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Sample records for ultrananocrystalline diamond layers

  1. Nitrogen-incorporated ultrananocrystalline diamond and multi-layer-graphene-like hybrid carbon films

    PubMed Central

    Tzeng, Yonhua; Yeh, Shoupu; Fang, Wei Cheng; Chu, Yuehchieh

    2014-01-01

    Nitrogen-incorporated ultrananocrystalline diamond (N-UNCD) and multi-layer-graphene-like hybrid carbon films have been synthesized by microwave plasma enhanced chemical vapor deposition (MPECVD) on oxidized silicon which is pre-seeded with diamond nanoparticles. MPECVD of N-UNCD on nanodiamond seeds produces a base layer, from which carbon structures nucleate and grow perpendicularly to form standing carbon platelets. High-resolution transmission electron microscopy and Raman scattering measurements reveal that these carbon platelets are comprised of ultrananocrystalline diamond embedded in multilayer-graphene-like carbon structures. The hybrid carbon films are of low electrical resistivity. UNCD grains in the N-UNCD base layer and the hybrid carbon platelets serve as high-density diamond nuclei for the deposition of an electrically insulating UNCD film on it. Biocompatible carbon-based heaters made of low-resistivity hybrid carbon heaters encapsulated by insulating UNCD for possible electrosurgical applications have been demonstrated. PMID:24681781

  2. Systematic studies of the nucleation and growth of ultrananocrystalline diamond films on silicon substrates coated with a tungsten layer

    NASA Astrophysics Data System (ADS)

    Chu, Yueh-Chieh; Tu, Chia-Hao; Jiang, Gerald; Chang, Chi; Liu, Chuan-pu; Ting, Jyh-Ming; Lee, Hsin-Li; Tzeng, Yonhua; Auciello, Orlando

    2012-06-01

    We report on effects of a tungsten layer deposited on silicon surface on the effectiveness for diamond nanoparticles to be seeded for the deposition of ultrananocrystalline diamond (UNCD). Rough tungsten surface and electrostatic forces between nanodiamond seeds and the tungsten surface layer help to improve the adhesion of nanodiamond seeds on the tungsten surface. The seeding density on tungsten coated silicon thus increases. Tungsten carbide is formed by reactions of the tungsten layer with carbon containing plasma species. It provides favorable (001) crystal planes for the nucleation of (111) crystal planes by Microwave Plasma Enhanced Chemical Vapor Deposition (MPECVD) in argon diluted methane plasma and further improves the density of diamond seeds/nuclei. UNCD films grown at different gas pressures on tungsten coated silicon which is pre-seeded by nanodiamond along with heteroepitaxially nucleated diamond nuclei were characterized by Raman scattering, field emission-scanning electron microscopy, and high resolution-transmission electron microscopy.

  3. Systematic studies of the nucleation and growth of ultrananocrystalline diamond films on silicon substrates coated with a tungsten layer

    SciTech Connect

    Chu, Yueh-Chieh; Jiang, Gerald; Tu, Chia-Hao; Chang Chi; Liu, Chuan-pu; Ting, Jyh-Ming; Lee, Hsin-Li; Tzeng, Yonhua; Auciello, Orlando

    2012-06-15

    We report on effects of a tungsten layer deposited on silicon surface on the effectiveness for diamond nanoparticles to be seeded for the deposition of ultrananocrystalline diamond (UNCD). Rough tungsten surface and electrostatic forces between nanodiamond seeds and the tungsten surface layer help to improve the adhesion of nanodiamond seeds on the tungsten surface. The seeding density on tungsten coated silicon thus increases. Tungsten carbide is formed by reactions of the tungsten layer with carbon containing plasma species. It provides favorable (001) crystal planes for the nucleation of (111) crystal planes by Microwave Plasma Enhanced Chemical Vapor Deposition (MPECVD) in argon diluted methane plasma and further improves the density of diamond seeds/nuclei. UNCD films grown at different gas pressures on tungsten coated silicon which is pre-seeded by nanodiamond along with heteroepitaxially nucleated diamond nuclei were characterized by Raman scattering, field emission-scanning electron microscopy, and high resolution-transmission electron microscopy.

  4. Observation of a carbon-based protective layer on the sidewalls of boron doped ultrananocrystalline diamond-based MEMS during in situ tribotests

    NASA Astrophysics Data System (ADS)

    Buja, Federico; Kokorian, Jaap; Gulotty, Richard; Sumant, Anirudha V.; Merlijn van Spengen, W.

    2015-12-01

    We have fabricated dedicated MEMS tribotesters made from boron doped ultrananocrystalline diamond (B-UNCD) as the structural material, and carried out comprehensive nano-tribological measurements when two B-UNCD sidewall surfaces underwent sliding interaction in a micro-electromechanical systems (MEMS) in a humid and dry atmosphere. We have investigated the evolution of tribological contacts during sliding interactions and corresponding surface modification under repeated cyclic sliding conditions, while measuring displacement and lateral force with 4?nm and 64 nN resolution, respectively. We have observed the formation of carbon-based ultra-thin protective layer at the sliding interface as characterized by Raman spectroscopy and scanning electron microscopy. Interestingly, the formation of this protective layer occurs in both a dry and wet atmosphere, albeit at different rates when the energy dissipated due to friction reaches a plateau, starting from 200?000 and 400?000 cycles, respectively. Once this layer is formed, we do not observe any measurable wear indicating stable operation for an extended time period. Our results demonstrate that B-UNCD is a very promising material to overcome the wear-related reliability problems in MEMS.

  5. Ultra-nanocrystalline diamond electrodes: optimization towards neural stimulation applications.

    PubMed

    Garrett, David J; Ganesan, Kumaravelu; Stacey, Alastair; Fox, Kate; Meffin, Hamish; Prawer, Steven

    2012-02-01

    Diamond is well known to possess many favourable qualities for implantation into living tissue including biocompatibility, biostability, and for some applications hardness. However, conducting diamond has not, to date, been exploited in neural stimulation electrodes due to very low electrochemical double layer capacitance values that have been previously reported. Here we present electrochemical characterization of ultra-nanocrystalline diamond electrodes grown in the presence of nitrogen (N-UNCD) that exhibit charge injection capacity values as high as 163 µC cm(-2) indicating that N-UNCD is a viable material for microelectrode fabrication. Furthermore, we show that the maximum charge injection of N-UNCD can be increased by tailoring growth conditions and by subsequent electrochemical activation. For applications requiring yet higher charge injection, we show that N-UNCD electrodes can be readily metalized with platinum or iridium, further increasing charge injection capacity. Using such materials an implantable neural stimulation device fabricated from a single piece of bio-permanent material becomes feasible. This has significant advantages in terms of the physical stability and hermeticity of a long-term bionic implant. PMID:22156061

  6. Characterization of ultrananocrystalline diamond microsensors for in vivo dopamine detection

    PubMed Central

    Arumugam, Prabhu U.; Zeng, Hongjun; Siddiqui, Shabnam; Covey, Dan P.; Carlisle, John A.; Garris, Paul A.

    2013-01-01

    We show the technical feasibility of coating and micro patterning boron-doped ultrananocrystalline diamond (UNCD®) on metal microwires and of applying them as microsensors for the detection of dopamine in vivo using fast-scan cyclic voltammetry. UNCD electrode surface consistently generated electrochemical signals with high signal-to-noise ratio of >800 using potassium ferrocyanide-ferricyanide redox couple. Parylene patterned UNCD microelectrodes were effectively applied to detect dopamine reliably in vitro using flow injection analysis with a detection limit of 27?nM and in the striatum of the anesthetized rat during electrical stimulation of dopamine neurons. PMID:23918991

  7. Charging characteritiscs of ultrananocrystalline diamond in RF MEMS capacitive switches.

    SciTech Connect

    Sumant, A. V.; Goldsmith, C.; Auciello, O.; Carlisle, J.; Zheng, H.; Hwang, J. C. M.; Palego, C.; Wang, W.; Carpick, R.; Adiga, V.; Datta, A.; Gudeman, C.; O'Brien, S.; Sampath, S.

    2010-05-01

    Modifications to a standard capacitive MEMS switch process have been made to allow the incorporation of ultra-nano-crystalline diamond as the switch dielectric. The impact on electromechanical performance is minimal. However, these devices exhibit uniquely different charging characteristics, with charging and discharging time constants 5-6 orders of magnitude quicker than conventional materials. This operation opens the possibility of devices which have no adverse effects of dielectric charging and can be operated near-continuously in the actuated state without significant degradation in reliability.

  8. Enhanced electron field emission properties by tuning the microstructure of ultrananocrystalline diamond film

    NASA Astrophysics Data System (ADS)

    Cheng, Hsiu-Fung; Chiang, Horng-Yi; Horng, Chuang-Chi; Chen, Huang-Chin; Wang, Chuan-Sheng; Lin, I.-Nan

    2011-02-01

    Synthesis of microcrystalline-ultrananocrystalline composite diamond (MCD-UNCD) films, which exhibit marvelous electron field emission (EFE) properties, was reported. The EFE of MCD-UNCD composite diamond film can be turned on at a low field as 6.5 V/?m and attain large EFE current density about 1.0 mA/cm2 at 30 V/?m applied field, which is better than the EFE behavior of the nondoped planar diamond films ever reported. The MCD-UNCD films were grown by a two-step microwave plasma enhanced chemical vapor deposition (MPECVD) process, including forming an UNCD layer in CH4/Ar plasma that contains no extra H2, followed by growing MCD layer using CH4/H2/Ar plasma that contains large proportion of H2. Microstructure examinations using high resolution transmission electron microscopy shows that the secondary MPECVD process modifies the granular structure of the UNCD layer, instead of forming a large grain diamond layer on top of UNCD films. The MCD-UNCD composite diamond films consist of numerous ultrasmall grains (˜5 nm in size), surrounding large grains about hundreds of nanometer in size. Moreover, there exist abundant nanographites in the interfacial region between the grains that were presumed to form interconnected channels for electron transport, resulting in superior EFE properties for MCD-UNCD composite films.

  9. Ultrananocrystalline diamond thin films functionalized with therapeutically active collagen networks.

    SciTech Connect

    Huang, H.; Chen, M.; Bruno, P.; Lam, R.; Robinson, E.; Gruen, D.; Ho, D.; Materials Science Division; Northwestern Univ.

    2009-01-01

    The fabrication of biologically amenable interfaces in medicine bridges translational technologies with their surrounding biological environment. Functionalized nanomaterials catalyze this coalescence through the creation of biomimetic and active substrates upon which a spectrum of therapeutic elements can be delivered to adherent cells to address biomolecular processes in cancer, inflammation, etc. Here, we demonstrate the robust functionalization of ultrananocrystalline diamond (UNCD) with type I collagen and dexamethasone (Dex), an anti-inflammatory drug, to fabricate a hybrid therapeutically active substrate for localized drug delivery. UNCD oxidation coupled with a pH-mediated collagen adsorption process generated a comprehensive interface between the two materials, and subsequent Dex integration, activity, and elution were confirmed through inflammatory gene expression assays. These studies confer a translational relevance to the biofunctionalized UNCD in its role as an active therapeutic network for potent regulation of cellular activity toward applications in nanomedicine.

  10. Elasticity, strength, and toughness of single crystal silicon carbide, ultrananocrystalline diamond, and hydrogen-free tetrahedral amorphous

    E-print Network

    Espinosa, Horacio D.

    Elasticity, strength, and toughness of single crystal silicon carbide, ultrananocrystalline diamond report the mechanical properties of three emerging materials in thin film form: single crystal silicon carbide 3C-SiC , ultrananocrystalline diamond, and hydrogen-free tetrahedral amorphous carbon

  11. Integration of piezoelectric aluminum nitride and ultrananocrystalline diamond films for implantable biomedical microelectromechanical devices

    NASA Astrophysics Data System (ADS)

    Zalazar, M.; Gurman, P.; Park, J.; Kim, D.; Hong, S.; Stan, L.; Divan, R.; Czaplewski, D.; Auciello, O.

    2013-03-01

    The physics for integration of piezoelectric aluminum nitride (AlN) films with underlying insulating ultrananocrystalline diamond (UNCD), and electrically conductive grain boundary nitrogen-incorporated UNCD (N-UNCD) and boron-doped UNCD (B-UNCD) layers, as membranes for microelectromechanical system implantable drug delivery devices, has been investigated. AlN films deposited on platinum layers on as grown UNCD or N-UNCD layer (5-10 nm rms roughness) required thickness of ˜400 nm to induce (002) AlN orientation with piezoelectric d33 coefficient ˜1.91 pm/V at ˜10 V. Chemical mechanical polished B-UNCD films (0.2 nm rms roughness) substrates enabled (002) AlN film 200 nm thick, yielding d33 = 5.3 pm/V.

  12. Mechanical stiffness and dissipation in ultrananocrystalline diamond micro-resonators.

    SciTech Connect

    Sumant, A. V.; Adiga, V. P.; Suresh, S.; Gudeman, C.; Auciello, O.; Carlis, J. A.; Carpick, R. W.

    2009-01-01

    We have characterized mechanical properties of ultrananocrystalline diamond (UNCD) thin films grown using the hot filament chemical vapor deposition (HFCVD) technique at 680 C, significantly lower than the conventional growth temperature of {approx}800 C. The films have {approx}4.3% sp{sup 2} content in the near-surface region as revealed by near edge x-ray absorption fine structure spectroscopy. The films, {approx}1 {micro}m thick, exhibit a net residual compressive stress of 370 {+-} 1 MPa averaged over the entire 150 mm wafer. UNCD microcantilever resonator structures and overhanging ledges were fabricated using lithography, dry etching, and wet release techniques. Overhanging ledges of the films released from the substrate exhibited periodic undulations due to stress relaxation. This was used to determine a biaxial modulus of 838 {+-} 2 GPa. Resonant excitation and ring-down measurements in the kHz frequency range of the microcantilevers were conducted under ultrahigh vacuum (UHV) conditions in a customized UHV atomic force microscope system to determine Young's modulus as well as mechanical dissipation of cantilever structures at room temperature. Young's modulus is found to be 790 {+-} 30 GPa. Based on these measurements, Poisson's ratio is estimated to be 0.057 {+-} 0.038. The quality factors (Q) of these resonators ranged from 5000 to 16000. These Q values are lower than theoretically expected from the intrinsic properties of diamond. The results indicate that surface and bulk defects are the main contributors to the observed dissipation in UNCD resonators.

  13. Effects of pretreatment processes on improving the formation of ultrananocrystalline diamond

    SciTech Connect

    Chen, Li-Ju; Tai, Nyan-Hwa; Lee, Chi-Young; Lin, I-Nan.

    2007-03-15

    Effects of pretreatment on the nuclei formation of ultrananocrystalline diamond (UNCD) on Si substrates were studied. Either precoating a thin layer of titanium ({approx}400 nm) or ultrasonication pretreatment using diamond and titanium mixed powder (D and T process) enhances the nucleation process on Si substrates markedly, and the UNCD nuclei formed and fully covered the Si substrate, when deposition was processed using the microwave-plasma-enhanced chemical-vapor deposition process for 10 min. In contrast, during the same period, ultrasonication pretreatment using diamond powders (D process) can only form large UNCD clusters, which were scarcely distributed on Si substrates. The analyses using x-ray diffractometer, secondary ion mass spectroscopy, and electron spectroscopy for chemical analysis reveal that the titanium layer reacted with carbon species in the plasma, forming crystalline TiC phase, which facilitates the subsequent formation of UNCD nuclei. The beneficial effect of Ti layer on enhancing the nucleation of UNCD is presumably owing to high solubility and high diffusivity of carbon species in Ti materials, as compared with those of Si materials.

  14. Using an Au interlayer to enhance electron field emission properties of ultrananocrystalline diamond films

    NASA Astrophysics Data System (ADS)

    Chen, Huang-Chin; Jothiramalingam Sankaran, Kamatchi; Lo, Shen-Chuan; Lin, Li-Jiaun; Tai, Nyan-Hwa; Lee, Chi-Young; Lin, I.-Nan

    2012-11-01

    We observe that an Au interlayer markedly enhances the electrical field emission (EFE) properties of ultrananocrystalline diamond (UNCD) films on Si substrates. The EFE properties of UNCD/Au/Si films can be turned on at a lower field and attain a higher current density than in UNCD films grown on Si substrates without an Au interlayer. Transmission electron microscopy reveals that the Au interlayer induces the formation of SiC clusters, preventing the formation of a resistive amorphous carbon layer that nucleates the diamond clusters. This improves the diamond-to-substrate interfacial conductivity. Moreover, there is an abundant nano-graphite phase, which is presumably induced by the coalescence of nano-sized diamond clusters. The percolation of the nano-graphite clusters helps transport electrons, improving the conductivity of the UNCD films. We believe that the simultaneous increase in the conductivity of the UNCD-to-Si interface and the bulk of the UNCD films is the main factor enhancing electrical conductivity and EFE properties of the films.

  15. Preventing nanoscale wear of atomic force microscopy tips through the use of monolithic ultrananocrystalline diamond probes.

    PubMed

    Liu, J; Grierson, D S; Moldovan, N; Notbohm, J; Li, S; Jaroenapibal, P; O'Connor, S D; Sumant, A V; Neelakantan, N; Carlisle, J A; Turner, K T; Carpick, R W

    2010-05-21

    Nanoscale wear is a key limitation of conventional atomic force microscopy (AFM) probes that results in decreased resolution, accuracy, and reproducibility in probe-based imaging, writing, measurement, and nanomanufacturing applications. Diamond is potentially an ideal probe material due to its unrivaled hardness and stiffness, its low friction and wear, and its chemical inertness. However, the manufacture of monolithic diamond probes with consistently shaped small-radius tips has not been previously achieved. The first wafer-level fabrication of monolithic ultrananocrystalline diamond (UNCD) probes with <5-nm grain sizes and smooth tips with radii of 30-40 nm is reported, which are obtained through a combination of microfabrication and hot-filament chemical vapor deposition. Their nanoscale wear resistance under contact-mode scanning conditions is compared with that of conventional silicon nitride (SiN(x)) probes of similar geometry at two different relative humidity levels (approximately 15 and approximately 70%). While SiN(x) probes exhibit significant wear that further increases with humidity, UNCD probes show little measurable wear. The only significant degradation of the UNCD probes observed in one case is associated with removal of the initial seed layer of the UNCD film. The results show the potential of a new material for AFM probes and demonstrate a systematic approach to studying wear at the nanoscale. PMID:20486220

  16. Bias-enhanced post-treatment process for enhancing the electron field emission properties of ultrananocrystalline diamond films

    SciTech Connect

    Saravanan, A.; Huang, B. R.; Sankaran, K. J.; Tai, N. H.; Dong, C. L.; Lin, I. N.

    2015-03-16

    The electron field emission (EFE) properties of ultrananocrystalline diamond films were markedly improved via the bias-enhanced plasma post-treatment (bep) process. The bep-process induced the formation of hybrid-granular structure of the diamond (bep-HiD) films with abundant nano-graphitic phase along the grain boundaries that increased the conductivity of the films. Moreover, the utilization of Au-interlayer can effectively suppress the formation of resistive amorphous-carbon (a-C) layer, thereby enhancing the transport of electrons crossing the diamond-to-Si interface. Therefore, bep-HiD/Au/Si films exhibit superior EFE properties with low turn-on field of E{sub 0}?=?2.6?V/?m and large EFE current density of J{sub e}?=?3.2?mA/cm{sup 2} (at 5.3?V/?m)

  17. A conversion model of graphite to ultrananocrystalline diamond via laser processing at ambient temperature and normal pressure

    SciTech Connect

    Ren, X. D. Yang, H. M.; Zheng, L. M.; Tang, S. X.; Ren, N. F.; Xu, S. D.; Yuan, S. Q.

    2014-07-14

    The synthesis mechanism of ultrananocrystalline diamond via laser shock processing of graphite suspension was presented at room temperature and normal pressure, which yielded the ultrananocrystalline diamond in size of about 5?nm. X-ray diffraction, high-resolution transmission electron microscopy, and laser Raman spectroscopy were used to characterize the nano-crystals. The transformation model and growth restriction mechanism of high power density with short-pulsed laser shocking of graphite particles in liquid was put forward.

