray diffraction analysis of microcrystals under native growth conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Murray, Thomas D.; Lyubimov, Artem Y.; Ogata, Craig M.

Microcrystals present a significant impediment to the determination of macromolecular structures by X-ray diffraction methods. Although microfocus synchrotron beamlines and X-ray free-electron lasers (XFELs) can enable the collection of interpretable diffraction data from microcrystals, there is a need for efficient methods of harvesting small volumes (<2µl) of microcrystals grown under common laboratory formats and delivering them to an X-ray beam source under native growth conditions. One approach that shows promise in overcoming the challenges intrinsic to microcrystal analysis is to pair so-called `fixed-target' sample-delivery devices with microbeam-based X-ray diffraction methods. However, to record weak diffraction patterns it is necessary tomore » fabricate devices from X-ray-transparent materials that minimize background scattering. Presented here is the design of a new micro-diffraction device consisting of three layers fabricated from silicon nitride, photoresist and polyimide film. The chip features low X-ray scattering and X-ray absorption properties, and uses a customizable blend of hydrophobic and hydrophilic surface patterns to help localize microcrystals to defined regions. Microcrystals in their native growth conditions can be loaded into the chips with a standard pipette, allowing data collection at room temperature. Diffraction data collected from hen egg-white lysozyme microcrystals (10–15µm) loaded into the chips yielded a complete, high-resolution (<1.6Å) data set sufficient to determine a high-quality structure by molecular replacement. The features of the chip allow the rapid and user-friendly analysis of microcrystals grown under virtually any laboratory format at microfocus synchrotron beamlines and XFELs.« less

A high-transparency, micro-patternable chip for X-ray diffraction analysis of microcrystals under native growth conditions

PubMed Central

Murray, Thomas D.; Lyubimov, Artem Y.; Ogata, Craig M.; Vo, Huy; Uervirojnangkoorn, Monarin; Brunger, Axel T.; Berger, James M.

2015-01-01

Microcrystals present a significant impediment to the determination of macromolecular structures by X-ray diffraction methods. Although microfocus synchrotron beamlines and X-ray free-electron lasers (XFELs) can enable the collection of interpretable diffraction data from microcrystals, there is a need for efficient methods of harvesting small volumes (<2 µl) of microcrystals grown under common laboratory formats and delivering them to an X-ray beam source under native growth conditions. One approach that shows promise in overcoming the challenges intrinsic to microcrystal analysis is to pair so-called ‘fixed-target’ sample-delivery devices with microbeam-based X-ray diffraction methods. However, to record weak diffraction patterns it is necessary to fabricate devices from X-ray-transparent materials that minimize background scattering. Presented here is the design of a new micro-diffraction device consisting of three layers fabricated from silicon nitride, photoresist and polyimide film. The chip features low X-ray scattering and X-ray absorption properties, and uses a customizable blend of hydrophobic and hydrophilic surface patterns to help localize microcrystals to defined regions. Microcrystals in their native growth conditions can be loaded into the chips with a standard pipette, allowing data collection at room temperature. Diffraction data collected from hen egg-white lysozyme microcrystals (10–15 µm) loaded into the chips yielded a complete, high-resolution (<1.6 Å) data set sufficient to determine a high-quality structure by molecular replacement. The features of the chip allow the rapid and user-friendly analysis of microcrystals grown under virtually any laboratory format at microfocus synchrotron beamlines and XFELs. PMID:26457423
New process of preparation, X-ray characterisation, structure and vibrational studies of a solid solution LiTiOAs 1-xP xO 4 (0⩽ x⩽1)

NASA Astrophysics Data System (ADS)

Chakir, M.; El Jazouli, A.; Chaminade, J. P.; Bouree, F.; de Waal, D.

2006-01-01

LiTiOAs 1-xP xO 4 (0⩽ x⩽1) compounds have been prepared using solutions of Li, Ti, As and P elements as starting products. Selected compositions have been investigated by powder X-ray or neutrons diffraction analysis, Raman and infrared spectroscopy. The structure of LiTiOAs 1-xP xO 4 ( x=0, 0.5 and 1) samples determined by Rietveld analysis is orthorhombic with Pnma space group. It is formed by a 3D network of TiO 6 octahedra and XO 4 ( X=As 1-xP x) tetrahedra where octahedral cavities are occupied by lithium atoms. TiO 6 octahedra are linked together by corners and form infinite chains along a-axis. Ti atoms are displaced from the centre of octahedral units in alternating short (1.700-1.709 Å) and long (2.301-2.275 Å) Ti-O bonds. Raman and infrared studies confirm the existence of Ti-O-Ti chains. Thermal stability of LiTiOAsO 4 has been reported.
Influence of the divalent and trivalent ions substitution on the structural and magnetic properties of Mg0.5-xCdxCo0.5Cr0.04TbyFe1.96-yO4 ferrites prepared by sol-gel method

NASA Astrophysics Data System (ADS)

Mustafa, Ghulam; Islam, M. U.; Zhang, Wenli; Anwar, Abdul Waheed; Jamil, Yasir; Murtaza, Ghulam; Ali, Ihsan; Hussain, Mudassar; Ali, Akbar; Ahmad, Mukhtar

2015-08-01

A series of the divalent and trivalent co-substituted Mg0.5-xCdxCo0.5Cr0.04TbyFe1.96-yO4 spinel ferrite systems (where x=0-0.5 in steps of 0.1 and y=0.00-0.10 in steps 0.02) are synthesized by sol-gel auto combustion method. The product materials were characterized by the thermo gravimetric analysis and differential scanning calorimetry (TGA/DSC), Fourier transform infrared spectra (FTIR), nitrogen adsorption (BET), X-ray diffraction (XRD), scanning electron microscope (SEM), atomic force microscopy (AFM) and vibrating sample magnetometer (VSM). The X-ray diffraction patterns and Fourier transform infrared spectroscopy confirm spinel nanocrystalline phase. The crystallite size is determined by Scherer's formula from 36.6 to 69.4 nm. The X-ray density is found in the range of 5.09-6.43 (g/cm3). The morphological features are studied using scanning electron microscope and AFM. Saturation magnetization (Ms) and remanence (Mr) magnetization extracted from M-H loops exhibit the decreasing trends 21.4-16 emu/g and 9.1-6.3 emu/g, respectively. A significant decrease in the intrinsic parameters is observed in the prepared samples due to the weakening of the A-B interaction as iron enters into the tetrahedral A-site. The coercivity lies in the range of 300-869 Oe as a function of co-substitution contents. The coercivity of the sample with x=0.1, y=0.02 was found maximum i.e. 869 Oe. The obtained results suggest that the investigated materials may be potential candidates for high density recording media applications.
High-resolution x-ray diffraction microscopy of specifically labeled yeast cells

PubMed Central

Nelson, Johanna; Huang, Xiaojing; Steinbrener, Jan; Shapiro, David; Kirz, Janos; Marchesini, Stefano; Neiman, Aaron M.; Turner, Joshua J.; Jacobsen, Chris

2010-01-01

X-ray diffraction microscopy complements other x-ray microscopy methods by being free of lens-imposed radiation dose and resolution limits, and it allows for high-resolution imaging of biological specimens too thick to be viewed by electron microscopy. We report here the highest resolution (11–13 nm) x-ray diffraction micrograph of biological specimens, and a demonstration of molecular-specific gold labeling at different depths within cells via through-focus propagation of the reconstructed wavefield. The lectin concanavalin A conjugated to colloidal gold particles was used to label the α-mannan sugar in the cell wall of the yeast Saccharomyces cerevisiae. Cells were plunge-frozen in liquid ethane and freeze-dried, after which they were imaged whole using x-ray diffraction microscopy at 750 eV photon energy. PMID:20368463
High-resolution x-ray diffraction microscopy of specifically labeled yeast cells

DOE PAGES

Nelson, Johanna; Huang, Xiaojing; Steinbrener, Jan; ...

2010-04-20

X-ray diffraction microscopy complements other x-ray microscopy methods by being free of lens-imposed radiation dose and resolution limits, and it allows for high-resolution imaging of biological specimens too thick to be viewed by electron microscopy. We report here the highest resolution (11-13 nm) x-ray diffraction micrograph of biological specimens, and a demonstration of molecular-specific gold labeling at different depths within cells via through-focus propagation of the reconstructed wavefield. The lectin concanavalin A conjugated to colloidal gold particles was used to label the α-mannan sugar in the cell wall of the yeast Saccharomyces cerevisiae. Cells were plunge-frozen in liquid ethane andmore » freeze-dried, after which they were imaged whole using x-ray diffraction microscopy at 750 eV photon energy.« less
Optical properties of Y and Ti co-substituted BiFeO{sub 3} multiferroics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singh, Vikash, E-mail: rk.dwivedi@jiit.ac.in; Sharma, Subhash, E-mail: rk.dwivedi@jiit.ac.in; Kumar, Manoj, E-mail: rk.dwivedi@jiit.ac.in

2014-04-24

Pure and co substituted Bi{sub 1−x}Y{sub x}Fe{sub 1−x}Ti{sub x}O{sub 3} (x ≤ 0.24) ceramics were synthesized by solid state reaction method. X-ray diffraction patterns of Y and Ti codoped samples have shown single phase formation. Increasing Y and Ti concentration reveals structural transition from rhombohedral phase (R3c) for x ≤ 0.16 to orthorhombic phase (Pnma) for x = 0.24. FT-IR spectra exhibit broad absorption bands, which may be due to the overlapping of Fe-O and Bi-O vibrations. UV-visible spectroscopy results show strong absorption of light in the spectral range of 400-720 nm, indicating optical band gap in the visible regionmore » for these samples. These interesting optical properties of co-substituted BFO samples in visible region may find potential applications in optoelectronic devices.« less
New Polymorph Form of Dexamethasone Acetate.

PubMed

Silva, Ronaldo Pedro da; Ambrósio, Mateus Felipe Schuchter; Piovesan, Luciana Almeida; Freitas, Maria Clara Ramalho; Aguiar, Daniel Lima Marques de; Horta, Bruno Araújo Cautiero; Epprecht, Eugenio Kahn; San Gil, Rosane Aguiar da Silva; Visentin, Lorenzo do Canto

2018-02-01

A new monohydrated polymorph of dexamethasone acetate was crystallized and its crystal structure characterized. The different analytical techniques used for describing its structural and vibrational properties were: single crystal and polycrystal X-ray diffraction, solid state nuclear magnetic resonance, infrared spectroscopy. A Hirshfeld surface analysis was carried out through self-arrangement cemented by H-bonds observed in this new polymorph. This new polymorph form appeared because of self-arrangement via classical hydrogen bonds around the water molecule. Copyright © 2018 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.
Infrared and Raman spectroscopy and DFT calculations of DL amino acids: Valine and lysine hydrochloride

NASA Astrophysics Data System (ADS)

Paiva, F. M.; Batista, J. C.; Rêgo, F. S. C.; Lima, J. A.; Freire, P. T. C.; Melo, F. E. A.; Mendes Filho, J.; de Menezes, A. S.; Nogueira, C. E. S.

2017-01-01

Single crystals of DL-valine and DL-lysine hydrochloride were grown by slow evaporation method and the crystallographic structure were confirmed by X-ray diffraction experiment and Rietveld method. These two crystals have been studied by Raman spectroscopy in the 25-3600 cm-1 spectral range and by infrared spectroscopy through the interval 375-4000 cm-1 at room temperature. Experimental and theoretical vibrational spectra were compared and a complete analysis of the modes was done in terms of the Potential Energy Distribution (PED).
Coherent x-ray zoom condenser lens for diffractive and scanning microscopy.

PubMed

Kimura, Takashi; Matsuyama, Satoshi; Yamauchi, Kazuto; Nishino, Yoshinori

2013-04-22

We propose a coherent x-ray zoom condenser lens composed of two-stage deformable Kirkpatrick-Baez mirrors. The lens delivers coherent x-rays with a controllable beam size, from one micrometer to a few tens of nanometers, at a fixed focal position. The lens is suitable for diffractive and scanning microscopy. We also propose non-scanning coherent diffraction microscopy for extended objects by using an apodized focused beam produced by the lens with a spatial filter. The proposed apodized-illumination method will be useful in highly efficient imaging with ultimate storage ring sources, and will also open the way to single-shot coherent diffraction microscopy of extended objects with x-ray free-electron lasers.
Scanning force microscope for in situ nanofocused X-ray diffraction studies

PubMed Central

Ren, Zhe; Mastropietro, Francesca; Davydok, Anton; Langlais, Simon; Richard, Marie-Ingrid; Furter, Jean-Jacques; Thomas, Olivier; Dupraz, Maxime; Verdier, Marc; Beutier, Guillaume; Boesecke, Peter; Cornelius, Thomas W.

2014-01-01

A compact scanning force microscope has been developed for in situ combination with nanofocused X-ray diffraction techniques at third-generation synchrotron beamlines. Its capabilities are demonstrated on Au nano-islands grown on a sapphire substrate. The new in situ device allows for in situ imaging the sample topography and the crystallinity by recording simultaneously an atomic force microscope (AFM) image and a scanning X-ray diffraction map of the same area. Moreover, a selected Au island can be mechanically deformed using the AFM tip while monitoring the deformation of the atomic lattice by nanofocused X-ray diffraction. This in situ approach gives access to the mechanical behavior of nanomaterials. PMID:25178002
X-ray topography using the forward transmitted beam under multiple-beam diffraction conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsusaka, Y., E-mail: tsusaka@sci.u-hyogo.ac.jp; Takano, H.; Takeda, S.

2016-02-15

X-ray topographs are taken for a sapphire wafer with the [0001] surface normal, as an example, by forward transmitted synchrotron x-ray beams combined with two-dimensional electronic arrays in the x-ray detector having a spatial resolution of 1 μm. They exhibit no shape deformation and no position shift of the dislocation lines on the topographs. Since the topography is performed under multiple-beam diffraction conditions, the topographic images of a single diffraction (two-wave approximation condition) or plural diffractions (six-wave approximation condition) can be recorded without large specimen position changes. As usual Lang topographs, it is possible to determine the Burgers vector ofmore » each dislocation line. Because of high parallelism of the incoming x-rays and linear sensitivity of the electronic arrays to the incident x-rays, the present technique can be used to visualize individual dislocations in single crystals of the dislocation density as high as 1 × 10{sup 5} cm{sup −2}.« less
Multiple defocused coherent diffraction imaging: method for simultaneously reconstructing objects and probe using X-ray free-electron lasers.

PubMed

Hirose, Makoto; Shimomura, Kei; Suzuki, Akihiro; Burdet, Nicolas; Takahashi, Yukio

2016-05-30

The sample size must be less than the diffraction-limited focal spot size of the incident beam in single-shot coherent X-ray diffraction imaging (CXDI) based on a diffract-before-destruction scheme using X-ray free electron lasers (XFELs). This is currently a major limitation preventing its wider applications. We here propose multiple defocused CXDI, in which isolated objects are sequentially illuminated with a divergent beam larger than the objects and the coherent diffraction pattern of each object is recorded. This method can simultaneously reconstruct both objects and a probe from the coherent X-ray diffraction patterns without any a priori knowledge. We performed a computer simulation of the prposed method and then successfully demonstrated it in a proof-of-principle experiment at SPring-8. The prposed method allows us to not only observe broad samples but also characterize focused XFEL beams.
Angular rheology study of colloidal nanocrystals using Coherent X-ray Diffraction

NASA Astrophysics Data System (ADS)

Liang, Mengning; Harder, Ross; Robinson, Ian

2007-03-01

A new method using coherent x-ray diffraction provides a way to investigate the rotational motion of a colloidal suspension of crystals in real time. Coherent x-ray diffraction uses the long coherence lengths of synchrotron sources to illuminate a nanoscale particle coherently over its spatial dimensions. The penetration of high energy x-rays into various media allows for in-situ measurements making it ideal for suspensions. This technique has been used to image the structure of nanocrystals for some time but also has the capability of providing information about the orientation and dynamics of crystals. The particles are imaged in a specific diffraction condition allowing us to determine their orientation and observe how they rotate in real time with exceptional resolution. Such sensitivity allows for the study of rotational Brownian motion of nanocrystals in various suspensions and conditions. We present a study of the angular rheology of alumina and TiO2 colloidal nanocrystals in media using coherent x-ray diffraction.
Characterization of polycrystalline materials using synchrotron X-ray imaging and diffraction techniques

NASA Astrophysics Data System (ADS)

Ludwig, W.; King, A.; Herbig, M.; Reischig, P.; Marrow, J.; Babout, L.; Lauridsen, E. M.; Proudhon, H.; Buffière, J. Y.

2010-12-01

The combination of synchrotron radiation x-ray imaging and diffraction techniques offers new possibilities for in-situ observation of deformation and damage mechanisms in the bulk of polycrystalline materials. Minute changes in electron density (i.e., cracks, porosities) can be detected using propagation based phase contrast imaging, a 3-D imaging mode exploiting the coherence properties of third generation synchrotron beams. Furthermore, for some classes of polycrystalline materials, one may use a 3-D variant of x-ray diffraction imaging, termed x-ray diffraction contrast tomography. X-ray diffraction contrast tomography provides access to the 3-D shape, orientation, and elastic strain state of the individual grains from polycrystalline sample volumes containing up to thousand grains. Combining both imaging modalities, one obtains a comprehensive description of the materials microstructure at the micrometer length scale. Repeated observation during (interrupted) mechanical tests provide unprecedented insight into crystallographic and grain microstructure related aspects of polycrystalline deformation and degradation mechanisms.
Quantitative analysis of thoria phase in Th-U alloys using diffraction studies

NASA Astrophysics Data System (ADS)

Thakur, Shital; Krishna, P. S. R.; Shinde, A. B.; Kumar, Raj; Roy, S. B.

2017-05-01

In the present study the quantitative phase analysis of Th-U alloys in bulk form namely Th-52 wt% U and Th-3wt%U has been performed over the data obtained from both X ray diffraction and neutron diffraction technique using Rietveld method of FULLPROF software. Quantifying thoria (ThO2) phase present in bulk of the sample is limited due to surface oxidation and low penetration of x rays in high Z material. Neutron diffraction study probing bulk of the samples has been presented in comparison with x-ray diffraction study.
Selenium single-wavelength anomalous diffraction de novo phasing using an X-ray-free electron laser

DOE PAGES

Hunter, Mark S.; Yoon, Chun Hong; DeMirci, Hasan; ...

2016-11-04

Structural information about biological macromolecules near the atomic scale provides important insight into the functions of these molecules. To date, X-ray crystallography has been the predominant method used for macromolecular structure determination. However, challenges exist when solving structures with X-rays, including the phase problem and radiation damage. X-ray-free electron lasers (X-ray FELs) have enabled collection of diffraction information before the onset of radiation damage, yet the majority of structures solved at X-ray FELs have been phased using external information via molecular replacement. De novo phasing at X-ray FELs has proven challenging due in part to per-pulse variations in intensity andmore » wavelength. Here we report the solution of a selenobiotinyl-streptavidin structure using phases obtained by the anomalous diffraction of selenium measured at a single wavelength (Se-SAD) at the Linac Coherent Light Source. Finally, our results demonstrate Se-SAD, routinely employed at synchrotrons for novel structure determination, is now possible at X-ray FELs.« less
Macromolecular structures probed by combining single-shot free-electron laser diffraction with synchrotron coherent X-ray imaging.

PubMed

Gallagher-Jones, Marcus; Bessho, Yoshitaka; Kim, Sunam; Park, Jaehyun; Kim, Sangsoo; Nam, Daewoong; Kim, Chan; Kim, Yoonhee; Noh, Do Young; Miyashita, Osamu; Tama, Florence; Joti, Yasumasa; Kameshima, Takashi; Hatsui, Takaki; Tono, Kensuke; Kohmura, Yoshiki; Yabashi, Makina; Hasnain, S Samar; Ishikawa, Tetsuya; Song, Changyong

2014-05-02

Nanostructures formed from biological macromolecular complexes utilizing the self-assembly properties of smaller building blocks such as DNA and RNA hold promise for many applications, including sensing and drug delivery. New tools are required for their structural characterization. Intense, femtosecond X-ray pulses from X-ray free-electron lasers enable single-shot imaging allowing for instantaneous views of nanostructures at ambient temperatures. When combined judiciously with synchrotron X-rays of a complimentary nature, suitable for observing steady-state features, it is possible to perform ab initio structural investigation. Here we demonstrate a successful combination of femtosecond X-ray single-shot diffraction with an X-ray free-electron laser and coherent diffraction imaging with synchrotron X-rays to provide an insight into the nanostructure formation of a biological macromolecular complex: RNA interference microsponges. This newly introduced multimodal analysis with coherent X-rays can be applied to unveil nano-scale structural motifs from functional nanomaterials or biological nanocomplexes, without requiring a priori knowledge.
Exploration of New Principles in Spintronics Based on Topological Insulators (Option 1)

DTIC Science & Technology

2012-05-14

on the surface and found that our crystals are exceedingly homogeneous (Supplementary Information). The persistently narrow X - ray diffraction peaks...modified Bridgman method (see Supplementary Information for details). X - ray diffraction measurements indicated the monotonic shrinkage of a and c axis...and annealing at that temperature for 4 days. X - ray diffraction analyses confirmed that all the samples have the same crystal structure (R 3m
Efficient modeling of Bragg coherent x-ray nanobeam diffraction

DOE PAGES

Hruszkewycz, S. O.; Holt, M. V.; Allain, M.; ...

2015-07-02

X-ray Bragg diffraction experiments that utilize tightly focused coherent beams produce complicated Bragg diffraction patterns that depend on scattering geometry, characteristics of the sample, and properties of the x-ray focusing optic. In this paper, we use a Fourier-transform-based method of modeling the 2D intensity distribution of a Bragg peak and apply it to the case of thin films illuminated with a Fresnel zone plate in three different Bragg scattering geometries. Finally, the calculations agree well with experimental coherent diffraction patterns, demonstrating that nanodiffraction patterns can be modeled at nonsymmetric Bragg conditions with this approach—a capability critical for advancing nanofocused x-raymore » diffraction microscopy.« less
A simple growth method for Nb 2O 5 films and their optical properties

DOE PAGES

Dash, J. K.; Chen, L.; Topka, Michael R.; ...

2015-04-13

A simple method for the synthesis of Nb₂O₅ films of thicknesses ranging from tens to several hundreds of nanometers on amorphous silicon dioxide or quartz substrates is presented. Nb₂O₅ films were formed by annealing the sputter deposited Nb films under an Ar flow and without oxygen plasma in a quartz tube within a furnace at 850 °C. The structural, compositional, optical, and vibrational properties were characterized by grazing incidence X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, ultraviolet visible spectroscopy, and Raman scattering. Each of the Nb₂O₅ films is polycrystalline with an orthorhombic crystal structure. We observed vibrational modes includingmore » longitudinal optical, transverse optical, and triply degenerate modes, and measured the indirect optical band gap to be ~3.65 eV. The transmittance spectrum of the ~20 nm thick Nb₂O₅ film shows over 90% transmittance below the band gap energy in the visible wavelength range and decreases to less than 20% in the ultraviolet regime. As a result, the optical properties of the films in the UV-vis range show potential applications as UV detectors.« less

Growth, characterization and estimation of lattice strain and size in CdS nanoparticles: X-ray peak profile analysis

NASA Astrophysics Data System (ADS)

Solanki, Rekha Garg; Rajaram, Poolla; Bajpai, P. K.

2018-05-01

This work is based on the growth, characterization and estimation of lattice strain and crystallite size in CdS nanoparticles by X-ray peak profile analysis. The CdS nanoparticles were synthesized by a non-aqueous solvothermal method and were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman and UV-visible spectroscopy. XRD confirms that the CdS nanoparticles have the hexagonal structure. The Williamson-Hall (W-H) method was used to study the X-ray peak profile analysis. The strain-size plot (SSP) was used to study the individual contributions of crystallite size and lattice strain from the X-rays peaks. The physical parameters such as strain, stress and energy density values were calculated using various models namely, isotropic strain model, anisotropic strain model and uniform deformation energy density model. The particle size was estimated from the TEM images to be in the range of 20-40 nm. The Raman spectrum shows the characteristic optical 1LO and 2LO vibrational modes of CdS. UV-visible absorption studies show that the band gap of the CdS nanoparticles is 2.48 eV. The results show that the crystallite size estimated from Scherrer's formula, W-H plots, SSP and the particle size calculated by TEM images are approximately similar.
HiSPoD: a program for high-speed polychromatic X-ray diffraction experiments and data analysis on polycrystalline samples

DOE PAGES

Sun, Tao; Fezzaa, Kamel

2016-06-17

Here, a high-speed X-ray diffraction technique was recently developed at the 32-ID-B beamline of the Advanced Photon Source for studying highly dynamic, yet non-repeatable and irreversible, materials processes. In experiments, the microstructure evolution in a single material event is probed by recording a series of diffraction patterns with extremely short exposure time and high frame rate. Owing to the limited flux in a short pulse and the polychromatic nature of the incident X-rays, analysis of the diffraction data is challenging. Here, HiSPoD, a stand-alone Matlab-based software for analyzing the polychromatic X-ray diffraction data from polycrystalline samples, is described. With HiSPoD,more » researchers are able to perform diffraction peak indexing, extraction of one-dimensional intensity profiles by integrating a two-dimensional diffraction pattern, and, more importantly, quantitative numerical simulations to obtain precise sample structure information.« less
X-ray diffraction and X-ray standing-wave study of the lead stearate film structure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blagov, A. E.; Dyakova, Yu. A.; Kovalchuk, M. V.

2016-05-15

A new approach to the study of the structural quality of crystals is proposed. It is based on the use of X-ray standing-wave method without measuring secondary processes and considers the multiwave interaction of diffraction reflections corresponding to different harmonics of the same crystallographic reflection. A theory of multiwave X-ray diffraction is developed to calculate the rocking curves in the X-ray diffraction scheme under consideration for a long-period quasi-one-dimensional crystal. This phase-sensitive method is used to study the structure of a multilayer lead stearate film on a silicon substrate. Some specific structural features are revealed for the surface layer ofmore » the thin film, which are most likely due to the tilt of the upper layer molecules with respect to the external normal to the film surface.« less
Molybdenum cell for x-ray diffraction measurements of fluid alkali metals at high temperatures and high pressures

NASA Astrophysics Data System (ADS)

Matsuda, Kazuhiro; Tamura, Kozaburo; Katoh, Masahiro; Inui, Masanori

2004-03-01

We have developed a sample cell for x-ray diffraction measurements of fluid alkali metals at high temperatures and high pressures. All parts of the cell are made of molybdenum which is resistant to the chemical corrosion of alkali metals. Single crystalline molybdenum disks electrolytically thinned down to 40 μm were used as the walls of the cell through which x rays pass. The crystal orientation of the disks was controlled in order to reduce the background from the cell. All parts of the cell were assembled and brazed together using a high-temperature Ru-Mo alloy. Energy dispersive x-ray diffraction measurements have been successfully carried out for fluid rubidium up to 1973 K and 16.2 MPa. The obtained S(Q) demonstrates the applicability of the molybdenum cell to x-ray diffraction measurements of fluid alkali metals at high temperatures and high pressures.
High-resolution ab initio three-dimensional x-ray diffraction microscopy

DOE PAGES

Chapman, Henry N.; Barty, Anton; Marchesini, Stefano; ...

2006-01-01

Coherent x-ray diffraction microscopy is a method of imaging nonperiodic isolated objects at resolutions limited, in principle, by only the wavelength and largest scattering angles recorded. We demonstrate x-ray diffraction imaging with high resolution in all three dimensions, as determined by a quantitative analysis of the reconstructed volume images. These images are retrieved from the three-dimensional diffraction data using no a priori knowledge about the shape or composition of the object, which has never before been demonstrated on a nonperiodic object. We also construct two-dimensional images of thick objects with greatly increased depth of focus (without loss of transverse spatialmore » resolution). These methods can be used to image biological and materials science samples at high resolution with x-ray undulator radiation and establishes the techniques to be used in atomic-resolution ultrafast imaging at x-ray free-electron laser sources.« less
Enhancing resolution in coherent x-ray diffraction imaging.

PubMed

Noh, Do Young; Kim, Chan; Kim, Yoonhee; Song, Changyong

2016-12-14

Achieving a resolution near 1 nm is a critical issue in coherent x-ray diffraction imaging (CDI) for applications in materials and biology. Albeit with various advantages of CDI based on synchrotrons and newly developed x-ray free electron lasers, its applications would be limited without improving resolution well below 10 nm. Here, we review the issues and efforts in improving CDI resolution including various methods for resolution determination. Enhancing diffraction signal at large diffraction angles, with the aid of interference between neighboring strong scatterers or templates, is reviewed and discussed in terms of increasing signal-to-noise ratio. In addition, we discuss errors in image reconstruction algorithms-caused by the discreteness of the Fourier transformations involved-which degrade the spatial resolution, and suggest ways to correct them. We expect this review to be useful for applications of CDI in imaging weakly scattering soft matters using coherent x-ray sources including x-ray free electron lasers.
A portable X-ray diffraction apparatus for in situ analyses of masters' paintings

NASA Astrophysics Data System (ADS)

Eveno, Myriam; Duran, Adrian; Castaing, Jacques

2010-09-01

It is rare that the analyses of materials in paintings can be carried out by taking micro-samples. Valuable works of art are best studied in situ by non-invasive techniques. For that purpose, a portable X-ray diffraction and fluorescence apparatus has been designed and constructed at the C2RMF. This apparatus has been used for paintings of Rembrandt, Leonardo da Vinci, Van Gogh, Mantegna, etc. Results are given to illustrate the performance of X-ray diffraction, especially when X-ray fluorescence does not bring sufficient information to conclude.
Diversity of band gap and photoluminescence properties of lead halide perovskite: A halogen-dependent spectroscopic study

NASA Astrophysics Data System (ADS)

Yu, Wenlei; Jiang, Yunfeng; Zhu, Xiuwei; Luo, Chunhua; Jiang, Kai; Chen, Liangliang; Zhang, Juan

2018-05-01

The effects of halogen substitution on microstructure, optical absorption, and phonon modes for perovskite CH3NH3PbX3 (MAPbX3, X = I/Br/Cl) films grown on FTO substrates have been investigated. The X-ray diffraction analysis exhibited good crystallization, and the strong diffraction peak assigned to (1 0 0) c for X = Br/Cl shifted toward a higher angle compared to (1 1 0) t of MAPbI3. Band-gap tuning from 1.63 to 2.37 to 3.11 eV in the I-Br-Cl series can be found due to the halogen effects. These energy values closely match the positions of peak determined from photoluminescence experiments. The remarkable absorption dip and emission peak appear for the MAPbBr3, suggesting higher crystallinity under the same preparation conditions. The wavenumbers of main IR-vibrations slightly decrease with ionic radius of the halogen increasing (in the order of Cl-Br-I), which related to the increasing polarizability. These results provide important progress towards the understanding of the halide role in the realization of high performance MAPbX3-based solar cells.
X-ray fractography on fatigue fractured surface of austenitic stainless steel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yajima, Zenjiro; Tokuyama, Hideki; Kibayashi, Yasuo

1995-12-31

X-ray diffraction observation of the material internal structure beneath fracture surfaces provide fracture analysis with useful information to investigate the conditions and mechanisms of fracture. X-ray fractography is a generic name given to this technique. In the present study, X-ray fractography was applied to fatigue fracture surfaces of austenitic stainless steel (AISI 304) which consisted of solution treatment. The fatigue tests were carried out on compact tension (CT) specimens. The plastic strain on the fracture surface was estimated from measuring the line broadening of X-ray diffraction profiles. The line broadening of X-ray diffraction profiles was measured on and beneath fatiguemore » fracture surfaces. The depth of the plastic zone left on fracture surfaces was evaluated from the line broadening. The results are discussed on the basis of fracture mechanics.« less
Toward in situ x-ray diffraction imaging at the nanometer scale

NASA Astrophysics Data System (ADS)

Zatsepin, Nadia A.; Dilanian, Ruben A.; Nikulin, Andrei Y.; Gable, Brian M.; Muddle, Barry C.; Sakata, Osami

2008-08-01

We present the results of preliminary investigations determining the sensitivity and applicability of a novel x-ray diffraction based nanoscale imaging technique, including simulations and experiments. The ultimate aim of this nascent technique is non-destructive, bulk-material characterization on the nanometer scale, involving three dimensional image reconstructions of embedded nanoparticles and in situ sample characterization. The approach is insensitive to x-ray coherence, making it applicable to synchrotron and laboratory hard x-ray sources, opening the possibility of unprecedented nanometer resolution with the latter. The technique is being developed with a focus on analyzing a technologically important light metal alloy, Al-xCu (where x is 2.0-5.0 %wt). The mono- and polycrystalline samples contain crystallographically oriented, weakly diffracting Al2Cu nanoprecipitates in a sparse, spatially random dispersion within the Al matrix. By employing a triple-axis diffractometer in the non-dispersive setup we collected two-dimensional reciprocal space maps of synchrotron x-rays diffracted from the Al2Cu nanoparticles. The intensity profiles of the diffraction peaks confirmed the sensitivity of the technique to the presence and orientation of the nanoparticles. This is a fundamental step towards in situ observation of such extremely sparse, weakly diffracting nanoprecipitates embedded in light metal alloys at early stages of their growth.
Diffraction and Imaging Study of Imperfections of Protein Crystals with Coherent X-rays

NASA Technical Reports Server (NTRS)

Hu, Z. W.; Thomas, B. R.; Chernov, A. A.; Chu, Y. S.; Lai, B.

2004-01-01

High angular-resolution x-ray diffraction and phase contrast x-ray imaging were combined to study defects and perfection of protein crystals. Imperfections including line defects, inclusions and other microdefects were observed in the diffraction images of a uniformly grown lysozyme crystal. The observed line defects carry distinct dislocation features running approximately along the <110> growth front and have been found to originate mostly in a central growth area and occasionally in outer growth regions. Slow dehydration led to the broadening of a fairly symmetric 4 4 0 rocking curve by a factor of approximately 2.6, which was primarily attributed to the dehydration-induced microscopic effects that are clearly shown in diffraction images. X-ray imaging and diffraction characterization of the quality of apoferritin crystals will also be discussed in the presentation.
THE EFFECT OF SATELLITE LINES FROM THE X-RAY SOURCE ON X-RAY DIFFRACTION PEAKS

EPA Science Inventory

The article discusses the development of a method for relating reactivity to crystallite size and strain parameters obtained by the Warren-Averbach technique. EPA has been using crystallite size and strain data obtained from x-ray diffraction (XRD) peak profile analysis to predic...
History and Solution of the Phase Problem in theTheory of Structure Determination of Crystals from X-ray Diffraction Experiments

ScienceCinema

Wolf, Emil [University of Rochester, Rochester, New York, United States

2017-12-09

Since the pioneering work of Max von Laue on interference and diffraction of x-rays, carried out almost 100 years ago, numerous attempts have been made to determine structures of crystalline media from x-ray diffraction experiments. The usefulness of all of them has been limited by the inability of measuring phases of the diffracted beams. In this talk, the most important research carried out in this field will be reviewed and a recently obtained solution of the phase problem will be presented.
XRayView: a teaching aid for X-ray crystallography.

PubMed

Phillips, G N

1995-10-01

A software package, XRayView, has been developed that uses interactive computer graphics to introduce basic concepts of x-ray diffraction by crystals, including the reciprocal lattice, the Ewald sphere construction, Laue cones, the wavelength dependence of the reciprocal lattice, primitive and centered lattices and systematic extinctions, rotation photography. Laue photography, space group determination and Laue group symmetry, and the alignment of crystals by examination of reciprocal space. XRayView is designed with "user-friendliness" in mind, using pull-down menus to control the program. Many of the experiences of using real x-ray diffraction equipment to examine crystalline diffraction can be simulated. Exercises are available on-line to guide the users through many typical x-ray diffraction experiments.
Studies of structural, morphological, electrical, and magnetic properties of Mg-substituted Co-ferrite materials synthesized using sol-gel autocombustion method

NASA Astrophysics Data System (ADS)

Mammo, Tulu Wegayehu; Murali, N.; Sileshi, Yonatan Mulushoa; Arunamani, T.