  18. Diamond nanowires and the insulator-metal transition in ultrananocrystalline diamond films.

    SciTech Connect

    Arenal, R.; Bruno, P.; Miller, D. J.; Bleuel, M.; Lai, J.; Gruen, D. M.

    2007-05-01

    Further progress in the development of the remarkable electrochemical, electron field emission, high-temperature diode, and optical properties of n-type ultrananocrystalline diamond films requires a better understanding of electron transport in this material. Of particular interest is the origin of the transition to the metallic regime observed when about 10% by volume of nitrogen has been added to the synthesis gas. Here, we present data showing that the transition to the metallic state is due to the formation of partially oriented diamond nanowires surrounded by an sp{sup 2}-bonded carbon sheath. These have been characterized by scanning electron microscopy, transmission electron microscopy techniques (high-resolution mode, selected area electron diffraction, and electron-energy-loss spectroscopy), Raman spectroscopy, and small-angle neutron scattering. The nanowires are 80-100 nm in length and consist of {approx}5 nm wide and 6-10 nm long segments of diamond crystallites exhibiting atomically sharp interfaces. Each nanowire is enveloped in a sheath of sp{sup 2}-bonded carbon that provides the conductive path for electrons. Raman spectroscopy on the films coupled with a consideration of plasma chemical and physical processes reveals that the sheath is likely composed of a nanocarbon material resembling in some respects a polymer-like mixture of polyacetylene and polynitrile. The complex interactions governing the simultaneous growth of the diamond core and the sp{sup 2} sheath responsible for electrical conductivity are discussed as are attempts at a better theoretical understanding of the transport mechanism.

  19. Extreme synthesis and characterization of an ultrananocrystalline diamond aerogel in a diamond anvil cell

    NASA Astrophysics Data System (ADS)

    Pauzauskie, Peter

    2013-06-01

    High-surface-area mesostructured carbon materials have attracted a great amount attention in recent years because of a growing number of applications in energy storage, chemical catalysis, separations, and sensing. In particular, amorphous carbon aerogels have attracted much interest since the 1980's due to their low density, large intrinsic surface areas (>1000 m2/g), large pore volume, low dielectric constant, and high strength. In this talk we present the use of high-pressure (>20 GPa) laser-heating (>1500 °C) within a diamond anvil cell (DAC) to convert the amorphous network of a low-density (40 mg/cc) carbon aerogel into an ultrananocrystalline diamond aerogel. Raman spectroscopy is used to probe the amorphous-to-diamond phase transition at pressure within the DAC. High-resolution transmission electron microscopy images of recovered material indicate diamond crystallite sizes range from 1 to 100 nm, with electron diffraction and electron energy loss confirming the presence of the diamond phase. Photoluminescence spectroscopy and confocal time-correlated single-photon counting indicate the recovered material contains both negatively-charged and neutral nitrogen-vacancy (NV) complexes. Synchrotron scanning transmission x-ray microscopy (STXM) is used to compare the carbon electronic density-of-states of the amorphous starting material with the recovered diamond aerogel with <100 meV energy resolution. Finally, we use nanoscale secondary ion mass spectrometry to investigate doping of the resorcinol-formaldehyde starting material with the aim of chemically tuning heteroatomic point defects within this diamond material system.

  20. Multiwavelength Raman spectroscopy of diamond nanowires present in n-type ultrananocrystalline films.

    SciTech Connect

    Arenal , R.; Montagnac, G.; Bruno, P.; Gruen, D. M.; Materials Science Division; ONERA-CNRS; Ecole Normale Superieure de Lyon

    2007-12-01

    Multiwavelength Raman spectroscopy is employed to investigate ultrananocrystalline diamond films deposited by the plasma enhanced chemical vapor deposition technique. Recently, we have shown that the addition of nitrogen in the gas source during synthesis induce the formation of diamond n-type films, exhibiting the highest electrical conductivity at ambient temperature. This point is related with the formation of elongated diamond nanostructures and the presence of sp{sup 2}-bonded carbon in these films. The Raman results presented here confirm these aspects and provide a better and deeper understanding of the nature of these films and their related optical and electronic properties.

  1. Planar ultrananocrystalline diamond field emitter in accelerator radio frequency electron injector: Performance metrics

    SciTech Connect

    Baryshev, Sergey V. Antipov, Sergey; Jing, Chunguang; Qiu, Jiaqi; Shao, Jiahang; Liu, Wanming; Gai, Wei; Pérez Quintero, Kenneth J.; Sumant, Anirudha V.; Kanareykin, Alexei D.

    2014-11-17

    A case performance study of a planar field emission cathode (FEC) based on nitrogen-incorporated ultrananocrystalline diamond, (N)UNCD, was carried out in an RF 1.3?GHz electron gun. The FEC was a 100?nm (N)UNCD film grown on a 20?mm diameter stainless steel disk with a Mo buffer layer. At surface gradients 45–65?MV/m, peak currents of 1–80?mA (equivalent to 0.3–25?mA/cm{sup 2}) were achieved. Imaging with two YAG screens confirmed emission from the (N)UNCD surface with (1) the beam emittance of 1.5?mm?×?mrad/mm-rms and (2) longitudinal FWHM and rms widths of non-Gaussian energy spread of 0.7% and 11% at an electron energy of 2?MeV. Current stability was tested over the course of 36?×?10{sup 3} RF pulses (equivalent to 288?×?10{sup 6?}GHz oscillations)

  2. Synthesis method for ultrananocrystalline diamond in powder employing a coaxial arc plasma gun

    NASA Astrophysics Data System (ADS)

    Naragino, Hiroshi; Tominaga, Aki; Hanada, Kenji; Yoshitake, Tsuyoshi

    2015-07-01

    A new method that enables us to synthesize ultrananocrystalline diamond (UNCD) in powder is proposed. Highly energetic carbon species ejected from a graphite cathode of a coaxial arc plasma gun were provided on a quartz plate at a high density by repeated arc discharge in a compact vacuum chamber, and resultant films automatically peeled from the plate were aggregated and powdered. The grain size was easily controlled from 2.4 to 15.0 nm by changing the arc discharge energy. It was experimentally demonstrated that the proposed method is a new and promising method that enables us to synthesize UNCD in powder easily and controllably.

  3. Ultrananocrystalline and nanocrystalline diamond thin films for NEMS/MEMS applications.

    SciTech Connect

    Sumant, A. V.; Auciello, O.; Carpick, R. W.; Srinivasan, S.; Butler, J. E.

    2010-04-01

    There has been a tireless quest by the designers of micro- and nanoelectro mechanical systems (MEMS/NEMS) to find a suitable material alternative to conventional silicon. This is needed to develop robust, reliable, and long-endurance MEMS/NEMS with capabilities for working under demanding conditions, including harsh environments, high stresses, or with contacting and sliding surfaces. Diamond is one of the most promising candidates for this because of its superior physical, chemical, and tribomechanical properties. Ultrananocrystalline diamond (UNCD) and nanocrystalline diamond (NCD) thin films, the two most studied forms of diamond films in the last decade, have distinct growth processes and nanostructures but complementary properties. This article reviews the fundamental and applied science performed to understand key aspects of UNCD and NCD films, including the nucleation and growth, tribomechanical properties, electronic properties, and applied studies on integration with piezoelectric materials and CMOS technology. Several emerging diamond-based MEMS/NEMS applications, including high-frequency resonators, radio frequency MEMS and photonic switches, and the first commercial diamond MEMS product - monolithic diamond atomic force microscopy probes - are discussed.

  4. Direct observation of enhanced emission sites in nitrogen implanted hybrid structured ultrananocrystalline diamond films

    SciTech Connect

    Panda, Kalpataru; Sundaravel, B.; Panigrahi, B. K.; Chen, Huang-Chin; Lin, I.-Nan

    2013-02-07

    A hybrid-structured ultrananocrystalline diamond (h-UNCD) film, synthesized on Si-substrates by a two-step microwave plasma enhanced chemical vapour deposition (MPECVD) process, contains duplex structure with large diamond aggregates evenly dispersed in a matrix of ultra-small grains ({approx}5 nm). The two-step plasma synthesized h-UNCD films exhibit superior electron field emission (EFE) properties than the one-step MPECVD deposited UNCD films. Nitrogen-ion implantation/post-annealing processes further improve the EFE properties of these films. Current imaging tunnelling spectroscopy in scanning tunnelling spectroscopy mode directly shows increased density of emission sites in N implanted/post-annealed h-UNCD films than as-prepared one. X-ray photoelectron spectroscopy measurements show increased sp{sup 2} phase content and C-N bonding fraction in N ion implanted/post-annealed films. Transmission electron microscopic analysis reveals that the N implantation/post-annealing processes induce the formation of defects in the diamond grains, which decreases the band gap and increases the density of states within the band gap of diamond. Moreover, the formation of nanographitic phase surrounding the small diamond grains enhanced the conductivity at the diamond grain boundaries. Both of the phenomena enhance the EFE properties.

  5. Piezoelectric/ultrananocrystalline diamond heterostructures for high-performance multifunctional micro/nanoelectromechanical systems.

    SciTech Connect

    Srinivasan, S.; Hiller, J.; Kabius, B.; Auciello, O.

    2007-01-01

    Most current micro/nanoelectromechanical systems (MEMS/NEMS) are based on silicon. However, silicon exhibits relatively poor mechanical/tribological properties, compromising applications to some devices. Diamond films with superior mechanical/tribological properties provide an excellent alternative platform material. Ultrananocrystalline diamond (UNCD{reg_sign}) in film form with 2-5 nm grains exhibits excellent properties for high-performance MEMS/NEMS devices. Concurrently, piezoelectric Pb(Zr{sub x}Ti{sub 1-x})O{sub 3} (PZT) films provide high sensitivity/low electrical noise for sensing/high-force actuation at relatively low voltages. Therefore, integration of PZT and UNCD films provides a high-performance platform for advanced MEMS/NEMS devices. This letter describes the bases of such integration and demonstration of low voltage piezoactuated hybrid PZT/UNCD cantilevers.

  6. Piezoelectric/ultrananocrystalline diamond heterostructures for a new generation of multifunctional micro/nanoelectromechanical systems.

    SciTech Connect

    Srinivasan, S.; Hiller, J.; Kabius, B.; Auciello, O.

    2007-01-01

    Most current micro/nanoelectromechanical systems (MEMS/NEMS) are based on silicon. However, silicon exhibits relatively poor mechanical/tribological properties, compromising applications to some devices. Diamond films with superior mechanical/tribological properties provide an excellent alternative platform material. Ultrananocrystalline diamond (UNCD{reg_sign}) in film form with 2-5 nm grains exhibits excellent properties for high-performance MEMS/NEMS devices. Concurrently, piezoelectric Pb(Zr{sub x}Ti{sub 1-x})O{sub 3} (PZT) films provide high sensitivity/low electrical noise for sensing/high-force actuation at relatively low voltages. Therefore, integration of PZT and UNCD films provides a high-performance platform for advanced MEMS/NEMS devices. This letter describes the bases of such integration and demonstration of low voltage piezoactuated hybrid PZT/UNCD cantilevers.

  7. Low-temperature electrical transport in B-doped ultrananocrystalline diamond film

    SciTech Connect

    Li, Lin; Zhao, Jing; Hu, Zhaosheng; Quan, Baogang; Li, Junjie Gu, Changzhi

    2014-05-05

    B-doped ultrananocrystalline diamond (UNCD) films are grown using hot-filament chemical vapor deposition method, and their electrical transport properties varying with temperature are investigated. When the B-doped concentration of UNCD film is low, a step-like increase feature of the resistance is observed with decreasing temperature, reflecting at least three temperature-modified electronic state densities at the Fermi level according to three-dimensional Mott's variable range hopping transport mechanism, which is very different from that of reported B-doped nanodiamond. With increasing B-doped concentration, a superconductive transformation occurs in the UNCD film and the highest transformation temperature of 5.3?K is observed, which is higher than that reported for superconducting nanodiamond films. In addition, the superconducting coherence length is about 0.63?nm, which breaks a reported theoretical and experimental prediction about ultra-nanoscale diamond's superconductivity.

  8. Flexible electron field emitters fabricated using conducting ultrananocrystalline diamond pyramidal microtips on polynorbornene films

    SciTech Connect

    Sankaran, K. J.; Tai, N. H.; Lin, I. N.

    2014-01-20

    High performance flexible field emitters made of aligned pyramidal shaped conducting ultrananocrystalline diamond (C-UNCD) microtips on polynorbornene substrates is demonstrated. Flexible C-UNCD pyramidal microtips show a low turn-on field of 1.80?V/?m with a field enhancement factor of 4580 and a high emission current density of 5.8?mA/cm{sup 2} (at an applied field of 4.20?V/?m) with life-time stability of 210 min. Such an enhancement in the field emission is due to the presence of sp{sup 2}-graphitic sheath with a nanowire-like diamond core. This high performance flexible C-UNCD field emitter is potentially useful for the fabrication of diverse, flexible electronic devices.

  9. Fabrication of free-standing highly conducting ultrananocrystalline diamond films with enhanced electron field emission properties

    NASA Astrophysics Data System (ADS)

    Sankaran, K. J.; Chen, H. C.; Lee, C. Y.; Tai, N. H.; Lin, I. N.

    2012-12-01

    Fabrication of free-standing/highly conducting ultrananocrystalline diamond (fc-UNCD) films at low growth temperature (<475 °C) is demonstrated. The fc-UNCD films show high conductivity of ? = 146 (? cm)-1 with superior electron field emission (EFE) properties, viz. low turn-on field of 4.35 V/?m and high EFE current density of 3.76 mA/cm2 at an applied field of 12.5 V/?m. Transmission electron microscopy examinations reveal the presence of Au/Cu clusters in film-to-substrate interface, which consequences in the induction of nanographite phases, surrounding the diamond grains that form conduction channels for electrons transport, ensuing in marvelous EFE properties of fc-UNCD films.

  10. Low-temperature electrical transport in B-doped ultrananocrystalline diamond film

    NASA Astrophysics Data System (ADS)

    Li, Lin; Zhao, Jing; Hu, Zhaosheng; Quan, Baogang; Li, Junjie; Gu, Changzhi

    2014-05-01

    B-doped ultrananocrystalline diamond (UNCD) films are grown using hot-filament chemical vapor deposition method, and their electrical transport properties varying with temperature are investigated. When the B-doped concentration of UNCD film is low, a step-like increase feature of the resistance is observed with decreasing temperature, reflecting at least three temperature-modified electronic state densities at the Fermi level according to three-dimensional Mott's variable range hopping transport mechanism, which is very different from that of reported B-doped nanodiamond. With increasing B-doped concentration, a superconductive transformation occurs in the UNCD film and the highest transformation temperature of 5.3 K is observed, which is higher than that reported for superconducting nanodiamond films. In addition, the superconducting coherence length is about 0.63 nm, which breaks a reported theoretical and experimental prediction about ultra-nanoscale diamond's superconductivity.

  11. Mechanical Properties of Ultrananocrystalline Diamond Thin Films for MEMS Applications

    E-print Network

    Espinosa, Horacio D.

    , extremely low friction coefficient and wear, high thermal and electrical conductivity, the latter when doped diamond [5]), unique tribological properties (coefficient of friction of the order of ~0.02-0.03, [6 Engineering, Northwestern University Evanston, IL 60208-3111, USA 2 Materials Research and Education Center

  12. DEVELOPMENT OF A SCALABLE, LOW-COST, ULTRANANOCRYSTALLINE DIAMOND ELECTROCHEMICAL PROCESS FOR THE DESTRUCTION OF CONTAMINANTS OF EMERGING CONCERN (CECS) - PHASE II

    EPA Science Inventory

    This Small Business Innovation Research (SBIR) Phase II project will employ the large scale; highly reliable boron-doped ultrananocrystalline diamond (BD-UNCD®) electrodes developed during Phase I project to build and test Electrochemical Anodic Oxidation process (EAOP)...

  13. High Stability Electron Field Emitters Synthesized via the Combination of Carbon Nanotubes and N2-Plasma Grown Ultrananocrystalline Diamond Films.

    PubMed

    Chang, Ting-Hsun; Hsieh, Ping-Yen; Kunuku, Srinivasu; Lou, Shiu-Cheng; Manoharan, Divinah; Leou, Keh-Chyang; Lin, I-Nan; Tai, Nyan-Hwa

    2015-12-16

    An electron field emitter with superior electron field emission (EFE) properties and improved lifetime stability is being demonstrated via the combination of carbon nanotubes and the CH4/N2 plasma grown ultrananocrystalline diamond (N-UNCD) films. The resistance of the carbon nanotubes to plasma ion bombardment is improved by the formation of carbon nanocones on the side walls of the carbon nanotubes, thus forming strengthened carbon nanotubes (s-CNTs). The N-UNCD films can thus be grown on s-CNTs, forming N-UNCD/s-CNTs carbon nanocomposite materials. The N-UNCD/s-CNTs films possess good conductivity of ? = 237 S/cm and marvelous EFE properties, such as low turn-on field of (E0) = 3.58 V/?m with large EFE current density of (Je) = 1.86 mA/cm(2) at an applied field of 6.0 V/?m. Moreover, the EFE emitters can be operated under 0.19 mA/cm(2) for more than 350 min without showing any sign of degradation. Such a superior EFE property along with high robustness characteristic of these combination of materials are not attainable with neither N-UNCD films nor s-CNTs films alone. Transmission electron microscopic investigations indicated that the N-UNCD films contain needle-like diamond grains encased in a few layers of nanographitic phase, which enhanced markedly the transport of electrons in the N-UNCD films. Moreover, the needle-like diamond grains were nucleated from the s-CNTs without the necessity of forming the interlayer that facilitate the transport of electrons crossing the diamond-to-Si interface. Both these factors contributed to the enhanced EFE behavior of the N-UNCD/s-CNTs films. PMID:26600097

  14. Effects of Boron Doping on the Properties of Ultrananocrystalline Diamond Films

    NASA Astrophysics Data System (ADS)

    Yuan, Wen-Xiang; WU, Q. X.; Luo, Z. K.; Wu, H. S.

    2014-04-01

    Boron-doped ultrananocrystalline diamond (UNCD) films were fabricated on silicon substrates by microwave plasma chemical vapor deposition. UNCD films containing different concentrations of boron were prepared by using trimethylboron (B(CH3)3, TMB) as boron doping source and varying the amount of boron in the gas mixture from 0 ppm to 1000 ppm. The effects of boron doping on morphology, lattice parameter, phase composition, crystal size, and residual stress of UNCD films were investigated. No obvious change of the morphology was observed on doping with boron, and all the films had the UNCD crystal grains. Boron doping enhanced (111) growth. The preferred growth direction of the UNCD films was . Residual tensile stress was present in all the films, and increased with increasing the amount of boron in the gas mixture.

  15. Science and technology of ultrananocrystalline diamond (UNCD) thin films for multifunctional devices.

    SciTech Connect

    Auciello, O.; Gruen, D. M.; Krauss, A. R.; Jayatissa, A.; Sumant, A.; Tucek, J.; Mancini, D.; Moldovan, N.; Erdemir, A.; Ersoy, D.; Gardos, M. N.; Busmann, H. G.; Meyer, E. M.

    2000-11-15

    MEMS devices are currently fabricated primarily in silicon because of the available surface machining technology. However, Si has poor mechanical and tribological properties, and practical MEMS devices are currently limited primarily to applications involving only bending and flexural motion, such as cantilever accelerometers and vibration sensors, However, because of the poor flexural strength and fracture toughness of Si, and the tendency of Si to adhere to hydrophyllic surfaces, even these simple devices have limited dynamic range. Future MEMS applications that involve significant rolling or sliding contact will require the use of new materials with significantly improved mechanical and tribological properties, and the ability to perform well in harsh environments. Diamond is a superhard material of high mechanical strength, exceptional chemical inertness, and outstanding thermal stability. The brittle fracture strength is 23 times that of Si, and the projected wear life of diamond MEMS moving mechanical assemblies (MEMS-MMAS) is 10,000 times greater than that of Si MMAs. However, as the hardest known material, diamond is notoriously difficult to fabricate. Conventional CVD thin film deposition methods offer an approach to the fabrication of ultra-small diamond structures, but the films have large grain size, high internal stress, poor intergranular adhesion, and very rough surfaces, and are consequently ill-suited for MEMS-MMA applications. A thin film deposition process has been developed that produces phase-pure ultrananocrystalline diamond (UNCD) with morphological and mechanical properties that are ideally suited for MEMS applications in general, and MMA use in particular. We have developed lithographic techniques for the fabrication of diamond microstructure including cantilevers and multi-level devices, acting as precursors to micro-bearings and gears, making UNCD a promising material for the development of high performance MEMS devices.

  16. Development of ultrananocrystalline diamond (UNCD) coatings for multipurpose mechanical pump seals.

    SciTech Connect

    Kovalchenko, A. M.; Elam, J. W.; Erdemir, A.; Carlisle, J. A.; Auciello, O.; Libera, J. A.; Pellin, M. J.; Gruen, D. M.; Hryn, J. N.

    2011-01-01

    The reliability and performance of silicon carbide (SiC) shaft seals on multipurpose mechanical pumps are improved by applying a protective coating of ultrananocrystalline diamond (UNCD). UNCD exhibits extreme hardness (97 GPa), low friction (0.1 in air) and outstanding chemical resistance. Consequently, the application of UNCD coatings to multipurpose mechanical pump seals can reduce frictional energy losses and eliminate the downtime and hazardous emissions from seal failure and leakage. In this study, UNCD films were prepared by microwave plasma chemical vapor deposition utilizing an argon/methane gas mixture. Prior to coating, the SiC seals were subjected to mechanical polishing using different grades of micron-sized diamond powder to produce different starting surfaces with well-controlled surface roughnesses. Following this roughening process, the seals were seeded by mechanical abrasion with diamond nanopowder, and subsequently coated with UNCD. The coated seals were subjected to dynamic wear testing performed at 3600 RPM and 100 psi for up to 10 days during which the seals were periodically removed and inspected. The UNCD-coated seals were examined using Raman microanalysis, scanning electron microscopy, optical profilometry, and adhesion testing before and after the wear testing. These analyses revealed that delamination of the UNCD films was prevented when the initial SiC seal surface had an initial roughness >0.1 {micro}m. In addition, the UNCD surfaces showed no measurable wear as compared to approximately 0.2 {micro}m of wear for the untreated SiC surfaces.

  17. Nitrogen incorporated ultrananocrystalline diamond based field emitter array for a flat-panel x-ray source

    NASA Astrophysics Data System (ADS)

    Posada, Chrystian M.; Grant, Edwin J.; Divan, Ralu; Sumant, Anirudha V.; Rosenmann, Daniel; Stan, Liliana; Lee, Hyoung K.; Castaño, Carlos H.

    2014-04-01

    A field emission based flat-panel transmission x-ray source is being developed as an alternative for medical and industrial imaging. A field emitter array (FEA) prototype based on nitrogen incorporated ultrananocrystalline diamond film has been fabricated to be used as the electron source of this flat panel x-ray source. The FEA prototype was developed using conventional microfabrication techniques. The field emission characteristics of the FEA prototype were evaluated. Results indicated that emission current densities of the order of 6 mA/cm2 could be obtained at electric fields as low as 10 V/?m to 20 V/?m. During the prototype microfabrication process, issues such as delamination of the extraction gate and poor etching of the SiO2 insulating layer located between the emitters and the extraction layer were encountered. Consequently, alternative FEA designs were investigated. Experimental and simulation data from the first FEA prototype were compared and the results were used to evaluate the performance of alternative single and double gate designs that would yield better field emission characteristics compared to the first FEA prototype. The best simulation results are obtained for the double gate FEA design, when the diameter of the collimator gate is around 2.6 times the diameter of the extraction gate.

  18. Nitrogen incorporated ultrananocrystalline diamond based field emitter array for a flat-panel x-ray source

    SciTech Connect

    Posada, Chrystian M.; Grant, Edwin J.; Lee, Hyoung K.; Castaño, Carlos H.; Divan, Ralu; Sumant, Anirudha V.; Rosenmann, Daniel; Stan, Liliana

    2014-04-07

    A field emission based flat-panel transmission x-ray source is being developed as an alternative for medical and industrial imaging. A field emitter array (FEA) prototype based on nitrogen incorporated ultrananocrystalline diamond film has been fabricated to be used as the electron source of this flat panel x-ray source. The FEA prototype was developed using conventional microfabrication techniques. The field emission characteristics of the FEA prototype were evaluated. Results indicated that emission current densities of the order of 6?mA/cm{sup 2} could be obtained at electric fields as low as 10?V/?m to 20?V/?m. During the prototype microfabrication process, issues such as delamination of the extraction gate and poor etching of the SiO{sub 2} insulating layer located between the emitters and the extraction layer were encountered. Consequently, alternative FEA designs were investigated. Experimental and simulation data from the first FEA prototype were compared and the results were used to evaluate the performance of alternative single and double gate designs that would yield better field emission characteristics compared to the first FEA prototype. The best simulation results are obtained for the double gate FEA design, when the diameter of the collimator gate is around 2.6 times the diameter of the extraction gate.

  19. Cell adhesion and growth on ultrananocrystalline diamond and diamond-like carbon films after different surface modifications

    NASA Astrophysics Data System (ADS)

    Miksovsky, J.; Voss, A.; Kozarova, R.; Kocourek, T.; Pisarik, P.; Ceccone, G.; Kulisch, W.; Jelinek, M.; Apostolova, M. D.; Reithmaier, J. P.; Popov, C.

    2014-04-01

    Diamond and diamond-like carbon (DLC) films possess a set of excellent physical and chemical properties which together with a high biocompatibility make them attractive candidates for a number of medical and biotechnological applications. In the current work thin ultrananocrystalline diamond (UNCD) and DLC films were comparatively investigated with respect to cell attachment and proliferation after different surface modifications. The UNCD films were prepared by microwave plasma enhanced chemical vapor deposition, the DLC films by pulsed laser deposition (PLD). The films were comprehensively characterized with respect to their basic properties, e.g. crystallinity, morphology, chemical bonding nature, etc. Afterwards the UNCD and DLC films were modified applying O2 or NH3/N2 plasmas and UV/O3 treatments to alter their surface termination. The surface composition of as-grown and modified samples was studied by X-ray photoelectron spectroscopy (XPS). Furthermore the films were characterized by contact angle measurements with water, formamide, 1-decanol and diiodomethane; from the results obtained the surface energy with its dispersive and polar components was calculated. The adhesion and proliferation of MG63 osteosarcoma cells on the different UNCD and DLC samples were assessed by measurement of the cell attachment efficiency and MTT assays. The determined cell densities were compared and correlated with the surface properties of as-deposited and modified UNCD and DLC films.

  20. Temperature dependence of mechanical stiffness and dissipation in ultrananocrystalline diamond films grown by the HFCVD techinque.

    SciTech Connect

    Adiga, V. P.; Sumant, A. V.; Suresh, S.; Gudeman, C.; Auciello, O.; Carlisle, J. A.; Carpick, R. W.; Materials Science Division; Univ. of Pennsylvania; Innovative Micro Tech.; Advanced Diamond Tech.

    2009-06-01

    We have characterized mechanical properties of ultrananocrystalline diamond (UNCD) thin films grown using the hot filament chemical vapor deposition (HFCVD) technique at 680 C, significantly lower than the conventional growth temperature of -800 C. The films have -4.3% sp{sup 2} content in the near-surface region as revealed by near edge x-ray absorption fine structure spectroscopy. The films, -1 {micro}m thick, exhibit a net residual compressive stress of 370 {+-} 1 MPa averaged over the entire 150 mm wafer. UNCD microcantilever resonator structures and overhanging ledges were fabricated using lithography, dry etching, and wet release techniques. Overhanging ledges of the films released from the substrate exhibited periodic undulations due to stress relaxation. This was used to determine a biaxial modulus of 838 {+-} 2 GPa. Resonant excitation and ring-down measurements in the kHz frequency range of the microcantilevers were conducted under ultrahigh vacuum (UHV) conditions in a customized UHV atomic force microscope system to determine Young's modulus as well as mechanical dissipation of cantilever structures at room temperature. Young's modulus is found to be 790 {+-} 30 GPa. Based on these measurements, Poisson's ratio is estimated to be 0.057 {+-} 0.038. The quality factors (Q) of these resonators ranged from 5000 to 16000. These Q values are lower than theoretically expected from the intrinsic properties of diamond. The results indicate that surface and bulk defects are the main contributors to the observed dissipation in UNCD resonators.

  1. Effects of Surface Pretreatment on Nucleation and Growth of Ultra-Nanocrystalline Diamond Films

    NASA Astrophysics Data System (ADS)

    Liu, Cong; Wang, Jianhua; Liu, Sijia; Xiong, Liwei; Weng, Jun; Cui, Xiaohui

    2015-06-01

    The effects of different surface pretreatment methods on the nucleation and growth of ultra-nanocrystalline diamond (UNCD) films grown from focused microwave Ar/CH4/H2 (argon-rich) plasma were systematically studied. The surface roughness, nucleation density, microstructure, and crystallinity of the obtained UNCD films were characterized by atomic force microscope (AFM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and Raman spectroscopy. The results indicate that the nucleation enhancement was found to be sensitive to the different surface pretreatment methods, and a higher initial nucleation density leads to highly smooth UNCD films. When the silicon substrate was pretreated by a two-step method, i.e., plasma treatment followed by ultrasonic vibration with diamond nanopowder, the grain size of the UNCD films was greatly decreased: about 7.5 nm can be achieved. In addition, the grain size of UNCD films depends on the substrate pretreatment methods and roughness, which indicates that the surface of substrate profile has a “genetic characteristic”. supported by National Natural Science Foundation of China (No. 11175137) and the Research Fund of Wuhan Institute of Technology, China (No. 11111051)

  2. Formation of Ultrananocrystalline Diamond/Amorphous Carbon Composite Films in Vacuum Using Coaxial Arc Plasma Gun

    NASA Astrophysics Data System (ADS)

    Hanada, Kenji; Yoshida, Tomohiro; Nakagawa, You; Yoshitake, Tsuyoshi

    2010-12-01

    Ultrananocrystalline diamond (UNCD)/nonhydrogenated amorphous carbon (a-C) composite films were grown in vacuum using a coaxial arc plasma gun. From the X-ray diffraction measurement, the UNCD crystallite size was estimated to be 1.6 nm. This size is dramatically reduced from that (2.3 nm) of UNCD/hydrogenated amorphous carbon (a-C:H) composite films grown in a hydrogen atmosphere. The sp3/(sp3 + sp2) value, which was estimated from the X-ray photoemission spectrum, was also reduced to be 41%. A reason for it might be the reduction in the UNCD crystallite size. From the near-edge X-ray absorption fine-structure (NEXAFS) spectrum, it was found that the ?*C=C and ?*C?C bonds are preferentially formed instead of the ?*C-H bonds in the UNCD/a-C:H films. Since the extremely small UNCD crystallites (1.6 nm) correspond to the nuclei of diamond, we consider that UNCD crystallite formation should be due predominantly to nucleation. The supersaturated condition required for nucleation is expected to be realized in the deposition using the coaxial arc plasma gun.

  3. Ultrananocrystalline diamond thin films for MEMS and moving mechanical assembly devices.

    SciTech Connect

    Krauss, A. R.; Gruen, D. M.; Jayatissa, A.; Sumant, A.; Tucek, J.; Auciello, O.; Mancini, D.; Moldovan, N.; Erdemir, A.; Ersoy, D.; Gardos, M. N.; Busmann, H. G.; Meyer, E. M.; Ding, M. Q.; Univ. of Illinois at Chicago; Raytheon Electronic Systems Comp.; Fraunhofer Inst. for Applied Materials Science; Univ. of Bremen; Beijing Inst. of Electronics

    2001-11-01

    MEMS devices are currently fabricated primarily in silicon because of the available surface machining technology. A major problem with the Si-based MEMS technology is that Si has poor mechanical and tribological properties [J.J. Sniegowski, in: B. Bushan (Ed.), Tribology Issues and Opportunities in MEMS, Kluwer Academic Publisher, The Netherlands, 1998, p. 325; A.P. Lee, A.P. Pisano, M.G. Lim, Mater. Res. Soc. Symp. Proc. 276 (1992) 67.], and practical MEMS devices are currently limited primarily to applications involving only bending and flexural motion, such as cantilever accelerometers and vibration sensors. However, because of the poor flexural strength and fracture toughness of Si, and the tendency of Si to adhere to hydrophilic surfaces, even these simple devices have limited dynamic range. Future MEMS applications that involve significant rolling or sliding contact will require the use of new materials with significantly improved mechanical and tribological properties, and the ability to perform well in harsh environments, Diamond is a superhard material of high mechanical strength, exceptional chemical inertness, and outstanding thermal stability. The brittle fracture strength is 23 times that of Si, and the projected wear life of diamond MEMS moving mechanical assemblies (MEMS MMAs) is 10 000 times greater than that of Si MMAs. However, as the hardest known material, diamond is notoriously difficult to fabricate. Conventional CVD thin film deposition methods offer an approach to the fabrication of ultra-small diamond structures, but the films have large grain size, high internal stress, poor intergranular adhesion, and very rough surfaces, and are consequently ill-suited for MEMS MMA applications. Diamond-like films are also being investigated for application to MEMS devices. However, they involve mainly physical vapor deposition methods that are not suitable for good conformal deposition on high aspect ratio features, and generally they do not exhibit the outstanding mechanical properties of diamond. We demonstrate here the application of a novel microwave plasma technique using a unique C{sub 60}/Ar or CH{sub 4}/Ar chemistry that produces phase-pure ultrananocrystalline diamond (UNCD) coatings with morphological and mechanical properties that are ideally suited for MEMS applications in general, and MMA use in particular. We have developed lithographic techniques for the fabrication of UNCD-MEMS components, including cantilevers and multi-level devices, acting as precursors to microbearings and gears, making UNCD a promising material for the development of high performance MEMS devices.

  4. Effect of gigaelectron volt Au-ion irradiation on the characteristics of ultrananocrystalline diamond films

    SciTech Connect

    Chen, Huang-Chin; Teng, Kuang-Yau; Tang, Chen-Yau; Lin, I-Nan; Sundaravel, Balakrishnan; Amirthapandian, Sankarakumar

    2010-12-15

    The effect of 2.245 GeV Au-ion irradiation/postannealing processes on the electron field emission (EFE) properties of ultrananocrystalline diamond (UNCD) films was investigated. Au-ion irradiation with a fluence of around 8.4x10{sup 13} ions/cm{sup 2} is required to induce a large improvement in the EFE properties of the UNCD films. Postannealing the Au-ion irradiated films at 1000 deg. C for 1 h slightly degraded the EFE properties of the films but the resulting EFE behavior was still markedly superior to that of pristine UNCD films. Transmission electron microscopy examinations revealed that the EFE properties of the UNCD films are primarily improved by Au-ion irradiation/postannealing processes because of the formation of nanographites along the trajectory of the irradiating ions, which results in an interconnected path for electron transport. In contrast, the induction of grain growth process due to Au-ion irradiation in UNCD films is presumed to insignificantly degrade the EFE properties for the films as the aggregates are scarcely distributed and do not block the electron conducting path.

  5. Growth of ultrananocrystalline diamond film by DC Arcjet plasma enhanced chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Chen, G. C.; Li, B.; Yan, Z. Q.; Liu, J.; Lu, F. X.; Ye, H.

    2012-06-01

    Self-standing diamond films were grown by DC Arcjet plasma enhanced chemical vapor deposition (CVD). The feed gasses were Ar/H2/CH4, in which the flow ratio of CH4 to H2 (F/F) was varied from 5% to 20%. Two distinct morphologies were observed by scanning electron microscope (SEM), i.e. the "pineapple-like" morphology and the "cauliflower-like" morphology. It was found that the morphologies of the as-grown films are strongly dependent on the flow ratio of CH4 to H2 in the feed gasses. High resolution transmission electron microscope (HRTEM) survey results revealed that there were nanocrystalline grains within the "pineapple-like" films whilst there were ultrananocrystalline grains within "cauliflower-like" films. X-ray diffraction (XRD) results suggested that (110) crystalline plane was the dominant surface in the "cauliflower-like" films whilst (100) crystalline plane was the dominant surface in the "pineapple-like" films. Raman spectroscopy revealed that nanostructured carbon features could be observed in both types of films. Plasma diagnosis was carried out in order to understand the morphology dependent growth mechanism. It could be concluded that the film morphology was strongly influenced by the density of gas phases. The gradient of C2 radical was found to be different along the growth direction under the different growth conditions.

  6. Ultrananocrystalline diamond cantilever wide dynamic range acceleration/vibration/pressure sensor

    DOEpatents

    Krauss, Alan R. (Naperville, IL); Gruen, Dieter M. (Downers Grove, IL); Pellin, Michael J. (Naperville, IL); Auciello, Orlando (Bolingbrook, IL)

    2002-07-23

    An ultrananocrystalline diamond (UNCD) element formed in a cantilever configuration is used in a highly sensitive, ultra-small sensor for measuring acceleration, shock, vibration and static pressure over a wide dynamic range. The cantilever UNCD element may be used in combination with a single anode, with measurements made either optically or by capacitance. In another embodiment, the cantilever UNCD element is disposed between two anodes, with DC voltages applied to the two anodes. With a small AC modulated voltage applied to the UNCD cantilever element and because of the symmetry of the applied voltage and the anode-cathode gap distance in the Fowler-Nordheim equation, any change in the anode voltage ratio V1/N2 required to maintain a specified current ratio precisely matches any displacement of the UNCD cantilever element from equilibrium. By measuring changes in the anode voltage ratio required to maintain a specified current ratio, the deflection of the UNCD cantilever can be precisely determined. By appropriately modulating the voltages applied between the UNCD cantilever and the two anodes, or limit electrodes, precise independent measurements of pressure, uniaxial acceleration, vibration and shock can be made. This invention also contemplates a method for fabricating the cantilever UNCD structure for the sensor.

  7. Ultrananocrystalline Diamond Cantilever Wide Dynamic Range Acceleration/Vibration /Pressure Sensor

    DOEpatents

    Krauss, Alan R. (Naperville, IL); Gruen, Dieter M. (Downers Grove, IL); Pellin, Michael J. (Naperville, IL); Auciello, Orlando (Bolingbrook, IL)

    2003-09-02

    An ultrananocrystalline diamond (UNCD) element formed in a cantilever configuration is used in a highly sensitive, ultra-small sensor for measuring acceleration, shock, vibration and static pressure over a wide dynamic range. The cantilever UNCD element may be used in combination with a single anode, with measurements made either optically or by capacitance. In another embodiment, the cantilever UNCD element is disposed between two anodes, with DC voltages applied to the two anodes. With a small AC modulated voltage applied to the UNCD cantilever element and because of the symmetry of the applied voltage and the anode-cathode gap distance in the Fowler-Nordheim equation, any change in the anode voltage ratio V1/V2 required to maintain a specified current ratio precisely matches any displacement of the UNCD cantilever element from equilibrium. By measuring changes in the anode voltage ratio required to maintain a specified current ratio, the deflection of the UNCD cantilever can be precisely determined. By appropriately modulating the voltages applied between the UNCD cantilever and the two anodes, or limit electrodes, precise independent measurements of pressure, uniaxial acceleration, vibration and shock can be made. This invention also contemplates a method for fabricating the cantilever UNCD structure for the sensor.

  8. Electroplate and Lift Lithography for Patterned Micro/Nanowires Using Ultrananocrystalline Diamond (UNCD) as a Reusable Template

    PubMed Central

    2011-01-01

    A fast, simple, scalable technique is described for the controlled, solution-based, electrochemical synthesis of patterned metallic and semiconducting nanowires from reusable, nonsacrificial, ultrananocrystalline diamond (UNCD) templates. This enables the repeated fabrication of arrays of complex patterns of nanowires, potentially made of any electrochemically depositable material. Unlike all other methods of patterning nanowires, this benchtop technique quickly mass-produces patterned nanowires whose diameters are not predefined by the template, without requiring intervening vacuum or clean room processing. This technique opens a pathway for studying nanoscale phenomena with minimal equipment, allowing the process-scale development of a new generation of nanowire-based devices. PMID:21405103

  9. Kinetics of the electrochemical mineralization of perfluorooctanoic acid on ultrananocrystalline boron doped conductive diamond electrodes.