2017-10-01

In this work,a nonmagnetic Mg partially substituted in CoFe2O4 was considered and has been shown to have an impact on structural, electrical and magnetic properties of ferrite materials with Co1-xMgxFe2O4 (x = 0, 0.25, 0.45, and 0.75) forms. Sol-gel synthesis route has been followed to synthesize these materials using citric acid as a fuel. Structural parameters were calculated from powder X-ray diffraction data. X-ray diffraction revealed that all the samples synthesized are pure cubic spinel structured materials with space group of Fd 3 ̅m and the lattice constant varying with Mg concentration. From the field emission scanning electron microscopy (FESEM) microstructure characterizations it has been shown that the synthesized materials are well defined crystalline structured with inhomogeneous grain sizes. Besides, the grain sizes were shown to decrease with increase of Mg-content. Fourier transform Infrared (FT-IR) characterization showed the cation vibrations and stretching of other groups in the wave number range of 400-4000 cm-1. The DC resistivity measurements showed an enhanced resistivity of the samples, in the order of 107 Ω cm, at the highest concentration of Mg. VSM magnetic properties analysis revealed that the Coercive force decreases with increase of Mg concentration whereas the saturation magnetization varies with Mg content.
Application of MEMS-based x-ray optics as tuneable nanosecond choppers

NASA Astrophysics Data System (ADS)

Chen, Pice; Walko, Donald A.; Jung, Il Woong; Li, Zhilong; Gao, Ya; Shenoy, Gopal K.; Lopez, Daniel; Wang, Jin

2017-08-01

Time-resolved synchrotron x-ray measurements often rely on using a mechanical chopper to isolate a set of x-ray pulses. We have started the development of micro electromechanical systems (MEMS)-based x-ray optics, as an alternate method to manipulate x-ray beams. In the application of x-ray pulse isolation, we recently achieved a pulse-picking time window of half a nanosecond, which is more than 100 times faster than mechanical choppers can achieve. The MEMS device consists of a comb-drive silicon micromirror, designed for efficiently diffracting an x-ray beam during oscillation. The MEMS devices were operated in Bragg geometry and their oscillation was synchronized to x-ray pulses, with a frequency matching subharmonics of the cycling frequency of x-ray pulses. The microscale structure of the silicon mirror in terms of the curvature and the quality of crystallinity ensures a narrow angular spread of the Bragg reflection. With the discussion of factors determining the diffractive time window, this report showed our approaches to narrow down the time window to half a nanosecond. The short diffractive time window will allow us to select single x-ray pulse out of a train of pulses from synchrotron radiation facilities.
Fabrication of high-resolution x-ray diffractive optics at King's College London

NASA Astrophysics Data System (ADS)

Charalambous, Pambos S.; Anastasi, Peter A. F.; Burge, Ronald E.; Popova, Katia

1995-09-01

The fabrication of high resolution x-ray diffractive optics, and Fresnel zone plates (ZPs) in particular, is a very demanding multifaceted technological task. The commissioning of more (and brighter) synchrotron radiation sources, has increased the number of x-ray imaging beam lines world wide. The availability of cheaper and more effective laboratory x-ray sources, has further increased the number of laboratories involved in x-ray imaging. The result is an ever increasing demand for x-ray optics with a very wide range of specifications, reflecting the particular type of x-ray imaging performed at different laboratories. We have been involved in all aspects of high resolution nanofabrication for a number of years, and we have explored many different methods of lithography, which, although unorthodox, open up possibilities, and increase our flexibility for the fabrication of different diffractive optical elements, as well as other types of nanostructures. The availability of brighter x-ray sources, means that the diffraction efficiency of the ZPs is becoming of secondary importance, a trend which will continue in the future. Resolution, however, is important and will always remain so. Resolution is directly related to the accuracy af pattern generation, as well as the ability to draw fine lines. This is the area towards which we have directed most of our efforts so far.
Influences of PZT addition on phase formation and magnetic properties of perovskite Pb(Fe0.5Nb0.5)O3-based ceramics

NASA Astrophysics Data System (ADS)

Amonpattaratkit, P.; Jantaratana, P.; Ananta, S.

2015-09-01

In this work, the investigation of phase formation, crystal structure, microstructure, microchemical composition and magnetic properties of perovskite (1-x)PFN-xPZT (x=0.1-0.5) multiferroic ceramics derived from a combination of perovskite stabilizer PZT and a wolframite-type FeNbO4 B-site precursor was carried out by using a combination of X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) analyzer and vibrating sample magnetometer (VSM) techniques. The addition of PZT phase and its concentration have been found to have pronounced effects on the perovskite phase formation, densification, grain growth and magnetic properties of the sintered ceramics. XRD spectra from these ceramics reveal transformation of the (pseudo) cubic into the tetragonal perovskite structure. When increasing PZT content, the degree of perovskite phase formation and the tetragonality value of the ceramics increase gradually accompanied with the variation of cell volume, the M-H hysteresis loops, however, become narrower accompanied by the decrease of maximum magnetization (Mmax), remanent polarization (Mr), and coercive field (HC).
Structure and magnetic/electrochemical properties of Cu-doped BiFeO3 nanoparticles prepared by a simple solution method

NASA Astrophysics Data System (ADS)

Khajonrit, Jessada; Phumying, Santi; Maensiri, Santi

2016-06-01

BiFe1- x Cu x O3 (x = 0, 0.05, 0.1, 0.2, and 0.3) nanoparticles were prepared by a simple solution method. The prepared nanoparticles were characterized by X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) method analysis using the Barret-Joyner-Halenda (BJH) model, and X-ray absorption spectroscopy (XAS). Magnetization properties were obtained using a vibrating sample magnetometer (VSM) at room temperature. Magnetization was clearly enhanced by increasing Cu content and decreasing particle size. Zero-field-cooled (ZFC) and field-cooled (FC) temperature-dependent magnetization measurements showed that blocking temperature increased with increasing Cu content. Electrochemical properties were investigated by cyclic voltammetry (CV) and the galvanostatic charge-discharge (GCD) method. The performance of the fabricated supercapacitor was improved for the BiFe0.95Cu0.05O3 electrode. The highest specific capacitance was 568.13 F g-1 at 1 A g-1 and the capacity retention was 77.13% after 500 cycles.
Synthesis, Characterization, and Theoretical Considerations of 1,2-bis(oxyamino)ethane Salts

NASA Technical Reports Server (NTRS)

Crake, Greg; Hawkins, Tom; Hall, Leslie; Tollison, Kerri; Brand, Adam

2003-01-01

The synthesis, characterization, theoretical calculations, and safety studies of energetic salts of 1,2- bis(oxyamino) ethane, (H2N-O-CH2-CH2-O-NH2), were carried out. The salts were characterized by vibrational (infrared, Raman), multinuclear nmr studies (1H, 13C), differential scanning calorimetry (DSC); elemental analysis; and initial safety testing (impact and friction sensitivity) . Theoretical calculations on the neutral, monoprotonated, and doubly protonated species of ethylene bisoxyamine were carried out using xxxx level of theory for the lowest energy structure and these theoretical results compared with the experimentally observed bond distances and vibrational (ir, Raman) frequency values. The single crystal X-ray diffraction study was carried out on the mono-perchlorate salt revealing a high degree of hydrogen bonding with an unexpected structure.

Comparative study of synthesis, structural and magnetic properties of Cu2+ substituted Co-Ni, Co-Zn and Co-Mg nano ferrites

NASA Astrophysics Data System (ADS)

Ramakrishna, A.; Murali, N.; Margarette, S. J.; Samatha, K.; Veeraiah, V.

2018-02-01

Mixed ferrites of the form Co0.5M0.1Cu0.4Fe2O4 (M = Ni, Zn and Mg) have been synthesized using the sol-gel auto combustion technique. Structural analyses are carried out using powder X-ray diffraction to idntify pure ferrite phases. SEM analysis revealed clear crystal morphology with relatively uniform grain sizes with polygonal structures. The FT-IR studies also confirm the bond formation and cation vibrations at low (365-392 cm-1) and high (579-587 cm-1) bands that correspond to the tetrahedral and octahedral sites, respectively. The magnetic properties studied through vibrating sample magnetometer showed that the Ni substituted sample has more magnetic character by exhibiting the highest saturation magnetization.
Vibrational spectroscopic studies of an organic non-linear optical crystal 8-hydroxyquinolinium picrate

NASA Astrophysics Data System (ADS)

Krishna Kumar, V.; Nagalakshmi, R.

2007-04-01

8-Hydroxyquinolinium picrate (8-HQP) was synthesized by the addition of equimolar quantities of 8-hydroxyquinoline (8-HQ) and picric acid (PA). Single crystals were grown from N, N dimethyl formamide (DMF) by restricted evaporation method at room temperature. The solubility of 8-HQP was determined in different solvents at various temperatures. The structural characterization of the grown crystals was carried out by X-ray diffraction. Vibrational modes were classified on the basis of group theoretical analysis and the spectral bands were compared with those of parent compounds in order to propose a tentative assignment by recording FT-IR, FT-Raman and polarized Raman spectra in different crystal orientations. The crystal possess lower cut-off at 230 nm and good transparency as confirmed by optical transmittance studies.
Raman scattering from superhard rhenium diboride under high pressure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xie, Miao; Winkler, Björn; Mao, Zhu

2014-01-06

Lattice vibrational properties of superhard rhenium diboride (ReB{sub 2}) were examined up to 8 GPa in a diamond anvil cell using Raman spectroscopy techniques. Linear pressure coefficients and mode Grüneisen parameters are obtained. Good agreement is found between the experimental and theoretical calculated Grüneisen parameters. Examination of the calculated mode Grüneisen parameters reveals that both B-B and Re-B covalent bonds play a dominant role in supporting the applied load under pressure. A comparison of vibrations parallel and perpendicular to the c-axis indicates that bonds along the c-axis tend to take greater loads. Our results agree with observations of elastic lattice anisotropymore » obtained from both in situ X-ray diffraction measurements and ultrasonic resonance spectra.« less
Fe{sub 3}O{sub 4}/CuO/ZnO/Nano graphene platelets (Fe{sub 3}O{sub 4}/CuO/ZnO/NGP) composites prepared by sol-gel method with enhanced sonocatalytic activity for the removal of dye

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hendry, Tju; Taufik, Ardiansyah; Saleh, Rosari, E-mail: rosari.saleh@gmail.com, E-mail: rosari.saleh@ui.ac.id

2016-04-19

In this study, an attempt has been made to synthesize nanographene platelets coupled with Fe3O4/CuO/ZnO (Fe3O4/CuO/ZnO/NGP) with various ZnO loadings using a two step methods, sol-gel followed by hydrothermal method. Characterization was carried out by X-ray diffraction, energy-dispersive X-ray spectroscopy and vibrating sample magnetometer. The sonocatalytic performance was evaluated by degradation of methylene blue under ultrasonic irradiation.The Fe3O4/CuO/ZnO/NGP showed superior sonocatalytic activity than the Fe3O4/CuO/ZnO materials. They also showed high stability and can be easily separated from the reaction system for recycling process.
Structural, Optical, and Vibrational Properties of ZnO Microrods Deposited on Silicon Substrate

NASA Astrophysics Data System (ADS)

Lahlouh, Bashar I.; Ikhmayies, Shadia J.; Juwhari, Hassan K.

2018-03-01

Zinc oxide (ZnO) microrod films deposited by spray pyrolysis on silicon substrate at 350 ± 5°C have been studied and evaluated, and compared with thin films deposited by electron beam to confirm the identity of the studied samples. The films were characterized using different techniques. The microrod structure was studied and confirmed by scanning electron microscopy. Fourier-transform infrared (FTIR) spectroscopy and x-ray diffraction analysis confirmed successful deposition of ZnO thin films with the expected wurtzite structure. Reflectance data showed a substantial drop across the whole studied wavelength range. The photoluminescence (PL) spectra of the studied samples showed a peak at ˜ 360 nm, representing a signature of ZnO. The shift in the PL peak position is due to defects and other species present in the films, as confirmed by FTIR and energy-dispersive x-ray spectroscopy results.
Effect of copper and nickel doping on the optical and structural properties of ZnO

NASA Astrophysics Data System (ADS)

Muǧlu, G. Merhan; Sarıtaş, S.; ćakıcı, T.; Şakar, B.; Yıldırım, M.

2017-02-01

The present study is focused on the Cu doped ZnO and Ni doped ZnO dilute magnetic semiconductor thin films. ZnO:Cu and ZnO:Ni thin films were grown by Chemically Spray Pyrolysis (CSP) method on glass substrates. Optical analysis of the films was done spectral absorption and transmittance measurements by UV-Vis double beam spectrophotometer technique. The structure, morphology, topology and elemental analysis of ZnO:Cu and ZnO:Ni dilute magnetic thin films were investigated by X-ray diffraction (XRD), Raman Analysis, field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM) techniques, respectively. Also The magnetic properties of the ZnO:Ni thin film was investigated by vibrating sample magnetometer (VSM) method. VSM measurements of ZnO:Ni thin film showed that the ferromagnetic behavior.
Synthesis and characterization of nanocrystalline Co-Fe-Nb-Ta-B alloy

NASA Astrophysics Data System (ADS)

Raanaei, Hossein; Fakhraee, Morteza

2017-09-01

In this research work, structural and magnetic evolution of Co57Fe13Nb8Ta4B18 alloy, during mechanical alloying process, have been investigated by using, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, electron dispersive X-ray spectroscopy, differential thermal analysis and also vibrating sample magnetometer. It is observed that at 120 milling time, the crystallite size reaches to about 7.8 nm. Structural analyses show that, the solid solution of the initial powder mixture occurs at160 h milling time. The coercivity behavior demonstrates a rise, up to 70 h followed by decreasing tendency up to final stage of milling process. Thermal analysis of 160 h milling time sample reveals two endothermic peaks. The characterization of annealed milled sample for 160 h milling time at 427 °C shows crystallite size growth accompanied by increasing in saturation magnetization.
Effect of substrate temperature in the synthesis of BN nanostructures

NASA Astrophysics Data System (ADS)

Sajjad, M.; Zhang, H. X.; Peng, X. Y.; Feng, P. X.

2011-06-01

Boron nitride (BN) nanostructures were grown on molybdenum discs at different substrate temperatures using the short-pulse laser plasma deposition technique. Large numbers of randomly oriented nanorods of fiber-like structures were obtained. The variation in the length and diameter of the nanorods as a function of the substrate temperature was systematically studied. The surface morphologies of the samples were studied using scanning electron microscopy. Energy dispersive x-ray spectroscopy confirmed that both the elements boron and nitrogen are dominant in the nanostructure. The x-ray diffraction (XRD) technique was used to analyse BN phases. The XRD peak that appeared at 26° showed the presence of hexagonal BN phase, whereas the peak at 44° was related to cubic BN content in the samples. Raman spectroscopic analysis showed vibrational modes of sp2- and sp3-type bonding in the sample. The Raman spectra agreed well with XRD results.
Raman and X-Ray Investigation of High-Temperature Methane in the Diamond Anvil Cell

NASA Astrophysics Data System (ADS)

Spaulding, D.; Weck, G.; Loubeyre, P.; Mezouar, M.

2016-12-01

The chemistry and equations of state of simple molecular systems are of extreme importance to planetary astrophysics and for accurate characterization of reaction products and pathways at high pressures and temperatures. Simple molecules such as H2O, CO2 and CH4 are model systems for understanding the effects of pressure on chemical bonding. Here we present recent work to conduct fine-scale studies of the vibrational, chemical and structural properties of CH4 at pressures and temperatures up to 12 GPa and 1000K, with particular attention to behavior in the vicinity of the melting curve. We present results from resistive and laser-heating experiments, coupled with Raman spectroscopy. In addition, high P/T synchrotron powder x-ray diffraction provides tight constraints on melting and solid structure. Our results favor a somewhat higher melting curve and lower dissociative stability limit for the CH4 molecule than other recent work.
Removal of selected pharmaceuticals from aqueous solution using magnetic chitosan: sorption behavior and mechanism.

PubMed

Zhang, Yalei; Shen, Zhe; Dai, Chaomeng; Zhou, Xuefei

2014-11-01

A novel-modified magnetic chitosan adsorbent was used to remove selected pharmaceuticals, i.e., diclofenac (DCF) and clofibric acid (CA) and carbamazepine (CBZ), from aqueous solutions. The characterization of magnetic chitosan was achieved by scanning electron and transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, vibrating sample magnetometer, and nitrogen sorption analysis. The magnetic chitosan had effective sorption affinity for DCF and CA but no sorption of CBZ was observed. The sorption capacities of CA and DCF in the individual solutions were 191.2 and 57.5 mg/g, respectively. While in mixed solution, DCF showed higher sorption affinity. Sorption kinetics indicated a quick equilibrium reached within 2 min. Lower solution pH values were found to be advantageous for the adsorption process. The sorption efficacy of CA declined significantly with increasing inorganic salt concentration. However, sorption performance of DCF was stable under different ionic strength conditions.
Two-photon x-ray diffraction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stohr, J.

The interference pattern of a circular photon source has long been used to define the optical diffraction limit. Here we show the breakdown of conventional x-ray diffraction theory for the fundamental case of a “source”, consisting of a back-illuminated thin film in a circular aperture. When the conventional spontaneous x-ray scattering by atoms in the film is replaced at high incident intensity by stimulated resonant scattering, the film becomes the source of cloned photon twins and the diffraction pattern becomes self-focused beyond the diffraction limit. Furthermore, the case of cloned photon pairs is compared to and distinguished from entangled photonmore » pairs or biphotons.« less
Two-photon x-ray diffraction

DOE PAGES

Stohr, J.

2017-01-11

The interference pattern of a circular photon source has long been used to define the optical diffraction limit. Here we show the breakdown of conventional x-ray diffraction theory for the fundamental case of a “source”, consisting of a back-illuminated thin film in a circular aperture. When the conventional spontaneous x-ray scattering by atoms in the film is replaced at high incident intensity by stimulated resonant scattering, the film becomes the source of cloned photon twins and the diffraction pattern becomes self-focused beyond the diffraction limit. Furthermore, the case of cloned photon pairs is compared to and distinguished from entangled photonmore » pairs or biphotons.« less
Characterization of X80 and X100 Microalloyed Pipeline Steel Using Quantitative X-ray Diffraction

NASA Astrophysics Data System (ADS)

Wiskel, J. B.; Li, X.; Ivey, D. G.; Henein, H.

2018-06-01

Quantitative X-ray diffraction characterization of four (4) X80 and three (3) X100 microalloyed steels was undertaken. The effect of through-thickness position, processing parameters, and composition on the measured crystallite size, microstrain, and J index (relative magnitude of crystallographic texture) was determined. Microstructure analysis using optical microscopy, scanning electron microscopy, transmission electron microscopy, and electron-backscattered diffraction was also undertaken. The measured value of microstrain increased with increasing alloy content and decreasing cooling interrupt temperature. Microstructural features corresponding to crystallite size in the X80 steels were both above and below the detection limit for quantitative X-ray diffraction. The X100 steels consistently exhibited microstructure features below the crystallite size detection limit. The yield stress of each steel increased with increasing microstrain. The increase in microstrain from X80 to X100 is also associated with a change in microstructure from predominantly polygonal ferrite to bainitic ferrite.
Crystal growth, structural, optical, spectral and thermal studies of tris(L-phenylalanine)L-phenylalaninium nitrate: a new organic nonlinear optical material.

PubMed

Prakash, M; Geetha, D; Lydia Caroline, M

2011-10-15

Tris(L-phenylalanine)L-phenylalaninium nitrate, C(9)H(12)NO(2)(+)·NO(3)(-)·3C(9)H(11)NO(2) (TPLPN), a new organic nonlinear optical material was grown from aqueous solution by slow evaporation solution growth at room temperature. The grown crystals were subjected to powder X-ray diffraction and single crystal X-ray diffraction studies to confirm the crystalline nature and crystal structure. The modes of vibration of different molecular groups present in TPLPN have been identified by FTIR spectral analysis. The presence of hydrogen and carbon in the grown crystal were confirmed by using proton and carbon nuclear magnetic resonance (NMR) spectral analyses. The optical transmission spectral study establishes good transmitting ability of the crystal in the entire visible region. The thermogravimetric (TG) and differential thermal analyses (DTA) were carried out to understand the thermal stability of the sample. The nonlinear optical property of the compound observed using Kurtz powder second harmonic generation test assets the suitability of the grown material for the frequency conversion of laser radiation of Nd:YAG. Copyright © 2011 Elsevier B.V. All rights reserved.
Growth, crystalline perfection, spectral and optical characterization of a novel optical material: l-tryptophan p-nitrophenol trisolvate single crystal.

PubMed

Sivakumar, N; Srividya, J; Mohana, J; Anbalagan, G

2015-03-15

l-tryptophan p-nitrophenol trisolvate (LTPN), an organic nonlinear optical material was synthesized using ethanol-water mixed solvent and the crystals were grown by a slow solvent evaporation method. The crystal structure and morphology were studied by single crystal X-ray diffraction analysis. The crystalline perfection of the LTPN crystal was analyzed by high-resolution X-ray diffraction study. The molecular structure of the crystal was confirmed by observing the various characteristic functional groups of the material using vibrational spectroscopy. The cut-off wavelength, optical transmission, refractive index and band gap energy were determined using UV-visible data. The variation of refractive index with wavelength shows the normal behavior. The second harmonic generation of the crystal was confirmed and the efficiency was measured using Kurtz Perry powder method. Single and multiple shot methods were employed to measure surface laser damage of the crystal. The photoluminescence spectral study revealed that the emission may be associated with the radiative recombination of trapped electrons and holes. Microhardness measurements revealed that LTPN belongs to a soft material category. Copyright © 2014 Elsevier B.V. All rights reserved.
1D cyanide complexes with 2-pyridinemethanol: Synthesis, crystal structures and spectroscopic properties

NASA Astrophysics Data System (ADS)

Sayın, Elvan; Kürkçüoğlu, Güneş Süheyla; Yeşilel, Okan Zafer; Hökelek, Tuncer

2015-12-01

Two new one-dimensional coordination polymers, [Cu(hmpH)2Pd(μ-CN)2(CN)2]n (1) and [Cu(hmpH)2Pt(μ-CN)2(CN)2]n (2), (hmpH = 2-pyridinemethanol), have been synthesized and characterized by vibrational (FT-IR and Raman) spectroscopy, single crystal X-ray diffraction, thermal and elemental analyses techniques. Single crystal X-ray diffraction analysis indicates that complexes 1 and 2 are isomorphous and isostructural, and crystallize in the triclinic system and P-1 space group. The Pd(II) or Pt(II) ions are four coordinated with four cyanide-carbon atoms in a square planar geometry. Cu(II) ion displays a distorted octahedral coordination by two N-atoms and two O-atoms of hmpH ligands, two bridging cyanide groups. In one dimensional structure of the complexes, [M(CN)4]2- (M = Pd(II) or Pt(II)) anions and [Cu(hmpH)2]2+ cations are linked via bridging cyanide ligands. In the complexes, the presence of intramolecular C-H⋯M (M = Pd(II) or Pt(II)) interactions with distance values of 3.00-2.95 Å are established, respectively.
Microwave synthesis and electrochemical characterization of Mn/Ni mixed oxide for supercapacitor application

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prasankumar, T.; Jose, Sujin P., E-mail: sujamystica@yahoo.com; Ilangovan, R.

Nanostructured Mn/Ni mixed metal oxide was synthesized at ambient temperature by facile microwave irradiation technique. The crystal structure and surface morphology were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. X-ray diffraction analysis confirmed the formation of Mn/Ni mixed oxide in rhombohedral phase and the grain size calculated was found to be 87 nm. The irregular spherical morphology of the prepared sample was exhibited by the SEM images. The characteristic peaks of FTIR at about 630 cm{sup −1} and 749 cm{sup −1} were attributed to the Mn-O and Ni-O stretching vibrations respectively. The presence of both Mn and Ni inmore » the prepared sample was validated by the EDS spectra which in turn confirmed the formation of mixed oxide. Cyclic voltammetry and galvanostatic chargedischarge measurements were employed to investigate the electrochemical performance of the mixed oxide. The cyclic voltammetry curves demonstrated good capacitive performance of the sample in the potential window −0.2V to 0.9V. The charge discharge study revealed the suitability of the prepared mixed oxide for the fabrication of supercapacitor electrode.« less
The effect of chemical modification on the physico-chemical characteristics of halloysite: FTIR, XRF, and XRD studies

NASA Astrophysics Data System (ADS)

Szczepanik, Beata; Słomkiewicz, Piotr; Garnuszek, Magdalena; Czech, Kamil; Banaś, Dariusz; Kubala-Kukuś, Aldona; Stabrawa, Ilona

2015-03-01

The effect of chemical modification of halloysite from a Polish strip mine "Dunino" on the chemical composition and structure of this clay mineral was studied using infrared spectroscopy (ATR FT-IR), wavelength dispersive X-ray fluorescence (WDXRF), and X-ray powder diffraction (XRPD) methods. The results obtained by the WDXRF technique confirm that the content of silica and alumina was the highest for bleached halloysite samples and the lowest for acid-treated halloysite. A higher content of Fe2O3 in comparison to halloysite samples coming from other countries was observed for raw halloysite samples. XRPD diffraction pattern obtained for raw halloysite confirmed the presence of halloysite, kaolinite, hematite, and calcite minerals in the sample. Bleaching the halloysite removes (or significantly reduces) the content of other minerals present in the raw halloysite. The FT-IR spectra of the studied halloysite samples show in the 3700-3600 cm-1 region well-defined hydroxyl stretching bands characteristic for the kaolin-group minerals and bands associated with the vibrations of the aluminium-silicon skeleton in the 1400-1000 cm-1 region. Modifying halloysite with 4-chloro-aniline causes successive incorporation of amine into the BH sample.
Synthesis, crystal structures and spectroscopic properties of triazine-based hydrazone derivatives; a comparative experimental-theoretical study.

PubMed

Arshad, Muhammad Nadeem; Bibi, Aisha; Mahmood, Tariq; Asiri, Abdullah M; Ayub, Khurshid

2015-04-03

We report here a comparative theoretical and experimental study of four triazine-based hydrazone derivatives. The hydrazones are synthesized by a three step process from commercially available benzil and thiosemicarbazide. The structures of all compounds were determined by using the UV-Vis., FT-IR, NMR (1H and 13C) spectroscopic techniques and finally confirmed unequivocally by single crystal X-ray diffraction analysis. Experimental geometric parameters and spectroscopic properties of the triazine based hydrazones are compared with those obtained from density functional theory (DFT) studies. The model developed here comprises of geometry optimization at B3LYP/6-31G (d, p) level of DFT. Optimized geometric parameters of all four compounds showed excellent correlations with the results obtained from X-ray diffraction studies. The vibrational spectra show nice correlations with the experimental IR spectra. Moreover, the simulated absorption spectra also agree well with experimental results (within 10-20 nm). The molecular electrostatic potential (MEP) mapped over the entire stabilized geometries of the compounds indicated their chemical reactivates. Furthermore, frontier molecular orbital (electronic properties) and first hyperpolarizability (nonlinear optical response) were also computed at the B3LYP/6-31G (d, p) level of theory.
Structural, spectroscopic and theoretical studies on 3,4,7,8-tetramethyl-1,10-phenantroline complex with picric acid

NASA Astrophysics Data System (ADS)

Bator, G.; Sobczyk, L.; Sawka-Dobrowolska, W.; Wuttke, J.; Pawlukojć, A.; Grech, E.; Nowicka-Scheibe, J.

2013-01-01

The almost planar molecular complex, formed by 3,4,7,8-tetramethyl-phenantroline (Me4phen) and picric acid (2,4,6-trinitrophenol, PA), has been investigated by using X-ray diffraction, vibrational spectroscopy, tunnel splitting and theoretical analysis. In the crystal of Me4phen·PA two short bifurcated hydrogen bonds N+-H···O- [2.6238(14) Å] and N+-H···N [2.6898(15) Å] are created. Infra-red spectra show the hydrogen bonds are short. The neutron backscattering spectrum of Me4phenṡPA at 3 K shows two tunneling peaks at ca. 1 and 3 μeV. The number of the peaks is consistent with X-ray diffraction studies, which disclosed the inequivalence of methyl groups in the crystal structure. The comparison of the tunnel splitting for neat Me4phen and for its complex with picric acid indicates that in the latter case the methyl groups are more strongly engaged in the intermolecular interactions, particularly with nitro group oxygen atoms of picric acid, leading to an increase of the CH3 rotational barrier height.

High Pressure Low Temperature X-Ray Diffraction Studies of UO2 and UN single crystals.

NASA Astrophysics Data System (ADS)

Antonio, Daniel; Mast, Daniel; Lavina, Barbara; Gofryk, Krzysztof

Uranium dioxide is the most commonly used nuclear fuel material in commercial reactors, while uranium nitride also has many thermal and physical properties that make it attractive for potential use in reactors. Both have a cubic fcc lattice structure at ambient conditions and transition to antiferromagnetic order at low temperature. UO2 is a Mott insulator that orders in a complex non-collinear 3k magnetic structure at about 30 K, while UN has appreciable conductivity and orders in a simpler 1k magnetic structure below 52 K. Both compounds are characterized by strong magneto-structural interactions, understanding of which is vital for modeling their thermo-physical properties. While UO2 and UN have been extensively studied at and above room temperature, little work has been done to directly study the structure of these materials at low temperatures where magnetic interactions are dominant. In the course of our systematic studies on magneto vibrational behavior of UO2 and UN, here we present our recent results of high pressure X-Ray Diffraction (up to 35 GPa) measured below the Neel temperature using synchrotron radiation. Work supported by the Department of Energy, Office of Basic Energy Sciences, Materials Sciences, and Engineering Division.
Diffractive-refractive optics: (+,-,-,+) X-ray crystal monochromator with harmonics separation.

PubMed

Hrdý, Jaromír; Mikulík, Petr; Oberta, Peter

2011-03-01

A new kind of two channel-cut crystals X-ray monochromator in dispersive (+,-,-,+) position which spatially separates harmonics is proposed. The diffracting surfaces are oriented so that the diffraction is inclined. Owing to refraction the diffracted beam is sagittally deviated. The deviation depends on wavelength and is much higher for the first harmonics than for higher harmonics. This leads to spatial harmonics separation. The idea is supported by ray-tracing simulation.
Growth, structure, and magnetic properties of {gamma}-Fe{sub 2}O{sub 3} epitaxial films on MgO

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gao, Y.; Kim, Y.J.; Thevuthasan, S.

1997-04-01

Single-crystal epitaxial thin films of {gamma}-Fe{sub 2}O{sub 3}(001) have been grown on MgO(001) using oxygen-plasma-assisted molecular beam epitaxy. The structure and magnetic properties of these films have been characterized by a variety of techniques, including reflection high-energy electron diffraction (RHEED), low-energy electron diffraction (LEED), x-ray photoelectron spectroscopy and x-ray photoelectron/Auger electron diffraction (XPD/AED), vibrating sample magnetometry, and ferromagnetic resonance. Real-time RHEED reveals that the film growth occurs in a layer-by-layer fashion. The {gamma}-Fe{sub 2}O{sub 3}(001) film surface exhibits a (1{times}1) LEED pattern. The growth of {gamma}-Fe{sub 2}O{sub 3} films at 450 {degree}C is accompanied by significant Mg outdiffusion. AED ofmore » Mg KLL Auger emission reveals that Mg substitutionally incorporates in the {gamma}-Fe{sub 2}O{sub 3} lattice, occupying the octahedral sites. Magnetic moments are {approximately}2300 G and {approximately}4500 G for {gamma}-Fe{sub 2}O{sub 3} films grown at 250{degree}C and 450{degree}C, respectively. The high magnetic moment for the films grown at 450{degree}C could be attributed to the high degree of structural order of the films and Mg substitution at octahedral sites. {copyright} {ital 1997 American Institute of Physics.}« less
Room Temperature Elastic Moduli and Vickers Hardness of Hot-Pressed LLZO Cubic Garnet

DTIC Science & Technology

2012-01-01

polishing compounds, Leco, St. Joseph, MI). X - ray diffraction and scanning electron microscopy (SEM) The microstructure of the hot-pressed specimens...was examined on uncoated fracture surfaces by SEM with an accelerating voltage of 1 and 3 kV. Phase purity was evaluated from X - ray diffraction data...the micro- structure appeared to be homogenous for the two hot- pressed LLZO specimens included in this study (Fig. 1). X - ray diffraction confirmed that
Method for improve x-ray diffraction determinations of residual stress in nickel-base alloys

DOEpatents

Berman, Robert M.; Cohen, Isadore

1990-01-01

A process for improving the technique of measuring residual stress by x-ray diffraction in pieces of nickel-base alloys which comprises covering part of a predetermined area of the surface of a nickel-base alloy with a dispersion, exposing the covered and uncovered portions of the surface of the alloy to x-rays by way of an x-ray diffractometry apparatus, making x-ray diffraction determinations of the exposed surface, and measuring the residual stress in the alloy based on these determinations. The dispersion is opaque to x-rays and serves a dual purpose since it masks off unsatisfactory signals such that only a small portion of the surface is measured, and it supplies an internal standard by providing diffractogram peaks comparable to the peaks of the nickel alloy so that the alloy peaks can be very accurately located regardless of any sources of error external to the sample.
Crystal structure and density of helium to 232 kbar

NASA Technical Reports Server (NTRS)

Mao, H. K.; Wu, Y.; Jephcoat, A. P.; Hemley, R. J.; Bell, P. M.; Bassett, W. A.

1988-01-01

The properties of helium and hydrogen at high pressure are topics of great interest to the understanding of planetary interiors. These materials constitute 95 percent of the entire solar system. A technique was presented for the measurement of X-ray diffraction from single-crystals of low-Z condenses gases in a diamond-anvil cell at high pressure. The first such single-crystal X-ray diffraction measurements on solid hydrogen to 26.5 GPa were presented. The application of this technique to the problem of the crystal structure, equation of state, and phase diagram of solid helium is reported. Crucial for X-ray diffraction studies of these materials is the use of a synchrotron radiation source which provides high brillance, narrow collimation of the incident and diffracted X-ray beams to reduce the background noise, and energy-dispersive diffraction techniques with polychromatic (white) radiation, which provides high detection efficiency.
Structural investigation of porcine stomach mucin by X-ray fiber diffraction and homology modeling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Veluraja, K., E-mail: veluraja@msuniv.ac.in; Vennila, K.N.; Umamakeshvari, K.

Research highlights: {yields} Techniques to get oriented mucin fibre. {yields} X-ray fibre diffraction pattern for mucin. {yields} Molecular modeling of mucin based on X-ray fibre diffraction pattern. -- Abstract: The basic understanding of the three dimensional structure of mucin is essential to understand its physiological function. Technology has been developed to achieve orientated porcine stomach mucin molecules. X-ray fiber diffraction of partially orientated porcine stomach mucin molecules show d-spacing signals at 2.99, 4.06, 4.22, 4.7, 5.37 and 6.5 A. The high intense d-spacing signal at 4.22 A is attributed to the antiparallel {beta}-sheet structure identified in the fraction of themore » homology modeled mucin molecule (amino acid residues 800-980) using Nidogen-Laminin complex structure as a template. The X-ray fiber diffraction signal at 6.5 A reveals partial organization of oligosaccharides in porcine stomach mucin. This partial structure of mucin will be helpful in establishing a three dimensional structure for the whole mucin molecule.« less
A nearly on-axis spectroscopic system for simultaneously measuring UV-visible absorption and X-ray diffraction in the SPring-8 structural genomics beamline.

PubMed

Sakaguchi, Miyuki; Kimura, Tetsunari; Nishida, Takuma; Tosha, Takehiko; Sugimoto, Hiroshi; Yamaguchi, Yoshihiro; Yanagisawa, Sachiko; Ueno, Go; Murakami, Hironori; Ago, Hideo; Yamamoto, Masaki; Ogura, Takashi; Shiro, Yoshitsugu; Kubo, Minoru

2016-01-01

UV-visible absorption spectroscopy is useful for probing the electronic and structural changes of protein active sites, and thus the on-line combination of X-ray diffraction and spectroscopic analysis is increasingly being applied. Herein, a novel absorption spectrometer was developed at SPring-8 BL26B2 with a nearly on-axis geometry between the X-ray and optical axes. A small prism mirror was placed near the X-ray beamstop to pass the light only 2° off the X-ray beam, enabling spectroscopic analysis of the X-ray-exposed volume of a crystal during X-ray diffraction data collection. The spectrometer was applied to NO reductase, a heme enzyme that catalyzes NO reduction to N2O. Radiation damage to the heme was monitored in real time during X-ray irradiation by evaluating the absorption spectral changes. Moreover, NO binding to the heme was probed via caged NO photolysis with UV light, demonstrating the extended capability of the spectrometer for intermediate analysis.
Investigating the Effects of Low Temperature Annealing of Amorphous Corrosion Resistant Alloys.

DTIC Science & Technology

1980-11-01

Ray Diffraction.................................................... 6 Differential Scanning Calorimetry....................................... 9...17 LIST OF FIGURES Figure 1. X- Ray Diffraction Results From Fe32Ni 36Cr 4P 2 B Annealed for One Hour at...Various Temperatures (Cr Ka Radiation) ................................. 7 Figure 2. X- Ray Diffraction Results From FeU2NiaeCr14SieB Annealed for One
Evidence from x-ray and neutron powder diffraction patterns that the so-called icosahedral and decagonal quasicrystals of MnAl(6) and other alloys are twinned cubic crystals.

PubMed

Pauling, L

1987-06-01

It is shown that the x-ray powder diffraction patterns of rapidly quenched MnAl(6) and Mg(32)(Al,Zn)(49) and the neutron powder diffraction pattern of MnAl(6) are compatible with the proposed 820-atom primitive cubic structure [Pauling, L. (1987) Phys. Rev. Lett. 58, 365-368]. The values found for the edge of the unit cube are 23.365 A (x-ray) and 23.416 A (neutron) for MnAl(6) and 24.313 A (x-ray) for Mg(32)(Al,Zn)(49).
Evidence from x-ray and neutron powder diffraction patterns that the so-called icosahedral and decagonal quasicrystals of MnAl6 and other alloys are twinned cubic crystals

PubMed Central

Pauling, Linus

1987-01-01

It is shown that the x-ray powder diffraction patterns of rapidly quenched MnAl6 and Mg32(Al,Zn)49 and the neutron powder diffraction pattern of MnAl6 are compatible with the proposed 820-atom primitive cubic structure [Pauling, L. (1987) Phys. Rev. Lett. 58, 365-368]. The values found for the edge of the unit cube are 23.365 Å (x-ray) and 23.416 Å (neutron) for MnAl6 and 24.313 Å (x-ray) for Mg32(Al,Zn)49. PMID:16593841
Ba2Mg(BO3)2:Bi3+ - A new phosphor with ultraviolet light emission

NASA Astrophysics Data System (ADS)

Lakshminarasimhan, N.; Jayakiruba, S.; Prabhavathi, K.

2017-10-01

Ultraviolet light emission was observed in a new Ba2Mg(BO3)2:Bi3+ phosphor. Bi3+ substitution for Ba2+ in the lattice was supplemented with K+ to maintain the charge neutrality. The samples of the formula Ba2-2xBixKxMg(BO3)2 [x = 0, 0.001, 0.01, 0.02, and 0.05] synthesized by solid state reaction were characterized using powder X-ray diffraction for their phase formation. Raman and diffuse reflectance UV-Vis spectroscopic techniques were used to obtain information on the vibrational modes and optical properties, respectively. The room temperature photoluminescence measurements revealed an ultraviolet emission at 370 nm when excited using 304 nm wavelength and the Stokes shift is 5868 cm-1.
High-energy X-ray diffraction using the Pixium 4700 flat-panel detector.