    PubMed

    Urtiaga, Ane; Fernández-González, Carolina; Gómez-Lavín, Sonia; Ortiz, Inmaculada

    2015-06-01

    This work deals with the electrochemical degradation and mineralization of perfluorooctanoic acid (PFOA). Model aqueous solutions of PFOA (100mg/L) were electro-oxidized under galvanostatic conditions in a flow-by undivided cell provided with a tungsten cathode and an anode formed by a commercial ultrananocrystalline boron doped diamond (BDD) coating on a niobium substrate. A systematic experimental study was conducted in order to analyze the influence of the following operation variables: (i) the supporting electrolyte, NaClO4 (1.4 and 8.4g/L) and Na2SO4 (5g/L); (ii) the applied current density, japp, in the range 50-200 A/m(2) and (iii) the hydrodynamic conditions, in terms of flowrate in the range 0.4×10(-4)-1.7×10(-4)m(3)/s and temperature in the range 293-313K. After 6h of treatment and at japp 200A/m(2), PFOA removal was higher than 93% and the mineralization ratio, obtained from the decrease of the total organic carbon (TOC) was 95%. The electrochemical generation of hydroxyl radicals in the supporting electrolyte was experimentally measured based on their reaction with dimethyl sulfoxide. The enhanced formation of hydroxyl radicals at higher japp was related to the faster kinetics of PFOA removal. The fitting of experimental data to the proposed kinetic model provided the first order rate constants of PFOA degradation, kc(1) that moved from 2.06×10(-4) to 15.58×10(-4)s(-1), when japp varied from 50 to 200A/m(2). PMID:24981910

  10. Direct observation and mechanism for enhanced field emission sites in platinum ion implanted/post-annealed ultrananocrystalline diamond films

    SciTech Connect

    Panda, Kalpataru E-mail: phy.kalpa@gmail.com; Inami, Eiichi; Sugimoto, Yoshiaki; Sankaran, Kamatchi J.; Tai, Nyan Hwa; Lin, I-Nan

    2014-10-20

    Enhanced electron field emission (EFE) properties for ultrananocrystalline diamond (UNCD) films upon platinum (Pt) ion implantation and subsequent post-annealing processes is reported, viz., low turn-on field of 4.17?V/?m with high EFE current density of 5.08?mA/cm{sup 2} at an applied field of 7.0?V/?m. Current imaging tunneling spectroscopy (CITS) mode in scanning tunneling spectroscopy directly revealed the increased electron emission sites density for Pt ion implanted/post-annealed UNCD films than the pristine one. The high resolution CITS mapping and local current–voltage characteristic curves demonstrated that the electrons are dominantly emitted from the diamond grain boundaries and Pt nanoparticles.

  11. Surface chemistry and bonding configuration of ultrananocrystalline diamond surfaces and their effects on nanotribological properties.

    SciTech Connect

    Sumant, A. V.; Grierson, D. S.; Gerbi, J. E.; Carlisle, J. A.; Auciello, O.; Carpick, R. W.; Univ. of Wisconsin at Madison

    2007-12-01

    We present a comprehensive study of surface composition and nanotribology for ultrananocrystalline diamond (UNCD) surfaces, including the influence of film nucleation on these properties. We describe a methodology to characterize the underside of the films as revealed by sacrificial etching of the underlying substrate. This enables the study of the morphology and composition resulting from the nucleation and initial growth of the films, as well as the characterization of nanotribological properties which are relevant for applications including micro-/nanoelectromechanical systems. We study the surface chemistry, bonding configuration, and nanotribological properties of both the topside and the underside of the film with synchrotron-based x-ray absorption near-edge structure spectroscopy to identify the bonding state of the carbon atoms, x-ray photoelectron spectroscopy to determine the surface chemical composition, Auger electron spectroscopy to further verify the composition and bonding configuration, and quantitative atomic force microscopy to study the nanoscale topography and nanotribological properties. The films were grown on SiO{sub 2} after mechanically polishing the surface with detonation synthesized nanodiamond powder, followed by ultrasonication in a methanol solution containing additional nanodiamond powder. The sp{sup 2} fraction, morphology, and chemistry of the as-etched underside are distinct from the topside, exhibiting a higher sp{sup 2} fraction, some oxidized carbon, and a smoother morphology. The nanoscale single-asperity work of adhesion between a diamond nanotip and the as-etched UNCD underside is far lower than for a silicon-silicon interface (59.2 {+-} 2 vs 826 {+-} 186 mJ/m{sup 2}, respectively). Exposure to atomic hydrogen dramatically reduces nanoscale adhesion to 10.2 {+-} 0.4 mJ/m{sup 2}, at the level of van der Waals interactions and consistent with recent ab initio calculations. Friction is substantially reduced as well, demonstrating a direct link between the surface chemistry and nanoscale friction. The proposed mechanism, supported by the detailed surface spectroscopic analysis, is the elimination of reactive (e.g., C*-), polar (e.g., C-O), and {pi}-bonded (C-C) surface groups, which are replaced by fully saturated, hydrogen-terminated surface bonds to produce an inert surface that interacts minimally with the contacting counterface.

  12. Fast Photoresponse and Long Lifetime UV Photodetectors and Field Emitters Based on ZnO/Ultrananocrystalline Diamond Films.

    PubMed

    Saravanan, Adhimoorthy; Huang, Bohr-Ran; Lin, Jun-Cheng; Keiser, Gerd; Lin, I-Nan

    2015-11-01

    We have designed photodetectors and UV field emitters based on a combination of ZnO nanowires/nanorods (ZNRs) and bilayer diamond films in a metal-semiconductor-metal (MSM) structure. The ZNRs were fabricated on different diamond films and systematic investigations showed an ultra-high photoconductive response from ZNRs prepared on ultrananocrystalline diamond (UNCD) operating at a lower voltage of 2?V. We found that the ZNRs/UNCD photodetector (PD) has improved field emission properties and a reduced turn-on field of 2.9?V??m(-1) with the highest electron field emission (EFE) by simply illuminating the sample with ultraviolet (UV) light. The photoresponse (Iphoto /Idark ) behavior of the ZNRs/UNCD PD exhibits a much higher photoresponse (912) than bare ZNRs (229), ZNRs/nanocrystalline diamond (NCD; 518), and ZNRs/microcrystalline diamond (MCD; 325) under illumination at ?=365?nm. A photodetector with UNCD films offers superior stability and a longer lifetime compared with carbon materials and bare ZNRs. The lifetime stability of the ZNRs/UNCD-based device is about 410?min, which is markedly superior to devices that use bare ZNRs (92?min). The ZNRs/UNCD PD possesses excellent photoresponse properties with improved lifetime and stability; in addition, ZNRs/UNCD-based UV emitters have great potential for applications such as cathodes in flat-panel displays and microplasma display devices. PMID:26382200

  13. Improvement on electrical conductivity and electron field emission properties of Au-ion implanted ultrananocrystalline diamond films by using Au-Si eutectic substrates

    NASA Astrophysics Data System (ADS)

    Sankaran, K. J.; Sundaravel, B.; Tai, N. H.; Lin, I. N.

    2015-08-01

    In the present work, Au-Si eutectic layer was used to enhance the electrical conductivity/electron field emission (EFE) properties of Au-ion implanted ultrananocrystalline diamond (Au-UNCD) films grown on Si substrates. The electrical conductivity was improved to a value of 230 (? cm)-1, and the EFE properties was enhanced reporting a low turn-on field of 2.1 V/?m with high EFE current density of 5.3 mA/cm2 (at an applied field of 4.9 V/?m) for the Au-UNCD films. The formation of SiC phase circumvents the formation of amorphous carbon prior to the nucleation of diamond on Si substrates. Consequently, the electron transport efficiency of the UNCD-to-Si interface increases, thereby improving the conductivity as well as the EFE properties. Moreover, the salient feature of these processes is that the sputtering deposition of Au-coating for preparing the Au-Si interlayer, the microwave plasma enhanced chemical vapor deposition process for growing the UNCD films, and the Au-ion implantation process for inducing the nanographitic phases are standard thin film preparation techniques, which are simple, robust, and easily scalable. The availability of these highly conducting UNCD films with superior EFE characteristics may open up a pathway for the development of high-definition flat panel displays and plasma devices.

  14. Structural and Physical Characteristics of Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Composite Films Deposited Using a Coaxial Arc Plasma Gun

    NASA Astrophysics Data System (ADS)

    Yoshitake, Tsuyoshi; Nakagawa, You; Nagano, Akira; Ohtani, Ryota; Setoyama, Hiroyuki; Kobayashi, Eiichi; Sumitani, Kazushi; Agawa, Yoshiaki; Nagayama, Kunihito

    2010-01-01

    Ultrananocrystalline diamond (UNCD)/hydrogenated amorphous carbon (a-C:H) films were formed without initial nucleation using a coaxial arc plasma gun. The UNCD crystallite diameters estimated from the X-ray diffraction peaks were approximately 2 nm. The Fourier transform infrared absorption spectrum exhibited an intense sp3-CH peak that might originate from the grain boundaries between UNCD crystallites whose dangling bonds are terminated with hydrogen atoms. A narrow sp3 peak in the photoemission spectrum implied that the film comprises a large number of UNCD crystallites. Large optical absorption coefficients at photon energies larger than 3 eV that might be due to the grain boundaries are specific to the UNCD/a-C:H films.

  15. Synthesis of highly transparent ultrananocrystalline diamond films from a low-pressure, low-temperature focused microwave plasma jet.

    PubMed

    Liao, Wen-Hsiang; Wei, Da-Hua; Lin, Chii-Ruey

    2012-01-01

    This paper describes a new low-temperature process underlying the synthesis of highly transparent ultrananocrystalline diamond [UNCD] films by low-pressure and unheated microwave plasma jet-enhanced chemical vapor deposition with Ar-1%CH4-10%H2 gas chemistry. The unique low-pressure/low-temperature [LPLT] plasma jet-enhanced growth even with added H2 and unheated substrates yields UNCD films similar to those prepared by plasma-enhanced growth without addition of H2 and heating procedure. This is due to the focused plasma jet which effectively compensated for the sluggish kinetics associated with LPLT growth. The effects of pressure on UNCD film synthesis from the microwave plasma jet were systematically investigated. The results indicated that the substrate temperature, grain size, surface roughness, and sp3 carbon content in the films decreased with decreasing pressure. The reason is due to the great reduction of H? emission to lower the etching of sp2 carbon phase, resulting from the increase of mean free path with decreasing pressure. We have demonstrated that the transition from nanocrystalline (80 nm) to ultrananocrystalline (3 to 5 nm) diamond films grown via microwave Ar-1%CH4-10%H2 plasma jets could be controlled by changing the pressure from 100 to 30 Torr. The 250-nm-thick UNCD film was synthesized on glass substrates (glass transition temperature [Tg] 557°C) using the unique LPLT (30 Torr/460°C) microwave plasma jet, which produced UNCD films with a high sp3 carbon content (95.65%) and offered high optical transmittance (approximately 86% at 700 nm). PMID:22260391

  16. Synthesis of highly transparent ultrananocrystalline diamond films from a low-pressure, low-temperature focused microwave plasma jet

    NASA Astrophysics Data System (ADS)

    Liao, Wen-Hsiang; Wei, Da-Hua; Lin, Chii-Ruey

    2012-01-01

    This paper describes a new low-temperature process underlying the synthesis of highly transparent ultrananocrystalline diamond [UNCD] films by low-pressure and unheated microwave plasma jet-enhanced chemical vapor deposition with Ar-1%CH4-10%H2 gas chemistry. The unique low-pressure/low-temperature [LPLT] plasma jet-enhanced growth even with added H2 and unheated substrates yields UNCD films similar to those prepared by plasma-enhanced growth without addition of H2 and heating procedure. This is due to the focused plasma jet which effectively compensated for the sluggish kinetics associated with LPLT growth. The effects of pressure on UNCD film synthesis from the microwave plasma jet were systematically investigated. The results indicated that the substrate temperature, grain size, surface roughness, and sp 3 carbon content in the films decreased with decreasing pressure. The reason is due to the great reduction of H ? emission to lower the etching of sp 2 carbon phase, resulting from the increase of mean free path with decreasing pressure. We have demonstrated that the transition from nanocrystalline (80 nm) to ultrananocrystalline (3 to 5 nm) diamond films grown via microwave Ar-1%CH4-10%H2 plasma jets could be controlled by changing the pressure from 100 to 30 Torr. The 250-nm-thick UNCD film was synthesized on glass substrates (glass transition temperature [ T g] 557°C) using the unique LPLT (30 Torr/460°C) microwave plasma jet, which produced UNCD films with a high sp 3 carbon content (95.65%) and offered high optical transmittance (approximately 86% at 700 nm).

  17. Ultrananocrystalline diamond films with optimized dielectric properties for advanced RF MEMS capacitive switches

    DOEpatents

    Sumant, Anirudha V.; Auciello, Orlando H.; Mancini, Derrick C.

    2013-01-15

    An efficient deposition process is provided for fabricating reliable RF MEMS capacitive switches with multilayer ultrananocrystalline (UNCD) films for more rapid recovery, charging and discharging that is effective for more than a billion cycles of operation. Significantly, the deposition process is compatible for integration with CMOS electronics and thereby can provide monolithically integrated RF MEMS capacitive switches for use with CMOS electronic devices, such as for insertion into phase array antennas for radars and other RF communication systems.

  18. Role of carbon nanotube interlayer in enhancing the electron field emission behavior of ultrananocrystalline diamond coated Si-tip arrays.

    PubMed

    Chang, Ting-Hsun; Kunuku, Srinivasu; Kurian, Joji; Manekkathodi, Afsal; Chen, Lih-Juann; Leou, Keh-Chyang; Tai, Nyan-Hwa; Lin, I-Nan

    2015-04-15

    We improved the electron field emission properties of ultrananocrystalline diamond (UNCD) films grown on Si-tip arrays by using the carbon nanotubes (CNTs) as interlayer and post-treating the films in CH4/Ar/H2 plasma. The use of CNTs interlayer effectively suppresses the presence of amorphous carbon in the diamond-to-Si interface that enhances the transport of electrons from Si, across the interface, to diamond. The post-treatment process results in hybrid-granular-structured diamond (HiD) films via the induction of the coalescence of the ultrasmall grains in these films that enhanced the conductivity of the films. All these factors contribute toward the enhancement of the electron field emission (EFE) process for the HiDCNT/Si-tip emitters, with low turn-on field of E0 = 2.98 V/?m and a large current density of 1.68 mA/cm(2) at an applied field of 5.0 V/?m. The EFE lifetime stability under an operation current of 6.5 ?A was improved substantially to ?HiD/CNT/Si-tip = 365 min. Interestingly, these HiDCNT/Si-tip materials also show enhanced plasma illumination behavior, as well as improved robustness against plasma ion bombardment when they are used as the cathode for microplasma devices. The study concludes that the use of CNT interlayers not only increase the potential of these materials as good EFE emitters, but also prove themselves to be good microplasma devices with improved performance. PMID:25793425

  19. Enhancement in electron field emission in ultrananocrystalline and microcrystalline diamond films upon 100 MeV silver ion irradiation

    SciTech Connect

    Chen, H.-C.; Palnitkar, Umesh; Pong, W.-F.; Lin, I-N.; Singh, Abhinav Pratap; Kumar, Ravi

    2009-04-15

    Enhanced electron field emission (EFE) behavior was observed in ultrananocrystalline diamond (UNCD) and microcrystalline diamond (MCD) films upon irradiation with 100 MeV Ag{sup 9+}-ions in a fluence of 5x10{sup 11} ions/cm{sup 2}. Transmission electron microscopy indicated that while the overall crystallinity of these films remained essentially unaffected, the local microstructure of the materials was tremendously altered due to heavy ion irradiation, which implied that the melting and recrystallization process have occurred along the trajectory of the heavy ions. Such a process induced the formation of interconnected nanocluster networks, facilitating the electron conduction and enhancing the EFE properties for the materials. The enhancement in the EFE is more prominent for MCD films than that for UNCD films, reaching a low turn-on field of E{sub 0}=3.2 V/mum and large EFE current density of J{sub e}=3.04 mA/cm{sup 2} for 5x10{sup 11} ions/cm{sup 2} heavy ion irradiated samples.

  20. Fundamentals and application of materials integration for low-power piezoelectrically actuated ultra-nanocrystalline diamond MEMS/NEMS.

    SciTech Connect

    Auciello, O.; Srinivasan, S.; Hiller, J.; Kabius, B.

    2009-01-01

    Most current micro/nanoelectromechanical systems (MEMS/NEMS) are based on silicon. However, silicon exhibits relatively poor mechanical/tribological properties, compromising applications to several projected MEMS/NEMS devices, particularly those that require materials with high Young's modulus for MEMS resonators or low surface adhesion forces for MEMS/NEMS working in conditions with extensive surface contact. Diamond films with superior mechanical/tribological properties provide an excellent alternative platform material. Ultrananocrystalline diamond (UNCD{cflx W}) in film form with 2-5 nm grains exhibits excellent properties for high-performance MEMS/NEMS devices. Concurrently, piezoelectric Pb(Zr{sub x}Ti{sub 1-x})O{sub 3} (PZT) films provide high sensitivity/low electrical noise for sensing/high-force actuation at relatively low voltages. Therefore, integration of PZT and UNCD films provides a high-performance platform for advanced MEMS/NEMS devices. This paper describes the bases of such integration and demonstration of low voltage piezoactuated hybrid PZT/UNCD cantilevers.

  1. All diamond self-aligned thin film transistor

    DOEpatents

    Gerbi, Jennifer (Champaign, IL)

    2008-07-01

    A substantially all diamond transistor with an electrically insulating substrate, an electrically conductive diamond layer on the substrate, and a source and a drain contact on the electrically conductive diamond layer. An electrically insulating diamond layer is in contact with the electrically conductive diamond layer, and a gate contact is on the electrically insulating diamond layer. The diamond layers may be homoepitaxial, polycrystalline, nanocrystalline or ultrananocrystalline in various combinations.A method of making a substantially all diamond self-aligned gate transistor is disclosed in which seeding and patterning can be avoided or minimized, if desired.

  2. Improvement of field emission performance on nitrogen ion implanted ultrananocrystalline diamond films through visualization of structure modificaitons.

    SciTech Connect

    Chen, Y.-C.; Zhong, X-Y.; Kabius, B.; Hiller, J. M.; Tai, N.-H.; Lin, I.-N.

    2011-02-01

    The relationship between the electron field emission properties and structure of ultra-nanocrystalline diamond (UNCD) films implanted by nitrogen ions or carbon ions was investigated. The electron field emission properties of nitrogen-implanted UNCD films and carbon-implanted UNCD films were pronouncedly improved with respect to those of as-grown UNCD films, that is, the turn-on field decreased from 23.2 V/{micro}m to 12.5 V/{micro}m and the electron field emission current density increased from 10E-5 mA/cm{sup 2} to 1 x 10E-2 mA/cm{sup 2}. The formation of a graphitic phase in the nitrogen-implanted UNCD films was demonstrated by Raman microscopy and cross-sectional high-resolution transmission electron microscopy. The possible mechanism is presumed to be that the nitrogen ion irradiation induces the structure modification (converting sp{sup 3}-bonded carbons into sp{sup 2}-bonded ones) in UNCD films.

  3. Enhancing electrical conductivity and electron field emission properties of ultrananocrystalline diamond films by copper ion implantation and annealing

    SciTech Connect

    Sankaran, K. J.; Tai, N. H. E-mail: inanlin@mail.tku.edu.tw; Panda, K.; Sundaravel, B.; Lin, I. N. E-mail: inanlin@mail.tku.edu.tw

    2014-02-14

    Copper ion implantation and subsequent annealing at 600?°C achieved high electrical conductivity of 95.0 (?cm){sup ?1} for ultrananocrystalline diamond (UNCD) films with carrier concentration of 2.8?×?10{sup 18}?cm{sup ?2} and mobility of 6.8?×?10{sup 2} cm{sup 2}/V s. Transmission electron microscopy examinations reveal that the implanted Cu ions first formed Cu nanoclusters in UNCD films, which induced the formation of nanographitic grain boundary phases during annealing process. From current imaging tunneling spectroscopy and local current-voltage curves of scanning tunneling spectroscopic measurements, it is observed that the electrons are dominantly emitted from the grain boundaries. Consequently, the nanographitic phases presence in the grain boundaries formed conduction channels for efficient electron transport, ensuing in excellent electron field emission (EFE) properties for copper ion implanted/annealed UNCD films with low turn-on field of 4.80?V/?m and high EFE current density of 3.60?mA/cm{sup 2} at an applied field of 8.0?V/?m.

  4. A quantitative study of detection mechanism of a label-free impedance biosensor using ultrananocrystalline diamond microelectrode array.

    PubMed

    Siddiqui, Shabnam; Dai, Zhenting; Stavis, Courtney J; Zeng, Hongjun; Moldovan, Nicolaie; Hamers, Robert J; Carlisle, John A; Arumugam, Prabhu U

    2012-05-15

    It is well recognized that label-free biosensors are the only class of sensors that can rapidly detect antigens in real-time and provide remote environmental monitoring and point-of-care diagnosis that is low-cost, specific, and sensitive. Electrical impedance spectroscopy (EIS) based label-free biosensors have been used to detect a wide variety of antigens including bacteria, viruses, DNA, and proteins due to the simplicity of their detection technique. However, their commercial development has been hindered due to difficulty in interpreting the change in impedance upon antigen binding and poor signal reproducibility as a result of surface fouling and non-specific binding. In this study, we develop a circuit model to adequately describe the physical changes at bio functionalized surface and provide an understanding of the detection mechanism based on electron exchange between electrolyte and surface through pores surrounding antibody-antigen. The model was successfully applied to extract quantitative information about the bio surface at different stages of surface functionalization. Further, we demonstrate boron-doped ultrananocrystalline diamond (UNCD) microelectrode array (3 × 3 format, 200 ?m diameter) improves signal reproducibility significantly and increases sensitivity by four orders of magnitude. This study marks the first demonstration of UNCD array based biosensor that can reliably detect a model Escherichia coli K12 bacterium using EIS, positioning this technology for rapid adoption in point-of-use applications. PMID:22456097

  5. Fast growth of ultrananocrystalline diamond films by bias-enhanced nucleation and growth process in CH{sub 4}/Ar plasma

    SciTech Connect

    Saravanan, A.; Huang, B. R.; Sankaran, K. J.; Tai, N. H.; Dong, C. L.; Lin, I. N.

    2014-05-05

    This letter describes the fast growth of ultrananocrystalline diamond (UNCD) films by bias-enhanced nucleation and growth process in CH{sub 4}/Ar plasma. The UNCD grains were formed at the beginning of the film's growth without the necessity of forming the amorphous carbon interlayer, reaching a thickness of ?380?nm in 10?min. Transmission electron microscopic investigations revealed that the application of bias voltage induced the formation of graphitic phase both in the interior and at the interface regions of UNCD films that formed interconnected paths, facilitating the transport of electrons and resulting in enhanced electron field emission properties.

  6. High efficiency diamond solar cells

    DOEpatents

    Gruen, Dieter M. (Downers Grove, IL)

    2008-05-06

    A photovoltaic device and method of making same. A layer of p-doped microcrystalline diamond is deposited on a layer of n-doped ultrananocrystalline diamond such as by providing a substrate in a chamber, providing a first atmosphere containing about 1% by volume CH.sub.4 and about 99% by volume H.sub.2 with dopant quantities of a boron compound, subjecting the atmosphere to microwave energy to deposit a p-doped microcrystalline diamond layer on the substrate, providing a second atmosphere of about 1% by volume CH.sub.4 and about 89% by volume Ar and about 10% by volume N.sub.2, subjecting the second atmosphere to microwave energy to deposit a n-doped ultrananocrystalline diamond layer on the p-doped microcrystalline diamond layer. Electrodes and leads are added to conduct electrical energy when the layers are irradiated.

  7. Near-Edge X-ray Absorption Fine Structure Imaging of Spherical and Flat Counterfaces of Ultrananocrystalline Diamond Tribological Contacts: A Correlation of Surface Chemistry and Friction

    SciTech Connect

    A Konicek; C Jaye; M Hamilton; W Sawyer; D Fischer; R Carpick

    2011-12-31

    A recently installed synchrotron radiation near-edge X-ray absorption fine structure (NEXAFS) full field imaging electron spectrometer was used to spatially resolve the chemical changes of both counterfaces from an ultra-nanocrystalline diamond (UNCD) tribological contact. A silicon flat and Si{sub 3}N{sub 4} sphere were both coated with UNCD, and employed to form two wear tracks on the flat in a linear reciprocating tribometer. The first wear track was produced using a new, unconditioned sphere whose surface was thus conditioned during this first experiment. This led to faster run-in and lower friction when producing a second wear track using the conditioned sphere. The large depth of field of the magnetically guided NEXAFS imaging detector enabled rapid, large area spectromicroscopic imaging of both the spherical and flat surfaces. Laterally resolved NEXAFS data from the tribological contact area revealed that both substrates had an as-grown surface layer that contained a higher fraction of sp{sup 2}-bonded carbon and oxygen which was mechanically removed. Unlike the flat, the film on the sphere showed evidence of having graphitic character, both before and after sliding. These results show that the graphitic character of the sphere is not solely responsible for low friction and short run-in. Rather, conditioning the sphere, likely by removing asperities and passivating dangling bonds, leads to lower friction with less chemical modification of the substrate in subsequent tests. The new NEXAFS imaging spectroscopy detector enabled a more complete understanding of the tribological phenomena by imaging, for the first time, the surface chemistry of the spherical counterface which had been in continual contact during wear track formation.

  8. Science and technology of ultrananocrystalline diamond (UNCD) thin films for multifunctional devices

    SciTech Connect

    Auciello, O.; Krauss, A. R.; Gruen, D. M.; Jayatissa, A.; Sumant, A.; Tucek, J.; Mancini, D.; Molodvan, N.; Erdemir, A.; Ersoy, D.; Gardos, M. N.; Busman, H. G.; Meyer, E. M.

    2000-08-24

    MEMS devices are currently fabricated primarily in silicon because of the available surface machining technology. However, Si has poor mechanical and tribological properties, and practical MEMS devices are currently limited primarily to applications involving only bending and flexural motion, such as cantilever accelerometers and vibration sensors. However, because of the poor flexural strength and fracture toughness of Si, and the tendency of Si to adhere to hydrophyllic surfaces, even these simple devices have limited dynamic range. Future MEMS applications that involve significant rolling or sliding contact will require the use of new materials with significantly improved mechanical and tribological properties, and the ability to perform well in harsh environments. Diamond is a superhard material of high mechanical strength, exceptional chemical inertness, and outstanding thermal stability. The brittle fracture strength is 23 times that of Si, and the projected wear life of diamond MEMS moving mechanical assemblies (MEMS-MMAs) is 10,000 times greater than that of Si MMAs. However, as the hardest known material, diamond is notoriously difficult to fabricate. Conventional CVD thin film deposition methods offer an approach to the fabrication of ultra-small diamond structures, but the films have large grain size, high internal stress, poor intergranular adhesion, and very rough surfaces, and are consequently ill-suited for MEMS-MMA applications. A thin film deposition process has been developed that produces phase-pure nanocrystalline diamond with morphological and mechanical properties that are ideally suited for MEMS applications in general, and MMA use in particular. The authors have developed lithographic techniques for the fabrication of diamond microstructure including cantilevers and multi-level devices, acting as precursors to micro-bearings and gears, making nanocrystalline diamond a promising material for the development of high performance MEMS devices.

  9. Ultrananocrystalline diamond-CMOS device integration route for high acuity retinal prostheses.

    PubMed

    Ahnood, A; Escudie, M C; Cicione, R; Abeyrathne, C D; Ganesan, K; Fox, K E; Garrett, D J; Stacey, A; Apollo, N V; Lichter, S G; Thomas, C D L; Tran, N; Meffin, H; Prawer, S

    2015-01-01

    High density electrodes are a new frontier for biomedical implants. Increasing the density and the number of electrodes used for the stimulation of retinal ganglion cells is one possible strategy for enhancing the quality of vision experienced by patients using retinal prostheses. The present work presents an integration strategy for a diamond based, high density, stimulating electrode array with a purpose built application specific integrated circuit (ASIC). The strategy is centered on flip-chip bonding of indium bumps to create high count and density vertical interconnects between the stimulator ASIC and an array of diamond neural stimulating electrodes. The use of polydimethylsiloxane (PDMS) housing prevents cross-contamination of the biocompatible diamond electrode with non-biocompatible materials, such as indium, used in the microfabrication process. Micro-imprint lithography allowed edge-to-edge micro-scale pattering of the indium bumps on non-coplanar substrates that have a form factor that can conform to body organs and thus are ideally suited for biomedical applications. Furthermore, micro-imprint lithography ensures the compatibility of lithography with the silicon ASIC and aluminum contact pads. Although this work focuses on 256 stimulating diamond electrode arrays with a pitch of 150 ?m, the use of indium bump bonding technology and vertical interconnects facilitates implants with tens of thousands electrodes with a pitch as low as 10 ?m, thus ensuring validity of the strategy for future high acuity retinal prostheses, and bionic implants in general. PMID:25877379

  10. A Comparison of Mechanical Properties of Three MEMS Materials -Silicon Carbide, Ultrananocrystalline Diamond, and Hydrogen-Free Tetrahedral

    E-print Network

    Espinosa, Horacio D.

    A Comparison of Mechanical Properties of Three MEMS Materials - Silicon Carbide investigated the mechanical properties of three new materials for MEMS/NEMS devices: silicon carbide (SiC) from mechanical, electrical, and tribological properties such as silicon carbide (SiC), ultrananocrystalline

  11. Time-Resolved Spectroscopic Observation of Deposition Processes of Ultrananocrystalline Diamond/Amorphous Carbon Composite Films by Using a Coaxial Arc Plasma Gun

    NASA Astrophysics Data System (ADS)

    Hanada, Kenji; Yoshitake, Tsuyoshi; Nishiyama, Takashi; Nagayama, Kunihito

    2010-08-01

    The deposition of ultrananocrystalline diamond (UNCD)/amorphous carbon composite films using a coaxial arc plasma gun in vacuum and, for comparison, in a 53.3 Pa hydrogen atmosphere was spectroscopically observed using a high-speed camera equipped with narrow-band-pass filters. UNCD crystallites with diameters of approximately 1.6 nm were formed even in vacuum. These extremely small crystallites imply that the formation is predominantly due to nucleation without the subsequent growth. Even in vacuum, emissions from C+ ions, C atoms, and C2 dimers lasted for approximately 100 µs, although the emission lifetimes of these species are generally 10 ns. We consider that the nucleation is due to the supersaturated environment containing excited carbon species with large number densities.

  12. Origin of graphitic filaments on improving the electron field emission properties of negative bias-enhanced grown ultrananocrystalline diamond films in CH{sub 4}/Ar plasma

    SciTech Connect

    Sankaran, K. J.; Tai, N. H. E-mail: nhtai@mse.nthu.edu.tw; Huang, B. R.; Saravanan, A.; Lin, I. N. E-mail: nhtai@mse.nthu.edu.tw

    2014-10-28

    Microstructural evolution of bias-enhanced grown (BEG) ultrananocrystalline diamond (UNCD) films has been investigated using microwave plasma enhanced chemical vapor deposition in gas mixtures of CH{sub 4} and Ar under different negative bias voltages ranging from ?50 to ?200?V. Scanning electron microscopy and Raman spectroscopy were used to characterize the morphology, growth rate, and chemical bonding of the synthesized films. Transmission electron microscopic investigation reveals that the application of bias voltage induced the formation of the nanographitic filaments in the grain boundaries of the films, in addition to the reduction of the size of diamond grains to ultra-nanosized granular structured grains. For BEG-UNCD films under ?200?V, the electron field emission (EFE) process can be turned on at a field as small as 4.08?V/?m, attaining a EFE current density as large as 3.19?mA/cm{sup 2} at an applied field of 8.64?V/?m. But the films grown without bias (0?V) have mostly amorphous carbon phases in the grain boundaries, possessing poorer EFE than those of the films grown using bias. Consequently, the induction of nanographitic filaments in grain boundaries of UNCD films grown in CH{sub 4}/Ar plasma due to large applied bias voltage of ?200?V is the prime factor, which possibly forms interconnected paths for facilitating the transport of electrons that markedly enhance the EFE properties.

  13. Patterning of nanocrystalline diamond films for diamond microstructures useful in MEMS and other devices

    DOEpatents

    Gruen, Dieter M. (Downers Grove, IL); Busmann, Hans-Gerd (Bremen, DE); Meyer, Eva-Maria (Bremen, DE); Auciello, Orlando (Bolingbrook, IL); Krauss, Alan R. (late of Naperville, IL); Krauss, Julie R. (Naperville, IL)

    2004-11-02

    MEMS structure and a method of fabricating them from ultrananocrystalline diamond films having average grain sizes of less than about 10 nm and feature resolution of less than about one micron . The MEMS structures are made by contacting carbon dimer species with an oxide substrate forming a carbide layer on the surface onto which ultrananocrystalline diamond having average grain sizes of less than about 10 nm is deposited. Thereafter, microfabrication process are used to form a structure of predetermined shape having a feature resolution of less than about one micron.

  14. Science and technology of piezoelectric/diamond heterostructures for monolithically integrated high performance MEMS/NEMS/CMOS devices.

    SciTech Connect

    Auciello, O.; Sumant, A. V.; Hiller, J.; Kabius, B.; Ma, Z.; Srinivasan, S.

    2008-12-01

    This paper describes the fundamental and applied science performed to integrate piezoelectric PbZr{sub x}Ti{sub 1-x}O{sub 3} and AlN films with a novel mechanically robust ultrananocrystalline diamond layer to enable a new generation of low voltage/high-performance piezoactuated hybrid piezoelectric/diamond MEMS/NEMS devices.

  15. The microstructural evolution of ultrananocrystalline diamond films due to P ion implantation process—the annealing effect

    SciTech Connect

    Lin, Sheng-Chang; Yeh, Chien-Jui; Leou, Keh-Chyang; Kurian, Joji; Lin, I.-Nan; Dong, Chung-Li; Niu, Huan

    2014-11-14

    The microstructural evolution of UNCD films which are P-ion implanted and annealed at 600?°C (or 800?°C) is systematically investigated. The difference of interaction that the UNCD content undergoes along the trajectory of the incident P-ions is reflected in the alteration of the granular structure. In regions where the P-ions reside, the “interacting zone,” which is found at about 300?nm beneath the surface of the films, coalescence of diamond grains occurs inducing nano-graphitic clusters. The annealing at 600?°C (or 800?°C) heals the defects and, in some cases, forms interconnected graphitic filaments that result in the decrease in surface resistance. However, the annealing at 600?°C (800?°C) induces marked UNCD-to-Si layers interaction. This interaction due to the annealing processes hinders the electron transport across the interface and degrades the electron field emission properties of the UNCD films. These microstructural evolution processes very well account for the phenomenon elaborating that, in spite of enhanced conductivity of the UNCD films along the film's surface due to the P-ion implantation and annealing processes, the electron field emission properties for these UNCD films do not improve.

  16. DEVELOPMENT OF A SCALABLE, LOW-COST, ULTRANANOCRYSTALLINE DIAMOND ELECTROCHEMICAL PROCESS FOR THE DESTRUCTION OF CONTAMINANTS OF EMERGING CONCERN (CECS) - PHASE I

    EPA Science Inventory

    This Small Business Innovative Research (SBIR) project will develop and ready for commercialization a scalable, low-cost process for purification of water containing Contaminants of Emerging Concern (CECs) using anodic oxidation with boron-doped ultrananocrystalline diam...

  17. Electrospray deposition of diamond nanoparticle nucleation layers for subsequent CVD diamond growth

    E-print Network

    Bristol, University of

    Electrospray deposition of diamond nanoparticle nucleation layers for subsequent CVD diamond growth stages of most chemical vapour deposition processes. In order to achieve uniform deposition of diamond thin films it is necessary to seed non-diamond substrates. Here we discuss a simple electrospray

  18. Nanostructured diamond layers enhance the infrared spectroscopy of biomolecules.

    PubMed

    Kozak, Halyna; Babchenko, Oleg; Artemenko, Anna; Ukraintsev, Egor; Remes, Zdenek; Rezek, Bohuslav; Kromka, Alexander

    2014-03-01

    We report on the fabrication and practical use of high-quality optical elements based on Au mirrors coated with diamond layers with flat, nanocolumnar, and nanoporous morphologies. Diamond layers (100 nm thickness) are grown at low temperatures (about 300 °C) from a methane, carbon dioxide, and hydrogen gas mixture by a pulsed microwave plasma system with linear antennas. Using grazing angle reflectance (GAR) Fourier transform infrared spectroscopy with p-polarized light, we compare the IR spectra of fetal bovine serum proteins adsorbed on diamond layers with oxidized (hydrophilic) surfaces. We show that the nanoporous diamond layers provide IR spectra with a signal gain of about 600% and a significantly improved sensitivity limit. This is attributed to its enhanced internal surface area. The improved sensitivity enabled us to distinguish weak infrared absorption peaks of <10-nm-thick protein layers and thereby to analyze the intimate diamond-molecule interface. PMID:24524343

  19. Plasma-activated direct bonding of diamond-on-insulator wafers to thermal oxide grown silicon wafers

    E-print Network

    Akin, Tayfun

    Plasma-activated direct bonding of diamond-on-insulator wafers to thermal oxide grown silicon September 2010 Keywords: Diamond-on-insulator Plasma activation Ultrananocrystalline diamond Direct bonding Diamond-on-insulator (DOI) wafers featuring ultrananocrystalline diamond are studied via atomic force

  20. Effect of pretreatment bias on the nucleation and growth mechanisms of ultrananocrystalline diamond films via bias-enhanced nucleation and growth: An approach to interfacial chemistry analysis via chemical bonding mapping

    SciTech Connect

    Zhong, X. Y.; Hiller, J. M.; Chen, Y. C.; Tai, N. H.; Lin, I. N.; Auciello, O.

    2009-02-01

    The effect of pretreatment bias on the nucleation and growth mechanisms of the ultrananocrystalline diamond (UNCD) films on the Si substrate via bias-enhanced nucleation and bias-enhanced growth (BEN-BEG) was investigated using cross-sectional high-resolution transmission electron microscopy, chemical bonding mapping, and Raman spectroscopy. The mirror-polished substrate surface showed the formation of a triangular profile produced by a dominant physical sputtering mechanism induced by ion bombardment of ions from the hydrogen plasma accelerated toward the substrate due to biasing and a potential hydrogen-induced chemical reaction component before synthesizing the UNCD films. The BEN-BEG UNCD films grown on the Si substrate with biased and unbiased pretreatments in the hydrogen plasma were compared. In the case of the bias-pretreated substrate, the SiC phases were formed at the peaks of the Si surface triangular profile due to the active unsaturated Si bond and the enhanced local electrical field. The UNCD grains grew preferentially at the peaks of the triangular substrate surface profile and rapidly covered the amorphous carbon (a-C) and oriented graphite phases formed in the valley of the surface profile. In the case of the substrate with unbiased pretreatment, the SiC phases were formed via the reactions between the hydrocarbon species and the active Si atoms released from the substrate with assistance of the hydrogen plasma. The UNCD grains nucleated on the nucleating sites consisting of the SiC, a-C, and graphite phases. Growth mechanisms for the BEN-BEG UNCD films on both Si substrates were proposed to elucidate the different nucleation processes. Applying bias on the Si substrate pretreated in the hydrogen plasma optimized the nucleation sites for growth of UNCD grains, resulting in the low content of the nondiamond phases in UNCD films.

  1. High Spectral Resolution Lidar Observations of Diamond Dust Layers in Eureka, AU: * Bourdages, L

    E-print Network

    Eloranta, Edwin W.

    of Atmospheric Change (CANDAC). We expect the results to improve the understanding of diamond dust formation High Spectral Resolution Lidar Observations of Diamond Dust Layers in Eureka, Canada. AU 53706, United States Surfacebased ice crystal layers, also referred to as diamond dust layers, occur

  2. Effects of disorder state and interfacial layer on thermal transport in copper/diamond system

    SciTech Connect

    Sinha, V.; Gengler, J. J.; Muratore, C.; Spowart, J. E.