PubMed

Daniels, J E; Drakopoulos, M

2009-07-01

The Pixium 4700 detector represents a significant step forward in detector technology for high-energy X-ray diffraction. The detector design is based on digital flat-panel technology, combining an amorphous Si panel with a CsI scintillator. The detector has a useful pixel array of 1910 x 2480 pixels with a pixel size of 154 microm x 154 microm, and thus it covers an effective area of 294 mm x 379 mm. Designed for medical imaging, the detector has good efficiency at high X-ray energies. Furthermore, it is capable of acquiring sequences of images at 7.5 frames per second in full image mode, and up to 60 frames per second in binned region of interest modes. Here, the basic properties of this detector applied to high-energy X-ray diffraction are presented. Quantitative comparisons with a widespread high-energy detector, the MAR345 image plate scanner, are shown. Other properties of the Pixium 4700 detector, including a narrow point-spread function and distortion-free image, allows for the acquisition of high-quality diffraction data at high X-ray energies. In addition, high frame rates and shutterless operation open new experimental possibilities. Also provided are the necessary data for the correction of images collected using the Pixium 4700 for diffraction purposes.
Crystallization and preliminary X-ray diffraction analysis of a chitin-binding domain of hyperthermophilic chitinase from Pyrococcus furiosus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nakamura, Tsutomu; Ishikawa, Kazuhiko; Hagihara, Yoshihisa

The expression, purification and preliminary X-ray diffraction studies of a chitin-binding domain of the chitinase from P. furiosus are reported. The crystallization and preliminary X-ray diffraction analysis of the chitin-binding domain of chitinase from a hyperthermophilic archaeon, Pyrococcus furiosus, are reported. The recombinant protein was prepared using an Escherichia coli overexpression system and was crystallized by the hanging-drop vapour-diffusion method. An X-ray diffraction data set was collected to 1.70 Å resolution. The crystal belonged to space group P4{sub 3}2{sub 1}2 or P4{sub 1}2{sub 1}2. The unit-cell parameters were determined to be a = b = 48.8, c = 85.0 Å.
Long-Wavelength X-Ray Diffraction and Its Applications in Macromolecular Crystallography.

PubMed

Weiss, Manfred S

2017-01-01

For many years, diffraction experiments in macromolecular crystallography at X-ray wavelengths longer than that of Cu-K α (1.54 Å) have been largely underappreciated. Effects caused by increased X-ray absorption result in the fact that these experiments are more difficult than the standard diffraction experiments at short wavelengths. However, due to the also increased anomalous scattering of many biologically relevant atoms, important additional structural information can be obtained. This information, in turn, can be used for phase determination, for substructure identification, in molecular replacement approaches, as well as in structure refinement. This chapter reviews the possibilities and the difficulties associated with such experiments, and it provides a short description of two macromolecular crystallography synchrotron beam lines dedicated to long-wavelength X-ray diffraction experiments.
Synthesis and Characterization of Mixed Iron-Manganese Oxide Nanoparticles and Their Application for Efficient Nickel Ion Removal from Aqueous Samples

PubMed Central

Serra, Antonio; Monteduro, Anna Grazia; Padmanabhan, Sanosh Kunjalukkal; Licciulli, Antonio; Bonfrate, Valentina; Salvatore, Luca; Calcagnile, Lucio

2017-01-01

Mixed iron-manganese oxide nanoparticles, synthesized by a simple procedure, were used to remove nickel ion from aqueous solutions. Nanostructures, prepared by using different weight percents of manganese, were characterized by transmission electron microscopy, selected area diffraction, X-ray diffraction, Raman spectroscopy, and vibrating sample magnetometry. Adsorption/desorption isotherm curves demonstrated that manganese inclusions enhance the specific surface area three times and the pores volume ten times. This feature was crucial to decontaminate both aqueous samples and food extracts from nickel ion. Efficient removal of Ni2+ was highlighted by the well-known dimethylglyoxime test and by ICP-MS analysis and the possibility of regenerating the nanostructure was obtained by a washing treatment in disodium ethylenediaminetetraacetate solution. PMID:28804670
Structural properties and electrochemistry of α-LiFeO2

NASA Astrophysics Data System (ADS)

Abdel-Ghany, A. E.; Mauger, A.; Groult, H.; Zaghib, K.; Julien, C. M.

2012-01-01

In this work, we study the physico-chemistry and electrochemistry of lithium ferrite synthesized by solid-state reaction. Characterization included X-ray diffraction (XRD), scanning electronic microscopy (SEM), Raman scattering (RS), Fourier transform infrared spectroscopy (FTIR), and SQUID magnetometry. XRD peaks gradually sharpen with increasing firing temperature; all the diffraction peaks can be indexed to the cubic α-LiFeO2 phase (Fm3m space group) with the refined cell parameter a = 4.155 Å. RS and FTIR spectra show the vibrational modes due to covalent Fe-O bonds and the Li-cage mode at low-frequency. The electrochemical properties of Li/LiFeO2 are revisited along with the post-mortem analysis of the positive electrode material using XRD and Raman experiments.
Data processing software suite SITENNO for coherent X-ray diffraction imaging using the X-ray free-electron laser SACLA.

PubMed

Sekiguchi, Yuki; Oroguchi, Tomotaka; Takayama, Yuki; Nakasako, Masayoshi

2014-05-01

Coherent X-ray diffraction imaging is a promising technique for visualizing the structures of non-crystalline particles with dimensions of micrometers to sub-micrometers. Recently, X-ray free-electron laser sources have enabled efficient experiments in the `diffraction before destruction' scheme. Diffraction experiments have been conducted at SPring-8 Angstrom Compact free-electron LAser (SACLA) using the custom-made diffraction apparatus KOTOBUKI-1 and two multiport CCD detectors. In the experiments, ten thousands of single-shot diffraction patterns can be collected within several hours. Then, diffraction patterns with significant levels of intensity suitable for structural analysis must be found, direct-beam positions in diffraction patterns determined, diffraction patterns from the two CCD detectors merged, and phase-retrieval calculations for structural analyses performed. A software suite named SITENNO has been developed to semi-automatically apply the four-step processing to a huge number of diffraction data. Here, details of the algorithm used in the suite are described and the performance for approximately 9000 diffraction patterns collected from cuboid-shaped copper oxide particles reported. Using the SITENNO suite, it is possible to conduct experiments with data processing immediately after the data collection, and to characterize the size distribution and internal structures of the non-crystalline particles.
Data processing software suite SITENNO for coherent X-ray diffraction imaging using the X-ray free-electron laser SACLA

PubMed Central

Sekiguchi, Yuki; Oroguchi, Tomotaka; Takayama, Yuki; Nakasako, Masayoshi

2014-01-01

Coherent X-ray diffraction imaging is a promising technique for visualizing the structures of non-crystalline particles with dimensions of micrometers to sub-micrometers. Recently, X-ray free-electron laser sources have enabled efficient experiments in the ‘diffraction before destruction’ scheme. Diffraction experiments have been conducted at SPring-8 Angstrom Compact free-electron LAser (SACLA) using the custom-made diffraction apparatus KOTOBUKI-1 and two multiport CCD detectors. In the experiments, ten thousands of single-shot diffraction patterns can be collected within several hours. Then, diffraction patterns with significant levels of intensity suitable for structural analysis must be found, direct-beam positions in diffraction patterns determined, diffraction patterns from the two CCD detectors merged, and phase-retrieval calculations for structural analyses performed. A software suite named SITENNO has been developed to semi-automatically apply the four-step processing to a huge number of diffraction data. Here, details of the algorithm used in the suite are described and the performance for approximately 9000 diffraction patterns collected from cuboid-shaped copper oxide particles reported. Using the SITENNO suite, it is possible to conduct experiments with data processing immediately after the data collection, and to characterize the size distribution and internal structures of the non-crystalline particles. PMID:24763651
Phase diagram and high-pressure boundary of hydrate formation in the ethane-water system.

PubMed

Kurnosov, Alexander V; Ogienko, Andrey G; Goryainov, Sergei V; Larionov, Eduard G; Manakov, Andrey Y; Lihacheva, Anna Y; Aladko, Eugeny Y; Zhurko, Fridrikh V; Voronin, Vladimir I; Berger, Ivan F; Ancharov, Aleksei I

2006-11-02

Dissociation temperatures of gas hydrate formed in the ethane-water system were studied at pressures up to 1500 MPa. In situ neutron diffraction analysis and X-ray diffraction analysis in a diamond anvil cell showed that the gas hydrate formed in the ethane-water system at 340, 700, and 1840 MPa and room temperature belongs to the cubic structure I (CS-I). Raman spectra of C-C vibrations of ethane molecules in the hydrate phase, as well as the spectra of solid and liquid ethane under high-pressure conditions were studied at pressures up to 6900 MPa. Within 170-3600 MPa Raman shift of the C-C vibration mode of ethane in the hydrate phase did not show any discontinuities, which could be evidence of possible phase transformations. The upper pressure boundary of high-pressure hydrate existence was discovered at the pressure of 3600 MPa. This boundary corresponds to decomposition of the hydrate to solid ethane and ice VII. The type of phase diagram of ethane-water system was proposed in the pressure range of hydrate formation (0-3600 MPa).

Spectroscopic imaging, diffraction, and holography with x-ray photoemission

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1992-02-01

X-ray probes are capable of determining the spatial structure of an atom in a specific chemical state, over length scales from about a micron all the way down to atomic resolution. Examples of these probes include photoemission microscopy, energy-dependent photoemission diffraction, photoelectron holography, and X-ray absorption microspectroscopy. Although the method of image formation, chemical-state sensitivity, and length scales can be very different, these X-ray techniques share a common goal of combining a capability for structure determination with chemical-state specificity. This workshop will address recent advances in holographic, diffraction, and direct imaging techniques using X-ray photoemission on both theoretical and experimentalmore » fronts. A particular emphasis will be on novel structure determinations with atomic resolution using photoelectrons.« less
An instrument for in situ coherent x-ray studies of metal-organic vapor phase epitaxy of III-nitrides.

PubMed

Ju, Guangxu; Highland, Matthew J; Yanguas-Gil, Angel; Thompson, Carol; Eastman, Jeffrey A; Zhou, Hua; Brennan, Sean M; Stephenson, G Brian; Fuoss, Paul H

2017-03-01

We describe an instrument that exploits the ongoing revolution in synchrotron sources, optics, and detectors to enable in situ studies of metal-organic vapor phase epitaxy (MOVPE) growth of III-nitride materials using coherent x-ray methods. The system includes high-resolution positioning of the sample and detector including full rotations, an x-ray transparent chamber wall for incident and diffracted beam access over a wide angular range, and minimal thermal sample motion, giving the sub-micron positional stability and reproducibility needed for coherent x-ray studies. The instrument enables surface x-ray photon correlation spectroscopy, microbeam diffraction, and coherent diffraction imaging of atomic-scale surface and film structure and dynamics during growth, to provide fundamental understanding of MOVPE processes.
An instrument for in situ coherent x-ray studies of metal-organic vapor phase epitaxy of III-nitrides

NASA Astrophysics Data System (ADS)

Ju, Guangxu; Highland, Matthew J.; Yanguas-Gil, Angel; Thompson, Carol; Eastman, Jeffrey A.; Zhou, Hua; Brennan, Sean M.; Stephenson, G. Brian; Fuoss, Paul H.

2017-03-01

We describe an instrument that exploits the ongoing revolution in synchrotron sources, optics, and detectors to enable in situ studies of metal-organic vapor phase epitaxy (MOVPE) growth of III-nitride materials using coherent x-ray methods. The system includes high-resolution positioning of the sample and detector including full rotations, an x-ray transparent chamber wall for incident and diffracted beam access over a wide angular range, and minimal thermal sample motion, giving the sub-micron positional stability and reproducibility needed for coherent x-ray studies. The instrument enables surface x-ray photon correlation spectroscopy, microbeam diffraction, and coherent diffraction imaging of atomic-scale surface and film structure and dynamics during growth, to provide fundamental understanding of MOVPE processes.
Combined X-ray and neutron fibre diffraction studies of biological and synthetic polymers

NASA Astrophysics Data System (ADS)

Parrot, I. M.; Urban, V.; Gardner, K. H.; Forsyth, V. T.

2005-08-01

The fibrous state is a natural one for polymer molecules which tend to assume regular helical conformations rather than the globular structures characteristic of many proteins. Fibre diffraction therefore has broad application to the study of a wide range of biological and synthetic polymers. The purpose of this paper is to illustrate the general scope of the method and in particular to demonstrate the impact of a combined approach involving both X-ray and neutron diffraction methods. While the flux of modern X-ray synchrotron radiation sources allows high quality datasets to be recorded with good resolution within a very short space of time, neutron studies can provide unique information through the ability to locate hydrogen or deuterium atoms that are often difficult or impossible to locate using X-ray methods. Furthermore, neutron fibre diffraction methods can, through the ability to selectively label specific parts of a structure, be used to highlight novel aspects of polymer structure that can not be studied using X-rays. Two examples are given. The first describes X-ray and neutron diffraction studies of conformational transitions in DNA. The second describes structural studies of the synthetic high-performance polymer poly(p-phenylene terephthalamide) (PPTA), known commercially as Kevlar® or Twaron®.
Conceptual Design for Time-Resolved X-ray Diffraction in a Single Laser-Driven Compression Experiment

NASA Astrophysics Data System (ADS)

Benedetti, Laura Robin; Eggert, J. H.; Kilkenny, J. D.; Bradley, D. K.; Bell, P. M.; Palmer, N. E.; Rygg, J. R.; Boehly, T. R.; Collins, G. W.; Sorce, C.

2017-06-01

Since X-ray diffraction is the most definitive method for identifying crystalline phases of a material, it is an important technique for probing high-energy-density materials during laser-driven compression experiments. We are developing a design for collecting several x-ray diffraction datasets during a single laser-driven experiment, with a goal of achieving temporal resolution better than 1ns. The design combines x-ray streak cameras, for a continuous temporal record of diffraction, with fast x-ray imagers, to collect several diffraction patterns with sufficient solid angle range and resolution to identify crystalline texture. Preliminary experiments will be conducted at the Omega laser and then implemented at the National Ignition Facility. We will describe the status of the conceptual design, highlighting tradeoffs in the design process. We will also discuss the technical issues that must be addressed in order to develop a successful experimental platform. These include: Facility-specific geometric constraints such as unconverted laser light and target alignment; EMP issues when electronic diagnostics are close to the target; X-ray source requirements; and detector capabilities. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344, LLNL-ABS-725146.
IDATEN and G-SITENNO: GUI-assisted software for coherent X-ray diffraction imaging experiments and data analyses at SACLA.

PubMed

Sekiguchi, Yuki; Yamamoto, Masaki; Oroguchi, Tomotaka; Takayama, Yuki; Suzuki, Shigeyuki; Nakasako, Masayoshi

2014-11-01

Using our custom-made diffraction apparatus KOTOBUKI-1 and two multiport CCD detectors, cryogenic coherent X-ray diffraction imaging experiments have been undertaken at the SPring-8 Angstrom Compact free electron LAser (SACLA) facility. To efficiently perform experiments and data processing, two software suites with user-friendly graphical user interfaces have been developed. The first is a program suite named IDATEN, which was developed to easily conduct four procedures during experiments: aligning KOTOBUKI-1, loading a flash-cooled sample into the cryogenic goniometer stage inside the vacuum chamber of KOTOBUKI-1, adjusting the sample position with respect to the X-ray beam using a pair of telescopes, and collecting diffraction data by raster scanning the sample with X-ray pulses. Named G-SITENNO, the other suite is an automated version of the original SITENNO suite, which was designed for processing diffraction data. These user-friendly software suites are now indispensable for collecting a large number of diffraction patterns and for processing the diffraction patterns immediately after collecting data within a limited beam time.
Dynamical diffraction imaging (topography) with X-ray synchrotron radiation

NASA Technical Reports Server (NTRS)

Kuriyama, M.; Steiner, B. W.; Dobbyn, R. C.

1989-01-01

By contrast to electron microscopy, which yields information on the location of features in small regions of materials, X-ray diffraction imaging can portray minute deviations from perfect crystalline order over larger areas. Synchrotron radiation-based X-ray optics technology uses a highly parallel incident beam to eliminate ambiguities in the interpretation of image details; scattering phenomena previously unobserved are now readily detected. Synchrotron diffraction imaging renders high-resolution, real-time, in situ observations of materials under pertinent environmental conditions possible.
Development of Thin Films as Potential Structural Cathodes to Enable Multifunctional Energy-Storage Structural Composite Batteries for the U.S. Army’s Future Force

DTIC Science & Technology

2011-09-01

glancing angle X - ray diffraction (GAXRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), and electrochemical...Emission SEM FWHM full width at half maximum GAXRD glancing angle X - ray diffraction H3COCH2CH2OH 2-methoxyethanol LiMn2O4 lithium manganese oxide...were characterized by scanning electron microscopy (SEM), X - ray diffraction (XRD), and atomic force microscopy (AFM). In addition,
Structural elucidation and magnetic behavior evaluation of Cu-Cr doped BaCo-X hexagonal ferrites

NASA Astrophysics Data System (ADS)

Azhar Khan, Muhammad; Hussain, Farhat; Rashid, Muhammad; Mahmood, Asif; Ramay, Shahid M.; Majeed, Abdul

2018-04-01

Ba2-xCuxCo2CryFe28-yO46 (x = 0.0, 0.1, 0.2, 0.3, 0.4, y = 0.0, 0.2, 0.4, 0.6, 0.8) X-type hexagonal ferrites were synthesized via micro-emulsion route. The techniques which were applied to characterize the prepared samples are as follows: X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Dielectric measurements and vibrating sample magnetometer (VSM). The structural parameters i.e. lattice constant (a, c), cell volume (V), X-ray density, bulk density and crystallite size of all the prepared samples were obtained using XRD analysis. The lattice parameters 'a' and 'c' increase from 5.875 Å to 5.934 Å and 83.367 Å to 83.990 Å respectively. The crystallite size of investigated samples lies in the range of 28-32 nm. The magnetic properties of all samples have been calculated by vibrating sample magnetometer (VSM) analysis. The increase in coercivity (Hc) was observed with the increase of doping contents. It was observed that the coercivity (Hc) of all prepared samples is inversely related to the crystalline size which reflects that all materials are super-paramagnetic. The dielectric parameters i.e. dielectric constant, dielectric loss, tangent loss etc were obtained in the frequency range of 1 MHz-3 GHz and followed the Maxwell-Wagner's model. The significant variation the dielectric parameters are observed with increasing frequency. The maximum Q value is obtained at ∼2 GHz due to which these materials are used for high frequency multilayer chip inductors.
Simultaneous X-ray fluorescence and scanning X-ray diffraction microscopy at the Australian Synchrotron XFM beamline

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, Michael W. M.; Phillips, Nicholas W.; van Riessen, Grant A.

2016-08-11

Owing to its extreme sensitivity, quantitative mapping of elemental distributionsviaX-ray fluorescence microscopy (XFM) has become a key microanalytical technique. The recent realisation of scanning X-ray diffraction microscopy (SXDM) meanwhile provides an avenue for quantitative super-resolved ultra-structural visualization. The similarity of their experimental geometries indicates excellent prospects for simultaneous acquisition. Here, in both step- and fly-scanning modes, robust, simultaneous XFM-SXDM is demonstrated.
Structural and magnetic properties of chromium doped zinc ferrite

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sebastian, Rintu Mary; Thankachan, Smitha; Xavier, Sheena

2014-01-28

Zinc chromium ferrites with chemical formula ZnCr{sub x}Fe{sub 2−x}O{sub 4} (x = 0.0, 0.2, 0.4, 0.6, 0.8, 1.0) were prepared by Sol - Gel technique. The structural as well as magnetic properties of the synthesized samples have been studied and reported here. The structural characterizations of the samples were analyzed by using X – Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM), and Transmission Electron Microscope (TEM). The single phase spinel cubic structure of all the prepared samples was tested by XRD and FTIR. The particle size was observed to decrease from 18.636 nm to 6.125more » nm by chromium doping and induced a tensile strain in all the zinc chromium mixed ferrites. The magnetic properties of few samples (x = 0.0, 0.4, 1.0) were investigated using Vibrating Sample Magnetometer (VSM)« less
An Excel Spreadsheet for a One-Dimensional Fourier Map in X-ray Crystallography

ERIC Educational Resources Information Center

Clegg, William

2004-01-01

The teaching of crystal structure determination with single-crystal X-ray diffraction at undergraduate level faces numerous challenges. Single-crystal X-ray diffraction is used in a vast range of chemical research projects and forms the basis for a high proportion of structural results that are presented to high-school, undergraduate, and graduate…
Laser-induced Multi-energy Processing in Diamond Growth

DTIC Science & Technology

2012-05-01

microscopy (SEM) and energy dispersive X - ray (EDX) measurements, Drs. Yi Liu and Shah Valloppilly from Nebraska Center for Materials and Nanoscience...NCMN) at UNL for help on X - Ray diffraction (XRD) measurements, and Professor Steve W. Martin and Dr. Young Sik Kim from the Department of Material...spectroscopy and X - ray diffraction ................... 62 4.4 Conclusions
Two-dimensional time-resolved X-ray diffraction study of liquid/solid fraction and solid particle size in Fe-C binary system with an electrostatic levitator furnace

NASA Astrophysics Data System (ADS)

Yonemura, M.; Okada, J.; Watanabe, Y.; Ishikawa, T.; Nanao, S.; Shobu, T.; Toyokawa, H.

2013-03-01

Liquid state provides functions such as matter transport or a reaction field and plays an important role in manufacturing processes such as refining, forging or welding. However, experimental procedures are significantly difficult for an observation of solidification process of iron and iron-based alloys in order to identify rapid transformations subjected to fast temperature evolution. Therefore, in order to study the solidification in iron and iron-based alloys, we considered a combination of high energy X-ray diffraction measurements and an electrostatic levitation method (ESL). In order to analyze the liquid/solid fraction, the solidification of melted spherical specimens was measured at a time resolution of 0.1 seconds during rapid cooling using the two-dimensional time-resolved X-ray diffraction. Furthermore, the observation of particle sizes and phase identification was performed on a trial basis using X-ray small angle scattering with X-ray diffraction.
Imaging single cells in a beam of live cyanobacteria with an X-ray laser.

PubMed

van der Schot, Gijs; Svenda, Martin; Maia, Filipe R N C; Hantke, Max; DePonte, Daniel P; Seibert, M Marvin; Aquila, Andrew; Schulz, Joachim; Kirian, Richard; Liang, Mengning; Stellato, Francesco; Iwan, Bianca; Andreasson, Jakob; Timneanu, Nicusor; Westphal, Daniel; Almeida, F Nunes; Odic, Dusko; Hasse, Dirk; Carlsson, Gunilla H; Larsson, Daniel S D; Barty, Anton; Martin, Andrew V; Schorb, Sebastian; Bostedt, Christoph; Bozek, John D; Rolles, Daniel; Rudenko, Artem; Epp, Sascha; Foucar, Lutz; Rudek, Benedikt; Hartmann, Robert; Kimmel, Nils; Holl, Peter; Englert, Lars; Duane Loh, Ne-Te; Chapman, Henry N; Andersson, Inger; Hajdu, Janos; Ekeberg, Tomas

2015-02-11

There exists a conspicuous gap of knowledge about the organization of life at mesoscopic levels. Ultra-fast coherent diffractive imaging with X-ray free-electron lasers can probe structures at the relevant length scales and may reach sub-nanometer resolution on micron-sized living cells. Here we show that we can introduce a beam of aerosolised cyanobacteria into the focus of the Linac Coherent Light Source and record diffraction patterns from individual living cells at very low noise levels and at high hit ratios. We obtain two-dimensional projection images directly from the diffraction patterns, and present the results as synthetic X-ray Nomarski images calculated from the complex-valued reconstructions. We further demonstrate that it is possible to record diffraction data to nanometer resolution on live cells with X-ray lasers. Extension to sub-nanometer resolution is within reach, although improvements in pulse parameters and X-ray area detectors will be necessary to unlock this potential.
Optical, electrical and ferromagnetic studies of ZnO:Fe diluted magnetic semiconductor nanoparticles for spintronic applications

NASA Astrophysics Data System (ADS)

Elilarassi, R.; Chandrasekaran, G.

2017-11-01

In the present investigation, diluted magnetic semiconductor (Zn1-xFexO) nanoparticles with different doping concentrations (x = 0, 0.02, 0.04, 0.06, and 0.08) were successfully synthesized by sol-gel auto-combustion method. The crystal structure, morphology, optical, electrical and magnetic properties of the prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive analysis using x-rays (EDAX), ultraviolet-visible spectrophotometer, fluorescence spectroscope (FS), vibrating sample magnetometer (VSM) and broad band dielectric spectrometer (BDS). XRD results reveal that all the samples possess hexagonal wurtzite crystal structure with good crystalline quality. The absence of impurity phases divulge that Fe ions are well incorporated into the ZnO crystal lattice. The substitutional incorporation of Fe3+ at Zn sites is reflected in optical absorption spectra of the samples. Flouorescence spectra of the samples show a strong near-band edge related UV emission as well as defect related visible emissions. The semiconducting behavior of the samples has been confirmed through electrical conductivity measurements. Magnetic measurements indicated that all the samples possess ferromagnetism at room temperature.
Investigations on structural, vibrational and dielectric properties of nanosized Cu doped Mg-Zn ferrites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yadav, Anand; Department of Physics, MEDICAPS Institute of Science and Technology, Pithampur 453331; Rajpoot, Rambabu

2016-05-23

Transition metal Cu{sup 2+} doped Mg-Zn ferrite [Mg{sub 0.5}Zn{sub 0.5-x}Cu{sub x}Fe{sub 2}O{sub 4} (0.0 ≤ x ≤ 0.5)] were prepared by sol gel auto combustion (SGAC) method to probe the structural, vibrational and electrical properties. X-ray diffraction (XRD) pattern reveals a single-phase cubic spinel structure without the presence of any secondary phase corresponding to other structure. The average particle size of the parent Mg{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} is found to be ~29.8 nm and is found to increase with Cu{sup 2+} doping. Progressive reduction in lattice parameter of Mg{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} has been observed due to difference inmore » ionic radii of cations with improved Cu doping. Spinel cubic structure is further confirmed by Raman spectroscopy. Small shift in Raman modes towards higher wave number has been observed in doped Mg-Zn ferrites. The permittivity and dielectric loss decreases at lower doping and increases at higher order doping of Cu{sup 2+}.« less
Removal of Cu(II) metal ions from aqueous solution by amine functionalized magnetic nanoparticles

NASA Astrophysics Data System (ADS)

Kothavale, V. P.; Karade, V. C.; Waifalkar, P. P.; Sahoo, Subasa C.; Patil, P. S.; Patil, P. B.

2018-04-01

The adsorption behavior of Cu(II) metal cations was investigated on the amine functionalized magnetic nanoparticles (MNPs). TheMNPs were synthesized by thesolvothermal method and functionalized with (3-Aminopropyl)triethoxysilane (APTES). MNPs were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and vibrating sample magnetometer (VSM). The MNPs have pure magnetite phase with particle size around 10-12 nm. MNPs exhibits superparamagnetic behavior with asaturation magnetization of 68 emu/g. The maximum 38 % removal efficiency was obtained for Cu(II) metal ions from the aqueous solution.
Synthesis and characterization of graphene quantum dots/cobalt ferrite nanocomposite

NASA Astrophysics Data System (ADS)

Ramachandran, Shilpa; Sathishkumar, M.; Kothurkar, Nikhil K.; Senthilkumar, R.

2018-02-01

A facile method has been developed for the synthesis of a graphene quantum dots/cobalt ferrite nanocomposite. Graphene quantum dots (GQDs) were synthesized by a simple bottom-up method using citric acid, followed by the co-precipitation of cobalt ferrite nanoparticles on the graphene quantum dots. The morphology, structural analysis, optical properties, magnetic properties were investigated using transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV-vis absorption spectroscopy, fluorescence spectroscopy, vibrating sample magnetometry (VSM) measurements. The synthesized nanocomposite showed good fluorescence and superparamagnetic properties, which are important for biomedical applications.
Amorphous Phase Characterization Through X-Ray Diffraction Profile Modeling: Implications for Amorphous Phases in Gale Crater Rocks and Soils

NASA Technical Reports Server (NTRS)

Achilles, C. N.; Downs, G. W.; Downs, R. T.; Morris, R. V.; Rampe, E. B.; Ming, D. W.; Chipera, S. J.; Blake, D. F.; Vaniman, D. T.; Bristow, T. F.;

2018-01-01

The CheMin X-ray diffraction instrument on the Mars Science Laboratory rover has analyzed 18 rock and soil samples in Gale crater. Diffraction data allow for the identification of major crystalline phases based on the positions and intensities of well-defined peaks and also provides information regarding amorphous and poorly-ordered materials based on the shape and positions of broad scattering humps. The combination of diffraction data, elemental chemistry from APXS (Alpha Particle X-ray Spectrometer) and evolved gas analyses (EGA) from SAM (Sample Analysis at Mars) help constrain possible amorphous materials present in each sample (e.g., glass, opal, iron oxides, sulfates) but are model dependent. We present a novel method to characterize amorphous material in diffraction data and, through this approach, aim to characterize the phases collectively producing the amorphous profiles in CheMin diffraction data. This method may be applied to any diffraction data from samples containing X-ray amorphous materials, not just CheMin datasets, but we re-strict our discussion to Martian-relevant amorphous phases and diffraction data measured by CheMin or CheMin-like instruments.

X-ray Diffraction, Big and Small

NASA Image and Video Library

2012-10-30

A conventional X-ray diffraction instrument left is the size of a large refrigerator, in contrast to the compact size of the Chemistry and Mineralogy CheMin instrument on NASA Curiosity rover top right.
Coherent diffraction of single Rice Dwarf virus particles using hard X-rays at the Linac Coherent Light Source

PubMed Central

Munke, Anna; Andreasson, Jakob; Aquila, Andrew; Awel, Salah; Ayyer, Kartik; Barty, Anton; Bean, Richard J.; Berntsen, Peter; Bielecki, Johan; Boutet, Sébastien; Bucher, Maximilian; Chapman, Henry N.; Daurer, Benedikt J.; DeMirci, Hasan; Elser, Veit; Fromme, Petra; Hajdu, Janos; Hantke, Max F.; Higashiura, Akifumi; Hogue, Brenda G.; Hosseinizadeh, Ahmad; Kim, Yoonhee; Kirian, Richard A.; Reddy, Hemanth K.N.; Lan, Ti-Yen; Larsson, Daniel S.D.; Liu, Haiguang; Loh, N. Duane; Maia, Filipe R.N.C.; Mancuso, Adrian P.; Mühlig, Kerstin; Nakagawa, Atsushi; Nam, Daewoong; Nelson, Garrett; Nettelblad, Carl; Okamoto, Kenta; Ourmazd, Abbas; Rose, Max; van der Schot, Gijs; Schwander, Peter; Seibert, M. Marvin; Sellberg, Jonas A.; Sierra, Raymond G.; Song, Changyong; Svenda, Martin; Timneanu, Nicusor; Vartanyants, Ivan A.; Westphal, Daniel; Wiedorn, Max O.; Williams, Garth J.; Xavier, Paulraj Lourdu; Yoon, Chun Hong; Zook, James

2016-01-01

Single particle diffractive imaging data from Rice Dwarf Virus (RDV) were recorded using the Coherent X-ray Imaging (CXI) instrument at the Linac Coherent Light Source (LCLS). RDV was chosen as it is a well-characterized model system, useful for proof-of-principle experiments, system optimization and algorithm development. RDV, an icosahedral virus of about 70 nm in diameter, was aerosolized and injected into the approximately 0.1 μm diameter focused hard X-ray beam at the CXI instrument of LCLS. Diffraction patterns from RDV with signal to 5.9 Ångström were recorded. The diffraction data are available through the Coherent X-ray Imaging Data Bank (CXIDB) as a resource for algorithm development, the contents of which are described here. PMID:27478984
Signal-to-noise and radiation exposure considerations in conventional and diffraction x-ray microscopy

DOE PAGES

Huang, Xiaojing; Miao, Huijie; Steinbrener, Jan; ...

2009-01-01

Using a signal-to-noise ratio estimation based on correlations between multiple simulated images, we compare the dose efficiency of two soft x-ray imaging systems: incoherent brightfield imaging using zone plate optics in a transmission x-ray microscope (TXM), and x-ray diffraction microscopy (XDM) where an image is reconstructed from the far-field coherent diffraction pattern. In XDM one must computationally phase weak diffraction signals; in TXM one suffers signal losses due to the finite numerical aperture and efficiency of the optics. In simulations with objects representing isolated cells such as yeast, we find that XDM has the potential for delivering equivalent resolution imagesmore » using fewer photons. As a result, this can be an important advantage for studying radiation-sensitive biological and soft matter specimens.« less
Utilizing broadband X-rays in a Bragg coherent X-ray diffraction imaging experiment

DOE PAGES

Cha, Wonsuk; Liu, Wenjun; Harder, Ross; ...

2016-07-26

A method is presented to simplify Bragg coherent X-ray diffraction imaging studies of complex heterogeneous crystalline materials with a two-stage screening/imaging process that utilizes polychromatic and monochromatic coherent X-rays and is compatible with in situ sample environments. Coherent white-beam diffraction is used to identify an individual crystal particle or grain that displays desired properties within a larger population. A three-dimensional reciprocal-space map suitable for diffraction imaging is then measured for the Bragg peak of interest using a monochromatic beam energy scan that requires no sample motion, thus simplifyingin situchamber design. This approach was demonstrated with Au nanoparticles and will enable,more » for example, individual grains in a polycrystalline material of specific orientation to be selected, then imaged in three dimensions while under load.« less
Coherent diffraction of single Rice Dwarf virus particles using hard X-rays at the Linac Coherent Light Source

DOE PAGES

Munke, Anna; Andreasson, Jakob; Aquila, Andrew; ...

2016-08-01

Single particle diffractive imaging data from Rice Dwarf Virus (RDV) were recorded using the Coherent X-ray Imaging (CXI) instrument at the Linac Coherent Light Source (LCLS). RDV was chosen as it is a well-characterized model system, useful for proof-of-principle experiments, system optimization and algorithm development. RDV, an icosahedral virus of about 70 nm in diameter, was aerosolized and injected into the approximately 0.1 μm diameter focused hard X-ray beam at the CXI instrument of LCLS. Diffraction patterns from RDV with signal to 5.9 Ångström were recorded. Here, the diffraction data are available through the Coherent X-ray Imaging Data Bank (CXIDB)more » as a resource for algorithm development, the contents of which are described here.« less
Influence of neutron irradiation on the microstructure of nuclear graphite: An X-ray diffraction study

NASA Astrophysics Data System (ADS)

Zhou, Z.; Bouwman, W. G.; Schut, H.; van Staveren, T. O.; Heijna, M. C. R.; Pappas, C.

2017-04-01

Neutron irradiation effects on the microstructure of nuclear graphite have been investigated by X-ray diffraction on virgin and low doses (∼ 1.3 and ∼ 2.2 dpa), high temperature (750° C) irradiated samples. The diffraction patterns were interpreted using a model, which takes into account the turbostratic disorder. Besides the lattice constants, the model introduces two distinct coherent lengths in the c-axis and the basal plane, that characterise the volumes from which X-rays are scattered coherently. The methodology used in this work allows to quantify the effect of irradiation damage on the microstructure of nuclear graphite seen by X-ray diffraction. The results show that the changes of the deduced structural parameters are in agreement with previous observations from electron microscopy, but not directly related to macroscopic changes.
Utilizing broadband X-rays in a Bragg coherent X-ray diffraction imaging experiment.

PubMed

Cha, Wonsuk; Liu, Wenjun; Harder, Ross; Xu, Ruqing; Fuoss, Paul H; Hruszkewycz, Stephan O

2016-09-01

A method is presented to simplify Bragg coherent X-ray diffraction imaging studies of complex heterogeneous crystalline materials with a two-stage screening/imaging process that utilizes polychromatic and monochromatic coherent X-rays and is compatible with in situ sample environments. Coherent white-beam diffraction is used to identify an individual crystal particle or grain that displays desired properties within a larger population. A three-dimensional reciprocal-space map suitable for diffraction imaging is then measured for the Bragg peak of interest using a monochromatic beam energy scan that requires no sample motion, thus simplifying in situ chamber design. This approach was demonstrated with Au nanoparticles and will enable, for example, individual grains in a polycrystalline material of specific orientation to be selected, then imaged in three dimensions while under load.
Coherent diffraction of single Rice Dwarf virus particles using hard X-rays at the Linac Coherent Light Source.