    2015-02-21

    The characterization of Cu/diamond interface thermal conductance (h{sub c}) along with an improved understanding of factors affecting it are becoming increasingly important, as Cu-diamond composites are being considered for electronic packaging applications. In this study, ?90?nm thick Cu layers were deposited on synthetic and natural single crystal diamond substrates. In several specimens, a Ti-interface layer of thickness ?3.5?nm was sputtered between the diamond substrate and the Cu top layer. The h{sub c} across Cu/diamond interfaces for specimens with and without a Ti-interface layer was determined using time-domain thermoreflectance. The h{sub c} is ?2× higher for similar interfacial layers on synthetic versus natural diamond substrate. The nitrogen concentration of synthetic diamond substrate is four orders of magnitude lower than natural diamond. The difference in nitrogen concentration can lead to variations in disorder state, with a higher nitrogen content resulting in a higher level of disorder. This difference in disorder state potentially can explain the variations in h{sub c}. Furthermore, h{sub c} was observed to increase with an increase of Ti-interface layer thickness. This was attributed to an increased adhesion of Cu top layer with increasing Ti-interface layer thickness, as observed qualitatively in the current study.

  3. Effects of disorder state and interfacial layer on thermal transport in copper/diamond system

    NASA Astrophysics Data System (ADS)

    Sinha, V.; Gengler, J. J.; Muratore, C.; Spowart, J. E.

    2015-02-01

    The characterization of Cu/diamond interface thermal conductance (hc) along with an improved understanding of factors affecting it are becoming increasingly important, as Cu-diamond composites are being considered for electronic packaging applications. In this study, ˜90 nm thick Cu layers were deposited on synthetic and natural single crystal diamond substrates. In several specimens, a Ti-interface layer of thickness ?3.5 nm was sputtered between the diamond substrate and the Cu top layer. The hc across Cu/diamond interfaces for specimens with and without a Ti-interface layer was determined using time-domain thermoreflectance. The hc is ˜2× higher for similar interfacial layers on synthetic versus natural diamond substrate. The nitrogen concentration of synthetic diamond substrate is four orders of magnitude lower than natural diamond. The difference in nitrogen concentration can lead to variations in disorder state, with a higher nitrogen content resulting in a higher level of disorder. This difference in disorder state potentially can explain the variations in hc. Furthermore, hc was observed to increase with an increase of Ti-interface layer thickness. This was attributed to an increased adhesion of Cu top layer with increasing Ti-interface layer thickness, as observed qualitatively in the current study.

  4. Note: Laser ablation technique for electrically contacting a buried implant layer in single crystal diamond

    SciTech Connect

    Ray, M. P.; Baldwin, J. W.; Butler, J. E.; Pate, B. B.; Feygelson, T. I.

    2011-05-15

    The creation of thin, buried, and electrically conducting layers within an otherwise insulating diamond by annealed ion implantation damage is well known. Establishing facile electrical contact to the shallow buried layer has been an unmet challenge. We demonstrate a new method, based on laser micro-machining (laser ablation), to make reliable electrical contact to a buried implant layer in diamond. Comparison is made to focused ion beam milling.

  5. Method of forming fluorine-bearing diamond layer on substrates, including tool substrates

    DOEpatents

    Chang, R. P. H. (Glenview, IL); Grannen, Kevin J. (Evanston, IL)

    2002-01-01

    A method of forming a fluorine-bearing diamond layer on non-diamond substrates, especially on tool substrates comprising a metal matrix and hard particles, such as tungsten carbide particles, in the metal matrix. The substrate and a fluorine-bearing plasma or other gas are then contacted under temperature and pressure conditions effective to nucleate fluorine-bearing diamond on the substrate. A tool insert substrate is treated prior to the diamond nucleation and growth operation by etching both the metal matrix and the hard particles using suitable etchants.

  6. Formation of detonation diamond layers on silicon by the aerosol method

    NASA Astrophysics Data System (ADS)

    Baidakova, M. V.; Dideikin, A. T.; Pavlov, S. I.; Sokolov, R. V.; Shnitov, V. V.

    2014-09-01

    An aerosol method for deposition of nanometer-thick layers of detonation diamonds has been developed. Application of a suspension of deagglomerated diamond particles onto substrates from an aerosol provides deposition of small-size drops, with the ultrasonic spraying of the suspension precluding formation of secondary agglomerates of nanodiamond particles in the course of sample drying. The layers are promising for high-precision studies of the structure and chemical composition of the surface of isolated nanodiamond particles.

  7. Graphene-on-Diamond Devices with Increased Current-Carrying Capacity: Carbon sp2

    E-print Network

    Graphene-on-Diamond Devices with Increased Current-Carrying Capacity: Carbon sp2 -on-sp3 Technology with synthetic diamond, one can substantially increase the current-carrying capacity of graphene to as high as 18 on the single-crystal diamond substrates but also on an inexpensive ultrananocrystalline diamond, which can

  8. Enhancement of the nucleation of smooth and dense nanocrystalline diamond films by using molybdenum seed layers

    SciTech Connect

    Buijnsters, J. G.; Vazquez, L.; Celis, J. P.

    2010-11-15

    A method for the nucleation enhancement of nanocrystalline diamond (NCD) films on silicon substrates at low temperature is discussed. A sputter deposition of a Mo seed layer with thickness 50 nm on Si substrates was applied followed by an ultrasonic seeding step with nanosized detonation diamond powders. Hot-filament chemical vapor deposition (HF-CVD) was used to nucleate and grow NCD films on substrates heated up at 550 deg. C. The nucleation of diamond and the early stages of NCD film formation were investigated at different methane percentages in methane/hydrogen gas mixtures by atomic force microscopy, micro-Raman spectroscopy, scanning electron microscopy, and grazing incidence x-ray analyses in order to gain specific insight in the nucleation process of NCD films. The nucleation kinetics of diamond on the Mo-coated Si substrates was found to be up to ten times higher than on blank Si substrates. The enhancement of the nucleation of diamond on thin Mo interlayers results from two effects, namely, (a) the nanometer rough Mo surface shows an improved embedding of ultrasonically introduced nanosized diamond seeds that act as starting points for the diamond nucleation during HF-CVD and (b) the rapid carbonization of the Mo surface causes the formation of Mo{sub 2}C onto which diamond easily nucleates. The diamond nucleation density progressively increases at increasing methane percentages and is about 5x10{sup 10} cm{sup -2} at 4.0% methane. The improved nucleation kinetics of diamond on Mo interlayers facilitates the rapid formation of NCD films possessing a very low surface roughness down to {approx}6 nm, and allows a submicron thickness control.

  9. Simulations of polycrystalline CVD diamond film growth using a simplified Monte Carlo model

    E-print Network

    Bristol, University of

    to microcrystalline, nanocrystalline and finally ultrananocrystalline diamond. With the formation of such defectsSimulations of polycrystalline CVD diamond film growth using a simplified Monte Carlo model P online 6 November 2009 Keywords: CVD diamond growth Modelling Nucleation Nanodiamond A simple 1

  10. Epitaxial synthesis of diamond layers on a monocrystalline diamond substrate in a torch microwave plasmatron

    SciTech Connect

    Sergeichev, K. F. Lukina, N. A.

    2011-12-15

    The epitaxial growth of a diamond single-crystal film in a torch microwave discharge excited by a magnetron of a domestic microwave oven with the power of {<=}1 kW in an argon-hydrogen-methane mixture with a high concentration of methane (up to 25% with respect to hydrogen) at atmospheric pressure on a sub-strate of a synthetic diamond single crystal (HPHP) with the orientation (100) and 4 Multiplication-Sign 4 mm in size is obtained. A discharge with the torch diameter of {approx}2 mm and the concentration of the microwave power absorbed in the torch volume of >10{sup 3} W/cm{sup 3} is shown to be effective for epitaxial enlargement of a single crystal of synthetic diamond. The structure of the deposited film with the thickness up to 10 {mu}m with high-quality morphology is investigated with an optical microscope as well as using the methods of the Raman scattering and scanning electron microscopy.

  11. Weak superconductivity in the surface layer of a bulk single-crystal boron-doped diamond

    NASA Astrophysics Data System (ADS)

    Blank, Vladimir; Buga, Sergei; Bormashov, Vitaly; Denisov, Victor; Kirichenko, Alexei; Kulbachinskii, Vladimir; Kuznetsov, Michail; Kytin, Vladimir; Kytin, Gennadii; Tarelkin, Sergei; Terentiev, Sergei

    2014-12-01

    We have grown and investigated bulk single-crystal heavily boron-doped diamonds possessing superconductivity with TC{onset} =1.7\\text-3.5 \\text{K} . Only the surface layer with the thickness less than 1 ? \\text{m} showed the degenerate semiconductor behavior with transition to the superconducting state, while the bulk of the crystal was a typical doped semiconductor. The morphology of the surface layer is dendritic polycrystalline with an average boron content of 2.5-2.9 at.%. The typical Josephson junction current-voltage characteristic was observed. The degenerate semiconductor-superconductor transition as in single-crystal high-temperature superconductors and the structural data analysis of the surface layer indicate the two-dimensional character of superconductivity, and the actual superconducting structure is a set of few-nanometer thick boron carbide layers embedded in a diamond structure.

  12. Tuneable anisotropic transport in nitrogen-doped nanocrystalline diamond films: Evidence of a graphite-diamond hybrid superlattice

    NASA Astrophysics Data System (ADS)

    Churochkin, Dmitry; Bhattacharyya, Somnath

    2012-12-01

    We show strong evidence of superlattice-like carbon layered structures in heavily nitrogen-doped ultrananocrystalline diamond (UNCD) films through the experimental demonstration of temperature-dependent anisotropic diffusive transport. The superlattice periodicity, in the range of several nanometers, is derived from the analysis of both magneto-resistance and the temperature-dependent conductivity based on the generalized diffusive Fermi surface model. The effect of quasi-two-dimensionality on the magneto-transport of these films yields a weak temperature dependence of the electron dephasing length. These results explain a reasonably strong coupling between the conducting carbon layers separated by the insulating nanodiamond grains producing the anisotropic transport in UNCD films controlled by the level of nitrogen incorporation.

  13. Hexagonal Diamonds (Lonsdaleite) Discovered in the K/T Impact Layer in Spain and New Zealand

    NASA Astrophysics Data System (ADS)

    Bunch, T. E.; Wittke, J. H.; West, A.; Kennett, J. P.; Kennett, D. J.; Que Hee, S. S.; Wolbach, W. S.; Stich, A.; Mercer, C.; Weaver, J. C.

    2008-12-01

    We present the first evidence from Cretaceous-Tertiary (K/T) boundary clay and rock for shocked hexagonal nanodiamonds (lonsdaleite), these being found in concentrations greater than 50 ppm at Needles Point, New Zealand, and Caravaca, Spain. This is also the first evidence for K/T diamonds of any kind outside of North America. No diamonds were detected immediately above or below the impact layer. Cubic diamonds have been reported earlier from North American K/T sediments by Carlisle and Braman (1991; 45 ppm) and Hough et al. (1997; 18 ppm), but lonsdaleite was not detected. Carlisle and Braman suggested that the cubic diamonds arrived already formed within the impactor, but Hough argued that they were shock-produced by the impact with Earth. Hence, it is not yet clear that K/T cubic diamonds were formed through shock. Lonsdaleite does not co-occur with terrestrial diamonds but is found with cubic diamonds in ET impact craters (e.g., Popigai, Sudbury). Both also have been reported in the impact layer of the proposed Younger Dryas impact event at 12.9 ka. Lonsdaleite is formed by shocking carbonaceous material, e. g., graphite, under extreme conditions of pressure and temperature (more than 15 GPa at more than 1000° C), thus making this mineral an excellent impact-shock indicator (DeCarli, 2002). Although lonsdaleite is also contained in meteorites, such as ureilites, there appears to be a consensus of opinion that crater-related lonsdaleite formed during ET impact. K/T sediment samples were acquired from the boundary layer, as well as above and below. To extract the diamonds from the sediments, we utilized the protocol from Amari (1994) and Huss and Lewis (1995), but modified their methodology after determining that phosphoric and perchloric acids oxidize metastable lonsdaleite. We extracted the diamonds successfully after eliminating those acids, which may explain why lonsdaleite was not apparent in extractions by others. The extracted lonsdaleite was analyzed by transmission electron microscopy (TEM) and by selected area diffraction (SAED), which displayed characteristic reflections corresponding to lattice planar spacings of 2.18, 1.26, 1.09, and 0.82 A. A scanning electron microscope (SEM) with energy dispersive X-ray spectroscopy (EDS) confirmed their carbon composition. With exposure to long-wave ultraviolet (365 nm) radiation, clusters of lonsdaleite crystals exhibited a blue fluorescence that is characteristic of many diamonds. Individual crystals were angular to sub-rounded in shape and ranged in size from 20 to 1000 nm, with a mean size of about 50 nm. This discovery represents (1) the strongest available evidence for K/T diamond formation during the impact; (2) the first discovery of K/T diamonds outside North America; and (3) the first occurrence of any form of K/T diamonds in the Southern Hemisphere, about 12,000 km from the Chicxulub Crater in Mexico.

  14. Analysis of diamond surface channel field-effect transistors with AlN passivation layers

    NASA Astrophysics Data System (ADS)

    Pietzka, C.; Scharpf, J.; Fikry, M.; Heinz, D.; Forghani, K.; Meisch, T.; Diemant, Th.; Behm, R. J.; Bernhard, J.; Biskupek, J.; Kaiser, U.; Scholz, F.; Kohn, E.

    2013-09-01

    Diamond surface channel field effect transistors were passivated with thin AlN layers grown by metal-organic chemical vapor deposition in order to improve the chemical stability of the surface-near p-type channel. Electrical characterization showed that the surface-near conductivity in the diamond is preserved during AlN overgrowth if the process temperature does not exceed 800 °C. However, the sheet carrier density is decreased by a factor of about 5 compared to the unpassivated hydrogen-terminated surface. A combination of TEM and XPS analysis showed that this effect is not induced by a partial modification of the surface termination or by a polarization of the AlN passivation. The preserved, but reduced surface-near conductivity in the diamond can however be explained by a hydrogen double bond between the diamond and the AlN film. Field-effect transistor structures fabricated on the passivated diamond substrates showed stable operation up drain-source voltages to -70 V and might therefore be promising candidates for future high-voltage applications.

  15. Enhancing secondary yield of a diamond amplifier using a nitrogen layer

    SciTech Connect

    Jensen, Kevin L.; Shaw, Jonathan L.; Yater, Joan E.; Pate, Bradford B.

    2015-06-07

    A thin nitrogen-doped layer less than 4% of the total thickness in diamond thin film amplifier is shown to reduce losses of generated secondaries to the back contact, generated by a high energy primary electron beam compared to a thin film without the substitutional nitrogen layer modification. Simulation indicates that the losses due to absorption of diffusing electrons by the back contact may be considerably reduced by a factor of 2 (depending on field across the film, width of the nitrogen layer, and boron doping level), thereby mitigating undesirable effects associated with trace amounts of boron.

  16. Temperature dependent creation of nitrogen-vacancy centers in single crystal CVD diamond layers

    NASA Astrophysics Data System (ADS)

    Tallaire, A.; Lesik, M.; Jacques, V.; Pezzagna, S.; Mille, V.; Brinza, O.; Meijer, J.; Abel, B.; Roch, J. F.; Gicquel, A.; Achard, J.

    2015-01-01

    In this work, we explore the ability of plasma assisted chemical vapor deposition (PACVD) operating under high power densities to produce thin high-quality diamond layers with a controlled doping with negatively-charged nitrogen-vacancy (NV-) centers. This luminescent defect possesses specific physical characteristics that make it suitable as an addressable solid-state electron spin for measuring magnetic fields with unprecedented sensitivity. To this aim, a relatively large number of NV- centers (> 10^12 cm^-3) should ideally be located in a thin diamond layer (a few tens of nm) close to the surface which is particularly challenging to achieve with the PACVD technique. Here we show that intentional temperature variations can be exploited to tune NV- creation efficiency during growth, allowing engineering complex stacking structures with a variable doping. Because such a temperature variation can be performed quickly and without any change of the gas phase composition, thin layers can be grown. Measurements show that despite the temperature variations, the luminescent centers incorporated using this technique exhibit spin coherence properties similar to those reached in ultra-pure bulk crystals, which suggests that they could be successfully employed in magnetometry applications.

  17. Conductive layers in diamond formed by hydrogen ion implantation and annealing

    NASA Astrophysics Data System (ADS)

    Popov, V. P.; Safronov, L. N.; Naumova, O. V.; Nikolaev, D. V.; Kupriyanov, I. N.; Palyanov, Yu. N.

    2012-07-01

    High conductivity is extremely difficult to obtain in diamond due to its wide band gap and low solubility of dopands. The goal of the investigation was to form a conductor inside HPHT synthetic diamond plates with initial high sheet resistivity ?s (˜1012 ?/sq) for 400 ?m thickness. We used metastable character of diamond structures relative to the graphitization of defective layers formed by 50 keV hydrogen molecular ions at high fluence ? = (1-13) × 1016 cm-2 ion implantation. High temperature (HT) (500-1600 °C) and vacuum or high pressure (VP/HP) (3 × 10-3/4 × 109 Pa) thermal annealing were chosen to provide the annealing regimes where the graphitic carbon is the most stable phase. Sheet resistance, dropped down up to nine orders of magnitude (?s ˜ 103 ?/sq), as well as Raman spectroscopy, and AFM measurements were used to determine electrical, optical and geometrical properties of multilayered heterostructures formed in the set of experiments. Temperature dependences of the conductivity show, that after highest fluencies and annealing temperatures the conductivity is quasimetallic and electronic system is above metal-insulator transition (MIT). At lower fluences and/or annealing temperatures the system is under MIT with the transport of charge carriers being well described by variable range hopping (VRH) mechanism with variable decay length of wave function for localized states. Two or three order of magnitude differences in the conductivity in VP and HP annealed samples are attributed with the higher dimensions of graphite nanocrystals in the case of vacuum annealing. This suggestion coincides with Raman spectra and optimum hopping length for carrier jumps in VRH model for conductivity in the buried layers.

  18. Diamonds from the iridium-rich K-T boundary layer at Arroyo el Mimbral, Tamaulipas, Mexico

    NASA Astrophysics Data System (ADS)

    Hough, R. M.; Gilmour, I.; Pillinger, C. T.; Langenhorst, F.; Montanari, A.

    1997-11-01

    Diamonds, up to 30 ?m in size, were found in the iridium-rich layer from the K-T boundary site at Arroyo El Mimbral and the spherule bed from Arroyo El Peñon, northeastern Mexico. Stepped heating experiments indicate two or more isotopically distinct diamond components with carbon isotopic compositions characteristic of a mixture of carbon sources. The diamonds' crystal form is cubic—not the hexagonal polymorph of diamond, lonsdaleite, which has been used previously to infer formation due to shock transformation of graphite. The size, crystallography, and mineralogic associations of K-T diamonds are similar to those of impact-produced diamonds from the Ries crater in Germany where both shock transformation of graphite and a mode of formation by condensation from a vapor plume have been inferred. The discovery of impact-produced diamonds in association with high Ir contents for these sediments supports their impact origin, K-T age, and the inference that their source was from the buried impact crater of Chicxulub on the Yucatan peninsula, Mexico.

  19. Thermally induced defects in a polycrystalline diamond layer on a tungsten carbide substrate

    NASA Astrophysics Data System (ADS)

    Masina, B. N.; Forbes, A.; Ndwandwe, O. M.; Hearne, G.; Mwakikunga, B. W.; Katumba, G.

    2009-12-01

    In this study we make use of laser heating of HTHP industrial diamond, to study temperature induced changes to the diamond structure, both chemically and mechanically, in the absence of mechanical forces. This has relevance to the efficacy of diamond as a hard material in such applications as rock drilling and material processing. We report on the induced defects when the diamond is irradiated with high power CO 2 and Nd:YAG lasers respectively, and show that the thermal induced stresses in the diamond are sufficient to radically alter its physical properties, resulting in critical fracture. Raman spectroscopy, X-ray diffraction and scanning electron microscopy indicate that the heating does not result in graphitisation of the diamond, but rather diffusion from the non-diamond base results in cobalt and tungsten oxides forming on the diamond surface. This has a deleterious effect on the diamond performance.