PubMed

Munke, Anna; Andreasson, Jakob; Aquila, Andrew; Awel, Salah; Ayyer, Kartik; Barty, Anton; Bean, Richard J; Berntsen, Peter; Bielecki, Johan; Boutet, Sébastien; Bucher, Maximilian; Chapman, Henry N; Daurer, Benedikt J; DeMirci, Hasan; Elser, Veit; Fromme, Petra; Hajdu, Janos; Hantke, Max F; Higashiura, Akifumi; Hogue, Brenda G; Hosseinizadeh, Ahmad; Kim, Yoonhee; Kirian, Richard A; Reddy, Hemanth K N; Lan, Ti-Yen; Larsson, Daniel S D; Liu, Haiguang; Loh, N Duane; Maia, Filipe R N C; Mancuso, Adrian P; Mühlig, Kerstin; Nakagawa, Atsushi; Nam, Daewoong; Nelson, Garrett; Nettelblad, Carl; Okamoto, Kenta; Ourmazd, Abbas; Rose, Max; van der Schot, Gijs; Schwander, Peter; Seibert, M Marvin; Sellberg, Jonas A; Sierra, Raymond G; Song, Changyong; Svenda, Martin; Timneanu, Nicusor; Vartanyants, Ivan A; Westphal, Daniel; Wiedorn, Max O; Williams, Garth J; Xavier, Paulraj Lourdu; Yoon, Chun Hong; Zook, James

2016-08-01

Single particle diffractive imaging data from Rice Dwarf Virus (RDV) were recorded using the Coherent X-ray Imaging (CXI) instrument at the Linac Coherent Light Source (LCLS). RDV was chosen as it is a well-characterized model system, useful for proof-of-principle experiments, system optimization and algorithm development. RDV, an icosahedral virus of about 70 nm in diameter, was aerosolized and injected into the approximately 0.1 μm diameter focused hard X-ray beam at the CXI instrument of LCLS. Diffraction patterns from RDV with signal to 5.9 Ångström were recorded. The diffraction data are available through the Coherent X-ray Imaging Data Bank (CXIDB) as a resource for algorithm development, the contents of which are described here.
Preliminary small-angle X-ray scattering and X-ray diffraction studies of the BTB domain of lola protein from Drosophila melanogaster

NASA Astrophysics Data System (ADS)

Boyko, K. M.; Nikolaeva, A. Yu.; Kachalova, G. S.; Bonchuk, A. N.; Dorovatovskii, P. V.; Popov, V. O.

2017-11-01

The Drosophila genome has several dozens of transcription factors (TTK group) containing BTB domains assembled into octamers. The LOLA protein belongs to this family. The purification, crystallization, and preliminary X-ray diffraction and small-angle X-ray scattering (SAXS) studies of the BTB domain of this protein are reported. The crystallization conditions were found by the vapor-diffusion technique. A very low diffraction resolution (8.7 Å resolution) of the crystals was insufficient for the determination of the threedimensional structure of the BTB domain. The SAXS study demonstrated that the BTB domain of the LOLA protein exists as an octamer in solution.
Cryogenic x-ray diffraction microscopy utilizing high-pressure cryopreservation

NASA Astrophysics Data System (ADS)

Lima, Enju; Chushkin, Yuriy; van der Linden, Peter; Kim, Chae Un; Zontone, Federico; Carpentier, Philippe; Gruner, Sol M.; Pernot, Petra

2014-10-01

We present cryo x-ray diffraction microscopy of high-pressure-cryofixed bacteria and report high-convergence imaging with multiple image reconstructions. Hydrated D. radiodurans cells were cryofixed at 200 MPa pressure into ˜10-μm-thick water layers and their unstained, hydrated cellular environments were imaged by phasing diffraction patterns, reaching sub-30-nm resolutions with hard x-rays. Comparisons were made with conventional ambient-pressure-cryofixed samples, with respect to both coherent small-angle x-ray scattering and the image reconstruction. The results show a correlation between the level of background ice signal and phasing convergence, suggesting that phasing difficulties with frozen-hydrated specimens may be caused by high-background ice scattering.
Synchrotron X-ray powder diffraction data of LASSBio-1515: A new N-acylhydrazone derivative compound

NASA Astrophysics Data System (ADS)

Costa, F. N.; Braz, D.; Ferreira, F. F.; da Silva, T. F.; Barreiro, E. J.; Lima, L. M.; Colaço, M. V.; Kuplich, L.; Barroso, R. C.

2014-02-01

In this work, synchrotron X-ray powder diffraction data allowed for a successful indexing of LASSBio-1515 compound, candidate to analgesic and anti-inflammatory activity. X-ray powder diffraction data collected in transmission and high-throughput geometries were used to analyze this compound. The X-ray wavelength of the synchrotron radiation used in this study was determined to be λ=1.55054 Å. LASSBio-1515 was found to be monoclinic with space group P21/c and unit cell parameters a=11.26255(16) Å, b=12.59785(16) Å, c=8.8540(1) Å, β=90.5972(7)° and V=1256.17(3) Å3.
DOE Office of Scientific and Technical Information (OSTI.GOV)

Mokshin, A. V., E-mail: anatolii.mokshin@mail.ru; Khusnutdinoff, R. M., E-mail: khrm@mail.ru; Novikov, A. G.

The features of the microscopic structure, as well as one-particle and collective dynamics of liquid gallium in the temperature range from T = 313 to 1273 K, are studied on the p = 1.0 atm isobar. Detailed analysis of the data on diffraction of neutrons and X-rays, as well as the results of atomic dynamics simulation, lead to some conclusions about the structure. In particular, for preset conditions, gallium is in the equilibrium liquid phase showing no features of any stable local crystalline clusters. The pronounced asymmetry of the principle peak of the static structure factor and the characteristic “shoulder”more » in its right-hand part appearing at temperatures close to the melting point, which are clearly observed in the diffraction data, are due to the fact that the arrangement of the nearest neighbors of an arbitrary atom in the system is estimated statistically from the range of correlation length values and not by a single value as in the case of simple liquids. Compactly located dimers with a very short bond make a significant contribution to the statistics of nearest neighbors. The temperature dependence of the self-diffusion coefficient calculated from atomic dynamics simulation agrees well with the results obtained from experimental spectra of the incoherent scattering function. Interpolation of the temperature dependence of the self-diffusion coefficient on a logarithmic scale reveals two linear regions with a transition temperature of about 600 K. The spectra of the dynamic structure factor and spectral densities of the local current calculated by simulating the atomic dynamics indicate the existence of acoustic vibrations with longitudinal and transverse polarizations in liquid gallium, which is confirmed by experimental data on inelastic scattering of neutrons and X-rays. It is found that the vibrational density of states is completely reproduced by the generalized Debye model, which makes it possible to decompose the total vibrational motion into individual contributions associated with the formation of acoustic waves with longitudinal and transverse polarizations. Comparison of the heights of the low-frequency component and of the high-frequency peak in the spectral density of vibrational states also indicates a temperature of T ≈ 600 K, at which the diffusion type of one-particle dynamics changes to the vibrational type upon a decrease in temperature. It is demonstrated that the modified Einstein–Stokes relation can be derived using the generalized Debye model.« less
High-speed classification of coherent X-ray diffraction patterns on the K computer for high-resolution single biomolecule imaging.

PubMed

Tokuhisa, Atsushi; Arai, Junya; Joti, Yasumasa; Ohno, Yoshiyuki; Kameyama, Toyohisa; Yamamoto, Keiji; Hatanaka, Masayuki; Gerofi, Balazs; Shimada, Akio; Kurokawa, Motoyoshi; Shoji, Fumiyoshi; Okada, Kensuke; Sugimoto, Takashi; Yamaga, Mitsuhiro; Tanaka, Ryotaro; Yokokawa, Mitsuo; Hori, Atsushi; Ishikawa, Yutaka; Hatsui, Takaki; Go, Nobuhiro

2013-11-01

Single-particle coherent X-ray diffraction imaging using an X-ray free-electron laser has the potential to reveal the three-dimensional structure of a biological supra-molecule at sub-nanometer resolution. In order to realise this method, it is necessary to analyze as many as 1 × 10(6) noisy X-ray diffraction patterns, each for an unknown random target orientation. To cope with the severe quantum noise, patterns need to be classified according to their similarities and average similar patterns to improve the signal-to-noise ratio. A high-speed scalable scheme has been developed to carry out classification on the K computer, a 10PFLOPS supercomputer at RIKEN Advanced Institute for Computational Science. It is designed to work on the real-time basis with the experimental diffraction pattern collection at the X-ray free-electron laser facility SACLA so that the result of classification can be feedback for optimizing experimental parameters during the experiment. The present status of our effort developing the system and also a result of application to a set of simulated diffraction patterns is reported. About 1 × 10(6) diffraction patterns were successfully classificatied by running 255 separate 1 h jobs in 385-node mode.
High-speed classification of coherent X-ray diffraction patterns on the K computer for high-resolution single biomolecule imaging

PubMed Central

Tokuhisa, Atsushi; Arai, Junya; Joti, Yasumasa; Ohno, Yoshiyuki; Kameyama, Toyohisa; Yamamoto, Keiji; Hatanaka, Masayuki; Gerofi, Balazs; Shimada, Akio; Kurokawa, Motoyoshi; Shoji, Fumiyoshi; Okada, Kensuke; Sugimoto, Takashi; Yamaga, Mitsuhiro; Tanaka, Ryotaro; Yokokawa, Mitsuo; Hori, Atsushi; Ishikawa, Yutaka; Hatsui, Takaki; Go, Nobuhiro

2013-01-01

Single-particle coherent X-ray diffraction imaging using an X-ray free-electron laser has the potential to reveal the three-dimensional structure of a biological supra-molecule at sub-nanometer resolution. In order to realise this method, it is necessary to analyze as many as 1 × 106 noisy X-ray diffraction patterns, each for an unknown random target orientation. To cope with the severe quantum noise, patterns need to be classified according to their similarities and average similar patterns to improve the signal-to-noise ratio. A high-speed scalable scheme has been developed to carry out classification on the K computer, a 10PFLOPS supercomputer at RIKEN Advanced Institute for Computational Science. It is designed to work on the real-time basis with the experimental diffraction pattern collection at the X-ray free-electron laser facility SACLA so that the result of classification can be feedback for optimizing experimental parameters during the experiment. The present status of our effort developing the system and also a result of application to a set of simulated diffraction patterns is reported. About 1 × 106 diffraction patterns were successfully classificatied by running 255 separate 1 h jobs in 385-node mode. PMID:24121336
Elucidating the Wavelength Dependence of Phonon Scattering in Nanoparticle-Matrix Composites using Phonon Spectroscopy

DTIC Science & Technology

2016-07-11

composites with x - ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), Rutherford backscattering spectroscopy...RBS), particle-induced x - ray emission (PIXE), and energy dispersive x - ray spectroscopy (EDX). This work complements earlier works on CdSe...sample shows only In2Se3 and CdIn2Se4 XRD peaks (Figure 1.4e), it is stoichiometrically Figure 1.4. X - ray diffraction patterns of (a) γ-In2Se3
Applications of High Throughput (Combinatorial) Methodologies to Electronic, Magnetic, Optical, and Energy-Related Materials

DTIC Science & Technology

2013-06-17

of the films without having to fabricate capacitors. In addition, the use of X - ray diffraction (XRD) analysis enabled Chikyow et al.40 to identify an...effects of Al doping and annealing on the thermal stabil- ity of the Y2O3/Si gate stack were studied by X - ray photoemission spectroscopy (XPS) and X - ray ...the major diffraction features in the phase distribution. For a given structural phase, the X - ray peak intensity allows one to track the compositional
Aplanatic and quasi-aplanatic diffraction gratings

DOEpatents

Hettrick, M.C.

1987-09-14

A reflection diffraction grating having a series of transverse minute grooves of progressively varying spacing along a concave surface enables use of such gratings for x-ray or longer wavelength imaging of objects. The variable groove spacing establishes aplanatism or substantially uniform magnetification across the optical aperture. The grating may be sued, for example, in x-ray microscopes or telescopes of the imaging type and in x-ray microprobed. Increased spatial resolution and field of view may be realized in x-ray imaging. 5 figs.
An instrument for in situ coherent x-ray studies of metal-organic vapor phase epitaxy of III-nitrides

DOE PAGES

Ju, Guangxu; Highland, Matthew J.; Yanguas-Gil, Angel; ...

2017-03-21

Here, we describe an instrument that exploits the ongoing revolution in synchrotron sources, optics, and detectors to enable in situ studies of metal-organic vapor phase epitaxy (MOVPE) growth of III-nitride materials using coherent x-ray methods. The system includes high-resolution positioning of the sample and detector including full rotations, an x-ray transparent chamber wall for incident and diffracted beam access over a wide angular range, and minimal thermal sample motion, giving the sub-micron positional stability and reproducibility needed for coherent x-ray studies. The instrument enables surface x-ray photon correlation spectroscopy, microbeam diffraction, and coherent diffraction imaging of atomic-scale surface and filmmore » structure and dynamics during growth, to provide fundamental understanding of MOVPE processes.« less
Towards shot-noise limited diffraction experiments with table-top femtosecond hard x-ray sources.

PubMed

Holtz, Marcel; Hauf, Christoph; Weisshaupt, Jannick; Salvador, Antonio-Andres Hernandez; Woerner, Michael; Elsaesser, Thomas

2017-09-01

Table-top laser-driven hard x-ray sources with kilohertz repetition rates are an attractive alternative to large-scale accelerator-based systems and have found widespread applications in x-ray studies of ultrafast structural dynamics. Hard x-ray pulses of 100 fs duration have been generated at the Cu K α wavelength with a photon flux of up to 10 9 photons per pulse into the full solid angle, perfectly synchronized to the sub-100-fs optical pulses from the driving laser system. Based on spontaneous x-ray emission, such sources display a particular noise behavior which impacts the sensitivity of x-ray diffraction experiments. We present a detailed analysis of the photon statistics and temporal fluctuations of the x-ray flux, together with experimental strategies to optimize the sensitivity of optical pump/x-ray probe experiments. We demonstrate measurements close to the shot-noise limit of the x-ray source.
Towards shot-noise limited diffraction experiments with table-top femtosecond hard x-ray sources

PubMed Central

Holtz, Marcel; Hauf, Christoph; Weisshaupt, Jannick; Salvador, Antonio-Andres Hernandez; Woerner, Michael; Elsaesser, Thomas

2017-01-01

Table-top laser-driven hard x-ray sources with kilohertz repetition rates are an attractive alternative to large-scale accelerator-based systems and have found widespread applications in x-ray studies of ultrafast structural dynamics. Hard x-ray pulses of 100 fs duration have been generated at the Cu Kα wavelength with a photon flux of up to 109 photons per pulse into the full solid angle, perfectly synchronized to the sub-100-fs optical pulses from the driving laser system. Based on spontaneous x-ray emission, such sources display a particular noise behavior which impacts the sensitivity of x-ray diffraction experiments. We present a detailed analysis of the photon statistics and temporal fluctuations of the x-ray flux, together with experimental strategies to optimize the sensitivity of optical pump/x-ray probe experiments. We demonstrate measurements close to the shot-noise limit of the x-ray source. PMID:28795079

Synthesis, molecular structure, FT-IR and XRD investigations of 2-(4-chlorophenyl)-2-oxoethyl 2-chlorobenzoate: a comparative DFT study.

PubMed

Chidan Kumar, C S; Fun, Hoong Kun; Tursun, Mahir; Ooi, Chin Wei; Chandraju, Siddegowda; Quah, Ching Kheng; Parlak, Cemal

2014-04-24

2-(4-Chlorophenyl)-2-oxoethyl 2-chlorobenzoate has been synthesized, its structural and vibrational properties have been reported using FT-IR and single-crystal X-ray diffraction (XRD) studies. The conformational analysis, optimized geometric parameters, normal mode frequencies and corresponding vibrational assignments of the synthesized compound (C15H10Cl2O3) have been examined by means of Becke-3-Lee-Yang-Parr (B3LYP) density functional theory (DFT) method together with 6-31++G(d,p) basis set. Furthermore, reliable conformational investigation and vibrational assignments have been made by the potential energy surface (PES) and potential energy distribution (PED) analyses, respectively. Calculations are performed with two possible conformations. The title compound crystallizes in orthorhombic space group Pbca with the unit cell dimensions a=12.312(5) Å, b=8.103(3) Å, c=27.565(11) Å, V=2750.0(19) Å(3). B3LYP method provides satisfactory evidence for the prediction of vibrational wavenumbers and structural parameters. Copyright © 2014 Elsevier B.V. All rights reserved.
Vibrational spectra and structure of benzil and its 18O- and d 10-labelled derivatives: a quantum chemical and experimental study

NASA Astrophysics Data System (ADS)

Kolev, Tsonko M.; Stamboliyska, Bistra A.

2002-12-01

Geometry and vibrational spectroscopic data of benzil-d 0 benzil-d 10 and benzil- 18O calculated at various levels of theory (RHF/6-31G*, B3LYP/6-31G*, BLYP/6-31G*) are reported. The theoretical results are discussed mainly in terms of the comparisons with infrared (4000-100 cm -1) and Raman (4000-50 cm -1) spectral data. The calculated isotopic frequency shifts, induced by the 18O- and d 10-labeling, are in a good agreement with the measured values. A complete vibrational assignment was made with the help of ab initio force field calculations. The data thus obtained were used for reassigning some vibrational frequencies. The results of the optimized molecular structure obtained on the basis of RHF and the DFT calculations are presented and compared with the experimental X-ray diffraction for the benzil-d 0 single crystal. It turns out that the best structural parameters are predicted by the B3LYP/6-31G* method.
Vibrational spectra and structure of benzil and its 18O- and d10-labelled derivatives: a quantum chemical and experimental study.

PubMed

Kolev, Tsonko M; Stamboliyska, Bistra A

2002-12-01

Geometry and vibrational spectroscopic data of benzil-d0 benzil-d10 and benzil-18O calculated at various levels of theory (RHF/6-31G*, B3LYP/6-31G*, BLYP/6-31G*) are reported. The theoretical results are discussed mainly in terms of the comparisons with infrared (4000-100 cm(-1)) and Raman (4000-50 cm(-1)) spectral data. The calculated isotopic frequency shifts, induced by the 18O- and d10-labeling, are in a good agreement with the measured values. A complete vibrational assignment was made with the help of ab initio force field calculations. The data thus obtained were used for reassigning some vibrational frequencies. The results of the optimized molecular structure obtained on the basis of RHF and the DFT calculations are presented and compared with the experimental X-ray diffraction for the benzil-d0 single crystal. It turns out that the best structural parameters are predicted by the B3LYP/6-31G* method.
Crystal structure, vibrational and DFT simulation studies of melaminium dihydrogen phosphite monohydrate

NASA Astrophysics Data System (ADS)

Arjunan, V.; Kalaivani, M.; Marchewka, M. K.; Mohan, S.

2013-08-01

The crystal structure investigations of melamine with phosphorous acid, namely melaminium dihydrogenphosphite monohydrate (C3N6H7·H2PO3·H2O) have been investigated by means of single crystal X-ray diffraction method. The title compound crystallizes in monoclinic crystal system, and the space group is P21/c with a = 10.069 Å, b = 21.592 Å, c = 12.409 Å and Z = 12. The vibrational assignments and analysis of melaminium dihydrogen phosphite monohydrate have also been performed by FTIR, FT-Raman and far-infrared spectral studies. The quantum chemical simulations were performed with DFT (B3LYP) method using 6-31G**, cc-pVTZ, and 6-311++G** basis sets to determine the energy, structural, thermodynamic parameters and vibrational frequencies of melaminium dihydrogen phosphite monohydrate. The hydrogen atom from phosphorous acid was transferred to the melamine molecule giving the singly protonated melaminium cation. The ability of ions to form spontaneous three-dimensional structure through weak Osbnd H···O and Nsbnd H···O hydrogen bonds shows notable vibrational effects.
Phase-contrast x-ray imaging of microstructure and fatigue-crack propagation in single-crystal nickel-base superalloys

NASA Astrophysics Data System (ADS)

Husseini, Naji Sami

Single-crystal nickel-base superalloys are ubiquitous in demanding turbine-blade applications, and they owe their remarkable resilience to their dendritic, hierarchical microstructure and complex composition. During normal operations, they endure rapid low-stress vibrations that may initiate fatigue cracks. This failure mode in the very high-cycle regime is poorly understood, in part due to inadequate testing and diagnostic equipment. Phase-contrast imaging with coherent synchrotron x rays, however, is an emergent technique ideally suited for dynamic processes such as crack initiation and propagation. A specially designed portable ultrasonic-fatigue apparatus, coupled with x-ray radiography, allows real-time, in situ imaging while simulating service conditions. Three contrast mechanisms - absorption, diffraction, and phase contrast - span the immense breadth of microstructural features in superalloys. Absorption contrast is sensitive to composition and crack displacements, and diffraction contrast illuminates dislocation aggregates and crystallographic misorientations. Phase contrast enhances electron-density gradients and is particularly useful for fatigue-crack studies, sensitive to internal crack tips and openings less than one micrometer. Superalloy samples were imaged without external stresses to study microstructure and mosaicity. Maps of rhenium and tungsten concentrations revealed strong segregation to the center of dendrites, as manifested by absorption contrast. Though nominally single crystals, dendrites were misoriented from the bulk by a few degrees, as revealed by diffraction contrast. For dynamic studies of cyclic fatigue, superalloys were mounted in the portable ultrasonic-fatigue apparatus, subjected to a mean tensile stress of ˜50-150 MPa, and cycled in tension to initiate and propagate fatigue cracks. Radiographs were recorded every thousand cycles over the multimillion-cycle lifetime to measure micron-scale crack growth. Crack openings were very small, as determined by absorption and phase contrast, and suggested multiple fracture modes for propagation along {111} planes at room temperature, which was verified by finite element analysis. With increasing temperature, cracks became Mode I (perpendicular to the loading axis) in character and more sensitive to the microstructure. Advancing plastic zones ahead of crack tips altered the crystallographic quality, from which diffraction contrast anticipated initiation and propagation. These studies demonstrate the extreme sensitivity of x-ray radiography for detailed studies of superalloys and crack growth processes.
X-ray shearing interferometer

DOEpatents

Koch, Jeffrey A [Livermore, CA

2003-07-08

An x-ray interferometer for analyzing high density plasmas and optically opaque materials includes a point-like x-ray source for providing a broadband x-ray source. The x-rays are directed through a target material and then are reflected by a high-quality ellipsoidally-bent imaging crystal to a diffraction grating disposed at 1.times. magnification. A spherically-bent imaging crystal is employed when the x-rays that are incident on the crystal surface are normal to that surface. The diffraction grating produces multiple beams which interfere with one another to produce an interference pattern which contains information about the target. A detector is disposed at the position of the image of the target produced by the interfering beams.
Effect of Guest Atom Composition on the Structural and Vibrational Properties of the Type II Clathrate-Based Materials AxSi136, AxGe136 and AxSn136 (A = Na, K, Rb, Cs; 0 ≤ x ≤ 24).

PubMed

Xue, Dong; Myles, Charles W; Higgins, Craig

2016-08-11

Type II clathrates are interesting due to their potential thermoelectric applications. Powdered X-ray diffraction (XRD) data and density functional calculations for Na x Si 136 found a lattice contraction as x increases for 0 < x < 8 and an expansion as x increases for x > 8. This is explained by XRD data that shows that as x increases, the Si 28 cages are filled first for x < 8 and the Si 20 cages are then filled for x > 8. Motivated by this work, here we report the results of first-principles calculations of the structural and vibrational properties of the Type II clathrate compounds A x Si 136 , A x Ge 136 , and A x Sn 136 . We present results for the variation of the lattice constants, bulk moduli, and other structural parameters with x. These are contrasted for the Si, Ge, and Sn compounds and for guests A = Na, K, Rb, and Cs. We also present calculated results of phonon dispersion relations for Na₄Si 136 , Na₄Ge 136 , and Na₄Sn 136 and we compare these for the three materials. Finally, we present calculated results for the elastic constants in Na x Si 136 , Na x Ge 136 , and Na x Sn 136 for x = 4 and 8. These are compared for the three hosts, as well as for the two compositions.
Symposium N: Materials and Devices for Thermal-to-Electric Energy Conversion

DTIC Science & Technology

2010-08-24

X - ray diffraction, transmission electron microscopy, scanning electron microscopy, and dynamic light scattering. Thermal conductivity measurements...SEM), X - ray diffraction (XRD) measurements as well as Raman spectroscopy. The results from these techniques indicate a clear modification...was examined by using scanning electron microscope (SEM; HITACHI S-4500 model) attached with an energy dispersive x - ray spectroscopy. The electrical
Synthesis, crystal structure, vibrational spectra and theoretical calculations of quantum chemistry of a potential antimicrobial Meldrum's acid derivative

NASA Astrophysics Data System (ADS)

Campelo, M. J. M.; Freire, P. T. C.; Mendes Filho, J.; de Toledo, T. A.; Teixeira, A. M. R.; da Silva, L. E.; Bento, R. R. F.; Faria, J. L. B.; Pizani, P. S.; Gusmão, G. O. M.; Coutinho, H. D. M.; Oliveira, M. T. A.

2017-10-01

A new derivative of Meldrum's acid 5-((5-chloropyridin-2-ylamino)methylene)-2,2-dimethyl-1,3-dioxane-4,6-dione (CYMM) of molecular formula C12H11ClN2O4 was synthesized and structurally characterized using single crystal X-ray diffraction technique. The vibrational properties of the crystal were studied by Fourier Transform infrared (FT-IR), Fourier Transform Raman (FT-Raman) techniques and theoretical calculations of quantum chemistry using Density functional theory (DFT) and Density functional perturbation theory (DFPT). A comparison with experimental spectra allowed the assignment of all the normal modes. The descriptions of the normal modes were carried by means of potential energy distribution (PED). Additionally, analysis of the antimicrobial activity and antibiotic resistance modulatory activity was carried out to evaluate the antibacterial potential of the CYMM.
Terahertz spectra of l-phenylalanine and its monohydrate.

PubMed

Pan, Tingting; Li, Shaoping; Zou, Tao; Yu, Zheng; Zhang, Bo; Wang, Chenyang; Zhang, Jianbing; He, Mingxia; Zhao, Hongwei

2017-05-05

The low-frequency vibrational property of l-phenylalanine (l-Phe) and l-phenylalanine monohydrate (l-Phe·H 2 O) has been investigated by terahertz time-domain spectroscopy (THz-TDS) at room and low temperature ranging from 0.5 to 4.5THz. Distinctive THz absorption spectra of the two compounds were observed. Density functional theory (DFT) calculations based on the crystal structures have been performed to simulate the vibrational modes of l-Phe and l-Phe·H 2 O and the results agree well with the experimental observations. The study indicates that the characterized features of l-Phe mainly originate from the collective vibration of molecules. And the characterized features of l-Phe·H 2 O mainly come from hydrogen bond interactions between l-Phe and water molecules. l-Phe and l-Phe·H 2 O were also verified by differential scanning calorimetry and thermogravimetry (DSC-TG) and powder X-ray diffraction (PXRD) examinations. Copyright © 2017. Published by Elsevier B.V.
Molecular structure and vibrational spectra of Bis(melaminium) terephthalate dihydrate: A DFT computational study

NASA Astrophysics Data System (ADS)

Tanak, Hasan; Marchewka, Mariusz K.; Drozd, Marek

2013-03-01

The experimental and theoretical vibrational spectra of Bis(melaminium) terephthalate dihydrate were studied. The Fourier transform infrared (FT-IR) spectra of the Bis(melaminium) terephthalate dihydrate and its deuterated analogue were recorded in the solid phase. The molecular geometry and vibrational frequencies of Bis(melaminium) terephthalate dihydrate in the ground state have been calculated by using the density functional method (B3LYP) with 6-31++G(d,p) basis set. The results of the optimized molecular structure are presented and compared with the experimental X-ray diffraction. The molecule contains the weak hydrogen bonds of Nsbnd H⋯O, Nsbnd H⋯N and Osbnd H⋯O types, and those bonds are calculated with DFT method. In addition, molecular electrostatic potential, frontier molecular orbitals and natural bond orbital analysis of the title compound were investigated by theoretical calculations. The lack of the second harmonic generation (SHG) confirms the presence of macroscopic center of inversion.
Structural and spectroscopic investigation of glycinium oxalurate

NASA Astrophysics Data System (ADS)

Kavitha, T.; Pasupathi, G.; Marchewka, M. K.; Anbalagan, G.; Kanagathara, N.

2017-09-01

Glycinium oxalurate (GO) single crystals has been synthesized and grown by the slow solvent evaporation method at room temperature. Single crystal X-ray diffraction study confirms that GO crystal crystallizes in the monoclinic system with centrosymmetric space group P121/c1. The grown crystals are built up from single protonated glycinium residues and single dissociated oxalurate anions. A combination of ionic and donor-acceptor hydrogen-bond interactions linking together the glycine and oxaluric acid residues forms a three-dimensional network. Hydrogen bonded network present in the crystal gives notable vibrational effect. The molecular geometry, vibrational frequencies and intensity of the vibrational bands have been interpreted with the aid of structure optimization based on HF and density functional theory B3LYP methods with 6-311++G(d,p) basis set. Frontier molecular orbital energies and other related electronic properties are calculated. The natural bonding orbital (NBO) charges have been calculated and interpreted. The molecular electrostatic potential map has been constructed and discussed in detail.
Molecular structure and vibrational spectra of Bis(melaminium) terephthalate dihydrate: a DFT computational study.

PubMed

Tanak, Hasan; Marchewka, Mariusz K; Drozd, Marek

2013-03-15

The experimental and theoretical vibrational spectra of Bis(melaminium) terephthalate dihydrate were studied. The Fourier transform infrared (FT-IR) spectra of the Bis(melaminium) terephthalate dihydrate and its deuterated analogue were recorded in the solid phase. The molecular geometry and vibrational frequencies of Bis(melaminium) terephthalate dihydrate in the ground state have been calculated by using the density functional method (B3LYP) with 6-31++G(d,p) basis set. The results of the optimized molecular structure are presented and compared with the experimental X-ray diffraction. The molecule contains the weak hydrogen bonds of N-H···O, N-H···N and O-H···O types, and those bonds are calculated with DFT method. In addition, molecular electrostatic potential, frontier molecular orbitals and natural bond orbital analysis of the title compound were investigated by theoretical calculations. The lack of the second harmonic generation (SHG) confirms the presence of macroscopic center of inversion. Copyright © 2012 Elsevier B.V. All rights reserved.
In situ electrochemical high-energy X-ray diffraction using a capillary working electrode cell geometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Young, Matthias J.; Bedford, Nicholas M.; Jiang, Naisheng

The ability to generate new electrochemically active materials for energy generation and storage with improved properties will likely be derived from an understanding of atomic-scale structure/function relationships during electrochemical events. Here, the design and implementation of a new capillary electrochemical cell designed specifically forin situhigh-energy X-ray diffraction measurements is described. By increasing the amount of electrochemically active material in the X-ray path while implementing low-Zcell materials with anisotropic scattering profiles, an order of magnitude enhancement in diffracted X-ray signal over traditional cell geometries for multiple electrochemically active materials is demonstrated. This signal improvement is crucial for high-energy X-ray diffraction measurementsmore » and subsequent Fourier transformation into atomic pair distribution functions for atomic-scale structural analysis. As an example, clear structural changes in LiCoO 2under reductive and oxidative conditions using the capillary cell are demonstrated, which agree with prior studies. Accurate modeling of the LiCoO 2diffraction data using reverse Monte Carlo simulations further verifies accurate background subtraction and strong signal from the electrochemically active material, enabled by the capillary working electrode geometry.« less
In Situ 3D Coherent X-ray Diffraction Imaging of Shock Experiments: Possible?

NASA Astrophysics Data System (ADS)

Barber, John

2011-03-01

In traditional coherent X-ray diffraction imaging (CXDI), a 2D or quasi-2D object is illuminated by a beam of coherent X-rays to produce a diffraction pattern, which is then manipulated via a process known as iterative phase retrieval to reconstruct an image of the original 2D sample. Recently, there have been dramatic advances in methods for performing fully 3D CXDI of a sample from a single diffraction pattern [Raines et al, Nature 463 214-7 (2010)], and these methods have been used to image samples tens of microns in size using soft X-rays. In this work, I explore the theoretical possibility of applying 3D CXDI techniques to the in situ imaging of the interaction between a shock front and a polycrystal, a far more stringent problem. A delicate trade-off is required between photon energy, spot size, imaging resolution, and the dimensions of the experimental setup. In this talk, I will outline the experimental and computational requirements for performing such an experiment, and I will present images and movies from simulations of one such hypothetical experiment, including both the time-resolved X-ray diffraction patterns and the time-resolved sample imagery.
High spatial resolution X-ray and gamma ray imaging system using diffraction crystals

DOEpatents

Smither, Robert K [Hinsdale, IL

2011-05-17

A method and a device for high spatial resolution imaging of a plurality of sources of x-ray and gamma-ray radiation are provided. The device comprises a plurality of arrays, with each array comprising a plurality of elements comprising a first collimator, a diffracting crystal, a second collimator, and a detector.
Photoluminescence studies on Cd(1-x)Zn(x)S:Mn2+ nanocrystals.

PubMed

Sethi, Ruchi; Kumar, Lokendra; Pandey, A C

2009-09-01

Highly monodispersed, undoped and doped with Mn2+, binary and ternary (CdS, ZnS, Cd(1-x)Zn(x)S) compound semiconductor nanocrystals have been synthesized by co-precipitation method using citric acid as a stabilizer. As prepared sample are characterized by X-ray diffraction, Small angle X-ray scattering, Transmission electron microscope, Optical absorption and Photoluminescence spectroscopy, for their optical and structural properties. X-ray diffraction, Small angle X-ray scattering and Transmission electron microscope results confirm the preparation of monodispersed nanocrystals. Photoluminescence studies show a significant blue shift in the wavelength with an increasing concentration of Zn in alloy nanocrystals.
Observation of sagittal X-ray diffraction by surface acoustic waves in Bragg geometry.

PubMed

Vadilonga, Simone; Zizak, Ivo; Roshchupkin, Dmitry; Evgenii, Emelin; Petsiuk, Andrei; Leitenberger, Wolfram; Erko, Alexei

2017-04-01

X-ray Bragg diffraction in sagittal geometry on a Y-cut langasite crystal (La 3 Ga 5 SiO 14 ) modulated by Λ = 3 µm Rayleigh surface acoustic waves was studied at the BESSY II synchrotron radiation facility. Owing to the crystal lattice modulation by the surface acoustic wave diffraction, satellites appear. Their intensity and angular separation depend on the amplitude and wavelength of the ultrasonic superlattice. Experimental results are compared with the corresponding theoretical model that exploits the kinematical diffraction theory. This experiment shows that the propagation of the surface acoustic waves creates a dynamical diffraction grating on the crystal surface, and this can be used for space-time modulation of an X-ray beam.
Observation of sagittal X-ray diffraction by surface acoustic waves in Bragg geometry1

PubMed Central

Vadilonga, Simone; Zizak, Ivo; Roshchupkin, Dmitry; Evgenii, Emelin; Petsiuk, Andrei; Leitenberger, Wolfram; Erko, Alexei

2017-01-01

X-ray Bragg diffraction in sagittal geometry on a Y-cut langasite crystal (La3Ga5SiO14) modulated by Λ = 3 µm Rayleigh surface acoustic waves was studied at the BESSY II synchrotron radiation facility. Owing to the crystal lattice modulation by the surface acoustic wave diffraction, satellites appear. Their intensity and angular separation depend on the amplitude and wavelength of the ultrasonic superlattice. Experimental results are compared with the corresponding theoretical model that exploits the kinematical diffraction theory. This experiment shows that the propagation of the surface acoustic waves creates a dynamical diffraction grating on the crystal surface, and this can be used for space–time modulation of an X-ray beam. PMID:28381976
Method for improving x-ray diffraction determinations of residual stress in nickel-base alloys

DOEpatents

Berman, R.M.; Cohen, I.

1988-04-26

A process for improving the technique of measuring residual stress by x-ray diffraction in pieces of nickel-base alloys is discussed. Part of a predetermined area of the surface of a nickel-base alloy is covered with a dispersion. This exposes the covered and uncovered portions of the surface of the alloy to x-rays by way of an x-ray diffractometry apparatus, making x-ray diffraction determinations of the exposed surface, and measuring the residual stress in the alloy based on these determinations. The dispersion is opaque to x-rays and serves a dual purpose, since it masks off unsatisfactory signals such that only a small portion of the surface is measured, and it supplies an internal standard by providing diffractogram peaks comparable to the peaks of the nickel alloy so that the alloy peaks can be very accurately located regardless of any sources of error external to the sample. 2 figs.

Dynamic x-ray imaging of laser-driven nanoplasmas

NASA Astrophysics Data System (ADS)

Fennel, Thomas

2016-05-01

A major promise of current x-ray science at free electron lasers is the realization of unprecedented imaging capabilities for resolving the structure and ultrafast dynamics of matter with nanometer spatial and femtosecond temporal resolution or even below via single-shot x-ray diffraction. Laser-driven atomic clusters and nanoparticles provide an ideal platform for developing and demonstrating the required technology to extract the ultrafast transient spatiotemporal dynamics from the diffraction images. In this talk, the perspectives and challenges of dynamic x-ray imaging will be discussed using complete self-consistent microscopic electromagnetic simulations of IR pump x-ray probe imaging for the example of clusters. The results of the microscopic particle-in-cell simulations (MicPIC) enable the simulation-assisted reconstruction of corresponding experimental data. This capability is demonstrated by converting recently measured LCLS data into a ultrahigh resolution movie of laser-induced plasma expansion. Finally, routes towards reaching attosecond time resolution in the visualization of complex dynamical processes in matter by x-ray diffraction will be discussed.
Infrastructure development for radioactive materials at the NSLS-II

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sprouster, D. J.; Weidner, R.; Ghose, S. K.

2018-02-01

The X-ray Powder Diffraction (XPD) Beamline at the National Synchrotron Light Source-II is a multipurpose instrument designed for high-resolution, high-energy X-ray scattering techniques. In this article, the capabilities, opportunities and recent developments in the characterization of radioactive materials at XPD are described. The overarching goal of this work is to provide researchers access to advanced synchrotron techniques suited to the structural characterization of materials for advanced nuclear energy systems. XPD is a new beamline providing high photon flux for X-ray Diffraction, Pair Distribution Function analysis and Small Angle X-ray Scattering. The infrastructure and software described here extend the existing capabilitiesmore » at XPD to accommodate radioactive materials. Such techniques will contribute crucial information to the characterization and quantification of advanced materials for nuclear energy applications. We describe the automated radioactive sample collection capabilities and recent X-ray Diffraction and Small Angle X-ray Scattering results from neutron irradiated reactor pressure vessel steels and oxide dispersion strengthened steels.« less
Infrastructure development for radioactive materials at the NSLS-II

DOE PAGES

Sprouster, David J.; Weidner, R.; Ghose, S. K.; ...