  20. Hydrogen-free diamond-like carbon deposited by a layer-by-layer technique using PECVD

    SciTech Connect

    Jang, J.; Chung, S.J.

    2000-01-30

    The authors developed a hydrogen-free diamond like carbon (DLC) film by a novel deposition technique of a layer-by-layer technique using plasma enhanced chemical vapor deposition (PECVD) in which a repeated deposition of a thin DLC layer and subsequently CF{sub 4} plasma treatment on its surface have been carried out. The electrical, optical and structural properties of the DLC films deposited depend on the CF{sub 4} plasma exposure time. The hydrogen content is less than 1 at % when the CF{sub 4} plasma exposure time is 140s. Its emission current is much higher and stability is much improved compared with conventional DLC.N-type, hydrogen-free DLC could be obtained by N ion doping or by N{sub 2} gas-phase doping in the CH{sub 4} plasma. The optimum [N{sub 2}]/[CH{sub 4}] flow rate ratio was found to be 9% for the efficient electron emission, at which the onset-field was 7.2 V/{micro}m. The nitrogen gas-phase doped hydrogen-free DLC coating on Mo tip field emitter arrays (FEAs) increased the electron emission current from 160{micro}A to 1.52 mA and improved the stability in electron emission current.

  1. Polarization dependent asymmetric magneto-resistance features in nanocrystalline diamond films

    SciTech Connect

    Bhattacharyya, Somnath

    2014-08-18

    Polar angle-dependence of magneto-resistance (AMR) in heavily nitrogen-incorporated ultra-nanocrystalline diamond (UNCD) films is recorded by applying high magnetic fields, which shows strong anisotropic features at low temperatures. The temperature-dependence of MR and AMR can reveal transport in the weak-localization regime, which is explained by using a superlattice model for arbitrary values of disorder and angles. While a propagative Fermi surface model explains the negative MR features for low degree of disorder the azimuthal angle-dependent MR shows field dependent anisotropy due to the aligned conducting channels on the layers normal to film growth direction. The analysis of MR and AMR can extract the temperature dependence of dephasing time with respect to the elastic scattering time which not only establishes quasi-two dimensional features in this system but also suggests a potential application in monitoring the performance of UNCD based quantum devices.

  2. Tantalum as a buffer layer in diamond-like carbon coated artificial hip joints.

    PubMed

    Kiuru, Mirjami; Alakoski, Esa; Tiainen, Veli-Matti; Lappalainen, Reijo; Anttila, Asko

    2003-07-15

    The acid resistance of tantalum coated and uncoated human hip joint prostheses was studied with commercial CrCoMo acetabular cups. The samples were exposed to 10% HCl solution and the quantities of dissolved Cr, Co, and Mo were measured with proton-induced X-ray emission (PIXE). The absolute quantities were obtained with the use of Cr and Se solution standards. Tantalum coatings (thicknesses 4-6 microm) were prepared in vacuum with magnetron sputtering. Tantalum coating decreased the corrosion rate by a factor of 10(6). As a spinoff from recent wear tests on artificial hip joints it was shown that tantalum has excellent mechanical properties as an intermediate layer of diamond-like carbon (DLC) coatings. When tantalum was tested together with DLC on three metal-on-metal hip joint pairs in a hip simulator, no observable defects occurred during 15 million walking cycles with a periodic 50-300-kg load (Paul curve). PMID:12808604

  3. Diamond-Like-Carbon LC-Alignment Layers for Application in LCOS Microdisplays

    SciTech Connect

    Bol,A.; Dvorak, J.; Arena, D.

    2005-01-01

    To improve the lifetime and yield of LCOS microdisplays, non-contact LC alignment techniques using inorganic materials are under investigation. This report focuses on oblique ion-beam treatment of diamond-like carbon (DLC) layers, and in particular on the influence of the ion dose on the LC alignment on DLC, keeping the ion-beam angle (40 degrees) and ion-beam energy (170 eV) the same. LC alignment on ion-milled DLC layers is uniform if the ion dose is between 3.8 x 10{sup -4} C/cm{sup 2} and 5.5x10{sup -3} C/cm{sup 2}. Above and below this ion dose range, non-uniform alignment is observed. NEXAFS experiments show that this is caused by lack of molecular anisotropy on the surface of the ion-milled DLC layers. By varying the ion dose between 3.8 x 10{sup -4} C/cm{sup 2} and 5.5 x 10{sup -3} C/cm{sup 2}, LC molecules have an average pre-tilt between 3 and 5 degrees, which is within the desired range for application in LCOS microdisplays. The lifetime of the LCOS microdisplays with ion-milled DLC for projection-TV application is, however, shorter than the lifetime of microdisplays with PI layers. Ion milling probably creates a reactive surface that is unstable under the high light fluxes used in projection TVs. A solution for this problem could be chemical passivation of the ion-milled alignment layers. Initial experiments with passivation of ion-milled PI resulted in an increase in lifetime, but the lifetime after passivation was still lower than the lifetime of rubbed PI layers (factor 0.7). Nevertheless, ion-milling of DLC or PI can be a good alternative LC alignment technique in other LCD applications. LC-alignment layers based on inorganic layers such as obliquely deposited SiO{sub 2} films would be a better option for application in LCOS microdisplays due to their higher light stability.

  4. Thin polycrystalline diamond films protecting zirconium alloys surfaces: From technology to layer analysis and application in nuclear facilities

    NASA Astrophysics Data System (ADS)

    Ashcheulov, P.; Škoda, R.; Škarohlíd, J.; Taylor, A.; Fekete, L.; Fendrych, F.; Vega, R.; Shao, L.; Kalvoda, L.; Vratislav, S.; Cháb, V.; Horáková, K.; K?sová, K.; Klimša, L.; Kope?ek, J.; Sajdl, P.; Macák, J.; Johnson, S.; Kratochvílová, I.

    2015-12-01

    Zirconium alloys can be effectively protected against corrosion by polycrystalline diamond (PCD) layers grown in microwave plasma enhanced linear antenna chemical vapor deposition apparatus. Standard and hot steam oxidized PCD layers grown on Zircaloy2 surfaces were examined and the specific impact of polycrystalline Zr substrate surface on PCD layer properties was investigated. It was found that the presence of the PCD coating blocks hydrogen diffusion into the Zircaloy2 surface and protects Zircaloy2 material from degradation. PCD anticorrosion protection of Zircaloy2 can significantly prolong life of Zircaloy2 material in nuclear reactors even at temperatures above Zr phase transition temperatures.

  5. Characterization of tribo-layer formed during sliding wear of SiC ball against nanocrystalline diamond coatings

    SciTech Connect

    Dumpala, Ravikumar; Kumar, N.; Samji, Sunil Kumar; Dash, S.; Ramamoorthy, B.; Ramachandra Rao, M.S.

    2014-09-15

    Tribo-layer formation and frictional characteristics of the SiC ball were studied with the sliding test against nanocrystalline diamond coating under atmospheric test conditions. Unsteady friction coefficients in the range of 0.04 to 0.1 were observed during the tribo-test. Friction and wear characteristics were found to be influenced by the formation of cohesive tribo-layer (thickness ? 1.3 ?m) in the wear track of nanocrystalline diamond coating. Hardness of the tribo-layer was measured using nanoindentation technique and low hardness of ? 1.2 GPa was observed. The presence of silicon and oxygen in the tribo-layer was noticed by the energy dispersive spectroscopy mapping and the chemical states of the silicon were analyzed using X-ray photoelectron spectroscopy. Large amount of oxygen content in the tribo-layer indicated tribo-oxidation wear mechanism. - Highlights: • Sliding wear and friction characteristics of SiC were studied against NCD coating. • Silicon oxide tribo-layer formation was observed in the NCD coating wear track. • Low hardness 1.2 GPa of tribo-layer was measured using nanoindentation technique. • Chemical states of silicon were analyzed using X-ray photoelectron spectroscopy.

  6. N-type droping of nanocrystalline diamond films with nitrogen and electrodes made therefrom

    DOEpatents

    Gruen, Dieter M. (Downers Grove, IL); Krauss, Alan R. (late of Naperville, IL); Auciello, Orlando H. (Bolingbrook, IL); Carlisle, John A. (Plainfield, IL)

    2004-09-21

    An electrically conducting n-type ultrananocrystalline diamond (UNCD) having no less than 10.sup.19 atoms/cm.sup.3 of nitrogen is disclosed. A method of making the n-doped UNCD. A method for predictably controlling the conductivity is also disclosed.

  7. Three-dimensional kinetic Monte Carlo simulations of diamond chemical vapor deposition.

    PubMed

    Rodgers, W J; May, P W; Allan, N L; Harvey, J N

    2015-06-01

    A three-dimensional kinetic Monte Carlo model has been developed to simulate the chemical vapor deposition of a diamond (100) surface under conditions used to grow single-crystal diamond (SCD), microcrystalline diamond (MCD), nanocrystalline diamond (NCD), and ultrananocrystalline diamond (UNCD) films. The model includes adsorption of CHx (x = 0, 3) species, insertion of CHy (y = 0-2) into surface dimer bonds, etching/desorption of both transient adsorbed species and lattice sidewalls, lattice incorporation, and surface migration but not defect formation or renucleation processes. A value of ?200 kJ mol(-1) for the activation Gibbs energy, ?G(‡) etch, for etching an adsorbed CHx species reproduces the experimental growth rate accurately. SCD and MCD growths are dominated by migration and step-edge growth, whereas in NCD and UNCD growths, migration is less and species nucleate where they land. Etching of species from the lattice sidewalls has been modelled as a function of geometry and the number of bonded neighbors of each species. Choice of appropriate parameters for the relative decrease in etch rate as a function of number of neighbors allows flat-bottomed etch pits and/or sharp-pointed etch pits to be simulated, which resemble those seen when etching diamond in H2 or O2 atmospheres. Simulation of surface defects using unetchable, immobile species reproduces other observed growth phenomena, such as needles and hillocks. The critical nucleus for new layer growth is 2 adjacent surface carbons, irrespective of the growth regime. We conclude that twinning and formation of multiple grains rather than pristine single-crystals may be a result of misoriented growth islands merging, with each island forming a grain, rather than renucleation caused by an adsorbing defect species. PMID:26049516

  8. Three-dimensional kinetic Monte Carlo simulations of diamond chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Rodgers, W. J.; May, P. W.; Allan, N. L.; Harvey, J. N.

    2015-06-01

    A three-dimensional kinetic Monte Carlo model has been developed to simulate the chemical vapor deposition of a diamond (100) surface under conditions used to grow single-crystal diamond (SCD), microcrystalline diamond (MCD), nanocrystalline diamond (NCD), and ultrananocrystalline diamond (UNCD) films. The model includes adsorption of CHx (x = 0, 3) species, insertion of CHy (y = 0-2) into surface dimer bonds, etching/desorption of both transient adsorbed species and lattice sidewalls, lattice incorporation, and surface migration but not defect formation or renucleation processes. A value of ˜200 kJ mol-1 for the activation Gibbs energy, ?G‡etch, for etching an adsorbed CHx species reproduces the experimental growth rate accurately. SCD and MCD growths are dominated by migration and step-edge growth, whereas in NCD and UNCD growths, migration is less and species nucleate where they land. Etching of species from the lattice sidewalls has been modelled as a function of geometry and the number of bonded neighbors of each species. Choice of appropriate parameters for the relative decrease in etch rate as a function of number of neighbors allows flat-bottomed etch pits and/or sharp-pointed etch pits to be simulated, which resemble those seen when etching diamond in H2 or O2 atmospheres. Simulation of surface defects using unetchable, immobile species reproduces other observed growth phenomena, such as needles and hillocks. The critical nucleus for new layer growth is 2 adjacent surface carbons, irrespective of the growth regime. We conclude that twinning and formation of multiple grains rather than pristine single-crystals may be a result of misoriented growth islands merging, with each island forming a grain, rather than renucleation caused by an adsorbing defect species.

  9. Prevention of nanoscale wear in atomic force microscopy through the use of monolithic ultrananocrystaline diamond probes.

    SciTech Connect

    Liu, J.; Grierson, D. S.; Notbohm, J.; Li, S.; O'Connor, S. D.; Turner, K. T.; Sumant, A. V.; Neelakantan, N.; Moldovan, N.; Carlisle, J. A.; Jaroenapibal, P.; Carpick, R. W.

    2010-01-01

    Nanoscale wear is a key limitation of conventional atomic force microscopy (AFM) probes that results in decreased resolution, accuracy, and reproducibility in probe-based imaging, writing, measurement, and nanomanufacturing applications. Diamond is potentially an ideal probe material due to its unrivaled hardness and stiffness, its low friction and wear, and its chemical inertness. However, the manufacture of monolithic diamond probes with consistently shaped small-radius tips has not been previously achieved. The first wafer-level fabrication of monolithic ultrananocrystalline diamond (UNCD) probes with <5-nm grain sizes and smooth tips with radii of 30-40 nm is reported, which are obtained through a combination of microfabrication and hot-filament chemical vapor deposition. Their nanoscale wear resistance under contact-mode scanning conditions is compared with that of conventional silicon nitride (SiN{sub x}) probes of similar geometry at two different relative humidity levels ({approx}15 and {approx}70%). While SiN{sub x} probes exhibit significant wear that further increases with humidity, UNCD probes show little measurable wear. The only significant degradation of the UNCD probes observed in one case is associated with removal of the initial seed layer of the UNCD film. The results show the potential of a new material for AFM probes and demonstrate a systematic approach to studying wear at the nanoscale.

  10. Single-crystal GaN/AlN layers on CVD diamond

    NASA Astrophysics Data System (ADS)

    Khrykin, O. I.; Drozdov, Yu. N.; Drozdov, M. N.; Yunin, P. A.; Shashkin, V. I.; Bogdanov, S. A.; Muchnikov, A. B.; Vikharev, A. L.; Radishev, D. B.

    2015-10-01

    Original approach to fabricating a GaN/AlN/nanocrystalline diamond structure has been suggested and implemented. The stages of deposition of a structure of this kind include the following: (a) growth of nanocrystalline CVD-diamond on single-crystal AlN (preliminarily grown on a silicon substrate), (b) etch removal of the silicon substrate, and (c) growth of single-crystal GaN on the surface of single-crystal AlN. Single-crystal gallium nitride with a width of the X-ray rocking curve for the (0002) reflection of 0.35° was obtained on a nanocrystalline-diamond substrate.

  11. Thermally stable diamond brazing

    DOEpatents

    Radtke, Robert P. (Kingwood, TX)

    2009-02-10

    A cutting element and a method for forming a cutting element is described and shown. The cutting element includes a substrate, a TSP diamond layer, a metal interlayer between the substrate and the diamond layer, and a braze joint securing the diamond layer to the substrate. The thickness of the metal interlayer is determined according to a formula. The formula takes into account the thickness and modulus of elasticity of the metal interlayer and the thickness of the TSP diamond. This prevents the use of a too thin or too thick metal interlayer. A metal interlayer that is too thin is not capable of absorbing enough energy to prevent the TSP diamond from fracturing. A metal interlayer that is too thick may allow the TSP diamond to fracture by reason of bending stress. A coating may be provided between the TSP diamond layer and the metal interlayer. This coating serves as a thermal barrier and to control residual thermal stress.

  12. Using stepped anvils to make even insulation layers in laser-heated diamond-anvil cell samples.

    PubMed

    Du, Zhixue; Gu, Tingting; Dobrosavljevic, Vasilije; Weir, Samuel T; Falabella, Steve; Lee, Kanani K M

    2015-09-01

    We describe a method to make even insulation layers for high-pressure laser-heated diamond-anvil cell samples using stepped anvils. The method works for both single-sided and double-sided laser heating using solid or fluid insulation. The stepped anvils are used as matched pairs or paired with a flat culet anvil to make gasket insulation layers and not actually used at high pressures; thus, their longevity is ensured. We compare the radial temperature gradients and Soret diffusion of iron between self-insulating samples and samples produced with stepped anvils and find that less pronounced Soret diffusion occurs in samples with even insulation layers produced by stepped anvils. PMID:26429476

  13. Diamond heteroepitaxial lateral overgrowth

    NASA Astrophysics Data System (ADS)

    Tang, Yung-Hsiu

    This dissertation describes improvements in the growth of single crystal diamond by microwave plasma-assisted chemical vapor deposition (CVD). Heteroepitaxial (001) diamond was grown on 1 cm. 2 a-plane sapphiresubstrates using an epitaxial (001) Ir thin-film as a buffer layer. Low-energy ion bombardment of the Ir layer, a process known as bias-enhanced nucleation, is a key step in achieving a high density of diamond nuclei. Bias conditions were optimized to form uniformly-high nucleation densities across the substrates, which led to well-coalesced diamond thin films after short growth times. Epitaxial lateral overgrowth (ELO) was used as a means of decreasing diamond internal stress by impeding the propagation of threading dislocations into the growing material. Its use in diamond growth requires adaptation to the aggressive chemical and thermal environment of the hydrogen plasma in a CVD reactor. Three ELO variants were developed. The most successful utilized a gold (Au) mask prepared by vacuum evaporation onto the surface of a thin heteroepitaxial diamond layer. The Au mask pattern, a series of parallel stripes on the micrometer scale, was produced by standard lift-off photolithography. When diamond overgrows the mask, dislocations are largely confined to the substrate. Differing degrees of confinement were studied by varying the stripe geometry and orientation. Significant improvement in diamond quality was found in the overgrown regions, as evidenced by reduction of the Raman scattering linewidth. The Au layer was found to remain intact during diamond overgrowth and did not chemically bond with the diamond surface. Besides impeding the propagation of threading dislocations, it was discovered that the thermally-induced stress in the CVD diamond was significantly reduced as a result of the ductile Au layer. Cracking and delamination of the diamond from the substrate was mostly eliminated. When diamond was grown to thicknesses above 0.1 mm it was found that crystallographic perfection continuously improved, leading to a diamond surface nearly free of stress.

  14. Band offsets of Al{sub 2}O{sub 3} and HfO{sub 2} oxides deposited by atomic layer deposition technique on hydrogenated diamond

    SciTech Connect

    Liu, J. W.; Liao, M. Y.; Imura, M.; Koide, Y.

    2012-12-17

    High-k oxide insulators (Al{sub 2}O{sub 3} and HfO{sub 2}) have been deposited on a single crystalline hydrogenated diamond (H-diamond) epilayer by an atomic layer deposition technique at temperature as low as 120 Degree-Sign C. Interfacial electronic band structures are characterized by X-ray photoelectron spectroscopy. Based on core-level binding energies and valence band maximum values, valence band offsets are found to be 2.9 {+-} 0.2 and 2.6 {+-} 0.2 eV for Al{sub 2}O{sub 3}/H-diamond and HfO{sub 2}/H-diamond heterojunctions, respectively. Band gaps of the Al{sub 2}O{sub 3} and HfO{sub 2} have been determined to be 7.2 {+-} 0.2 and 5.4 {+-} 0.2 eV by measuring O 1s energy loss spectra, respectively. Both the Al{sub 2}O{sub 3}/H-diamond and HfO{sub 2}/H-diamond heterojunctions are concluded to be type-II staggered band configurations with conduction band offsets of 1.2 {+-} 0.2 and 2.7 {+-} 0.2 eV, respectively.

  15. Modular design of locally ordered tetrahedral structures: III. Structural mechanism of nonequilibrium fibrous and rough-layer normal growth of diamond crystals

    NASA Astrophysics Data System (ADS)

    Bul'enkov, N. A.; Zheligovskaya, E. A.

    2015-05-01

    Structural mechanisms of nontangential nonequilibrium normal growth of natural and synthetic diamond crystals with a fibrous or layered structure, formed under particularly nonequilibrium conditions, are proposed. It is shown that their growth is based on strained noncrystalline structures rapidly growing in length: 30/11 and 40/9 helices. The fibrous growth of diamond crystals along the <111> and <100> directions occurs according to the helicoidal mechanism, with helicoid axes in the form of 30/11 and 40/9 helices, respectively. Stacks of rough {110} lamellae can be formed via branching of 30/11 helices, which are then overgrown by a crystalline layer. Lamellae with orientation {100}, formed during the growth of diamond and silicon from vapor phase, also grow according to the helicoidal mechanism based on 40/9 helices via the aggregation of helicoids into these lamellae. Due to the complicated internal structure of these diamond crystals, their physical properties differ from those of diamond single crystals grown according to the tangential growth mechanism.