2017-11-04

The X-ray Powder Diffraction (XPD) Beamline at the National Synchrotron Light Source-II is a multipurpose instrument designed for high-resolution, high-energy X-ray scattering techniques. In this paper, the capabilities, opportunities and recent developments in the characterization of radioactive materials at XPD are described. The overarching goal of this work is to provide researchers access to advanced synchrotron techniques suited to the structural characterization of materials for advanced nuclear energy systems. XPD is a new beamline providing high photon flux for X-ray Diffraction, Pair Distribution Function analysis and Small Angle X-ray Scattering. The infrastructure and software described here extend the existing capabilitiesmore » at XPD to accommodate radioactive materials. Such techniques will contribute crucial information to the characterization and quantification of advanced materials for nuclear energy applications. Finally, we describe the automated radioactive sample collection capabilities and recent X-ray Diffraction and Small Angle X-ray Scattering results from neutron irradiated reactor pressure vessel steels and oxide dispersion strengthened steels.« less
Illicit drug detection using energy dispersive x-ray diffraction

NASA Astrophysics Data System (ADS)

Cook, E. J.; Griffiths, J. A.; Koutalonis, M.; Gent, C.; Pani, S.; Horrocks, J. A.; George, L.; Hardwick, S.; Speller, R.

2009-05-01

Illicit drugs are imported into countries in myriad ways, including via the postal system and courier services. An automated system is required to detect drugs in parcels for which X-ray diffraction is a suitable technique as it is non-destructive, material specific and uses X-rays of sufficiently high energy to penetrate parcels containing a range of attenuating materials. A database has been constructed containing the measured powder diffraction profiles of several thousand materials likely to be found in parcels. These include drugs, cutting agents, packaging and other innocuous materials. A software model has been developed using these data to predict the diffraction profiles which would be obtained by X-ray diffraction systems with a range of suggested detector (high purity germanium, CZT and scintillation), source and collimation options. The aim of the model was to identify the most promising system geometries, which was done with the aid of multivariate analysis (MVA). The most promising systems were constructed and tested. The diffraction profiles of a range of materials have been measured and used to both validate the model and to identify the presence of drugs in sample packages.
Wavefront aberrations of x-ray dynamical diffraction beams.

PubMed

Liao, Keliang; Hong, Youli; Sheng, Weifan

2014-10-01

The effects of dynamical diffraction in x-ray diffractive optics with large numerical aperture render the wavefront aberrations difficult to describe using the aberration polynomials, yet knowledge of them plays an important role in a vast variety of scientific problems ranging from optical testing to adaptive optics. Although the diffraction theory of optical aberrations was established decades ago, its application in the area of x-ray dynamical diffraction theory (DDT) is still lacking. Here, we conduct a theoretical study on the aberration properties of x-ray dynamical diffraction beams. By treating the modulus of the complex envelope as the amplitude weight function in the orthogonalization procedure, we generalize the nonrecursive matrix method for the determination of orthonormal aberration polynomials, wherein Zernike DDT and Legendre DDT polynomials are proposed. As an example, we investigate the aberration evolution inside a tilted multilayer Laue lens. The corresponding Legendre DDT polynomials are obtained numerically, which represent balanced aberrations yielding minimum variance of the classical aberrations of an anamorphic optical system. The balancing of classical aberrations and their standard deviations are discussed. We also present the Strehl ratio of the primary and secondary balanced aberrations.
Langmuir-Blodgett films of random copolymers of fluoroalkyl(meth)acrylate and methacrylic acid: Fabrication and X-ray diffraction study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Safronov, V.; Feigin, L.A.; Budovskaya, L.D.

1994-12-31

Langmuir-Blodgett films of amphiphilic fluorinated copolymers were fabricated and studied by X-ray diffraction. Although these films show poor interlayer periodicity, they possess a uniform thickness even in the case of very thin films of one bilayer (22 {angstrom}). This feature was used to obtain complex LB structures (superlattices) with alteration of copolymer and fatty acid bilayers. X-ray diffraction data proved the regular periodical organization of these structures and allowed to calculate electron density distribution across the superlattices.
Crystallization and preliminary X-ray diffraction study of the protealysin precursor belonging to the peptidase family M4

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gromova, T. Yu., E-mail: duk@img.ras.ru; Demidyuk, I. V.; Kostrov, S. V.

2008-09-15

A protealysin precursor (the enzyme of the peptidase family M4) was crystallized for the first time. The crystal-growth conditions were found, and single crystals of the protein with dimensions of 0.3-0.5 mm were grown. The preliminary X-ray diffraction study of the enzyme was performed. The protealysin precursor was shown to crystallize in two crystal modifications suitable for the X-ray diffraction study of the three-dimensional structure of the protein molecule at atomic resolution.
Simulating Picosecond X-ray Diffraction from shocked crystals by Post-processing Molecular Dynamics Calculations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kimminau, G; Nagler, B; Higginbotham, A

2008-06-19

Calculations of the x-ray diffraction patterns from shocked crystals derived from the results of Non-Equilibrium-Molecular-Dynamics (NEMD) simulations are presented. The atomic coordinates predicted by the NEMD simulations combined with atomic form factors are used to generate a discrete distribution of electron density. A Fast-Fourier-Transform (FFT) of this distribution provides an image of the crystal in reciprocal space, which can be further processed to produce quantitative simulated data for direct comparison with experiments that employ picosecond x-ray diffraction from laser-irradiated crystalline targets.
Framework for three-dimensional coherent diffraction imaging by focused beam x-ray Bragg ptychography.

PubMed

Hruszkewycz, Stephan O; Holt, Martin V; Tripathi, Ash; Maser, Jörg; Fuoss, Paul H

2011-06-15

We present the framework for convergent beam Bragg ptychography, and, using simulations, we demonstrate that nanocrystals can be ptychographically reconstructed from highly convergent x-ray Bragg diffraction. The ptychographic iterative engine is extended to three dimensions and shown to successfully reconstruct a simulated nanocrystal using overlapping raster scans with a defocused curved beam, the diameter of which matches the crystal size. This object reconstruction strategy can serve as the basis for coherent diffraction imaging experiments at coherent scanning nanoprobe x-ray sources.
N-(4-Nitrobenzoyl)-N'-(1,5-dimethyl-3-oxo-2-phenyl-1H-3(2H)-pyrazolyl)-thiourea hydrate: Synthesis, spectroscopic characterization, X-ray structure and DFT studies

NASA Astrophysics Data System (ADS)

Arslan, N. Burcu; Kazak, Canan; Aydın, Fatma

2012-04-01

The title molecule (C19H17N5O4S·H2O) was synthesized and characterized by IR-NMR spectroscopy, MS and single-crystal X-ray diffraction. The molecular geometry, vibrational frequencies and gauge-independent atomic orbital (GIAO) 1H and 13C NMR chemical shift values of the compound in the ground state have been calculated by using the density functional theory (DFT) method with 6-31G(d) basis set, and compared with the experimental data. All the assignments of the theoretical frequencies were performed by potential energy distributions using VEDA 4 program. The calculated results show that the optimized geometries can well reproduce the crystal structural parameters, and the theoretical vibrational frequencies and 1H and 13C NMR chemical shift values show good agreement with experimental data. To determine conformational flexibility, the molecular energy profile of the title compound was obtained with respect to the selected torsion angle, which was varied from -180° to +180° in steps of 10°. Besides, molecular electrostatic potential (MEP), frontier molecular orbitals (FMO) analysis and thermodynamic properties of the compound were investigated by theoretical calculations.
New insights into the negative thermal expansion: Direct experimental evidence for the “guitar-string” effect in cubic ScF 3

DOE PAGES

Hu, Lei; Chen, Jun; Sanson, Andrea; ...

2016-06-23

The understanding of the negative thermal expansion (NTE) mechanism remains challenging but critical for the development of NTE materials. This study sheds light on NTE of ScF 3, one of the most outstanding materials with NTE. The local dynamics of ScF 3 has been investigated by a combined analysis of synchrotron-based X-ray total scattering, ex-tended X-ray absorption fine structure and neutron powder diffraction. Very interestingly, we observe that i) the Sc-F nearest-neighbor distance strongly expands with increasing temperature while the Sc-Sc next-nearest-neighbor distance contracts, ii) the thermal ellipsoids of relative vibrations be-tween Sc-F nearest-neighbors are highly elongated in the directionmore » perpendicular to the Sc-F bond, indicating that the Sc-F bond is much softer to bend than to stretch, and iii) there is mainly dynamically transverse motion of fluorine atoms, rather than static shifts. Here, these results are the direct experimental evidence for the NTE mechanism, in which the rigid unit is not necessary for the occurrence of NTE, and the key role is played by the transverse thermal vibrations of fluorine atoms through the “guitar-string” effect.« less
Three-dimensional imaging of nanoscale materials by using coherent x-rays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miao, Jianwei

X-ray crystallography is currently the primary methodology used to determine the 3D structure of materials and macromolecules. However, many nanostructures, disordered materials, biomaterials, hybrid materials and biological specimens are noncrystalline and, hence, their structures are not accessible by X-ray crystallography. Probing these structures therefore requires the employment of different approaches. A very promising technique currently under rapid development is X-ray diffraction microscopy (or lensless imaging), in which the coherent X-ray diffraction pattern of a noncrystalline specimen is measured and then directly phased to obtain a high-resolution image. Through the DOE support over the past three years, we have applied X-raymore » diffraction microscopy to quantitative imaging of GaN quantum dot particles, and revealed the internal GaN-Ga2O3 core shell structure in three dimensions. By exploiting the abrupt change in the scattering cross-section near electronic resonances, we carried out the first experimental demonstration of resonant X-ray diffraction microscopy for element specific imaging. We performed nondestructive and quantitative imaging of buried Bi structures inside a Si crystal by directly phasing coherent X-ray diffraction patterns acquired below and above the Bi M5 edge. We have also applied X-ray diffraction microscopy to nondestructive imaging of mineral crystals inside biological composite materials - intramuscular fish bone - at the nanometer scale resolution. We identified mineral crystals in collagen fibrils at different stages of mineralization and proposed a dynamic mechanism to account for the nucleation and growth of mineral crystals in the collagen matrix. In addition, we have also discovered a novel 3D imaging modality, denoted ankylography, which allows for complete 3D structure determination without the necessity of sample titling or scanning. We showed that when the diffraction pattern of a finite object is sampled at a sufficiently fine scale on the Ewald sphere, the 3D structure of the object is determined by the 2D spherical pattern. We confirmed the theoretical analysis by performing 3D numerical reconstructions of a sodium silicate glass structure at 2 A resolution from a 2D spherical diffraction pattern alone. As X-ray free electron lasers are under rapid development worldwide, ankylography may open up a new horizon to obtain the 3D structure of a non-crystalline specimen from a single pulse and allow time-resolved 3D structure determination of disordered materials.« less
Microfluidic Chips for In Situ Crystal X-ray Diffraction and In Situ Dynamic Light Scattering for Serial Crystallography.

PubMed

Gicquel, Yannig; Schubert, Robin; Kapis, Svetlana; Bourenkov, Gleb; Schneider, Thomas; Perbandt, Markus; Betzel, Christian; Chapman, Henry N; Heymann, Michael

2018-04-24

This protocol describes fabricating microfluidic devices with low X-ray background optimized for goniometer based fixed target serial crystallography. The devices are patterned from epoxy glue using soft lithography and are suitable for in situ X-ray diffraction experiments at room temperature. The sample wells are lidded on both sides with polymeric polyimide foil windows that allow diffraction data collection with low X-ray background. This fabrication method is undemanding and inexpensive. After the sourcing of a SU-8 master wafer, all fabrication can be completed outside of a cleanroom in a typical research lab environment. The chip design and fabrication protocol utilize capillary valving to microfluidically split an aqueous reaction into defined nanoliter sized droplets. This loading mechanism avoids the sample loss from channel dead-volume and can easily be performed manually without using pumps or other equipment for fluid actuation. We describe how isolated nanoliter sized drops of protein solution can be monitored in situ by dynamic light scattering to control protein crystal nucleation and growth. After suitable crystals are grown, complete X-ray diffraction datasets can be collected using goniometer based in situ fixed target serial X-ray crystallography at room temperature. The protocol provides custom scripts to process diffraction datasets using a suite of software tools to solve and refine the protein crystal structure. This approach avoids the artefacts possibly induced during cryo-preservation or manual crystal handling in conventional crystallography experiments. We present and compare three protein structures that were solved using small crystals with dimensions of approximately 10-20 µm grown in chip. By crystallizing and diffracting in situ, handling and hence mechanical disturbances of fragile crystals is minimized. The protocol details how to fabricate a custom X-ray transparent microfluidic chip suitable for in situ serial crystallography. As almost every crystal can be used for diffraction data collection, these microfluidic chips are a very efficient crystal delivery method.
Characterization of X-Ray Diffraction System with a Microfocus X-Ray Source and a Polycapillary Optic

NASA Technical Reports Server (NTRS)

Gubarev, Mikhail; Marshall, Joy K.; Ciszak, Ewa; Ponomarev, Igor

2000-01-01

We present here an optimized microfocus x-ray source and polycapillary optic system designed for diffraction of small protein crystals. The x-ray beam is formed by a 5.5mm focal length capillary collimator coupled with a 40 micron x-ray source operating at 46Watts. Measurements of the x-ray flux, the divergence and the spectral characteristics of the beam are presented, This optimized system provides a seven fold greater flux than our recently reported configuration [M. Gubarev, et al., J. of Applied Crystallography (2000) 33, in press]. We now make a comparison with a 5kWatts rotating anode generator (Rigaku) coupled with confocal multilayer focusing mirrors (Osmic, CMF12- 38Cu6). The microfocus x-ray source and polycapillary collimator system delivers 60% of the x-ray flux from the rotating anode system. Additional ways to improve our microfocus x-ray system, and thus increase the x-ray flux will be discussed.
Specimen preparation for cryogenic coherent X-ray diffraction imaging of biological cells and cellular organelles by using the X-ray free-electron laser at SACLA

PubMed Central

Kobayashi, Amane; Sekiguchi, Yuki; Oroguchi, Tomotaka; Okajima, Koji; Fukuda, Asahi; Oide, Mao; Yamamoto, Masaki; Nakasako, Masayoshi

2016-01-01

Coherent X-ray diffraction imaging (CXDI) allows internal structures of biological cells and cellular organelles to be analyzed. CXDI experiments have been conducted at 66 K for frozen-hydrated biological specimens at the SPring-8 Angstrom Compact Free-Electron Laser facility (SACLA). In these cryogenic CXDI experiments using X-ray free-electron laser (XFEL) pulses, specimen particles dispersed on thin membranes of specimen disks are transferred into the vacuum chamber of a diffraction apparatus. Because focused single XFEL pulses destroy specimen particles at the atomic level, diffraction patterns are collected through raster scanning the specimen disks to provide fresh specimen particles in the irradiation area. The efficiency of diffraction data collection in cryogenic experiments depends on the quality of the prepared specimens. Here, detailed procedures for preparing frozen-hydrated biological specimens, particularly thin membranes and devices developed in our laboratory, are reported. In addition, the quality of the frozen-hydrated specimens are evaluated by analyzing the characteristics of the collected diffraction patterns. Based on the experimental results, the internal structures of the frozen-hydrated specimens and the future development for efficient diffraction data collection are discussed. PMID:27359147
Specimen preparation for cryogenic coherent X-ray diffraction imaging of biological cells and cellular organelles by using the X-ray free-electron laser at SACLA.

PubMed

Kobayashi, Amane; Sekiguchi, Yuki; Oroguchi, Tomotaka; Okajima, Koji; Fukuda, Asahi; Oide, Mao; Yamamoto, Masaki; Nakasako, Masayoshi

2016-07-01

Coherent X-ray diffraction imaging (CXDI) allows internal structures of biological cells and cellular organelles to be analyzed. CXDI experiments have been conducted at 66 K for frozen-hydrated biological specimens at the SPring-8 Angstrom Compact Free-Electron Laser facility (SACLA). In these cryogenic CXDI experiments using X-ray free-electron laser (XFEL) pulses, specimen particles dispersed on thin membranes of specimen disks are transferred into the vacuum chamber of a diffraction apparatus. Because focused single XFEL pulses destroy specimen particles at the atomic level, diffraction patterns are collected through raster scanning the specimen disks to provide fresh specimen particles in the irradiation area. The efficiency of diffraction data collection in cryogenic experiments depends on the quality of the prepared specimens. Here, detailed procedures for preparing frozen-hydrated biological specimens, particularly thin membranes and devices developed in our laboratory, are reported. In addition, the quality of the frozen-hydrated specimens are evaluated by analyzing the characteristics of the collected diffraction patterns. Based on the experimental results, the internal structures of the frozen-hydrated specimens and the future development for efficient diffraction data collection are discussed.
Chalcogen analogues of nicotine lactam studied by NMR, FTIR, DFT and X-ray methods

NASA Astrophysics Data System (ADS)

Jasiewicz, Beata; Malczewska-Jaskóła, Karolina; Kowalczyk, Iwona; Warżajtis, Beata; Rychlewska, Urszula

2014-07-01

The selenoanalogue of nicotine has been synthesized and characterized by spectroscopic and X-ray diffraction methods. The crystals of selenonicotine are isomorphic with the thionicotine homologue and consist of molecules engaged in columnar π⋯π stacking interactions between antiparallely arranged pyridine moieties. These interactions, absent in other crystals containing nicotine fragments, seem to be induced by the presence of a lactam group. The molecular structures in the vacuum of the oxo-, thio- and selenonicotine homologues have been calculated by the DFT method and compared with the available X-ray data. The delocalized structure of thionicotine is stabilized by intramolecular Csbnd H⋯S hydrogen bond, which becomes weaker in the partial zwitterionic resonance structure of selenonicotine in favor of multiple Csbnd H⋯Se intermolecular hydrogen-bonds. The calculated data allow a complete assignment of vibration modes in the solid state FTIR spectra. The 1H and 13C NMR chemical shifts were calculated by the GIAO method with B3LYP/6-311G(3df) level. A comparison between experimental and calculated theoretical results indicates that the density functional B3LYP method provided satisfactory results for predicting FTIR, 1H, 13C NMR spectra properties.
DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaur, Maninder; McCloy, John S.; Kukkadapu, Ravi

Two sizes of iron/iron-oxide (Fe/Fe-oxide) nanoclusters (NCs) of 10 nm and 35 nm diameters were prepared using a cluster deposition technique. Both these NCs displayed XRD peaks due to body-centered cubic (bcc) Fe0 and magnetite-like phase. Mossbauer spectroscopy (MS) measurements: a) confirmed the core-shell nature of the NCs, b) the Fe-oxide shell to be nanocrystalline and partially oxidized, and c) the Fe-oxide spins are significantly canted. In addition to the bcc Fe and magnetite-like phases, a phase similar to tetragonal σ-Fe-Cr (8% Cr) was CLEARLY evident in the larger NC, based on X-ray diffraction. Origin of the tetragonallike phase inmore » the larger NC was not clear but could be due to significant distortion of the Fe0 core lattice planes; subtle peaks due to this phase were also apparent in the smaller NC. Unambiguous evidence for the presence of such a phase, however, was not clear from MS, X-ray photoelectron spectroscopy, vibrating sample magnetometry, X-ray magnetic circular dichroism, nor transmission electron microscopy. To our knowledge, this is the first report of tetragonallike phase in the Fe/Fe-oxide core-shell systems.« less
Emerging opportunities in structural biology with X-ray free-electron lasers

PubMed Central

Schlichting, Ilme; Miao, Jianwei

2012-01-01

X-ray free-electron lasers (X-FELs) produce X-ray pulses with extremely brilliant peak intensity and ultrashort pulse duration. It has been proposed that radiation damage can be “outrun” by using an ultra intense and short X-FEL pulse that passes a biological sample before the onset of significant radiation damage. The concept of “diffraction-before-destruction” has been demonstrated recently at the Linac Coherent Light Source, the first operational hard X-ray FEL, for protein nanocrystals and giant virus particles. The continuous diffraction patterns from single particles allow solving the classical “phase problem” by the oversampling method with iterative algorithms. If enough data are collected from many identical copies of a (biological) particle, its three-dimensional structure can be reconstructed. We review the current status and future prospects of serial femtosecond crystallography (SFX) and single-particle coherent diffraction imaging (CDI) with X-FELs. PMID:22922042
Fabrication of multilayered Ge nanocrystals embedded in SiO xGeN y films

NASA Astrophysics Data System (ADS)

Gao, Fei; Green, Martin A.; Conibeer, Gavin; Cho, Eun-Chel; Huang, Yidan; Perez-Wurfl, Ivan; Flynn, Chris

2008-09-01

Multilayered Ge nanocrystals embedded in SiO xGeN y films have been fabricated on Si substrate by a (Ge + SiO 2)/SiO xGeN y superlattice approach, using a rf magnetron sputtering technique with a Ge + SiO 2 composite target and subsequent thermal annealing in N 2 ambient at 750 °C for 30 min. X-ray diffraction (XRD) measurement indicated the formation of Ge nanocrystals with an average size estimated to be 5.4 nm. Raman scattering spectra showed a peak of the Ge-Ge vibrational mode downward shifted to 299.4 cm -1, which was caused by quantum confinement of phonons in the Ge nanocrystals. Transmission electron microscopy (TEM) revealed that Ge nanocrystals were confined in (Ge + SiO 2) layers. This superlattice approach significantly improved both the size uniformity of Ge nanocrystals and their uniformity of spacing on the 'Z' growth direction.

Publications - GMC 58 | Alaska Division of Geological & Geophysical Surveys

Science.gov Websites

DGGS GMC 58 Publication Details Title: X-ray diffraction and scanning electron microscopy mineral , Michael, and Core Laboratories, 1985, X-ray diffraction and scanning electron microscopy mineral analyses
Observation of divergent-beam X-ray diffraction from a crystal of diamond using synchrotron radiation.

PubMed

Glazer, A M; Collins, S P; Zekria, D; Liu, J; Golshan, M

2004-03-01

In 1947 Kathleen Lonsdale conducted a series of experiments on X-ray diffraction using a divergent beam external to a crystal sample. Unlike the Kossel technique, where divergent X-rays are excited by the presence of fluorescing atoms within the crystal, the use of an external divergent source made it possible to study non-fluorescing crystals. The resulting photographs not only illustrated the complexity of X-ray diffraction from crystals in a truly beautiful way, but also demonstrated unprecedented experimental precision. This long-forgotten work is repeated here using a synchrotron radiation source and, once again, considerable merit is found in Lonsdale's technique. The results of this experiment suggest that, through the use of modern 'third-generation' synchrotron sources, divergent-beam diffraction could soon enjoy a renaissance for high-precision lattice-parameter determination and the study of crystal perfection.
Soft X-ray spectromicroscopy using ptychography with randomly phased illumination

NASA Astrophysics Data System (ADS)

Maiden, A. M.; Morrison, G. R.; Kaulich, B.; Gianoncelli, A.; Rodenburg, J. M.

2013-04-01

Ptychography is a form of scanning diffractive imaging that can successfully retrieve the modulus and phase of both the sample transmission function and the illuminating probe. An experimental difficulty commonly encountered in diffractive imaging is the large dynamic range of the diffraction data. Here we report a novel ptychographic experiment using a randomly phased X-ray probe to considerably reduce the dynamic range of the recorded diffraction patterns. Images can be reconstructed reliably and robustly from this setup, even when scatter from the specimen is weak. A series of ptychographic reconstructions at X-ray energies around the L absorption edge of iron demonstrates the advantages of this method for soft X-ray spectromicroscopy, which can readily provide chemical sensitivity without the need for optical refocusing. In particular, the phase signal is in perfect registration with the modulus signal and provides complementary information that can be more sensitive to changes in the local chemical environment.
Thermal analysis, X-ray powder diffraction and electron microscopy data related with the production of 1:1 Caffeine:Glutaric Acid cocrystals.

PubMed

Duarte, Íris; Andrade, Rita; Pinto, João F; Temtem, Márcio

2016-09-01

The data presented in this article are related to the production of 1:1 Caffeine:Glutaric Acid cocrystals as part of the research article entitled "Green production of cocrystals using a new solvent-free approach by spray congealing" (Duarte et al., 2016) [1]. More specifically, here we present the thermal analysis and the X-ray powder diffraction data for pure Glutaric Acid, used as a raw material in [1]. We also include the X-ray powder diffraction and electron microscopy data obtained for the 1:1 Caffeine:Glutaric Acid cocrystal (form II) produced using the cooling crystallization method reported in "Operating Regions in Cooling Cocrystallization of Caffeine and Glutaric Acid in Acetonitrile" (Yu et al., 2010) [2]. Lastly, we show the X-ray powder diffraction data obtained for assessing the purity of the 1:1 Caffeine:Glutaric cocrystals produced in [1].
Submicron x-ray diffraction and its applications to problems in materials and environmental science

NASA Astrophysics Data System (ADS)

Tamura, N.; Celestre, R. S.; MacDowell, A. A.; Padmore, H. A.; Spolenak, R.; Valek, B. C.; Meier Chang, N.; Manceau, A.; Patel, J. R.

2002-03-01

The availability of high brilliance third generation synchrotron sources together with progress in achromatic focusing optics allows us to add submicron spatial resolution to the conventional century-old x-ray diffraction technique. The new capabilities include the possibility to map in situ, grain orientations, crystalline phase distribution, and full strain/stress tensors at a very local level, by combining white and monochromatic x-ray microbeam diffraction. This is particularly relevant for high technology industry where the understanding of material properties at a microstructural level becomes increasingly important. After describing the latest advances in the submicron x-ray diffraction techniques at the Advanced Light Source, we will give some examples of its application in material science for the measurement of strain/stress in metallic thin films and interconnects. Its use in the field of environmental science will also be discussed.
Ultrahigh vacuum/high pressure chamber for surface x-ray diffraction experiments

NASA Astrophysics Data System (ADS)

Bernard, P.; Peters, K.; Alvarez, J.; Ferrer, S.

1999-02-01

We describe an ultrahigh vacuum chamber that can be internally pressurized to several bars and that is designed to perform surface x-ray diffraction experiments on solid-gas interfaces. The chamber has a cylindrical beryllium window that serves as the entrance and exit for the x rays. The sample surface can be ion bombarded with an ancillary ion gun and annealed to 1200 K.
Symposium LL: Nanowires--Synthesis Properties Assembly and Application

DTIC Science & Technology

2010-09-10

dedicated hard x - ray microscopy beamline is operated in partnership with the Advanced Photon Source to provide fluorescence, diffraction, and...characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X - ray diffraction (XRD) measurements, proving it to be...Investigation of Preferred Growth Direction of GaN Nanorods by Synchrotron X - ray Reciprocal Space Mapping. Yuri Sohn1, Sanghwa Lee1, Chinkyo Kim1 and Dong
X-ray diffraction-based electronic structure calculations and experimental x-ray analysis for medical and materials applications

NASA Astrophysics Data System (ADS)

Mahato, Dip Narayan

This thesis includes x-ray experiments for medical and materials applications and the use of x-ray diffraction data in a first-principles study of electronic structures and hyperfine properties of chemical and biological systems. Polycapillary focusing lenses were used to collect divergent x rays emitted from conventional x-ray tubes and redirect them to form an intense focused beam. These lenses are routinely used in microbeam x-ray fluorescence analysis. In this thesis, their potential application to powder diffraction and focused beam orthovoltage cancer therapy has been investigated. In conventional x-ray therapy, very high energy (˜ MeV) beams are used, partly to reduce the skin dose. For any divergent beam, the dose is necessarily highest at the entry point, and decays exponentially into the tissue. To reduce the skin dose, high energy beams, which have long absorption lengths, are employed, and rotated about the patient to enter from different angles. This necessitates large expensive specialized equipment. A focused beam could concentrate the dose within the patient. Since this is inherently skin dose sparing, lower energy photons could be employed. A primary concern in applying focused beams to therapy is whether the focus would be maintained despite Compton scattering within the tissue. To investigate this, transmission and focal spot sizes as a function of photon energy of two polycapillary focusing lenses were measured. The effects of tissue-equivalent phantoms of different thicknesses on the focal spot size were studied. Scatter fraction and depth dose were calculated. For powder diffraction, the polycapillary optics provide clean Gaussian peaks, which result in angular resolution that is much smaller than the peak width due to the beam convergence. Powder diffraction (also called coherent scatter) without optics can also be used to distinguish between tissue types that, because they have different nanoscale structures, scatter at different angles. Measurements were performed on the development of coherent scatter imaging to provide tissue type information in mammography. Atomic coordinates from x-ray diffraction data were used to study the nuclear quadrupole interactions and nature of molecular binding in DNA/RNA nucleobases and molecular solid BF3 systems.
XRD, vibrational spectra and quantum chemical studies of an anticancer drug: 6-Mercaptopurine.

PubMed

Kumar, S Suresh; Athimoolam, S; Sridhar, B

2015-07-05

The single crystal of the hydrated anticancer drug, 6-Mercaptopurine (6-MP), has been grown by slow evaporation technique under room temperature. The structure was determined by single crystal X-ray diffraction. The vibrational spectral analysis was carried out using Laser Raman and FT-IR spectroscopy in the range of 3300-100 and 4000-400 cm(-1). The single crystal X-ray studies shows that the crystal packing is dominated by N-H⋯O and O-H⋯N classical hydrogen bonds leading to a hydrogen bonded ensemble. This classical hydrogen bonds were further connected through O-H⋯S hydrogen bond to form two primary ring R4(4)(16) and R4(4)(12) motifs. These two primary ring motifs are interlinked with each other to build a ladder like structure. These ladders are connected through N-H⋯N hydrogen bond along c-axis of the unit cell through chain C(5) motifs. Further, the strength of the hydrogen bonds is studied through vibrational spectral measurements. The shifting of bands due to the intermolecular interactions was also analyzed in the solid crystalline state. Geometrical optimizations of the drug molecule were done by Density Functional Theory (DFT) using the B3LYP function and Hartree-Fock (HF) level with 6-311++G(d,p) basis set. The optimized molecular geometry and computed vibrational spectra are compared with experimental results which show significant agreement. The natural bond orbital (NBO) analysis was carried out to interpret hyperconjugative interaction and intramolecular charge transfer (ICT). The chemical hardness, electro-negativity and chemical potential of the molecule are carried out by HOMO-LUMO plot. In which, the frontier orbitals has lower band gap value indicating the possible pharmaceutical activity of the molecule. Copyright © 2015 Elsevier B.V. All rights reserved.
Sequential x-ray diffraction topography at 1-BM x-ray optics testing beamline at the advanced photon source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoupin, Stanislav, E-mail: sstoupin@aps.anl.gov; Shvyd’ko, Yuri; Trakhtenberg, Emil

2016-07-27

We report progress on implementation and commissioning of sequential X-ray diffraction topography at 1-BM Optics Testing Beamline of the Advanced Photon Source to accommodate growing needs of strain characterization in diffractive crystal optics and other semiconductor single crystals. The setup enables evaluation of strain in single crystals in the nearly-nondispersive double-crystal geometry. Si asymmetric collimator crystals of different crystallographic orientations were designed, fabricated and characterized using in-house capabilities. Imaging the exit beam using digital area detectors permits rapid sequential acquisition of X-ray topographs at different angular positions on the rocking curve of a crystal under investigation. Results on sensitivity andmore » spatial resolution are reported based on experiments with high-quality Si and diamond crystals. The new setup complements laboratory-based X-ray topography capabilities of the Optics group at the Advanced Photon Source.« less
Curved focusing crystals for hard X-ray astronomy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ferrari, C., E-mail: ferrari@imem.cnr.it; Buffagni, E.; Bonnini, E.

A lens made by a properly arranged array of crystals can be used to focus x-rays of energy ranging from 30 to 500 keV for x-ray astronomy. Mosaic or curved crystals can be employed as x-ray optical elements. In this work self standing curved focusing Si and GaAs crystals in which the lattice bending is induced by a controlled damaging process on one side of planar crystals are characterized. Diffraction profiles in Laue geometry have been measured in crystals at x-ray energies E = 17, 59 and 120 keV. An enhancement of diffraction efficiency is found in asymmetric geometries.
Sealed-tube synthesis and phase diagram of Li{sub x}TiS{sub 2} (0 ≤ x ≤1)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Ziping; National Laboratory for Superconductivity, Institute of Physics, Chinese Academy of Science, Beijing 100190; Dong, Cheng, E-mail: chengdon@aphy.iphy.ac.cn

2015-01-15

Graphical abstract: We reported a new method to prepare Li{sub x}TiS{sub 2} (0 ≤ x ≤ 1) at 600 °C in sealed tube using Li{sub 2}S aslithium source. A schematic phase diagram of the Li{sub x}TiS{sub 2} system has been constructed based on the DTA and XRD data. - Abstract: We reported a new method to prepare Li{sub x}TiS{sub 2} (0 ≤ x ≤ 1) at 600 °C in sealed tube using Li{sub 2}S as lithium source. The Li{sub x}TiS{sub 2} samples were characterized by powder X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, and differential thermal analysis. Themore » variations of the lattice parameters with lithium content x in Li{sub x}TiS{sub 2} were determined by X-ray powder diffraction analysis for both 1T and 3R phases. The phase transition between low-temperature 1T phase and high-temperature 3R phase was confirmed by the powder X-ray diffraction analysis. Based on the differential thermal analysis and X-ray diffraction results, a schematic phase diagram of the Li{sub x}TiS{sub 2} system has been constructed, providing a guideline to synthesize Li{sub x}TiS{sub 2} in 1T structure or 3R structure.« less
X-ray diffraction on radioactive materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schiferl, D.; Roof, R.B.

1978-01-01

X-ray diffraction studies on radioactive materials are discussed with the aim of providing a guide to new researchers in the field. Considerable emphasis is placed on the safe handling and loading of not-too-exotic samples. Special considerations such as the problems of film blackening by the gamma rays and changes induced by the self-irradiation of the sample are covered. Some modifications of common diffraction techniques are presented. Finally, diffraction studies on radioactive samples under extreme conditions are discussed, with primary emphasis on high-pressure studies involving diamond-anvil cells.
Analytical characterization of a new mobile X-ray fluorescence and X-ray diffraction instrument combined with a pigment identification case study

NASA Astrophysics Data System (ADS)

Van de Voorde, Lien; Vekemans, Bart; Verhaeven, Eddy; Tack, Pieter; De Wolf, Robin; Garrevoet, Jan; Vandenabeele, Peter; Vincze, Laszlo

2015-08-01

A new, commercially available, mobile system combining X-ray diffraction and X-ray fluorescence has been evaluated which enables both elemental analysis and phase identification simultaneously. The instrument makes use of a copper or molybdenum based miniature X-ray tube and a silicon-Pin diode energy-dispersive detector to count the photons originating from the samples. The X-ray tube and detector are both mounted on an X-ray diffraction protractor in a Bragg-Brentano θ:θ geometry. The mobile instrument is one of the lightest and most compact instruments of its kind (3.5 kg) and it is thus very useful for in situ purposes such as the direct (non-destructive) analysis of cultural heritage objects which need to be analyzed on site without any displacement. The supplied software allows both the operation of the instrument for data collection and in-depth data analysis using the International Centre for Diffraction Data database. This paper focuses on the characterization of the instrument, combined with a case study on pigment identification and an illustrative example for the analysis of lead alloyed printing letters. The results show that this commercially available light-weight instrument is able to identify the main crystalline phases non-destructively, present in a variety of samples, with a high degree of flexibility regarding sample size and position.
DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Cheng-Jun, E-mail: cjsun@aps.anl.gov; Brewe, Dale L.; Heald, Steve M.

X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS) are two main x-ray techniques in synchrotron radiation facilities. In this Note, we present an experimental setup capable of performing simultaneous XRD and XAS measurements by the application of a pixel-array area detector. For XRD, the momentum transfer in specular diffraction was measured by scanning the X-ray energy with fixed incoming and outgoing x-ray angles. By selecting a small fixed region of the detector to collect the XRD signal, the rest of the area was available for collecting the x-ray fluorescence for XAS measurements. The simultaneous measurement of XRD and X-ray absorptionmore » near edge structure for Pr{sub 0.67}Sr{sub 0.33}MnO{sub 3} film was demonstrated as a proof of principle for future time-resolved pump-probe measurements. A static sample makes it easy to maintain an accurate overlap of the X-ray spot and laser pump beam.« less
A von Hamos x-ray spectrometer based on a segmented-type diffraction crystal for single-shot x-ray emission spectroscopy and time-resolved resonant inelastic x-ray scattering studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Szlachetko, J.; Institute of Physics, Jan Kochanowski University, 25-406 Kielce; Nachtegaal, M.

2012-10-15

We report on the design and performance of a wavelength-dispersive type spectrometer based on the von Hamos geometry. The spectrometer is equipped with a segmented-type crystal for x-ray diffraction and provides an energy resolution in the order of 0.25 eV and 1 eV over an energy range of 8000 eV-9600 eV. The use of a segmented crystal results in a simple and straightforward crystal preparation that allows to preserve the spectrometer resolution and spectrometer efficiency. Application of the spectrometer for time-resolved resonant inelastic x-ray scattering and single-shot x-ray emission spectroscopy is demonstrated.
A multi-dataset data-collection strategy produces better diffraction data

PubMed Central

Liu, Zhi-Jie; Chen, Lirong; Wu, Dong; Ding, Wei; Zhang, Hua; Zhou, Weihong; Fu, Zheng-Qing; Wang, Bi-Cheng

2011-01-01

A multi-dataset (MDS) data-collection strategy is proposed and analyzed for macromolecular crystal diffraction data acquisition. The theoretical analysis indicated that the MDS strategy can reduce the standard deviation (background noise) of diffraction data compared with the commonly used single-dataset strategy for a fixed X-ray dose. In order to validate the hypothesis experimentally, a data-quality evaluation process, termed a readiness test of the X-ray data-collection system, was developed. The anomalous signals of sulfur atoms in zinc-free insulin crystals were used as the probe to differentiate the quality of data collected using different data-collection strategies. The data-collection results using home-laboratory-based rotating-anode X-ray and synchrotron X-ray systems indicate that the diffraction data collected with the MDS strategy contain more accurate anomalous signals from sulfur atoms than the data collected with a regular data-collection strategy. In addition, the MDS strategy offered more advantages with respect to radiation-damage-sensitive crystals and better usage of rotating-anode as well as synchrotron X-rays. PMID:22011470
Powder diffraction and crystal structure prediction identify four new coumarin polymorphs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shtukenberg, Alexander G.; Zhu, Qiang; Carter, Damien J.

Coumarin, a simple, commodity chemical isolated from beans in 1820, has, to date, only yielded one solid state structure. Here, we report a rich polymorphism of coumarin grown from the melt. Four new metastable forms were identified and their crystal structures were solved using a combination of computational crystal structure prediction algorithms and X-ray powder diffraction. With five crystal structures, coumarin has become one of the few rigid molecules showing extensive polymorphism at ambient conditions. We demonstrate the crucial role of advanced electronic structure calculations including many-body dispersion effects for accurate ranking of the stability of coumarin polymorphs and themore » need to account for anharmonic vibrational contributions to their free energy. As such, coumarin is a model system for studying weak intermolecular interactions, crystallization mechanisms, and kinetic effects.« less
[The spectrum studies of structure characteristics in magma contact metamorphic coal].

PubMed

Wu, Dun; Sun, Ruo-Yu; Liu, Gui-Jian; Yuan, Zi-Jiao

2013-10-01

The structural parameters evolution of coal due to the influence of intrusions of hot magma was investigated and analyzed. X-ray diffraction and laser confocal microscope Raman spectroscopy were used to test and analyze 4 coal samples undergoing varying contact-metamorphism by igneous magmas in borehole No. 13-4 of Zhuji coal mine, Huainan coalfield. The result showed that coal XRD spectrum showed higher background intensity, with the 26 degrees and 42 degrees nearby apparent graphite diffraction peak. Two significant vibration peaks of coal Raman spectra were observed in the 1 000-2 000 cm(-1) frequency range: broad "D" peak at 1 328-1 369 cm(-1) and sharp "G" peak at 1 564-1 599 cm(-1). With the influence of magma intrusion, the relationship between coal structural parameters and coal ranks was excellent.
Powder diffraction and crystal structure prediction identify four new coumarin polymorphs

DOE PAGES

Shtukenberg, Alexander G.; Zhu, Qiang; Carter, Damien J.; ...

2017-05-15

Coumarin, a simple, commodity chemical isolated from beans in 1820, has, to date, only yielded one solid state structure. Here, we report a rich polymorphism of coumarin grown from the melt. Four new metastable forms were identified and their crystal structures were solved using a combination of computational crystal structure prediction algorithms and X-ray powder diffraction. With five crystal structures, coumarin has become one of the few rigid molecules showing extensive polymorphism at ambient conditions. We demonstrate the crucial role of advanced electronic structure calculations including many-body dispersion effects for accurate ranking of the stability of coumarin polymorphs and themore » need to account for anharmonic vibrational contributions to their free energy. As such, coumarin is a model system for studying weak intermolecular interactions, crystallization mechanisms, and kinetic effects.« less

Effects of rare-earth co-doping on the local structure of rare-earth phosphate glasses using high and low energy X-ray diffraction.

PubMed

Cramer, Alisha J; Cole, Jacqueline M; FitzGerald, Vicky; Honkimaki, Veijo; Roberts, Mark A; Brennan, Tessa; Martin, Richard A; Saunders, George A; Newport, Robert J

2013-06-14

Rare-earth co-doping in inorganic materials has a long-held tradition of facilitating highly desirable optoelectronic properties for their application to the laser industry. This study concentrates specifically on rare-earth phosphate glasses, (R2O3)x(R'2O3)y(P2O5)(1-(x+y)), where (R, R') denotes (Ce, Er) or (La, Nd) co-doping and the total rare-earth composition corresponds to a range between metaphosphate, RP3O9, and ultraphosphate, RP5O14. Thereupon, the effects of rare-earth co-doping on the local structure are assessed at the atomic level. Pair-distribution function analysis of high-energy X-ray diffraction data (Q(max) = 28 Å(-1)) is employed to make this assessment. Results reveal a stark structural invariance to rare-earth co-doping which bears testament to the open-framework and rigid nature of these glasses. A range of desirable attributes of these glasses unfold from this finding; in particular, a structural simplicity that will enable facile molecular engineering of rare-earth phosphate glasses with 'dial-up' lasing properties. When considered together with other factors, this finding also demonstrates additional prospects for these co-doped rare-earth phosphate glasses in nuclear waste storage applications. This study also reveals, for the first time, the ability to distinguish between P-O and P[double bond, length as m-dash]O bonding in these rare-earth phosphate glasses from X-ray diffraction data in a fully quantitative manner. Complementary analysis of high-energy X-ray diffraction data on single rare-earth phosphate glasses of similar rare-earth composition to the co-doped materials is also presented in this context. In a technical sense, all high-energy X-ray diffraction data on these glasses are compared with analogous low-energy diffraction data; their salient differences reveal distinct advantages of high-energy X-ray diffraction data for the study of amorphous materials.
{ital In-situ} x-ray investigation of hydrogen charging in thin film bimetallic electrodes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jisrawi, N.M.; Wiesmann, H.; Ruckman, M.W.

Hydrogen uptake and discharge by thin metallic films under potentiostatic control was studied using x-ray diffraction at the National Synchrotron Light Source (NSLS). The formation of metal-hydrogen phases in Pd, Pd-capped Nb and Pd/Nb multilayer electrode structures was deduced from x-ray diffraction data and correlated with the cyclic voltammetry (CV) peaks. The x-ray data was also used to construct a plot of the hydrogen concentration as a function of cell potential for a multilayered thin film. {copyright} {ital 1997 Materials Research Society.}
Quantitative analysis of crystalline pharmaceuticals in tablets by pattern-fitting procedure using X-ray diffraction pattern.

PubMed

Takehira, Rieko; Momose, Yasunori; Yamamura, Shigeo

2010-10-15

A pattern-fitting procedure using an X-ray diffraction pattern was applied to the quantitative analysis of binary system of crystalline pharmaceuticals in tablets. Orthorhombic crystals of isoniazid (INH) and mannitol (MAN) were used for the analysis. Tablets were prepared under various compression pressures using a direct compression method with various compositions of INH and MAN. Assuming that X-ray diffraction pattern of INH-MAN system consists of diffraction intensities from respective crystals, observed diffraction intensities were fitted to analytic expression based on X-ray diffraction theory and separated into two intensities from INH and MAN crystals by a nonlinear least-squares procedure. After separation, the contents of INH were determined by using the optimized normalization constants for INH and MAN. The correction parameter including all the factors that are beyond experimental control was required for quantitative analysis without calibration curve. The pattern-fitting procedure made it possible to determine crystalline phases in the range of 10-90% (w/w) of the INH contents. Further, certain characteristics of the crystals in the tablets, such as the preferred orientation, size of crystallite, and lattice disorder were determined simultaneously. This method can be adopted to analyze compounds whose crystal structures are known. It is a potentially powerful tool for the quantitative phase analysis and characterization of crystals in tablets and powders using X-ray diffraction patterns. Copyright 2010 Elsevier B.V. All rights reserved.
Structural, spectroscopic, and magnetic properties of Eu3+-doped GdVO4 nanocrystals synthesized by a hydrothermal method.

PubMed

Szczeszak, Agata; Grzyb, Tomasz; Śniadecki, Zbigniew; Andrzejewska, Nina; Lis, Stefan; Matczak, Michał; Nowaczyk, Grzegorz; Jurga, Stefan; Idzikowski, Bogdan

2014-12-01

New interesting aspects of the spectroscopic properties, magnetism, and method of synthesis of gadolinium orthovanadates doped with Eu(3+) ions are discussed. Gd(1-x)Eu(x)VO4 (x = 0, 0.05, 0.2) bifunctional luminescent materials with complex magnetic properties were synthesized by a microwave-assisted hydrothermal method. Products were formed in situ without previous precipitation. The crystal structures and morphologies of the obtained nanomaterials were analyzed by X-ray diffraction and transmission and scanning electron microscopy. Crystallographic data were analyzed using Rietveld refinement. The products obtained were nanocrystalline with average grain sizes of 70-80 nm. The qualitative and quantitative elemental composition as well as mapping of the nanocrystals was proved using energy-dispersive X-ray spectroscopy. The spectroscopic properties of red-emitting nanophosphors were characterized by their excitation and emission spectra and luminescence decays. Magnetic measurements were performed by means of vibrating sample magnetometry. GdVO4 and Gd0.8Eu0.2VO4 exhibited paramagnetic behavior with a weak influence of antiferromagnetic couplings between rare-earth ions. In the substituted sample, an additional magnetic contribution connected with the population of low-lying excited states of europium was observed.
Synthesis of MnxGa1-xFe2O4 magnetic nanoparticles by thermal decomposition method for medical diagnosis applications

NASA Astrophysics Data System (ADS)

Sánchez, Javier; Cortés-Hernández, Dora Alicia; Escobedo-Bocardo, José Concepción; Almanza-Robles, José Manuel; Reyes-Rodríguez, Pamela Yajaira; Jasso-Terán, Rosario Argentina; Bartolo-Pérez, Pascual; De-León-Prado, Laura Elena

2017-04-01

In this work, the synthesis of MnxGa1-xFe2O4 (x=0-1) nanosized particles by thermal decomposition method, using tetraethylene glycol (TEG) as a reaction medium, has been performed. The crystalline structure of the inverse spinel obtained in all the cases was identified by X-ray diffraction (XRD). Vibration sample magnetometry (VSM) was used to evaluate the magnetic properties of ferrites and to demonstrate their superparamagnetic behavior and the increase of magnetization values due to the Mn2+ ions incorporation into the FeGa2O4 structure. Transmission electron microscopy, energy dispersive spectroscopy (TEM-EDS) and X-ray photoelectron spectroscopy (XPS) were used to characterize the obtained magnetic nanoparticles (MNPs). These MNPs showed a near spherical morphology, an average particle size of 5.6±1.5 nm and a TEG coating layer on their surface. In all the cases MNPs showed no response when submitted to an alternating magnetic field (AMF, 10.2 kA/m, 354 kHz) using magnetic induction tests. These results suggest that the synthesized nanoparticles can be potential candidates for their use in biomedical areas.
Optical, electrical and ferromagnetic studies of ZnO:Fe diluted magnetic semiconductor nanoparticles for spintronic applications.

PubMed

Elilarassi, R; Chandrasekaran, G

2017-11-05

In the present investigation, diluted magnetic semiconductor (Zn 1-x Fe x O) nanoparticles with different doping concentrations (x=0, 0.02, 0.04, 0.06, and 0.08) were successfully synthesized by sol-gel auto-combustion method. The crystal structure, morphology, optical, electrical and magnetic properties of the prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive analysis using x-rays (EDAX), ultraviolet-visible spectrophotometer, fluorescence spectroscope (FS), vibrating sample magnetometer (VSM) and broad band dielectric spectrometer (BDS). XRD results reveal that all the samples possess hexagonal wurtzite crystal structure with good crystalline quality. The absence of impurity phases divulge that Fe ions are well incorporated into the ZnO crystal lattice. The substitutional incorporation of Fe 3+ at Zn sites is reflected in optical absorption spectra of the samples. Flouorescence spectra of the samples show a strong near-band edge related UV emission as well as defect related visible emissions. The semiconducting behavior of the samples has been confirmed through electrical conductivity measurements. Magnetic measurements indicated that all the samples possess ferromagnetism at room temperature. Copyright © 2017 Elsevier B.V. All rights reserved.
Rosalind Franklin's X-ray photo of DNA as an undergraduate optical diffraction experiment

NASA Astrophysics Data System (ADS)

Thompson, J.; Braun, G.; Tierney, D.; Wessels, L.; Schmitzer, H.; Rossa, B.; Wagner, H. P.; Dultz, W.

2018-02-01

Rosalind Franklin's X-ray diffraction patterns of DNA molecules rendered the important clue that DNA has the structure of a double helix. The most famous X-ray photograph, Photo 51, is still printed in most Biology textbooks. We suggest two optical experiments for undergraduates that make this historic achievement comprehensible for students by using macromodels of DNA and visible light to recreate a diffraction pattern similar to Photo 51. In these macromodels, we replace the double helix both mathematically and experimentally with its two-dimensional (flat) projection and explain why this is permissible. Basic optical concepts are used to infer certain well-known characteristics of DNA from the diffraction pattern.
Femtosecond X-ray diffraction from an aerosolized beam of protein nanocrystals

DOE PAGES

Awel, Salah; Kirian, Richard A.; Wiedorn, Max O.; ...

2018-02-01

High-resolution Bragg diffraction from aerosolized single granulovirus nanocrystals using an X-ray free-electron laser is demonstrated. The outer dimensions of the in-vacuum aerosol injector components are identical to conventional liquid-microjet nozzles used in serial diffraction experiments, which allows the injector to be utilized with standard mountings. As compared with liquid-jet injection, the X-ray scattering background is reduced by several orders of magnitude by the use of helium carrier gas rather than liquid. Such reduction is required for diffraction measurements of small macromolecular nanocrystals and single particles. High particle speeds are achieved, making the approach suitable for use at upcoming high-repetition-rate facilities.
Incoherent Diffractive Imaging via Intensity Correlations of Hard X Rays

NASA Astrophysics Data System (ADS)

Classen, Anton; Ayyer, Kartik; Chapman, Henry N.; Röhlsberger, Ralf; von Zanthier, Joachim

2017-08-01

Established x-ray diffraction methods allow for high-resolution structure determination of crystals, crystallized protein structures, or even single molecules. While these techniques rely on coherent scattering, incoherent processes like fluorescence emission—often the predominant scattering mechanism—are generally considered detrimental for imaging applications. Here, we show that intensity correlations of incoherently scattered x-ray radiation can be used to image the full 3D arrangement of the scattering atoms with significantly higher resolution compared to conventional coherent diffraction imaging and crystallography, including additional three-dimensional information in Fourier space for a single sample orientation. We present a number of properties of incoherent diffractive imaging that are conceptually superior to those of coherent methods.
Titration of a Solid Acid Monitored by X-Ray Diffraction

ERIC Educational Resources Information Center

Dungey, Keenan E.; Epstein, Paul

2007-01-01

An experiment is described to introduce students to an important class of solid-state reactions while reinforcing concepts of titration by using a pH meter and a powder X-ray diffractometer. The experiment was successful in teaching students the abstract concepts of solid-state structure and diffraction by applying the diffraction concepts learned…
Publications - GMC 42 | Alaska Division of Geological & Geophysical Surveys

Science.gov Websites

DGGS GMC 42 Publication Details Title: X-ray diffraction clay mineralogy analysis of the J.W. Dalton #1 for more information. Bibliographic Reference Unknown, 1984, X-ray diffraction clay mineralogy
Publications - GMC 297 | Alaska Division of Geological & Geophysical

Science.gov Websites

DGGS GMC 297 Publication Details Title: X-ray diffraction analysis of cuttings from the: Texaco Inc information. Bibliographic Reference Unknown, 2001, X-ray diffraction analysis of cuttings from the: Texaco
Publications - GMC 196 | Alaska Division of Geological & Geophysical

Science.gov Websites

DGGS GMC 196 Publication Details Title: X-ray diffraction patterns of clay from the following wells for more information. Bibliographic Reference Unknown, 1992, X-ray diffraction patterns of clay from
Publications - GMC 43 | Alaska Division of Geological & Geophysical Surveys

Science.gov Websites

DGGS GMC 43 Publication Details Title: X-ray diffraction clay mineralogy analysis of 23 North Slope more information. Bibliographic Reference Unknown, 1983, X-ray diffraction clay mineralogy analysis of
Multiple film plane diagnostic for shocked lattice measurements (invited)

NASA Astrophysics Data System (ADS)

Kalantar, Daniel H.; Bringa, E.; Caturla, M.; Colvin, J.; Lorenz, K. T.; Kumar, M.; Stölken, J.; Allen, A. M.; Rosolankova, K.; Wark, J. S.; Meyers, M. A.; Schneider, M.; Boehly, T. R.

2003-03-01

Laser-based shock experiments have been conducted in thin Si and Cu crystals at pressures above the Hugoniot elastic limit. In these experiments, static film and x-ray streak cameras recorded x rays diffracted from lattice planes both parallel and perpendicular to the shock direction. These data showed uniaxial compression of Si(100) along the shock direction and three-dimensional compression of Cu(100). In the case of the Si diffraction, there was a multiple wave structure observed, which may be due to a one-dimensional phase transition or a time variation in the shock pressure. A new film-based detector has been developed for these in situ dynamic diffraction experiments. This large-angle detector consists of three film cassettes that are positioned to record x rays diffracted from a shocked crystal anywhere within a full π steradian. It records x rays that are diffracted from multiple lattice planes both parallel and at oblique angles with respect to the shock direction. It is a time-integrating measurement, but time-resolved data may be recorded using a short duration laser pulse to create the diffraction source x rays. This new instrument has been fielded at the OMEGA and Janus lasers to study single-crystal materials shock compressed by direct laser irradiation. In these experiments, a multiple wave structure was observed on many different lattice planes in Si. These data provide information on the structure under compression.
Optically induced lattice deformations, electronic structure changes, and enhanced superconductivity in YBa 2Cu 3O 6.48

DOE PAGES

Mankowsky, R.; Fechner, M.; Forst, M.; ...

2017-02-28

Resonant optical excitation of apical oxygen vibrational modes in the normal state of underdoped YBa 2Cu 3O 6+x induces a transient state with optical properties similar to those of the equilibrium superconducting state. Amongst these, a divergent imaginary conductivity and a plasma edge are transiently observed in the photo-stimulated state. Femtosecond hard x-ray diffraction experiments have been used in the past to identify the transient crystal structure in this non-equilibrium state. Here, we start from these crystallographic features and theoretically predict the corresponding electronic rearrangements that accompany these structural deformations. Using density functional theory, we predict enhanced hole-doping of themore » CuO 2 planes. The empty chain Cu dy2-z2 orbital is calculated to strongly reduce in energy, which would increase c-axis transport and potentially enhance the interlayer Josephson coupling as observed in the THz-frequency response. From these results, we calculate changes in the soft x-ray absorption spectra at the Cu L-edge. As a result, femtosecond x-ray pulses from a free electron laser are used to probe changes in absorption at two photon energies along this spectrum and provide data consistent with these predictions.« less
Nanomodulated electron beams via electron diffraction and emittance exchange for coherent x-ray generation

NASA Astrophysics Data System (ADS)

Nanni, E. A.; Graves, W. S.; Moncton, D. E.

2018-01-01

We present a new method for generation of relativistic electron beams with current modulation on the nanometer scale and below. The current modulation is produced by diffracting relativistic electrons in single crystal Si, accelerating the diffracted beam and imaging the crystal structure, then transferring the image into the temporal dimension via emittance exchange. The modulation period can be tuned by adjusting electron optics after diffraction. This tunable longitudinal modulation can have a period as short as a few angstroms, enabling production of coherent hard x-rays from a source based on inverse Compton scattering with total accelerator length of approximately ten meters. Electron beam simulations from cathode emission through diffraction, acceleration, and image formation with variable magnification are presented along with estimates of the coherent x-ray output properties.
Magnetic and Dielectric Investigations of Mn-Doped Ba Hexaferrite Nanoparticles by Hydrothermal Approach

NASA Astrophysics Data System (ADS)

Adeela, N.; Khan, U.; Iqbal, M.; Riaz, S.; Ali, H.; Maaz, K.; Naseem, S.

2016-11-01

A hydrothermal method followed by heat treatment was used to synthesize Mn-substituted Ba2Co2- x Mn x Fe12O22 nanoparticles with a nominal chemical composition of 0 ≤ x < 1 and step gap of 0.3. In this study, the effect of Mn substitution on Co2Y-type barium hexaferrite is investigated after employing x-ray diffraction for crystal structure, field emission scanning electron microscopy for morphology, energy dispersive analysis of x-ray spectroscopy for elemental composition, Fourier transform infrared spectroscopy to confirm bond modes, and vibrating sample magnetometry for magnetic measurements. It was found that the sample at x = 0.9 is of particular interest due to its large coercivity and anisotropy. Later on, for x = 0.9, temperature-dependent magnetic analyses including hysteresis loops, zero-field-cooled, and field-cooled at a particular field of 100 Oe were performed. The decreasing trend in saturation magnetization with increase in temperature was estimated. On the other hand, first an increase and then decrease in coercivity values were observed. These loops also revealed dependence of coercivity on magneto-crystalline anisotropy and average crystallite size of nanoparticles. Dielectric measurements at x = 0.9 make it suitable for high frequency applications.
Theoretical calculation of coherent Laue-case conversion between x-rays and ALPs for an x-ray light-shining-through-a-wall experiment

NASA Astrophysics Data System (ADS)

Yamaji, T.; Yamazaki, T.; Tamasaku, K.; Namba, T.

2017-12-01

Single crystals have high atomic electric fields as much as 1 011 V /m , which correspond to magnetic fields of ˜103 T . These fields can be utilized to convert x-rays into axionlike particles (ALPs) coherently similar to x-ray diffraction. In this paper, we perform the first theoretical calculation of the Laue-case conversion in crystals based on the Darwin dynamical theory of x-ray diffraction. The calculation shows that the Laue-case conversion has longer interaction length than the Bragg case, and that ALPs in the keV range can be resonantly converted by tuning an incident angle of x-rays. ALPs with mass up to O (10 keV ) can be searched by light-shining-through-a-wall (LSW) experiments at synchrotron x-ray facilities.
DOE Office of Scientific and Technical Information (OSTI.GOV)

Chuvashova, Irina, E-mail: irina.chuvashova@gmail.com; Bayerisches Geoinstitut, University of Bayreuth, D-95440 Bayreuth; Bykova, Elena

In the present study single crystals of rhombohedral α-B were investigated under pressure to 60 GPa by means of single-crystal X-ray diffraction. The bulk modulus of α-B was found to be K=224(7) GPa (K′=3.0(3)). Measurements of interatomic distances as a function of pressure revealed that the intericosahedral two-center two-electron (2c–2e) bonds are almost as stiff as some of intraicosahedral ones. The three-center two-electron (3c–2e) intericosahedral bonds show much higher compliance compared to other bonds in α-B. The vibrational properties of α-B under pressure were investigated by Raman spectroscopy at pressures up to 160 GPa and IR spectroscopy at pressures upmore » to 53 GPa. - Graphical abstract: The rhombohedral α-B is highly incompressible and extremely stable: it maintains its crystal structure up to 160 GPa and its intericosahedral 2e2c bonds are almost as stiff as some of intraicosahedral ones. - Highlights: • Structural stability of α-B has been investigated up to 160 GPa on single crystals. • Single-crystal x-ray diffraction reveals that α-B is highly incompressible. • Compressibility of B{sub 12} icosahedra is considerably lower than that of the bulk material. • Intericosahedral 2e2c bonds are almost as stiff as some of intraicosahedral ones.« less

Quantitative assessment of copper proteinates used as animal feed additives using ATR-FTIR spectroscopy and powder X-ray diffraction (PXRD) analysis.

PubMed

Cantwell, Caoimhe A; Byrne, Laurann A; Connolly, Cathal D; Hynes, Michael J; McArdle, Patrick; Murphy, Richard A

2017-08-01

The aim of the present work was to establish a reliable analytical method to determine the degree of complexation in commercial metal proteinates used as feed additives in the solid state. Two complementary techniques were developed. Firstly, a quantitative attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopic method investigated modifications in vibrational absorption bands of the ligand on complex formation. Secondly, a powder X-ray diffraction (PXRD) method to quantify the amount of crystalline material in the proteinate product was developed. These methods were developed in tandem and cross-validated with each other. Multivariate analysis (MVA) was used to develop validated calibration and prediction models. The FTIR and PXRD calibrations showed excellent linearity (R 2 > 0.99). The diagnostic model parameters showed that the FTIR and PXRD methods were robust with a root mean square error of calibration RMSEC ≤3.39% and a root mean square error of prediction RMSEP ≤7.17% respectively. Comparative statistics show excellent agreement between the MVA packages assessed and between the FTIR and PXRD methods. The methods can be used to determine the degree of complexation in complexes of both protein hydrolysates and pure amino acids.
Establishment of the structural and enhanced physicochemical properties of the cocrystal-2-benzyl amino pyridine with oxalic acid

NASA Astrophysics Data System (ADS)

Sangeetha, M.; Mathammal, R.

2017-09-01

We report on a cocrystal of 2-(benzyl amino) pyridine (BAP) with oxalic acid (OA) in the ratio 1:1. The cocrystal was synthesised and single crystals were grown under slow evaporation technique at room temperature. Single crystal X-ray diffraction (SCXRD) analysis determined the structure of the cocrystal formed and it belongs to orthorhombic system with Cc space group. It was also subjected to X-ray Powder diffraction (XRPD) to confirm the cocrystal structure. Hirshfeld surfaces and fingerprints were plotted to analyze the intermolecular interactions. Spectroscopic techniques such as FTIR, FT-Raman and NMR were carried out to identify the functional groups present in the cocrystal. The bioactivity of the cocrystal was revealed from the UV-Vis analysis. Computational Density Functional Theory (DFT) was adopted at the B3LYP/6-31+G** level to calculate the optimized geometrical parameters and the vibrational frequencies of the cocrystal. The non-linear optical property of the cocrystal was revealed from the SHG test. The different types of interactions and delocalization of charge were analysed from Natural Bond Orbital (NBO) calculations. The HOMO-LUMO energies and MEP surface maps confirmed the pharmaceutical importance of the (1:1) BAPOA cocrystal. The cocrystal has been explored for the invitro antioxidant activity and insilico molecular docking studies.
The effects of fuel type in synthesis of NiFe2O4 nanoparticles by microwave assisted combustion method

NASA Astrophysics Data System (ADS)

Karcıoğlu Karakaş, Zeynep; Boncukçuoğlu, Recep; Karakaş, İbrahim H.

2016-04-01

In this study, it was investigated the effects of the used fuels on structural, morphological and magnetic properties of nanoparticles in nanoparticle synthesis with microwave assisted combustion method with an important method in quick, simple and low cost at synthesis of the nanoparticles. In this aim, glycine, urea and citric acid were used as fuel, respectively. The synthesised nanoparticles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer-Emmet-Teller surface area (BET), and vibrating sample magnetometry (VSM) techniques. We observed that fuel type is quite effective on magnetic properties and surface properties of the nanoparticles. X-ray difractograms of the obtained nanoparticles were compared with standard powder diffraction cards of NiFe2O4 (JCPDS Card Number 54-0964). The results demonstrated that difractograms are fully compatible with standard reflection peaks. According to the results of the XRD analysis, the highest crystallinity was observed at nanoparticles synthesized with glycine. The results demonstrated that the nanoparticles prepared with urea has the highest surface area. The micrographs of SEM showed that all of the nanoparticles have nano-crystalline behaviour and particles indication cubic shape. VSM analysis demonstrated that the type of fuel used for synthesis is highly effective a parameter on magnetic properties of nanoparticles.
Synthetic hydroxyapatites doped with Zn(II) studied by X-ray diffraction, infrared, Raman and thermal analysis

NASA Astrophysics Data System (ADS)

Guerra-López, José R.; Echeverría, Gustavo A.; Güida, Jorge A.; Viña, Raúl; Punte, Graciela

2015-06-01

Calcium hydroxyapatite (CaHap) formation when different amounts of Zn(II) are present in the mother solution has been investigated by atomic absorption, infrared and Raman spectroscopies, X-ray diffraction and thermal analysis (DTA and TG). The studied samples have been synthesized at T=95 °C and pH 9 in air. The analysis of the results have shown that the pure CaHap sample crystallizes in the monoclinic form P21/b. Concentrations up to 20% of Zn(II) in the mother solution, equivalent to smaller concentrations in solid (up to 9.1% in wt), favor the formation of the hexagonal apatite, P63/m, while Zn(II) concentrations higher than 20% in solution help an amorphous phase development where vibrational spectra indicated coexistence of two phases: an apatite and ZnNH4PO4·H2O. Infrared data of thermal treated samples endorse that HPO42- ion had not been incorporated in Zn(II) doped samples during the synthesis process. Present results also allow to conclude that Zn(II) cation exhibits a preference to occupy the Ca2 site of the apatite structure and induces water adsorption and a small quantity of CO32- cation incorporation, leading to formation of a less crystalline Ca deficient apatite.
Synthesis, DFT calculations of structure, vibrational and thermal decomposition studies of the metal complex Pb[Mn(C3H2O4)2(H2O)2].

PubMed

Gil, Diego M; Carbonio, Raúl E; Gómez, María Inés

2015-04-15

The metallo-organic complex Pb[Mn(C3H2O4)2(H2O)2] was synthesized and characterized by IR and Raman spectroscopy and powder X-ray diffraction methods. The cell parameters for the complex were determined from powder X-ray diffraction using the autoindexing program TREOR, and refined by the Le Bail method with the Fullprof program. A hexagonal unit cell was determined with a=b=13.8366(7)Å, c=9.1454(1)Å, γ=120°. The DFT calculated geometry of the complex anion [Mn(C3H2O4)2(H2O)2](2-) is very close to the experimental data reported for similar systems. The IR and Raman spectra and the thermal analysis of the complex indicate that only one type of water molecules is present in the structure. The thermal decomposition of Pb[Mn(C3H2O4)2(H2O)2] at 700 °C in air produces PbO and Pb2MnO4 as final products. The crystal structure of the mixed oxide is very similar to that reported for Pb3O4. Copyright © 2015 Elsevier B.V. All rights reserved.
Structural and DC electrical resistivity, magnetic properties of Co0.5M0.5Fe2O4 (M= Ni, Zn, and Mg) ferrite nanoparticles

NASA Astrophysics Data System (ADS)

Ramakrishna, A.; Murali, N.; Mammo, Tulu Wegayehu; Samatha, K.; Veeraiah, V.

2018-04-01

Inverse spinel structured nanoparticles of cobalt ferrite partially substituted by divalent cations of Ni, Zn, and Mg have been synthesized through sol-gel auto combustion route. Structural parameters are studied by powder X-ray diffraction at the diffraction angle range of 10-80°; and FT-IR spectroscopy in the wavenumber range of 1600-400 cm-1. Lattice parameters were calculated from the (hkl) values of the diffraction planes and interplanar spacing and found to be in the range of 8.3659-8.4197 Å. The surface morphology and crystalline nature are studied using scanning electron microscopy and also using HRTEM. The magnetic properties are analyzed through vibrating sample magnetometer. High saturation magnetization of 90.12 emu/g has been achieved from Co-Zn sample whereas high coercive force of 883.45 Oe is achieved in Co-Ni sample. A two-probe DC resistivity was measured in temperature ranges of 300-450 K.
X-ray phase Identification of Chocolate is Possible

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guthrie,S.; Mazzanti, G.; Idziak, S.

2005-01-01

When examining chocolate samples by means of X-ray diffraction, it has become common practice for any sugar to be removed through repeated rinsing in cold water. While necessary in some cases, we show that it is possible to determine the phase of certain dark chocolate samples without sugar removal, through examination of distinctive X-ray diffraction peaks corresponding to lattice spacings of 3.98 and 3.70 Angstroms.
The effect of laser radiation on the diffraction of X-rays in crystals

NASA Astrophysics Data System (ADS)

Trushin, V. N.; Chuprunov, E. V.; Khokhlov, A. F.

1988-10-01

The effect of laser radiation on the intensity of the X-ray diffraction peaks of KDP, ADP, and CuSO4-5H2O crystals was studied experimentally. This intensity was found to increase as a function of the laser beam power. This result suggests that it is possible to use laser beams to control X-ray intensity in the crystals considered.
X-ray laser–induced electron dynamics observed by femtosecond diffraction from nanocrystals of Buckminsterfullerene

PubMed Central

Abbey, Brian; Dilanian, Ruben A.; Darmanin, Connie; Ryan, Rebecca A.; Putkunz, Corey T.; Martin, Andrew V.; Wood, David; Streltsov, Victor; Jones, Michael W. M.; Gaffney, Naylyn; Hofmann, Felix; Williams, Garth J.; Boutet, Sébastien; Messerschmidt, Marc; Seibert, M. Marvin; Williams, Sophie; Curwood, Evan; Balaur, Eugeniu; Peele, Andrew G.; Nugent, Keith A.; Quiney, Harry M.

2016-01-01

X-ray free-electron lasers (XFELs) deliver x-ray pulses with a coherent flux that is approximately eight orders of magnitude greater than that available from a modern third-generation synchrotron source. The power density of an XFEL pulse may be so high that it can modify the electronic properties of a sample on a femtosecond time scale. Exploration of the interaction of intense coherent x-ray pulses and matter is both of intrinsic scientific interest and of critical importance to the interpretation of experiments that probe the structures of materials using high-brightness femtosecond XFEL pulses. We report observations of the diffraction of extremely intense 32-fs nanofocused x-ray pulses by a powder sample of crystalline C60. We find that the diffraction pattern at the highest available incident power significantly differs from the one obtained using either third-generation synchrotron sources or XFEL sources operating at low output power and does not correspond to the diffraction pattern expected from any known phase of crystalline C60. We interpret these data as evidence of a long-range, coherent dynamic electronic distortion that is driven by the interaction of the periodic array of C60 molecular targets with intense x-ray pulses of femtosecond duration. PMID:27626076
Near Edge X-Ray Absorption and X-Ray Photoelectron Diffraction Studies of the Structural Environment of Ge-Si Systems

NASA Astrophysics Data System (ADS)

Castrucci, P.; Gunnella, R.; Pinto, N.; Bernardini, R.; de Crescenzi, M.; Sacchi, M.

Near edge X-ray absorption spectroscopy (XAS), X-ray photoelectron diffraction (XPD) and Auger electron diffraction (AED) are powerful techniques for the qualitative study of the structural and electronic properties of several systems. The recent development of a multiple scattering approach to simulating experimental spectra opened a friendly way to the study of structural environments of solids and surfaces. This article reviews recent X-ray absorption experiments using synchrotron radiation which were performed at Ge L edges and core level electron diffraction measurements obtained using a traditional X-ray source from Ge core levels for ultrathin Ge films deposited on silicon substrates. Thermodynamics and surface reconstruction have been found to play a crucial role in the first stages of Ge growth on Si(001) and Si(111) surfaces. Both techniques show the occurrence of intermixing processes even for room-temperature-grown Ge/Si(001) samples and give a straightforward measurement of the overlayer tetragonal distortion. The effects of Sb as a surfactant on the Ge/Si(001) interface have also been investigated. In this case, evidence of layer-by-layer growth of the fully strained Ge overlayer with a reduced intermixing is obtained when one monolayer of Sb is predeposited on the surface.
Compact ultrahigh vacuum sample environments for x-ray nanobeam diffraction and imaging.

PubMed

Evans, P G; Chahine, G; Grifone, R; Jacques, V L R; Spalenka, J W; Schülli, T U

2013-11-01

X-ray nanobeams present the opportunity to obtain structural insight in materials with small volumes or nanoscale heterogeneity. The effective spatial resolution of the information derived from nanobeam techniques depends on the stability and precision with which the relative position of the x-ray optics and sample can be controlled. Nanobeam techniques include diffraction, imaging, and coherent scattering, with applications throughout materials science and condensed matter physics. Sample positioning is a significant mechanical challenge for x-ray instrumentation providing vacuum or controlled gas environments at elevated temperatures. Such environments often have masses that are too large for nanopositioners capable of the required positional accuracy of the order of a small fraction of the x-ray spot size. Similarly, the need to place x-ray optics as close as 1 cm to the sample places a constraint on the overall size of the sample environment. We illustrate a solution to the mechanical challenge in which compact ion-pumped ultrahigh vacuum chambers with masses of 1-2 kg are integrated with nanopositioners. The overall size of the environment is sufficiently small to allow their use with zone-plate focusing optics. We describe the design of sample environments for elevated-temperature nanobeam diffraction experiments demonstrate in situ diffraction, reflectivity, and scanning nanobeam imaging of the ripening of Au crystallites on Si substrates.
Compact ultrahigh vacuum sample environments for x-ray nanobeam diffraction and imaging

NASA Astrophysics Data System (ADS)

Evans, P. G.; Chahine, G.; Grifone, R.; Jacques, V. L. R.; Spalenka, J. W.; Schülli, T. U.

2013-11-01

X-ray nanobeams present the opportunity to obtain structural insight in materials with small volumes or nanoscale heterogeneity. The effective spatial resolution of the information derived from nanobeam techniques depends on the stability and precision with which the relative position of the x-ray optics and sample can be controlled. Nanobeam techniques include diffraction, imaging, and coherent scattering, with applications throughout materials science and condensed matter physics. Sample positioning is a significant mechanical challenge for x-ray instrumentation providing vacuum or controlled gas environments at elevated temperatures. Such environments often have masses that are too large for nanopositioners capable of the required positional accuracy of the order of a small fraction of the x-ray spot size. Similarly, the need to place x-ray optics as close as 1 cm to the sample places a constraint on the overall size of the sample environment. We illustrate a solution to the mechanical challenge in which compact ion-pumped ultrahigh vacuum chambers with masses of 1-2 kg are integrated with nanopositioners. The overall size of the environment is sufficiently small to allow their use with zone-plate focusing optics. We describe the design of sample environments for elevated-temperature nanobeam diffraction experiments demonstrate in situ diffraction, reflectivity, and scanning nanobeam imaging of the ripening of Au crystallites on Si substrates.
X-ray characterization of curved crystals for hard x-ray astronomy

NASA Astrophysics Data System (ADS)

Buffagni, Elisa; Bonnini, Elisa; Ferrari, Claudio; Virgilli, Enrico; Frontera, Filippo

2015-05-01

Among the methods to focus photons the diffraction in crystals results as one of the most effective for high energy photons. An assembling of properly oriented crystals can form a lens able to focus x-rays at high energy via Laue diffraction in transmission geometry; this is a Laue lens. The x-ray diffraction theory provides that the maximum diffraction efficiency is achieved in ideal mosaic crystals, but real mosaic crystals show diffraction efficiencies several times lower than the ideal case due to technological problems. An alternative and convenient approach is the use of curved crystals. We have recently optimized an efficient method based on the surface damage of crystals to produce self-standing uniformly curved Si, GaAs and Ge tiles of thickness up to 2-3 mm and curvature radii R down to a few meters. We show that, for curved diffracting planes, such crystals have a diffraction efficiency nearly forty times higher than the diffraction efficiency of perfect similar flat crystals, thus very close to that of ideal mosaic crystals. Moreover, in an alternative configuration where the diffracting planes are perpendicular to the curved ones, a focusing effect occurs and will be shown. These results were obtained for several energies between 17 and 120 keV with lab sources or at high energy facilities such as LARIX at Ferrara (Italy), ESRF at Grenoble (France), and ANKA at Karlsruhe (Germany).
Publications - GMC 95 | Alaska Division of Geological & Geophysical Surveys

Science.gov Websites

DGGS GMC 95 Publication Details Title: X-ray diffraction analysis of seven core samples from the information. Bibliographic Reference Bergman, S.C., and Stuart, C.J., 1988, X-ray diffraction analysis of
X-Ray Topography of Tetragonal Lysozyme Grown by the Temperature-Controlled Technique

NASA Technical Reports Server (NTRS)

Stojanoff, V.; Siddons, D. P.; Monaco, Lisa A.; Vekilov, Peter; Rosenberger, Franz

1997-01-01

Growth-induced defects in lysozyme crystals were observed by white-beam and monochromatic X-ray topography at the National Synchrotron Light Source (NSLS) at the Brookhaven National Laboratory (BNL). The topographic methods were non-destructive to the extent that traditional diffraction data collection could be performed to high resolution after topography. It was found that changes in growth parameters, defect concentration as detected by X-ray topography, and the diffraction quality obtainable from the crystals were all strongly correlated. In addition, crystals with fewer defects showed lower mosaicity and higher diffraction resolution as expected.
Crystallization and X-ray diffraction analysis of a catalytic domain of hyperthermophilic chitinase from Pyrococcus furiosus

PubMed Central

Mine, Shouhei; Nakamura, Tsutomu; Hirata, Kunio; Ishikawa, Kazuhiko; Hagihara, Yoshihisa; Uegaki, Koichi

2006-01-01

The crystallization and preliminary X-ray diffraction analysis of a catalytic domain of chitinase (PF1233 gene) from the hyperthermophilic archaeon Pyrococcus furiosus is reported. The recombinant protein, prepared using an Escherichia coli expression system, was crystallized by the hanging-drop vapour-diffusion method. An X-ray diffraction data set was collected at the undulator beamline BL44XU at SPring-8 to a resolution of 1.50 Å. The crystals belong to space group P212121, with unit-cell parameters a = 90.0, b = 92.8, c = 107.2 Å. PMID:16880559
Coded diffraction system in X-ray crystallography using a boolean phase coded aperture approximation

NASA Astrophysics Data System (ADS)

Pinilla, Samuel; Poveda, Juan; Arguello, Henry

2018-03-01

Phase retrieval is a problem present in many applications such as optics, astronomical imaging, computational biology and X-ray crystallography. Recent work has shown that the phase can be better recovered when the acquisition architecture includes a coded aperture, which modulates the signal before diffraction, such that the underlying signal is recovered from coded diffraction patterns. Moreover, this type of modulation effect, before the diffraction operation, can be obtained using a phase coded aperture, just after the sample under study. However, a practical implementation of a phase coded aperture in an X-ray application is not feasible, because it is computationally modeled as a matrix with complex entries which requires changing the phase of the diffracted beams. In fact, changing the phase implies finding a material that allows to deviate the direction of an X-ray beam, which can considerably increase the implementation costs. Hence, this paper describes a low cost coded X-ray diffraction system based on block-unblock coded apertures that enables phase reconstruction. The proposed system approximates the phase coded aperture with a block-unblock coded aperture by using the detour-phase method. Moreover, the SAXS/WAXS X-ray crystallography software was used to simulate the diffraction patterns of a real crystal structure called Rhombic Dodecahedron. Additionally, several simulations were carried out to analyze the performance of block-unblock approximations in recovering the phase, using the simulated diffraction patterns. Furthermore, the quality of the reconstructions was measured in terms of the Peak Signal to Noise Ratio (PSNR). Results show that the performance of the block-unblock phase coded apertures approximation decreases at most 12.5% compared with the phase coded apertures. Moreover, the quality of the reconstructions using the boolean approximations is up to 2.5 dB of PSNR less with respect to the phase coded aperture reconstructions.
X-ray absorption microtomography (microCT) and small beam diffraction mapping of sea urchin teeth.

PubMed

Stock, S R; Barss, J; Dahl, T; Veis, A; Almer, J D

2002-07-01

Two noninvasive X-ray techniques, laboratory X-ray absorption microtomography (microCT) and X-ray diffraction mapping, were used to study teeth of the sea urchin Lytechinus variegatus. MicroCT revealed low attenuation regions at near the tooth's stone part and along the carinar process-central prism boundary; this latter observation appears to be novel. The expected variation of Mg fraction x in the mineral phase (calcite, Ca(1-x)Mg(x)CO(3)) cannot account for all of the linear attenuation coefficient decrease in the two zones: this suggested that soft tissue is localized there. Transmission diffraction mapping (synchrotron X-radiation, 80.8 keV, 0.1 x 0.1mm(2) beam area, 0.1mm translation grid, image plate area detector) simultaneously probed variations in 3-D and showed that the crystal elements of the "T"-shaped tooth were very highly aligned. Diffraction patterns from the keel (adaxial web) and from the abaxial flange (containing primary plates and the stone part) differed markedly. The flange contained two populations of identically oriented crystal elements with lattice parameters corresponding to x=0.13 and x=0.32. The keel produced one set of diffraction spots corresponding to the lower x. The compositions were more or less equivalent to those determined by others for camarodont teeth, and the high Mg phase is expected to be disks of secondary mineral epitaxially related to the underlying primary mineral element. Lattice parameter gradients were not noted in the keel or flange. Taken together, the microCT and diffraction results indicated that there was a band of relatively high protein content, of up to approximately 0.25 volume fraction, in the central part of the flange and paralleling its adaxial and abaxial faces. X-ray microCT and microdiffraction data used in conjunction with protein distribution data will be crucial for understanding the properties of various biocomposites and their mechanical functions.
Reconstructive colour X-ray diffraction imaging--a novel TEDDI imaging method.

PubMed

Lazzari, Olivier; Jacques, Simon; Sochi, Taha; Barnes, Paul

2009-09-01

Tomographic Energy-Dispersive Diffraction Imaging (TEDDI) enables a unique non-destructive mapping of the interior of bulk objects, exploiting the full range of X-ray signals (diffraction, fluorescence, scattering, background) recorded. By analogy to optical imaging, a wide variety of features (structure, composition, orientation, strain) dispersed in X-ray wavelengths can be extracted and colour-coded to aid interpretation. The ultimate aim of this approach is to realise real-time high-definition colour X-ray diffraction imaging, on the timescales of seconds, so that one will be able to 'look inside' optically opaque apparatus and unravel the space/time-evolution of the materials chemistry taking place. This will impact strongly on many fields of science but there are currently two barriers to this goal: speed of data acquisition (a 2D scan currently takes minutes to hours) and loss of image definition through spatial distortion of the X-ray sampling volume. Here we present a data-collection scenario and reconstruction routine which overcomes the latter barrier and which has been successfully applied to a phantom test object and to real materials systems such as a carbonating cement block. These procedures are immediately transferable to the promising technology of multi-energy-dispersive-detector-arrays which are planned to deliver the other breakthrough, that of one-two orders of magnitude improvement in data acquisition rates, that will be needed to realise real-time high-definition colour X-ray diffraction imaging.
Nondestructive strain depth profiling with high energy X-ray diffraction: System capabilities and limitations

NASA Astrophysics Data System (ADS)

Zhang, Zhan; Wendt, Scott; Cosentino, Nicholas; Bond, Leonard J.

2018-04-01

Limited by photon energy, and penetration capability, traditional X-ray diffraction (XRD) strain measurements are only capable of achieving a few microns depth due to the use of copper (Cu Kα1) or molybdenum (Mo Kα1) characteristic radiation. For deeper strain depth profiling, destructive methods are commonly necessary to access layers of interest by removing material. To investigate deeper depth profiles nondestructively, a laboratory bench-top high-energy X-ray diffraction (HEXRD) system was previously developed. This HEXRD method uses an industrial 320 kVp X-Ray tube and the Kα1 characteristic peak of tungsten, to produces a higher intensity X-ray beam which enables depth profiling measurement of lattice strain. An aluminum sample was investigated with deformation/load provided using a bending rig. It was shown that the HEXRD method is capable of strain depth profiling to 2.5 mm. The method was validated using an aluminum sample where both the HEXRD method and the traditional X-ray diffraction method gave data compared with that obtained using destructive etching layer removal, performed by a commercial provider. The results demonstrate comparable accuracy up to 0.8 mm depth. Nevertheless, higher attenuation capabilities in heavier metals limit the applications in other materials. Simulations predict that HEXRD works for steel and nickel in material up to 200 µm, but experiment results indicate that the HEXRD strain profile is not practical for steel and nickel material, and the measured diffraction signals are undetectable when compared to the noise.

New software to model energy dispersive X-ray diffraction in polycrystalline materials

NASA Astrophysics Data System (ADS)

Ghammraoui, B.; Tabary, J.; Pouget, S.; Paulus, C.; Moulin, V.; Verger, L.; Duvauchelle, Ph.

2012-02-01

Detection of illicit materials, such as explosives or drugs, within mixed samples is a major issue, both for general security and as part of forensic analyses. In this paper, we describe a new code simulating energy dispersive X-ray diffraction patterns in polycrystalline materials. This program, SinFullscat, models diffraction of any object in any diffractometer system taking all physical phenomena, including amorphous background, into account. Many system parameters can be tuned: geometry, collimators (slit and cylindrical), sample properties, X-ray source and detector energy resolution. Good agreement between simulations and experimental data was obtained. Simulations using explosive materials indicated that parameters such as the diffraction angle or the energy resolution of the detector have a significant impact on the diffraction signature of the material inspected. This software will be a convenient tool to test many diffractometer configurations, providing information on the one that best restores the spectral diffraction signature of the materials of interest.
Femtosecond X-ray coherent diffraction of aligned amyloid fibrils on low background graphene.

PubMed

Seuring, Carolin; Ayyer, Kartik; Filippaki, Eleftheria; Barthelmess, Miriam; Longchamp, Jean-Nicolas; Ringler, Philippe; Pardini, Tommaso; Wojtas, David H; Coleman, Matthew A; Dörner, Katerina; Fuglerud, Silje; Hammarin, Greger; Habenstein, Birgit; Langkilde, Annette E; Loquet, Antoine; Meents, Alke; Riek, Roland; Stahlberg, Henning; Boutet, Sébastien; Hunter, Mark S; Koglin, Jason; Liang, Mengning; Ginn, Helen M; Millane, Rick P; Frank, Matthias; Barty, Anton; Chapman, Henry N

2018-05-09

Here we present a new approach to diffraction imaging of amyloid fibrils, combining a free-standing graphene support and single nanofocused X-ray pulses of femtosecond duration from an X-ray free-electron laser. Due to the very low background scattering from the graphene support and mutual alignment of filaments, diffraction from tobacco mosaic virus (TMV) filaments and amyloid protofibrils is obtained to 2.7 Å and 2.4 Å resolution in single diffraction patterns, respectively. Some TMV diffraction patterns exhibit asymmetry that indicates the presence of a limited number of axial rotations in the XFEL focus. Signal-to-noise levels from individual diffraction patterns are enhanced using computational alignment and merging, giving patterns that are superior to those obtainable from synchrotron radiation sources. We anticipate that our approach will be a starting point for further investigations into unsolved structures of filaments and other weakly scattering objects.
Development of new magnetic nanoparticles: Oligochitosan obtained by γ-rays and -coated Fe3O4 nanoparticles

NASA Astrophysics Data System (ADS)

Le Thi, Thao Nguyen; Nguyen, Thi Hiep; Hoang, Dong Quy; Tran, Tuong, Vi; Nguyen, Ngoc Thuy; Nguyen, Dai Hai

2017-11-01

Oligochitosan (OCS) have been utilized as a potential bioactive material for improving food quality and human health. In this study, superparamagnetic iron oxide (Fe3O4) nanoparticles were originally coated with OCS irradiated by gamma rays for their possible biomedical applications. The formation of Fe3O4@OCS was characterized by Fourier transform infrared (FT-IR), X-ray diffraction patterns (XRD), energy dispersive X-ray spectroscopy (EDS) and thermogravimetric analysis (TGA). In addition, the superparamagnetic properties and sizes and morphologies of Fe3O4 and Fe3O4@OCS nanoparticles were demonstrated by vibrating sample magnetometer (VSM) and transmission electron microscopy (TEM), respectively. These results indicated that Fe3O4@OCS nanoparticles still maintained their superparamagnetic properties after polymeric coating, and were nearly spherical in shape with average diameter of 14.4 ± 0.31 nm, compared with 11.8 ± 0.52 nm of bare Fe3O4 nanoparticles, respectively. As a result, Fe3O4@OCS nanoparticles may serve as a promising platform for the development of new magnetic materials, which could be useful for biomedical applications.
Diffracted diffraction radiation and its application to beam diagnostics

NASA Astrophysics Data System (ADS)

Goponov, Yu. A.; Shatokhin, R. A.; Sumitani, K.; Syshchenko, V. V.; Takabayashi, Y.; Vnukov, I. E.

2018-03-01

We present theoretical considerations for diffracted diffraction radiation and also propose an application of this process to diagnosing ultra-relativistic electron (positron) beams for the first time. Diffraction radiation is produced when relativistic particles move near a target. If the target is a crystal or X-ray mirror, diffraction radiation in the X-ray region is expected to be diffracted at the Bragg angle and therefore be detectable. We present a scheme for applying this process to measurements of the beam angular spread, and consider how to conduct a proof-of-principle experiment for the proposed method.
Absolute x-ray energy calibration and monitoring using a diffraction-based method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hong, Xinguo, E-mail: xhong@bnl.gov; Weidner, Donald J.; Duffy, Thomas S.

2016-07-27

In this paper, we report some recent developments of the diffraction-based absolute X-ray energy calibration method. In this calibration method, high spatial resolution of the measured detector offset is essential. To this end, a remotely controlled long-translation motorized stage was employed instead of the less convenient gauge blocks. It is found that the precision of absolute X-ray energy calibration (ΔE/E) is readily achieved down to the level of 10{sup −4} for high-energy monochromatic X-rays (e.g. 80 keV). Examples of applications to pair distribution function (PDF) measurements and energy monitoring for high-energy X-rays are presented.
High-energy cryo x-ray nano-imaging at the ID16A beamline of ESRF

NASA Astrophysics Data System (ADS)

da Silva, Julio C.; Pacureanu, Alexandra; Yang, Yang; Fus, Florin; Hubert, Maxime; Bloch, Leonid; Salome, Murielle; Bohic, Sylvain; Cloetens, Peter

2017-09-01

The ID16A beamline at ESRF offers unique capabilities for X-ray nano-imaging, and currently produces the worlds brightest high energy diffraction-limited nanofocus. Such a nanoprobe was designed for quantitative characterization of the morphology and the elemental composition of specimens at both room and cryogenic temperatures. Billions of photons per second can be delivered in a diffraction-limited focus spot size down to 13 nm. Coherent X-ray imaging techniques, as magnified holographic-tomography and ptychographic-tomography, are implemented as well as X-ray fluorescence nanoscopy. We will show the latest developments in coherent and spectroscopic X-ray nanoimaging implemented at the ID16A beamline
X-ray monitoring optical elements

DOEpatents

Stoupin, Stanislav; Shvydko, Yury; Katsoudas, John; Blank, Vladimir D.; Terentyev, Sergey A.

2016-12-27

An X-ray article and method for analyzing hard X-rays which have interacted with a test system. The X-ray article is operative to diffract or otherwise process X-rays from an input X-ray beam which have interacted with the test system and at the same time provide an electrical circuit adapted to collect photoelectrons emitted from an X-ray optical element of the X-ray article to analyze features of the test system.
Investigations on the properties of NH4HCO3 filled natural rubber based magnetorheological elastomers (MREs)

NASA Astrophysics Data System (ADS)

Fan, Lili; Wang, Guoping; Wang, Wenju; Shi, Guanxin; Yang, Fufeng; Rui, Xiaoting

2018-04-01

Various anisotropic magnetorheological elastomers (MREs) were synthesized using the rubber mixing technique. Magnetic and temperature distributions of the experimental equipment and test instruments were analyzed by the ANSYS. NH4HCO3 was filled in the natural rubber matrix to modify properties of MREs. Microstructures and compositions of samples were studied by the scanning electron microscope (SEM), the energy dispersive x-ray spectroscopy (EDAX) analysis and x-ray powder diffraction (XRD). Via vibrating sample magnetometer (VSM) and density functional theory (DFT) method, the magnetic property of carbonyl iron (CI) was illuminated. The shear storage modulus and MR effect of MREs were investigated by the dynamic mechanical analyzer (DMA). It indicated that distributions of magnetic and temperature in the experimental and testing devices were uniform. Before vulcanization, CI particles were uniformly distributed in the matrix, while a CI chain structure was formed and embedded in the matrix after the vulcanization process. Moderate addition of NH4HCO3 accelerated the rubber vulcanization and enhanced the MR effect.
Investigation of optical properties and the photocatalytic activity of synthesized YbYO4 nanoparticles and YbVO4/NiWO4 nanocomposites by polymeric capping agents

NASA Astrophysics Data System (ADS)

Pourmasoud, Saeid; Sobhani-Nasab, Ali; Behpour, Mohsen; Rahimi-Nasrabadi, Mehdi; Ahmadi, Farhad

2018-04-01

YbVO4 nanoparticles YbVO4/NiWO4 nanocomposites were synthesized by simple and new method. The effect of various polymeric capping agents such as Tween 80, Tween 20 and PEG on the shape and size of YbVO4/NiWO4 nanocomposites were investigated. YbVO4/NiWO4 nanocomposites were analyzed through some techniques including, X-ray diffraction (XRD), Fourier-transform infrared (FT-IR) spectroscopy, vibrating sample magnetometer (VSM), thermogravimetry differential thermal analysis (TG-DTA), transmission electron microscopy (TEM), field emission electron microscopy (FESEM), ultraviolet-visible spectroscopy (UV-Vis), and energy-dispersive X-ray spectroscopy (EDX). This attempt is the first study on the photocatalytic performance of the YbVO4/NiWO4 nanocomposites in various conditions such as size of particles and kind of dyes (rhodamine B (Rh B), methylene blue (MB), methyl orange (MO), and phenol red (Ph R)), under visible light.
Novel synthesis of cobalt/poly vinyl alcohol/gamma alumina nanocomposite for catalytic application

NASA Astrophysics Data System (ADS)

Hatamie, Shadie; Ahadian, Mohammad Mahdi; Rashidi, Alimoradeh; Karimi, Ali; Akhavan, Omid

2017-05-01

In this manuscript, synthesis of cobalt/poly vinyl alcohol (PVA)/gamma alumina nanocomposite via a simple room temperature, as well as its catalyst performance were explored. Brunauer-Emmett-Teller analysis, X-ray diffraction, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy were conducted. The surface area of the polymeric composite was obtained to be 280 m2/g. The cobalt loading on the nanocomposite was measured using inductivity couple plasma. Transmission electron microscopy analysis showed that the size of cobalt crystalline encapsulate inside the polymer was confined to 5 nm. Magnetic property analysis, using vibrating sample magnetometer, confirmed ferromagnetic nature of the composite. Thermo-gravimetric analyses were employed to explain the degradation process for the polymeric base nanocomposite. Temperature-programmed reduction was used to evaluate the structural form of cobalt oxide in nanocomposite. The catalysis activity was determined by Fischer-Tropsch synthesize, which showed a high catalyst selectivity to C2-C4 hydrocarbons.
Metal copper films deposited on cenosphere particles by magnetron sputtering method

NASA Astrophysics Data System (ADS)

Yu, Xiaozheng; Xu, Zheng; Shen, Zhigang

2007-05-01

Metal copper films with thicknesses from several nanometres to several micrometres were deposited on the surface of cenosphere particles by the magnetron sputtering method under different working conditions. An ultrasonic vibrating generator equipped with a conventional magnetron sputtering apparatus was used to prevent the cenosphere substrates from accumulating during film growth. The surface morphology, the chemical composition, the average grain size and the crystallization of cenosphere particles were characterized by field emission scanning electron microscopy (FE-SEM), inductively coupled plasma-atom emission spectrometer, x-ray photoelectron spectroscopy and x-ray diffraction (XRD) analysis, respectively, before and after the plating process. The results indicate that the copper films were successfully deposited on cenosphere particles. It was found from the FE-SEM results that the films were well compacted and highly uniform in thickness. The XRD results show that the copper film coated on cenospheres has a face centred cubic structure and the crystallization of the film sample increases with increasing sputtering power.
Preparation of Nano-sized Bismuth-Doped Fe3O4 as an Excellent Magnetic Material for Supercapacitor Electrodes

NASA Astrophysics Data System (ADS)

Aghazadeh, Mustafa; Karimzadeh, Isa; Ganjali, Mohammad Reza

2018-03-01

Nano-sized Bi3+-doped iron oxide (n-Bi-IO) particles were prepared through a one-pot electrochemical procedure, and the product was evaluated using x-ray diffraction, field-emission scanning electron microscopy and energy-dispersive x-ray spectroscopy. Based on the analyses, the average size of the n-Bi-IO was determined to be 10 nm. Galvanostatic charge-discharge (GCD) evaluations revealed that the specific capacitance of the material reached 235 F g-1 at a discharge condition of 0.2 A g-1. n-Bi-IO had a 94.2% capacity retention after 2000 GCD cycles. Further vibrating sample magnetometery analyses showed that the product has enhanced superparamagnetic qualities (i.e. M r = 0.15 emu g-1 and H Ci = 2.71 G) in comparison to iron oxide nanoparticles (i.e. M r = 0.95 emu g-1 and H Ci = 14.62 G). Given the results, the product is considered to be a promising material for developing high performance supercapacitor electrodes.
Green Synthesis and Characterization of SmVO4 Nanoparticles in the Presence of Carbohydrates As Capping Agents with Investigation of Visible-Light Photocatalytic Properties

NASA Astrophysics Data System (ADS)

Eghbali-Arani, Mohammad; Sobhani-Nasab, Ali; Rahimi-Nasrabadi, Mehdi; Pourmasoud, Saeid

2018-03-01

SmVO4 nanoparticles were synthesized through a fast and simple procedure (green method). The effects of three parameters including temperature, type of capping agent, and concentration on the size and morphology behavior of SmVO4 nanoparticles were explored. The analysis of SmVO4 nanoparticles was performed through some techniques including, Fourier transform infrared spectroscopy, x-ray diffraction, energy dispersive x-ray microanalysis, scanning electron microscopy, transmission electron microscopy, thermogravimetry, differential thermal analysis, ultraviolet-visible spectroscopy, and vibrating sample magnetometers. The study of photocatalytic behaviour of the SmVO4 nanoparticles in various conditions has been carried out. The impacts of different factors such as dosage, grain size, and kind of pollutant (methylene blue = MB and methyl orange = MO) on the photocatalytic property of SmVO4 nanoparticles were assessed. The photocatalytic activities of SmVO4 catalysts were studied for the degradation of dye under visible light (λ > 400 nm).
Eco-friendly and green synthesis of BiVO4 nanoparticle using microwave irradiation as photocatalayst for the degradation of Alizarin Red S

NASA Astrophysics Data System (ADS)

Abraham, S. Daniel; David, S. Theodore; Bennie, R. Biju; Joel, C.; Kumar, D. Sanjay

2016-06-01

Bismuth vanadate (BiVO4) nanocrystals have been successfully synthesised using microwave-assisted combustion synthesis (MCS), and characterised using Fourier transform infrared (FT-IR) and Raman spectra, surface area analysis (BET), X-ray diffraction (XRD), scanning electron microscopy (SEM), Energy Dispersive X-ray analysis (EDX), diffused reflectance spectroscopy (DRS) and Photoluminescence (PL) spectroscopy. The XRD results confirmed the formation of monoclinic bismuth vanadate. The formations of BiO & VO43-vibrations were ascertained from FT-IR data. The morphology of hallow internal structural micro entities were confirmed by SEM. The optical properties were determined by DRS and PL spectra. Hence, the influence of the preparation methods on the structure, morphology and optical activities of bismuth vanadate was investigated systematically. Photocatalytic degradation (PCD) of Alizarin Red S (ARS), an effective disrupting chemical in aqueous medium was investigated using BiVO4 nanoparticles. The kinetics of PCD was found to follow pseudo first-order.
Publications - GMC 45 | Alaska Division of Geological & Geophysical Surveys

Science.gov Websites

DGGS GMC 45 Publication Details Title: X-ray diffraction mineral percentages of chips from Exxon Pt , 1983, X-ray diffraction mineral percentages of chips from Exxon Pt. Thomson Unit #1 and #3 wells
Publications - GMC 361 | Alaska Division of Geological & Geophysical

Science.gov Websites

DGGS GMC 361 Publication Details Title: X-ray Diffraction Analysis of: Drew Point #1, East Simpson Test , 2009, X-ray Diffraction Analysis of: Drew Point #1, East Simpson Test Well #1, East Simpson #2
Publications - GMC 41 | Alaska Division of Geological & Geophysical Surveys

Science.gov Websites

DGGS GMC 41 Publication Details Title: X-ray diffraction clay mineralogy analysis of core samples from Unknown, [n.d.], X-ray diffraction clay mineralogy analysis of core samples from Mobil West Staines State
TAKASAGO-6 apparatus for cryogenic coherent X-ray diffraction imaging of biological non-crystalline particles using X-ray free electron laser at SACLA.

PubMed

Kobayashi, Amane; Sekiguchi, Yuki; Takayama, Yuki; Oroguchi, Tomotaka; Shirahama, Keiya; Torizuka, Yasufumi; Manoda, Masahiro; Nakasako, Masayoshi; Yamamoto, Masaki

2016-05-01

Coherent X-ray diffraction imaging (CXDI) is a technique for structure analyses of non-crystalline particles with dimensions ranging from micrometer to sub-micrometer. We have developed a diffraction apparatus named TAKASAGO-6 for use in single-shot CXDI experiments of frozen-hydrated non-crystalline biological particles at cryogenic temperature with X-ray free electron laser pulses provided at a repetition rate of 30 Hz from the SPring-8 Angstrom Compact free-electron LAser. Specimen particles are flash-cooled after being dispersed on thin membranes supported by specially designed disks. The apparatus is equipped with a high-speed translation stage with a cryogenic pot for raster-scanning of the disks at a speed higher than 25 μm/33 ms. In addition, we use devices assisting the easy transfer of cooled specimens from liquid-nitrogen storages to the cryogenic pot. In the current experimental procedure, more than 20 000 diffraction patterns can be collected within 1 h. Here we report the key components and performance of the diffraction apparatus. Based on the efficiency of the diffraction data collection and the structure analyses of metal particles, biological cells, and cellular organelles, we discuss the future application of this diffraction apparatus for structure analyses of biological specimens.
Synchrotron X-ray diffraction and Raman spectroscopy of Ln{sub 3}NbO{sub 7} (Ln=La, Pr, Nd, Sm-Lu) ceramics obtained by molten-salt synthesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Siqueira, K.P.F.; Soares, J.C.; Granado, E.

2014-01-15

Ln{sub 3}NbO{sub 7} (Ln=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) ceramics were obtained by molten-salt synthesis and their structures were systematically investigated by synchrotron X-ray diffraction (SXRD), second harmonic generation (SHG) and Raman spectroscopy. It was observed that ceramics with the largest ionic radii (La, Pr, Nd) crystallized into the Pmcn space group, while the ceramics with intermediate ionic radii (Sm-Gd) exhibited a different crystal structure belonging to the Ccmm space group. For this last group of ceramics, this result was corroborated by SHG and Raman scattering and ruled out any possibility formore » the non-centrosymmetric C 222{sub 1} space group, solving a recent controversy in the literature. Finally, according to SXRD, Tb-Lu containing samples exhibited an average defect fluorite structure (Fm3{sup ¯}m space group). Nonetheless, broad scattering at forbidden Bragg reflections indicates the presence of short-range domains with lower symmetry. Vibrational spectroscopy showed the presence of six Raman-active modes, inconsistent with the average cubic fluorite structure, and in line with the existence of lower-symmetry nano-domains immersed in the average fluorite structure of these ceramics. - Graphical abstract: Raman spectrum for Sm{sub 3}NbO{sub 7} ceramics showing their 27 phonon modes adjusted through Lorentzian lines. According to synchrotron X-ray diffraction and Raman scattering, this material belongs to the space group Cmcm. Display Omitted - Highlights: • Ln{sub 3}NbO{sub 7} ceramics were obtained by molten-salt synthesis. • SXRD, SHG and Raman scattering confirmed orthorhombic and cubic structures. • Ccmm instead of C222{sub 1} is the correct structure for Sm–Gd ceramics. • Pmcn space group was confirmed for La-, Pr- and Nd-based ceramics. • For Tb–Lu ceramics, ordered domains of a pyrochlore structure were observed.« less
Development of a magnetic system for the treatment of Helicobacter pylori infections

NASA Astrophysics Data System (ADS)

Silva, Érica L.; Carvalho, Juliana F.; Pontes, Thales R. F.; Oliveira, Elquio E.; Francelino, Bárbara L.; Medeiros, Aldo C.; do Egito, E. Sócrates T.; Araujo, José H.; Carriço, Artur S.

2009-05-01

We report a study to develop a magnetic system for local delivery of amoxicillin. Magnetite microparticles produced by coprecipitation were coated with a solution of amoxicillin and Eudragit ®S100 by spray drying. Scanning electron microscopy, optical microscopy, X-ray powder diffraction and vibrating sample magnetometry revealed that the particles were superparamagnetic, with an average diameter of 17.2 μm, and an initial susceptibility controllable by the magnetite content in the suspension feeding the sprayer. Our results suggest a possible way to treat Helicobacter pylori infections, using an oral drug delivery system, and open prospects to coat magnetic microparticles by spray drying for biomedical applications.

Raman analysis of an impacted α-GeO2-H2O mixture

NASA Astrophysics Data System (ADS)

Rosales, Ivonne; Thions-Renero, Claude; Martinez, Erendira; Agulló-Rueda, Fernando; Bucio, Lauro; Orozco, Eligio

2012-09-01

Through a Raman analysis, we detected polymorphism at high pressure on mixtures of α-GeO2 microcrystalline powder and water under impact experiments with a single-stage gas gun. The Raman measurements taken from recovered samples show two vibrational modes associated with water-related species. After the impact, the size of the α-GeO2 crystallites was approximately 10 times higher showing molten zones and a lot of porous faces. Raman examination showed some unknown peaks possibly associated with other GeO2 polymorphs detected by X-ray diffraction experiments and perhaps stabilized in the porous of the α-GeO2 crystallites.
Swift heavy ion irradiation studies of GdFeO3 orthoferrite thin films

NASA Astrophysics Data System (ADS)

Kaur, Pawanpreet; Pandit, Rabia; Sharma, K. K.; Kumar, Ravi

2018-04-01

Thin films of GdFeO3, orthoferrite have been grown on MgO (001) substrate by pulsed laser deposition technique (PLD) to investigate the effect of swift heavy ion irradiation on their structural and magnetic properties. Thin films were irradiated with 200 MeV Ag15+ ions with fluence of 1×1011ions/cm2. The results of X-ray diffraction, atomic force microscopy and vibrating sample magnetometer characterization techniques are found to be different for the irradiated film from that of the pristine sample. The modifications in the irradiated samples are explained in terms of the ion-induced disorder.
Observation of ferromagnetism in Mn doped KNbO3

NASA Astrophysics Data System (ADS)

Manikandan, M.; Venkateswaran, C.

2015-06-01

Pure and Mn doped KNbO3 have been prepared by ball milling assisted ceramic method. Mn ion had been doped at Nb site to induce ferromagnetism at room temperature. X-ray diffraction (XRD) patterns reveal the formation of orthorhombic phase. High resolution scanning electron micrograph (HR-SEM) of both pure and Mn doped samples show a mixture of spherical and plate like particles. Room temperature magnetic behavior of both the samples were analyzed using vibrating sample magnetometer (VSM). 5% Mn doped KNbO3 exhibits ferromagnetic behavior. Observed ferromagnetic feature has been explained by interactions between bound magnetic polarons which are created by Mn4+ ions.
The Pressure-Induced Polymorphic Transformations in Fluconazole.

PubMed

Gorkovenko, Ekaterina A; Kichanov, Sergey E; Kozlenko, Denis P; Belushkin, Alexandr V; Wąsicki, Jan; Nawrocik, Wojciech; Mielcarek, Jadwiga; Dubrovinsky, Leonid S; Lathe, Christian; Savenko, Boris N

2015-12-01

The structural properties and Raman spectra of fluconazole have been studied by means of X-ray diffraction and Raman spectroscopy at pressures up to 2.5 and 5.5 GPa, respectively. At a pressure of 0.8 GPa, a polymorphic phase transition from the initial form I to a new triclinic form VIII has been observed. At higher pressure of P = 3.2 GPa, possible transformation into another new polymorphic form IX has been detected. The unit cell parameters and volumes, and vibration modes as functions of pressure have been obtained for the different forms of fluconazole. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.
Inclusion compound of vitamin B6 in β-CD. Physico-chemical and structural investigations

NASA Astrophysics Data System (ADS)

Borodi, Gheorghe; Kacso, Irina; Farcaş, Sorin I.; Bratu, Ioan

2009-08-01

Structural and physico-chemical characterization of supramolecular assembly of vitamin B6 with β-cyclodextrin (β-CD) prepared by different methods (kneading, co-precipitation and freeze-drying) has been performed by using several spectroscopic techniques (FTIR, 1H NMR, UV-Vis), powder X-ray diffraction and DSC in order to evidence the inclusion compound formation. An analysis of the chemical shifts observed in the 1H-NMR spectra and of the vibrational frequency shifts led to the tentative conclusion that the vitamin B6 probably enters the cyclodextrin torus when forming the β-CD-vitamin B6 inclusion complex.
XRD, SEM and infrared study into the intercalation of sodium hexadecyl sulfate (SHS) into hydrocalumite.

PubMed

Zhang, Ping; Wang, Tianqi; Zhang, Longlong; Wu, Daishe; Frost, Ray L

2015-12-05

Hydrocalumite (CaAl-LDH-Cl) interacted with a natural anionic surfactant, sodium hexadecyl sulfate (SHS), was performed using an intercalation method. To understand the intercalation behavior and characterize the resulting products, powder X-ray diffraction (XRD), scan electron microscopy (SEM) and mid-infrared (MIR) spectroscopy combined with near-infrared (NIR) spectroscopy technique were used. The XRD analysis indicated that SHS was intercalated into CaAl-LDH-Cl successfully, resulting in an expansion of the interlayer (from 0.78 nm to 2.74 nm). The bands of C-H stretching vibrations of SHS were observed in the near-infrared spectra, which indicated that the resulting products were indeed CaAl-LDH-SHS. In addition, the bands of water stretching vibrations and OH groups shifted to higher wavenumbers when SHS was intercalated into CaAl-LDH-Cl interlayer space. Copyright © 2015 Elsevier B.V. All rights reserved.
Substitution effect on a hydroxylated chalcone: Conformational, topological and theoretical studies

NASA Astrophysics Data System (ADS)

Custodio, Jean M. F.; Vaz, Wesley F.; de Andrade, Fabiano M.; Camargo, Ademir J.; Oliveira, Guilherme R.; Napolitano, Hamilton B.

2017-05-01

The effect of substituents on two hydroxylated chalcones was studied in this work. The first chalcone, with a dimethylamine group (HY-DAC) and the second, with three methoxy groups (HY-TRI) were synthesized and crystallized from ethanol on centrosymmetric space group P21/c. The geometric parameters and supramolecular arrangement for both structures obtained from single crystal X-ray diffraction data were analyzed. The intermolecular interactions were investigated by Hirshfeld surfaces with their respective 2D plot for quantification of each type of contact. Additionally, the observed interactions were characterized by QTAIM analysis, and DFT calculations were applied for theoretical vibrational spectra, localization and quantification of frontier orbitals and potential electrostatic map. The flatness of both structures was affected by the substituents, which led to different monoclinic crystalline packing. The calculated harmonic vibrational frequencies and homo-lumo gap confirmed the stability of the structures, while intermolecular interactions were confirmed by potential electrostatic map and QTAIM analysis.
Fourier transform infrared spectra and molecular structure of 5-methoxytryptamine, N-acetyl-5-methoxytryptamine and N-phenylsulfonamide-5-methoxytryptamine

NASA Astrophysics Data System (ADS)

Bayari, S.; Ide, S.

2003-04-01

5-Methoxytryptamine (5-MT) is a potent antioxidant and has radioprotective action. N-acetyl-5-methoxytryptamine (melatonin, NA-5-MT) is a free radical scavenger and antioxidant, which protects against oxidative damage due to a variety of toxicants. The infrared spectra of 5-MT, NA-5-MT and new synthesized N-phenylsulfonamide-5-methoxytryptamine (PS-5-MT) were investigated in the region between 4000 and 400 cm -1. Vibrational assignments of the molecules have been made for fundamental modes on the basis of the group vibrational concept, infrared intensity and comparison with the assignments for related molecules. X-ray powder diffraction patterns of molecules were also recorded. In order to optimize the geometries of the molecules, molecular mechanic calculations (MM3) were performed. Conformational analysis of 5-MT, NA-5-MT and PS-5-MT was also established by the using PM3 method.
Electrochemical performance of PVA stabilized nickel ferrite nanoparticles via microwave route

NASA Astrophysics Data System (ADS)

William, J. Johnson; Babu, I. Manohara; Muralidharan, G.

2017-05-01

Nanosized nickel ferrite nanoparticles were effectively synthesized through microwave route.PVA is used as a stabilizer. The cubic inverse spinel crystal structure was identified from the X-ray diffraction pattern. FTIR spectrum identified the octahedral site vibrations of the Ni2+ ions and tetrahedral sites vibrations of Fe3+ ions, which additionally confirms the existence of nickel ferrite nanoparticles. Nano-granular morphology was observed from scanning electron microscope. The tuning of morphology was clearly seen in SEM images. Electrochemical performance of nickel ferrite nanoparticles was studied using cyclic voltammetry and chronopotentiometry. Highest specific capacitance of 459 F g-1 was achieved through cyclic voltammetry at 2 mV s-1 for NF10. Also, non-linearity was observed in chronopotentiometry which confirms the pseudocapacitance nature of nickel ferrite nanoparticles. The estimated specific capacitance was 341 F g-1 at 2.5 A g-1.
Roadmap of ultrafast x-ray atomic and molecular physics

NASA Astrophysics Data System (ADS)

Young, Linda; Ueda, Kiyoshi; Gühr, Markus; Bucksbaum, Philip H.; Simon, Marc; Mukamel, Shaul; Rohringer, Nina; Prince, Kevin C.; Masciovecchio, Claudio; Meyer, Michael; Rudenko, Artem; Rolles, Daniel; Bostedt, Christoph; Fuchs, Matthias; Reis, David A.; Santra, Robin; Kapteyn, Henry; Murnane, Margaret; Ibrahim, Heide; Légaré, François; Vrakking, Marc; Isinger, Marcus; Kroon, David; Gisselbrecht, Mathieu; L'Huillier, Anne; Wörner, Hans Jakob; Leone, Stephen R.

2018-02-01

X-ray free-electron lasers (XFELs) and table-top sources of x-rays based upon high harmonic generation (HHG) have revolutionized the field of ultrafast x-ray atomic and molecular physics, largely due to an explosive growth in capabilities in the past decade. XFELs now provide unprecedented intensity (1020 W cm-2) of x-rays at wavelengths down to ˜1 Ångstrom, and HHG provides unprecedented time resolution (˜50 attoseconds) and a correspondingly large coherent bandwidth at longer wavelengths. For context, timescales can be referenced to the Bohr orbital period in hydrogen atom of 150 attoseconds and the hydrogen-molecule vibrational period of 8 femtoseconds; wavelength scales can be referenced to the chemically significant carbon K-edge at a photon energy of ˜280 eV (44 Ångstroms) and the bond length in methane of ˜1 Ångstrom. With these modern x-ray sources one now has the ability to focus on individual atoms, even when embedded in a complex molecule, and view electronic and nuclear motion on their intrinsic scales (attoseconds and Ångstroms). These sources have enabled coherent diffractive imaging, where one can image non-crystalline objects in three dimensions on ultrafast timescales, potentially with atomic resolution. The unprecedented intensity available with XFELs has opened new fields of multiphoton and nonlinear x-ray physics where behavior of matter under extreme conditions can be explored. The unprecedented time resolution and pulse synchronization provided by HHG sources has kindled fundamental investigations of time delays in photoionization, charge migration in molecules, and dynamics near conical intersections that are foundational to AMO physics and chemistry. This roadmap coincides with the year when three new XFEL facilities, operating at Ångstrom wavelengths, opened for users (European XFEL, Swiss-FEL and PAL-FEL in Korea) almost doubling the present worldwide number of XFELs, and documents the remarkable progress in HHG capabilities since its discovery roughly 30 years ago, showcasing experiments in AMO physics and other applications. Here we capture the perspectives of 17 leading groups and organize the contributions into four categories: ultrafast molecular dynamics, multidimensional x-ray spectroscopies; high-intensity x-ray phenomena; attosecond x-ray science.
Roadmap of ultrafast x-ray atomic and molecular physics

DOE PAGES

Young, Linda; Ueda, Kiyoshi; Gühr, Markus; ...

2018-01-09

X-ray free-electron lasers (XFELs) and table-top sources of x-rays based upon high harmonic generation (HHG) have revolutionized the field of ultrafast x-ray atomic and molecular physics, largely due to an explosive growth in capabilities in the past decade. XFELs now provide unprecedented intensity (10 20 W cm -2) of x-rays at wavelengths down to ~1 Ångstrom, and HHG provides unprecedented time resolution (~50 attoseconds) and a correspondingly large coherent bandwidth at longer wavelengths. For context, timescales can be referenced to the Bohr orbital period in hydrogen atom of 150 attoseconds and the hydrogen-molecule vibrational period of 8 femtoseconds; wavelength scalesmore » can be referenced to the chemically significant carbon K-edge at a photon energy of ~280 eV (44 Ångstroms) and the bond length in methane of ~1 Ångstrom. With these modern x-ray sources one now has the ability to focus on individual atoms, even when embedded in a complex molecule, and view electronic and nuclear motion on their intrinsic scales (attoseconds and Ångstroms). These sources have enabled coherent diffractive imaging, where one can image non-crystalline objects in three dimensions on ultrafast timescales, potentially with atomic resolution. The unprecedented intensity available with XFELs has opened new fields of multiphoton and nonlinear x-ray physics where behavior of matter under extreme conditions can be explored. The unprecedented time resolution and pulse synchronization provided by HHG sources has kindled fundamental investigations of time delays in photoionization, charge migration in molecules, and dynamics near conical intersections that are foundational to AMO physics and chemistry. This roadmap coincides with the year when three new XFEL facilities, operating at Ångstrom wavelengths, opened for users (European XFEL, Swiss-FEL and PAL-FEL in Korea) almost doubling the present worldwide number of XFELs, and documents the remarkable progress in HHG capabilities since its discovery roughly 30 years ago, showcasing experiments in AMO physics and other applications. Here in this paper, we capture the perspectives of 17 leading groups and organize the contributions into four categories: ultrafast molecular dynamics, multidimensional x-ray spectroscopies; high-intensity x-ray phenomena; attosecond x-ray science.« less
Roadmap of ultrafast x-ray atomic and molecular physics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Young, Linda; Ueda, Kiyoshi; Gühr, Markus

X-ray free-electron lasers (XFELs) and table-top sources of x-rays based upon high harmonic generation (HHG) have revolutionized the field of ultrafast x-ray atomic and molecular physics, largely due to an explosive growth in capabilities in the past decade. XFELs now provide unprecedented intensity (10 20 W cm -2) of x-rays at wavelengths down to ~1 Ångstrom, and HHG provides unprecedented time resolution (~50 attoseconds) and a correspondingly large coherent bandwidth at longer wavelengths. For context, timescales can be referenced to the Bohr orbital period in hydrogen atom of 150 attoseconds and the hydrogen-molecule vibrational period of 8 femtoseconds; wavelength scalesmore » can be referenced to the chemically significant carbon K-edge at a photon energy of ~280 eV (44 Ångstroms) and the bond length in methane of ~1 Ångstrom. With these modern x-ray sources one now has the ability to focus on individual atoms, even when embedded in a complex molecule, and view electronic and nuclear motion on their intrinsic scales (attoseconds and Ångstroms). These sources have enabled coherent diffractive imaging, where one can image non-crystalline objects in three dimensions on ultrafast timescales, potentially with atomic resolution. The unprecedented intensity available with XFELs has opened new fields of multiphoton and nonlinear x-ray physics where behavior of matter under extreme conditions can be explored. The unprecedented time resolution and pulse synchronization provided by HHG sources has kindled fundamental investigations of time delays in photoionization, charge migration in molecules, and dynamics near conical intersections that are foundational to AMO physics and chemistry. This roadmap coincides with the year when three new XFEL facilities, operating at Ångstrom wavelengths, opened for users (European XFEL, Swiss-FEL and PAL-FEL in Korea) almost doubling the present worldwide number of XFELs, and documents the remarkable progress in HHG capabilities since its discovery roughly 30 years ago, showcasing experiments in AMO physics and other applications. Here in this paper, we capture the perspectives of 17 leading groups and organize the contributions into four categories: ultrafast molecular dynamics, multidimensional x-ray spectroscopies; high-intensity x-ray phenomena; attosecond x-ray science.« less
Thermal expansion in UO 2 determined by high-energy X-ray diffraction

DOE PAGES

Guthrie, M.; Benmore, C. J.; Skinner, L. B.; ...

2016-06-24

In this study, we present crystallographic analyses of high-energy X-ray diffraction data on polycrystalline UO 2 up to the melting temperature. The Rietveld refinements of our X-ray data are in agreement with previous measurements, but are systematically located around the upper bound of their uncertainty, indicating a slightly steeper trend of thermal expansion compared to established values. This observation is consistent with recent first principles calculations.
DOE Office of Scientific and Technical Information (OSTI.GOV)

Hunter, Mark S.; Yoon, Chun Hong; DeMirci, Hasan

Structural information about biological macromolecules near the atomic scale provides important insight into the functions of these molecules. To date, X-ray crystallography has been the predominant method used for macromolecular structure determination. However, challenges exist when solving structures with X-rays, including the phase problem and radiation damage. X-ray-free electron lasers (X-ray FELs) have enabled collection of diffraction information before the onset of radiation damage, yet the majority of structures solved at X-ray FELs have been phased using external information via molecular replacement. De novo phasing at X-ray FELs has proven challenging due in part to per-pulse variations in intensity andmore » wavelength. Here we report the solution of a selenobiotinyl-streptavidin structure using phases obtained by the anomalous diffraction of selenium measured at a single wavelength (Se-SAD) at the Linac Coherent Light Source. Finally, our results demonstrate Se-SAD, routinely employed at synchrotrons for novel structure determination, is now possible at X-ray FELs.« less
Phase modulation due to crystal diffraction by ptychographic imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Civita, M.; Diaz, A.; Bean, R. J.

Solving the phase problem in x-ray crystallography has occupied a considerable scientific effort in the 20th century and led to great advances in structural science. Here we use x-ray ptychography to demonstrate an interference method which measures the phase of the beam transmitted through a crystal, relative to the incoming beam, when diffraction takes place. The observed phase change of the direct beam through a small gold crystal is found to agree with both a quasikinematical model and full dynamical theories of diffraction. Our discovery of a diffraction contrast mechanism will enhance the interpretation of data obtained from crystalline samplesmore » using the ptychography method, which provides some of the most accurate x-ray phase-contrast images.« less
Track membranes with open pores used as diffractive filters for space-based x-ray and EUV solar observations.

PubMed

Dominique, Marie; Mitrofanov, A V; Hochedez, J-F; Apel, P Yu; Schühle, U; Pudonin, F A; Orelovich, O L; Zuev, S Yu; Bolsée, D; Hermans, C; BenMoussa, A

2009-02-10

We describe the fabrication and performance of diffractive filters designed for space-based x-ray and EUV solar observations. Unlike traditional thin film filters, diffractive filters can be made to have a high resistance against the destructive mechanical and acoustic loads of a satellite launch. The filters studied are made of plastic track-etched membranes that are metal-coated on one side only. They have all-through open cylindrical pores with diameters as small as 500 nm, limiting their transmittance to very short wavelengths. The spectral transmittance of various diffractive filters with different pore parameters was measured from the soft x-ray to the near IR range (namely, from 1-1100 nm).
Phase modulation due to crystal diffraction by ptychographic imaging

DOE PAGES

Civita, M.; Diaz, A.; Bean, R. J.; ...

2018-03-06

Solving the phase problem in x-ray crystallography has occupied a considerable scientific effort in the 20th century and led to great advances in structural science. Here we use x-ray ptychography to demonstrate an interference method which measures the phase of the beam transmitted through a crystal, relative to the incoming beam, when diffraction takes place. The observed phase change of the direct beam through a small gold crystal is found to agree with both a quasikinematical model and full dynamical theories of diffraction. Our discovery of a diffraction contrast mechanism will enhance the interpretation of data obtained from crystalline samplesmore » using the ptychography method, which provides some of the most accurate x-ray phase-contrast images.« less
Phase modulation due to crystal diffraction by ptychographic imaging

NASA Astrophysics Data System (ADS)

Civita, M.; Diaz, A.; Bean, R. J.; Shabalin, A. G.; Gorobtsov, O. Yu.; Vartanyants, I. A.; Robinson, I. K.

2018-03-01

Solving the phase problem in x-ray crystallography has occupied a considerable scientific effort in the 20th century and led to great advances in structural science. Here we use x-ray ptychography to demonstrate an interference method which measures the phase of the beam transmitted through a crystal, relative to the incoming beam, when diffraction takes place. The observed phase change of the direct beam through a small gold crystal is found to agree with both a quasikinematical model and full dynamical theories of diffraction. Our discovery of a diffraction contrast mechanism will enhance the interpretation of data obtained from crystalline samples using the ptychography method, which provides some of the most accurate x-ray phase-contrast images.
Effect of Co2+ and Y3+ ions insertion on the microstructure development and magnetic properties of Ni0.5Zn0.5Fe2O4 powders synthesized using Co-precipitation method

NASA Astrophysics Data System (ADS)

Rashad, M. M.; Rayan, D. A.; Turky, A. O.; Hessien, M. M.

2015-01-01

Nanocrystalline Ni0.5Zn0.5-xCoxFe2-zYzO4 powders (x=0-0.3 and z from 0 to 0.3) have been synthesized via a facile co-precipitation technique. X-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM) are utilized in order to study the effect of variation of cobalt and yttrium substitutions and its impact on crystalline size, lattice parameter, X-ray density, microstructure and magnetic properties of the formed powders. X-ray diffraction data indicated that, after doping, all samples consisted of the main spinel phase for the formed precursors precipitated at pH 10 annealed at 1000 oC for 2 h. The lattice parameter and the unit cell were decreased linearly with increasing Co content whereas they were increased with increasing the Y incorporation. Additionally, the porosity was increased with increasing Co concentration while it was decreased with increasing the Y insertion. The mean ionic radii and hopping and bond lengths was decreased with the value of Co2+ and they were increased with the value of Y3+ ion as well as both of Y3+ and Co2+ ions. The microstructures of the produced powders were found to be cubic like structure. The addition of Y3+ ion suppressed the grain size whereas addition of Co2+ ion enhanced the grain growth availably. An examination of the magnetic properties revealed an increase in saturation magnetization with increasing Co and Y concentrations incorporation up to x=0.3. Meanwhile, the formed powders exhibited superparamagnetic characteristics. A high saturation magnetization (77.0 emu/g) was achieved for Ni0.5Zn0.2Co0.3Fe2O4 sample annealed at 1000 oC for 2 h.
X-Ray Diffraction for In-Situ Mineralogical Analysis of Planetesimals.

NASA Astrophysics Data System (ADS)

Sarrazin, P.; Blake, D. F.; Dera, P.; Downs, R. T.; Taylor, J.

2017-12-01

X-ray diffraction (XRD) is a general purpose technique for definitive, quantitative mineralogical analysis. When combined with XRF data for sample chemistry, XRD analyses yield as complete a characterization as is possible by any spacecraft-capable techniques. The MSL CheMin instrument, the first XRD instrument flown in space, has been used to establish the quantitative mineralogy of the Mars global soil, to discover the first habitable environment on another planet, and to provide the first in-situ evidence of silicic volcanism on Mars. CheMin is now used to characterize the depositional and diagenetic environments associated with the mudstone sediments of lower strata of Mt. Sharp. Conventional powder XRD requires samples comprised of small grains presented in random orientations. In CheMin, sample cells are vibrated to cause loose powder to flow within the cell, driven by granular convection, which relaxes the requirement for fine grained samples. Nevertheless, CheMin still requires mechanisms to collect, crush, sieve and deliver samples before analysis. XTRA (Extraterrestrial Regolith Analyzer) is an evolution of CheMin intended to analyze fines in as-delivered surface regolith, without sample preparation. Fine-grained regolith coats the surfaces of most airless bodies in the solar system, and because this fraction is typically comminuted from the rocky regolith, it can often be used as a proxy for the surface as a whole. HXRD (Hybrid-XRD) is concept under development to analyze rocks or soils without sample preparation. Like in CheMin, the diffracted signal is collected with direct illumination CCD's. If the material is sufficiently fine-grained, a powder XRD pattern of the characteristic X-ray tube emission is obtained, similar to CheMin or XTRA. With coarse grained crystals, the white bremsstrahlung radiation of the tube is diffracted into Laue patterns. Unlike typical Laue applications, HXRD uses the CCD's capability to distinguish energy and analyze the "colors" of each Laue spot, which enable phase identification. The concept was demonstrated with prototypes and dedicated crystallographic software was developed for identification the minerals responsible for the Laue patterns. High TRL subsystems are under development for future deployment opportunities of these new XRD instruments.

Nanomodulated electron beams via electron diffraction and emittance exchange for coherent x-ray generation

DOE PAGES

Nanni, E. A.; Graves, W. S.; Moncton, D. E.

2018-01-19

We present a new method for generation of relativistic electron beams with current modulation on the nanometer scale and below. The current modulation is produced by diffracting relativistic electrons in single crystal Si, accelerating the diffracted beam and imaging the crystal structure, then transferring the image into the temporal dimension via emittance exchange. The modulation period can be tuned by adjusting electron optics after diffraction. This tunable longitudinal modulation can have a period as short as a few angstroms, enabling production of coherent hard x-rays from a source based on inverse Compton scattering with total accelerator length of approximately tenmore » meters. Electron beam simulations from cathode emission through diffraction, acceleration, and image formation with variable magnification are presented along with estimates of the coherent x-ray output properties.« less
Nanomodulated electron beams via electron diffraction and emittance exchange for coherent x-ray generation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nanni, E. A.; Graves, W. S.; Moncton, D. E.

We present a new method for generation of relativistic electron beams with current modulation on the nanometer scale and below. The current modulation is produced by diffracting relativistic electrons in single crystal Si, accelerating the diffracted beam and imaging the crystal structure, then transferring the image into the temporal dimension via emittance exchange. The modulation period can be tuned by adjusting electron optics after diffraction. This tunable longitudinal modulation can have a period as short as a few angstroms, enabling production of coherent hard x-rays from a source based on inverse Compton scattering with total accelerator length of approximately tenmore » meters. Electron beam simulations from cathode emission through diffraction, acceleration, and image formation with variable magnification are presented along with estimates of the coherent x-ray output properties.« less
Coherent diffraction imaging analysis of shape-controlled nanoparticles with focused hard X-ray free-electron laser pulses.

PubMed

Takahashi, Yukio; Suzuki, Akihiro; Zettsu, Nobuyuki; Oroguchi, Tomotaka; Takayama, Yuki; Sekiguchi, Yuki; Kobayashi, Amane; Yamamoto, Masaki; Nakasako, Masayoshi

2013-01-01

We report the first demonstration of the coherent diffraction imaging analysis of nanoparticles using focused hard X-ray free-electron laser pulses, allowing us to analyze the size distribution of particles as well as the electron density projection of individual particles. We measured 1000 single-shot coherent X-ray diffraction patterns of shape-controlled Ag nanocubes and Au/Ag nanoboxes and estimated the edge length from the speckle size of the coherent diffraction patterns. We then reconstructed the two-dimensional electron density projection with sub-10 nm resolution from selected coherent diffraction patterns. This method enables the simultaneous analysis of the size distribution of synthesized nanoparticles and the structures of particles at nanoscale resolution to address correlations between individual structures of components and the statistical properties in heterogeneous systems such as nanoparticles and cells.
Cryogenic X-Ray Diffraction Microscopy for Biological Samples

NASA Astrophysics Data System (ADS)

Lima, Enju; Wiegart, Lutz; Pernot, Petra; Howells, Malcolm; Timmins, Joanna; Zontone, Federico; Madsen, Anders

2009-11-01

X-ray diffraction microscopy (XDM) is well suited for nondestructive, high-resolution biological imaging, especially for thick samples, with the high penetration power of x rays and without limitations imposed by a lens. We developed nonvacuum, cryogenic (cryo-) XDM with hard x rays at 8 keV and report the first frozen-hydrated imaging by XDM. By preserving samples in amorphous ice, the risk of artifacts associated with dehydration or chemical fixation is avoided, ensuring the imaging condition closest to their natural state. The reconstruction shows internal structures of intact D. radiodurans bacteria in their natural contrast.
Single-pulse coherent diffraction imaging using soft x-ray laser.

PubMed

Kang, Hyon Chol; Kim, Hyung Taek; Kim, Sang Soo; Kim, Chan; Yu, Tae Jun; Lee, Seong Ku; Kim, Chul Min; Kim, I Jong; Sung, Jae Hee; Janulewicz, Karol A; Lee, Jongmin; Noh, Do Young

2012-05-15

We report a coherent diffraction imaging (CDI) using a single 8 ps soft x-ray laser pulse at a wavelength of 13.9 nm. The soft x-ray pulse was generated by a laboratory-scale intense pumping laser providing coherent x-ray pulses up to the level of 10(11) photons/pulse. A spatial resolution below 194 nm was achieved with a single pulse, and it was shown that a resolution below 55 nm is feasible with improved detector capability. The single-pulse CDI might provide a way to investigate dynamics of nanoscale molecules or particles.
Observation of the strain field near the Si(111) 7 x 7 surface with a new X-ray diffraction technique.

PubMed

Emoto, T; Akimoto, K; Ichimiya, A

1998-05-01

A new X-ray diffraction technique has been developed in order to measure the strain field near a solid surface under ultrahigh vacuum (UHV) conditions. The X-ray optics use an extremely asymmetric Bragg-case bulk reflection. The glancing angle of the X-rays can be set near the critical angle of total reflection by tuning the X-ray energy. Using this technique, rocking curves for Si surfaces with different surface structures, i.e. a native oxide surface, a slightly oxide surface and an Si(111) 7 x 7 surface, were measured. It was found that the widths of the rocking curves depend on the surface structures. This technique is efficient in distinguishing the strain field corresponding to each surface structure.
3-Iodobenzaldehyde: XRD, FT-IR, Raman and DFT studies.

PubMed

Kumar, Chandraju Sadolalu Chidan; Parlak, Cemal; Tursun, Mahir; Fun, Hoong-Kun; Rhyman, Lydia; Ramasami, Ponnadurai; Alswaidan, Ibrahim A; Keşan, Gürkan; Chandraju, Siddegowda; Quah, Ching Kheng

2015-06-15

The structure of 3-iodobenzaldehyde (3IB) was characterized by FT-IR, Raman and single-crystal X-ray diffraction techniques. The conformational isomers, optimized geometric parameters, normal mode frequencies and corresponding vibrational assignments of 3IB were examined using density functional theory (DFT) method, with the Becke-3-Lee-Yang-Parr (B3LYP) functional and the 6-311+G(3df,p) basis set for all atoms except for iodine. The LANL2DZ effective core basis set was used for iodine. Potential energy distribution (PED) analysis of normal modes was performed to identify characteristic frequencies. 3IB crystallizes in monoclinic space group P21/c with the O-trans form. There is a good agreement between the theoretically predicted structural parameters, and vibrational frequencies and those obtained experimentally. In order to understand halogen effect, 3-halogenobenzaldehyde [XC6H4CHO; X=F, Cl and Br] was also studied theoretically. The free energy difference between the isomers is small but the rotational barrier is about 8kcal/mol. An atypical behavior of fluorine affecting conformational preference is observed. Copyright © 2015 Elsevier B.V. All rights reserved.
Phase transformation of calcium oxalate dihydrate-monohydrate: Effects of relative humidity and new spectroscopic data

NASA Astrophysics Data System (ADS)

Conti, Claudia; Casati, Marco; Colombo, Chiara; Realini, Marco; Brambilla, Luigi; Zerbi, Giuseppe

2014-07-01

New data on vibrational properties of calcium oxalates and their controversial transformation mechanism are presented. We have focused on whewellite (CaC2O4·H2O) and weddellite [CaC2O4·(2 + x) H2O], the most common phases of calcium oxalate; these compounds occur in many organisms, in kidney stones and in particular kinds of films found on the surface of many works of art. Low temperature experiments carried out by Fourier transform infrared spectroscopy have highlighted both the high structural order in the crystalline state of whewellite and the disordered distribution of the zeolitic water molecules in weddellite. The synthesised nanocrystals of weddellite have been kept under different hygrometric conditions in order to study, by X-ray powder diffraction, the role of “external” water molecules on their stability. Moreover, in order to identify the different kinds of water molecules, a re-investigation, supported by quantum chemical calculations, of the observed vibrational spectra (IR and Raman) of whewellite has been conducted.
Structural, magnetic and magnetocaloric properties of Fe17‑xMnxPr2 compounds

NASA Astrophysics Data System (ADS)

Guo, Yongbin; Ma, Lei; Chen, Tingyi; Zhou, Liang; Wang, Dao; Zhou, Xin; Dong, Peilin

2018-03-01

Polycrystalline Fe17‑xMnxPr2 (x = 0–8) compounds were analyzed by x-ray diffraction (XRD) and vibrating sample magnetometer (VSM) measurements. The results show that Fe17‑xMnxPr2 compounds exhibited the rhombohedral Th2Zn17-type crystal structure. The lattice parameter and unit cell volume increase with Mn content. The magnetic transition is a typical second-order transition near the T C. The Curie temperature (T C) of Fe17‑xMnxPr2 compounds decrease sharply in the range of 300–27 K as the Mn content increase. The maximum magnetic entropy change (∣-ΔS M∣) for Fe17‑xMnxPr2 compounds is 6.25 J · kg‑1·K‑1 in a field of 5 T for the compounds with x = 0. The thermal hysteresis for Fe17‑xMnxPr2 are 6.59 K at x = 0 and 1.36 K at x = 8, which reduces with the increase in Mn content.
Impact of grain size and structural changes on magnetic, dielectric, electrical, impedance and modulus spectroscopic characteristics of CoFe2O4 nanoparticles synthesized by honey mediated sol-gel combustion method

NASA Astrophysics Data System (ADS)

Singh Yadav, Raghvendra; Kuřitka, Ivo; Vilcakova, Jarmila; Havlica, Jaromir; Masilko, Jiri; Kalina, Lukas; Tkacz, Jakub; Švec, Jiří; Enev, Vojtěch; Hajdúchová, Miroslava

2017-12-01

In this work CoFe2O4 spinel ferrite nanoparticles were synthesized by honey mediated sol-gel combustion method and further annealed at higher temperature 500 °C, 700 °C, 900 °C and 1100 °C. The synthesized spinel ferrite nanoparticles is investigated by x-ray diffraction, Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis/differential scanning calorimetry (TGA/DSC), field emission scanning electron microscopy, x-ray photoelectron spectroscopy and vibrating sample magnetometer. The x-ray diffraction study reveals face-centered cubic spinel cobalt ferrite crystal phase formation. The crystallite size and lattice parameter are increased with annealing temperature. Raman and Fourier transform infrared spectra also confirm spinel ferrite crystal structure of synthesized nanoparticles. The existence of cation at octahedral and tetrahedral site in cobalt ferrite nanoparticles is confirmed by x-ray photoelectron spectroscopy. Magnetic measurement shows increased saturation magnetization 74.4 emu g-1 at higher annealing temperature 1100 °C, high coercivity 1347.3 Oe at lower annealing temperature 500 °C, and high remanent magnetization 32.3 emu g-1 at 900 °C annealing temperature. The magnetic properties of synthesized ferrite nanoparticles can be tuned by adjusting sizes through annealing temperature. Furthermore, the dielectric constant and ac conductivity shows variation with frequency (1-107 Hz), grain size and cation redistribution. The modulus spectroscopy study reveals the role of bulk grain and grain boundary towards the resistance and capacitance. The cole-cole plots in modulus formalism also well support the electrical response of nanoparticles originated from both grain and grain boundaries. The dielectric, electrical, magnetic, impedance and modulus spectroscopic characteristics of synthesized CoFe2O4 spinel ferrite nanoparticles demonstrate the applicability of these nanoparticles for magnetic recording, memory devices and for microwave applications.
Single-particle coherent diffractive imaging with a soft x-ray free electron laser: towards soot aerosol morphology

NASA Astrophysics Data System (ADS)

Bogan, Michael J.; Starodub, Dmitri; Hampton, Christina Y.; Sierra, Raymond G.

2010-10-01

The first of its kind, the Free electron LASer facility in Hamburg, FLASH, produces soft x-ray pulses with unprecedented properties (10 fs, 6.8-47 nm, 1012 photons per pulse, 20 µm diameter). One of the seminal FLASH experiments is single-pulse coherent x-ray diffractive imaging (CXDI). CXDI utilizes the ultrafast and ultrabright pulses to overcome resolution limitations in x-ray microscopy imposed by x-ray-induced damage to the sample by 'diffracting before destroying' the sample on sub-picosecond timescales. For many lensless imaging algorithms used for CXDI it is convenient when the data satisfy an oversampling constraint that requires the sample to be an isolated object, i.e. an individual 'free-standing' portion of disordered matter delivered to the centre of the x-ray focus. By definition, this type of matter is an aerosol. This paper will describe the role of aerosol science methodologies used for the validation of the 'diffract before destroy' hypothesis and the execution of the first single-particle CXDI experiments being developed for biological imaging. FLASH CXDI now enables the highest resolution imaging of single micron-sized or smaller airborne particulate matter to date while preserving the native substrate-free state of the aerosol. Electron microscopy offers higher resolution for single-particle analysis but the aerosol must be captured on a substrate, potentially modifying the particle morphology. Thus, FLASH is poised to contribute significant advancements in our knowledge of aerosol morphology and dynamics. As an example, we simulate CXDI of combustion particle (soot) morphology and introduce the concept of extracting radius of gyration of fractal aggregates from single-pulse x-ray diffraction data. Future upgrades to FLASH will enable higher spatially and temporally resolved single-particle aerosol dynamics studies, filling a critical technological need in aerosol science and nanotechnology. Many of the methodologies described for FLASH will directly translate to use at hard x-ray free electron lasers.
Electronic and atomic structures of Ti{sub 1-x}Al{sub x}N thin films related to their damage behavior

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tuilier, M.-H.; Pac, M.-J.; Girleanu, M.

2008-04-15

Ti and Al K-edge x-ray absorption spectroscopy is used to investigate the electronic structure of Ti{sub 1-x}Al{sub x}N thin films deposited by reactive magnetron sputtering. The experimental near edge spectra of TiN and AlN are interpreted in the light of unoccupied density of state band structure calculations. The comparison of the structural parameters derived from x-ray absorption fine structure and x-ray diffraction reveals segregation between Al-rich and Ti-rich domains within the Ti{sub 1-x}Al{sub x}N films. Whereas x-ray diffraction probes only the crystallized domains, the structural information derived from extended x-ray absorption fine structure analysis turns on both crystalline and grainmore » boundaries. The results are discussed by considering the damage behavior of the films depending on the composition.« less
Structure of rare-earth chalcogenide glasses by neutron and x-ray diffraction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Drewitt, James W. E.; Salmon, Philip S.; Zeidler, Anita

The method of neutron diffraction with isomorphic substitution was used to measure the structure of the rare-earth chalcogenide glasses (R 2X 3) 0.07(Ga 2X 3) 0.33(GeX 2) 0.60 with R = La or Ce and X = S or Se. X-ray diffraction was also used to measure the structure of the sulphide glass. The results are consistent with networks that are built from GeX 4 and GaX 4 tetrahedra, and give R-S and R-Se coordination numbers of 8.0(2) and 8.5(4), respectively. The minimum nearest-neighbour R-R distance associated with rare-earth clustering is discussed.
Structure of rare-earth chalcogenide glasses by neutron and x-ray diffraction

DOE PAGES

Drewitt, James W. E.; Salmon, Philip S.; Zeidler, Anita; ...

2017-04-28

The method of neutron diffraction with isomorphic substitution was used to measure the structure of the rare-earth chalcogenide glasses (R 2X 3) 0.07(Ga 2X 3) 0.33(GeX 2) 0.60 with R = La or Ce and X = S or Se. X-ray diffraction was also used to measure the structure of the sulphide glass. The results are consistent with networks that are built from GeX 4 and GaX 4 tetrahedra, and give R-S and R-Se coordination numbers of 8.0(2) and 8.5(4), respectively. The minimum nearest-neighbour R-R distance associated with rare-earth clustering is discussed.
Publications - GMC 145 | Alaska Division of Geological & Geophysical

Science.gov Websites

DGGS GMC 145 Publication Details Title: Analytical results of x-ray diffraction studies on tuff beds , Analytical results of x-ray diffraction studies on tuff beds from core of the following 5 NPRA wells: U.S
Coherent Soft X-ray Diffraction Imaging of Coliphage PR772 at the Linac Coherent Light Source

DOE Data Explorer

Reddy, Hemanth, K.N.

2017-01-05

A dataset of coherent soft X-ray diffraction images of Coliphage PR772 virus, collected at the Atomic Molecular Optics (AMO) beamline with pnCCD detectors in the LAMP instrument at the Linac Coherent Light Source.
Crystal and Vibrational Structure of Energetic 3,5-dinitro 1,3,5-oxadiazinane (DOD) by Single Crystal X-ray Diffractometry and Raman Spectroscopy

DTIC Science & Technology

2018-03-19

calculations using a temperature of 298 K. 15. SUBJECT TERMS 3,5-dinitro-1,3,5-oxadiazinane (DOD), X-ray crystallography , Raman, energetic material...X-ray analysis. 2.2 Characterization X-ray Crystallography . DOD crystals were characterized with a SuperNova, Dualflex, EosS2 diffractometer using
Combined synchrotron X-ray tomography and X-ray powder diffraction using a fluorescing metal foil.

PubMed

Kappen, P; Arhatari, B D; Luu, M B; Balaur, E; Caradoc-Davies, T

2013-06-01

This study realizes the concept of simultaneous micro-X-ray computed tomography and X-ray powder diffraction using a synchrotron beamline. A thin zinc metal foil was placed in the primary, monochromatic synchrotron beam to generate a divergent wave to propagate through the samples of interest onto a CCD detector for tomographic imaging, thus removing the need for large beam illumination and high spatial resolution detection. Both low density materials (kapton tubing and a piece of plant) and higher density materials (Egyptian faience) were investigated, and elemental contrast was explored for the example of Cu and Ni meshes. The viability of parallel powder diffraction using the direct beam transmitted through the foil was demonstrated. The outcomes of this study enable further development of the technique towards in situ tomography∕diffraction studies combining micrometer and crystallographic length scales, and towards elemental contrast imaging and reconstruction methods using well defined fluorescence outputs from combinations of known fluorescence targets (elements).
AUSPEX: a graphical tool for X-ray diffraction data analysis.

PubMed

Thorn, Andrea; Parkhurst, James; Emsley, Paul; Nicholls, Robert A; Vollmar, Melanie; Evans, Gwyndaf; Murshudov, Garib N

2017-09-01

In this paper, AUSPEX, a new software tool for experimental X-ray data analysis, is presented. Exploring the behaviour of diffraction intensities and the associated estimated uncertainties facilitates the discovery of underlying problems and can help users to improve their data acquisition and processing in order to obtain better structural models. The program enables users to inspect the distribution of observed intensities (or amplitudes) against resolution as well as the associated estimated uncertainties (sigmas). It is demonstrated how AUSPEX can be used to visually and automatically detect ice-ring artefacts in integrated X-ray diffraction data. Such artefacts can hamper structure determination, but may be difficult to identify from the raw diffraction images produced by modern pixel detectors. The analysis suggests that a significant portion of the data sets deposited in the PDB contain ice-ring artefacts. Furthermore, it is demonstrated how other problems in experimental X-ray data caused, for example, by scaling and data-conversion procedures can be detected by AUSPEX.
Imaging nanoscale lattice variations by machine learning of x-ray diffraction microscopy data

DOE PAGES

Laanait, Nouamane; Zhang, Zhan; Schlepütz, Christian M.

2016-08-09

In this paper, we present a novel methodology based on machine learning to extract lattice variations in crystalline materials, at the nanoscale, from an x-ray Bragg diffraction-based imaging technique. By employing a full-field microscopy setup, we capture real space images of materials, with imaging contrast determined solely by the x-ray diffracted signal. The data sets that emanate from this imaging technique are a hybrid of real space information (image spatial support) and reciprocal lattice space information (image contrast), and are intrinsically multidimensional (5D). By a judicious application of established unsupervised machine learning techniques and multivariate analysis to this multidimensional datamore » cube, we show how to extract features that can be ascribed physical interpretations in terms of common structural distortions, such as lattice tilts and dislocation arrays. Finally, we demonstrate this 'big data' approach to x-ray diffraction microscopy by identifying structural defects present in an epitaxial ferroelectric thin-film of lead zirconate titanate.« less

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