  16. Photochromism-induced amplification of critical current density in superconducting boron-doped diamond with an azobenzene molecular layer.

    PubMed

    Natsui, Keisuke; Yamamoto, Takashi; Akahori, Miku; Einaga, Yasuaki

    2015-01-14

    A key issue in molecular electronics is the control of electronic states by optical stimuli, which enables fast and high-density data storage and temporal-spatial control over molecular processes. In this article, we report preparation of a photoswitchable superconductor using a heavily boron-doped diamond (BDD) with a photochromic azobenzene (AZ) molecular layer. BDDs electrode properties allow for electrochemical immobilization, followed by copper(I)-catalyzed alkyne-azide cycloaddition (a "click" reaction). Superconducting properties were examined with magnetic and electrical transport measurements, such as field-dependent isothermal magnetization, temperature-dependent resistance, and the low-temperature voltage-current response. These measurements revealed reversible amplification of the critical current density by 55% upon photoisomerization. This effect is explained as the reversible photoisomerization of AZ inducing an inhomogeneous electron distribution along the BDD surface that renormalizes the surface pinning contribution to the critical current. PMID:25494096

  17. High-reliability passivation of hydrogen-terminated diamond surface by atomic layer deposition of Al2O3

    NASA Astrophysics Data System (ADS)

    Daicho, Akira; Saito, Tatsuya; Kurihara, Shinichiro; Hiraiwa, Atsushi; Kawarada, Hiroshi

    2014-06-01

    Although the two-dimensional hole gas (2DHG) of a hydrogen-terminated diamond surface provides a unique p-type conducting layer for high-performance transistors, the conductivity is highly sensitive to its environment. Therefore, the surface must be passivated to preserve the 2DHG, especially at high temperature. We passivated the surface at high temperature (450 °C) without the loss of C-H surface bonds by atomic layer deposition (ALD) and investigated the thermal reliability of the Al2O3 film. As a result, C-H bonds were preserved, and the hole accumulation effect appeared after the Al2O3 deposition by ALD with H2O as an oxidant. The sheet resistivity and hole density were almost constant between room temperature and 500 °C by the passivation with thick Al2O3 film thicker than 38 nm deposited by ALD at 450 °C. After the annealing at 550 °C in air The sheet resistivity and hole density were preserved. These results indicate the possibility of high-temperature application of the C-H surface diamond device in air. In the case of lower deposition temperatures, the sheet resistivity increased after air annealing, suggesting an insufficient protection capability of these films. Given the result of sheet resistivity after annealing, the increase in the sheet resistivity of these samples was not greatly significant. However, bubble like patterns were observed in the Al2O3 films formed from 200 to 400 °C by air annealing at 550 °C for 1 h. On the other hand, the patterns were no longer observed at 450 °C deposition. Thus, this 450 °C deposition is the sole solution to enabling power device application, which requires high reliability at high temperatures.

  18. SAW COM-parameter extraction in AlN/diamond layered structures.

    PubMed

    Iriarte, Gonzalo F; Engelmark, Fredrik; Katardjiev, Ilia V; Plessky, Viktor; Yantchev, Ventsislav

    2003-11-01

    Highly c-axis oriented aluminum nitride (AlN) thin piezoelectric films have been grown on polycrystalline diamond substrates by pulsed direct current (DC) magnetron reactive sputter-deposition. The films were deposited at a substrate temperature below 50 degrees C (room temperature) and had a typical full width half maximum (FWHM) value of the rocking curve of the AlN-002-peak of 2.1 degrees. A variety of one-port surface acoustic wave (SAW) resonators have been designed and fabricated on top of the AlN films. The measurements indicate that various SAW modes are excited. The SAW phase velocities of up to 11.800 m/s have been measured. These results are in agreement with calculated dispersion curves of the AlN/diamond structure. Finally, the coupling of modes parameters have been extracted from S11 measurements using curve fitting for the first SAW mode, which indicate an effective coupling K2 of 0.91% and a Q factor of about 600 at a frequency of 1050 MHz. PMID:14682637

  19. Study of high-overtone bulk acoustic resonators based on the Me1/AlN/Me2/(100) diamond piezoelectric layered structure

    NASA Astrophysics Data System (ADS)

    Sorokin, B. P.; Kvashnin, G. M.; Telichko, A. V.; Gordeev, G. I.; Burkov, S. I.; Blank, V. D.

    2015-07-01

    The Me1/AlN/Me2/(100) diamond structure has been theoretically analyzed and experimentally investigated in the range 0.5-10 GHz using high-overtone bulk acoustic resonators with different electrodes topologies based on the Al/AlN/Mo/(100) diamond structure. The maximum quality parameter Q × f ? 1014 Hz was obtained at f = 9.5 GHz. The layered structure has been analyzed using the developed HBAR software v. 2.3. It is demonstrated that the features in the frequency dependences of the parameters of such resonators are related to the behavior of a loaded thin-film piezoelectric transducer. The calculation results are in good agreement with the experiment. The frequency dependences of the equivalent parameters of the resonators have been calculated. It is shown that the synthetic type IIa diamond single crystal in combination with aluminum nitride is promising for implementation of high-Q acoustoelectronic microwave devices.

  20. Electrical characteristics of hydrogen-terminated diamond metal-oxide-semiconductor with atomic layer deposited HfO2 as gate dielectric

    NASA Astrophysics Data System (ADS)

    Liu, J. W.; Liao, M. Y.; Imura, M.; Oosato, H.; Watanabe, E.; Koide, Y.

    2013-03-01

    HfO2 films have been deposited on hydrogen-terminated diamond (H-diamond) by an atomic layer deposition (ALD) technique at 120 °C. Effect of rapid thermal annealing treatment on electrical properties of Au/Ti/Pd/ALD-HfO2/H-diamond metal-oxide-semiconductor (MOS) diodes has been investigated. The leakage current density of the MOS diode after annealing at 300 °C is as small as 10-8 A/cm2 at gate biases from -5.0 to 4.0 V. The capacitance-voltage curve in the depletion mode of the MOS diode after annealing is much sharper than that of the MOS diode before annealing and close to the theoretical dependence, which indicates the small interface state density. The annealed MOS diode is concluded to be more suitable for the fabrication of field effect transistors.

  1. Surface damages in diamond by Ar/O{sub 2} plasma and their effect on the electrical and electrochemical characteristics of boron-doped layers

    SciTech Connect

    Denisenko, A.; Pietzka, C.; Scharpf, J.; Kohn, E.; Romanyuk, A.

    2010-10-15

    Epitaxial single crystal and boron-doped diamond layers were exposed to reactive ion etching in Ar/O{sub 2} plasma (rf power of 25 W and self-bias of 100 V); and the electrical, structural, and electrochemical characteristics of the exposed surface were investigated. Angle-resolved x-ray photoemission spectroscopy (XPS) measurements revealed a nonuniform layer of amorphous carbon at the exposed surface with an average thickness of approximately 4 nm, as confirmed also by atomic force microscopy profiling of selectively etched areas. On highly boron-doped diamond, the plasma-induced damages resulted also in a nonconductive surface layer. This damaged and insulating surface layer remained resistant to graphite-etching chemicals and to rf oxygen plasma but it was removed completely in microwave hydrogen plasma at 700 deg. C. The surface characteristics after the H-plasma process followed by wet chemical oxidation were restored back to the initial state, as confirmed by XPS. Such ''recovery'' treatment had been applied to an all-diamond submicrometer electrode array initially patterned by an Ar/O{sub 2} plasma etching. The electrochemical characteristics of this electrode array were improved by more than two orders of magnitude, approaching theoretical limit for the given geometrical configuration.

  2. Antibacterial efficacy of ultrahigh molecular weight polyethylene with silver containing diamond-like surface layers.

    PubMed

    Harrasser, Norbert; Jüssen, Sebastian; Banke, Ingo J; Kmeth, Ralf; von Eisenhart-Rothe, Ruediger; Stritzker, Bernd; Gollwitzer, Hans; Burgkart, Rainer

    2015-12-01

    Antibacterial coating of medical devices is a promising approach to reduce the risk of infection but has not yet been achieved on wear surfaces, e.g. polyethylene (PE). We quantitatively determined the antimicrobial potency of different PE surfaces, which had been conversed to diamond-like carbon (DLC-PE) and doped with silver ions (Ag-DLC-PE). Bacterial adhesion and planktonic growth of various strains of S. epidermidis on Ag-DLC-PE were compared to untreated PE by quantification of colony forming units on the adherent surface and in the growth medium as well as semiquantitatively by determining the grade of biofilm formation by scanning electron microscopy. (1) A significant (p < 0.05) antimicrobial effect could be found for Ag-DLC-PE. (2) The antimicrobial effect was positively correlated with the applied fluences of Ag (fivefold reduced bacterial surface growth and fourfold reduced bacterial concentration in the surrounding medium with fluences of 1 × 10(17) vs. 1 × 10(16) cm(-2) under implantation energy of 10 keV). (3) A low depth of Ag penetration using low ion energies (10 or 20 vs. 100 keV) led to evident antimicrobial effects (fourfold reduced bacterial surface growth and twofold reduced bacterial concentration in the surrounding medium with 10 or 20 keV and 1 × 10(17) cm(-2) vs. no reduction of growth with 100 keV and 1 × 10(17) cm(-2)). (4) Biofilm formation was decreased by Ag-DLC-PE surfaces. The results obtained in this study suggest that PE-surfaces can be equipped with antibacterial effects and may provide a promising platform to finally add antibacterial coatings on wear surfaces of joint prostheses. PMID:26391393

  3. Microstructural evolution of diamond growth during HFCVD

    NASA Technical Reports Server (NTRS)

    Singh, J.

    1994-01-01

    High resolution transmission electron microscopy (HRTEM) was used to study the nucleation and growth mechanism of diamond by hot filament chemical vapor deposition (HFCVD) process. A novel technique has shown a direct evidence for the formation of the diamond-like carbon layer 8-14 nm thick in which small diamond micro-crystallites were embedded. These diamond micro-crystallites were formed as a result of transformation of diamond-like carbon into diamond. The diamond micro-crystallites present in the amorphous diamond-like carbon layer provided nucleation sites for diamond growth. Large diamond crystallites were observed to grow from these micro-crystallites. The mechanism of diamond growth will be presented based on experimental findings.

  4. Industrial diamond

    USGS Publications Warehouse

    Olson, D.W.

    2001-01-01

    An overview of the industrial diamond industry is provided. More than 90 percent of the industrial diamond consumed in the U.S. and the rest of the world is manufactured diamond. Ireland, Japan, Russia, and the U.S. produce 75 percent of the global industrial diamond output. In 2000, the U.S. was the largest market for industrial diamond. Industrial diamond applications, prices for industrial diamonds, imports and exports of industrial diamonds, the National Defense Stockpile of industrial diamonds, and the outlook for the industrial diamond market are discussed.

  5. Diamond-Cutter Drill Bits

    SciTech Connect

    1995-11-01

    Geothermal Energy Program Office of Geothermal and Wind Technologies Diamond-Cutter Drill Bits Diamond-cutter drill bits cut through tough rock quicker, reducing the cost of drilling for energy resources The U.S. Department of Energy (DOE) contributed markedly to the geothermal, oil, and gas industries through the development of the advanced polycrystalline diamond compact (PDC) drill bit. Introduced in the 1970s by General Electric Company (GE), the PDC bit uses thin, diamond layers bonded to t

  6. The optical constants of the so-called ``diamond-like'' carbon layers and their description in terms of semiempirical dispersion models

    NASA Astrophysics Data System (ADS)

    Stenzel, Olaf; Petrich, Ralf; Vogel, Martina

    1993-07-01

    Data on the optical response of amorphous carbon layers are presented. The layers investigated ranged from well insulating polymer-like layers via hard "diamond-like" layers to well conducting graphite-like layers. The spectral range investigated covers parts of the far infrared, the middle infrared, the near infrared and the visible spectral regions. The data are presented and discussed in terms of parameters of commonly accepted dispersion models and absorption assumptions (Penn model, lorentzian oscillator model, Urbach edge, Tauc edge). Special attention is paid to the refractive index dispersion behaviour. The dependence of the refractive index on the mass density and the hydrogen content is experimentally obtained and reproduced in terms of a lorentzian model. The influence of contaminations such as nitrogen and oxygen is investigated. As typical applications, the status of amorphous carbon as a material of protective optical coating, SLAR coating and as a spectrally selective absorber coating is very briefly discussed.

  7. Boron concentration profiling by high angle annular dark field-scanning transmission electron microscopy in homoepitaxial ?-doped diamond layers

    SciTech Connect

    Araújo, D.; Alegre, M. P.; Piñero, J. C.; Fiori, A.; Bustarret, E.; Jomard, F.

    2013-07-22

    To develop further diamond related devices, the concentration and spatial location of dopants should be controlled down to the nanometer scale. Scanning transmission electron microscopy using the high angle annular dark field mode is shown to be sensitive to boron doping in diamond epilayers. An analytical procedure is described, whereby local boron concentrations above 10{sup 20} cm{sup ?3} were quantitatively derived down to nanometer resolution from the signal dependence on thickness and boron content. Experimental boron local doping profiles measured on diamond p{sup ?}/p{sup ++}/p{sup ?} multilayers are compared to macroscopic profiles obtained by secondary ion mass spectrometry, avoiding reported artefacts.

  8. Boron concentration profiling by high angle annular dark field-scanning transmission electron microscopy in homoepitaxial ?-doped diamond layers

    NASA Astrophysics Data System (ADS)

    Araújo, D.; Alegre, M. P.; Piñero, J. C.; Fiori, A.; Bustarret, E.; Jomard, F.

    2013-07-01

    To develop further diamond related devices, the concentration and spatial location of dopants should be controlled down to the nanometer scale. Scanning transmission electron microscopy using the high angle annular dark field mode is shown to be sensitive to boron doping in diamond epilayers. An analytical procedure is described, whereby local boron concentrations above 1020 cm-3 were quantitatively derived down to nanometer resolution from the signal dependence on thickness and boron content. Experimental boron local doping profiles measured on diamond p-/p++/p- multilayers are compared to macroscopic profiles obtained by secondary ion mass spectrometry, avoiding reported artefacts.

  9. On interlayer stability and high-cycle simulator performance of diamond-like carbon layers for articulating joint replacements.

    PubMed

    Thorwarth, Kerstin; Thorwarth, Götz; Figi, Renato; Weisse, Bernhard; Stiefel, Michael; Hauert, Roland

    2014-01-01

    Diamond like carbon (DLC) coatings have been proven to be an excellent choice for wear reduction in many technical applications. However, for successful adaption to the orthopaedic field, layer performance, stability and adhesion in physiologically relevant setups are crucial and not consistently investigated. In vitro wear testing as well as adequate corrosion tests of interfaces and interlayers are of great importance to verify the long term stability of DLC coated load bearing implants in the human body. DLC coatings were deposited on articulating lumbar spinal disks made of CoCr28Mo6 biomedical implant alloy using a plasma-activated chemical vapor deposition (PACVD) process. As an adhesion promoting interlayer, tantalum films were deposited by magnetron sputtering. Wear tests of coated and uncoated implants were performed in physiological solution up to a maximum of 101 million articulation cycles with an amplitude of ±2° and -3/+6° in successive intervals at a preload of 1200 N. The implants were characterized by gravimetry, inductively coupled plasma optical emission spectrometry (ICP-OES) and cross section scanning electron microscopy (SEM) analysis. It is shown that DLC coated surfaces with uncontaminated tantalum interlayers perform very well and no corrosive or mechanical failure could be observed. This also holds true in tests featuring overload and third-body wear by cortical bone chips present in the bearing pairs. Regarding the interlayer tolerance towards interlayer contamination (oxygen), limits for initiation of potential failure modes were established. It was found that mechanical failure is the most critical aspect and this mode is hypothetically linked to the ?-? tantalum phase switch induced by increasing oxygen levels as observed by X-ray diffraction (XRD). It is concluded that DLC coatings are a feasible candidate for near zero wear articulations on implants, potentially even surpassing the performance of ceramic vs. ceramic. PMID:24921709

  10. On Interlayer Stability and High-Cycle Simulator Performance of Diamond-Like Carbon Layers for Articulating Joint Replacements

    PubMed Central

    Thorwarth, Kerstin; Thorwarth, Götz; Figi, Renato; Weisse, Bernhard; Stiefel, Michael; Hauert, Roland

    2014-01-01

    Diamond like carbon (DLC) coatings have been proven to be an excellent choice for wear reduction in many technical applications. However, for successful adaption to the orthopaedic field, layer performance, stability and adhesion in physiologically relevant setups are crucial and not consistently investigated. In vitro wear testing as well as adequate corrosion tests of interfaces and interlayers are of great importance to verify the long term stability of DLC coated load bearing implants in the human body. DLC coatings were deposited on articulating lumbar spinal disks made of CoCr28Mo6 biomedical implant alloy using a plasma-activated chemical vapor deposition (PACVD) process. As an adhesion promoting interlayer, tantalum films were deposited by magnetron sputtering. Wear tests of coated and uncoated implants were performed in physiological solution up to a maximum of 101 million articulation cycles with an amplitude of ±2° and ?3/+6° in successive intervals at a preload of 1200 N. The implants were characterized by gravimetry, inductively coupled plasma optical emission spectrometry (ICP-OES) and cross section scanning electron microscopy (SEM) analysis. It is shown that DLC coated surfaces with uncontaminated tantalum interlayers perform very well and no corrosive or mechanical failure could be observed. This also holds true in tests featuring overload and third-body wear by cortical bone chips present in the bearing pairs. Regarding the interlayer tolerance towards interlayer contamination (oxygen), limits for initiation of potential failure modes were established. It was found that mechanical failure is the most critical aspect and this mode is hypothetically linked to the ?-? tantalum phase switch induced by increasing oxygen levels as observed by X-ray diffraction (XRD). It is concluded that DLC coatings are a feasible candidate for near zero wear articulations on implants, potentially even surpassing the performance of ceramic vs. ceramic. PMID:24921709

  11. Diamond Smoothing Tools

    NASA Technical Reports Server (NTRS)

    Voronov, Oleg

    2007-01-01

    Diamond smoothing tools have been proposed for use in conjunction with diamond cutting tools that are used in many finish-machining operations. Diamond machining (including finishing) is often used, for example, in fabrication of precise metal mirrors. A diamond smoothing tool according to the proposal would have a smooth spherical surface. For a given finish machining operation, the smoothing tool would be mounted next to the cutting tool. The smoothing tool would slide on the machined surface left behind by the cutting tool, plastically deforming the surface material and thereby reducing the roughness of the surface, closing microcracks and otherwise generally reducing or eliminating microscopic surface and subsurface defects, and increasing the microhardness of the surface layer. It has been estimated that if smoothing tools of this type were used in conjunction with cutting tools on sufficiently precise lathes, it would be possible to reduce the roughness of machined surfaces to as little as 3 nm. A tool according to the proposal would consist of a smoothing insert in a metal holder. The smoothing insert would be made from a diamond/metal functionally graded composite rod preform, which, in turn, would be made by sintering together a bulk single-crystal or polycrystalline diamond, a diamond powder, and a metallic alloy at high pressure. To form the spherical smoothing tip, the diamond end of the preform would be subjected to flat grinding, conical grinding, spherical grinding using diamond wheels, and finally spherical polishing and/or buffing using diamond powders. If the diamond were a single crystal, then it would be crystallographically oriented, relative to the machining motion, to minimize its wear and maximize its hardness. Spherically polished diamonds could also be useful for purposes other than smoothing in finish machining: They would likely also be suitable for use as heat-resistant, wear-resistant, unlubricated sliding-fit bearing inserts.

  12. Industrial diamond

    USGS Publications Warehouse

    Olson, D.W.

    2003-01-01

    Statistics on the production, consumption, cost, trade, and government stockpile of natural and synthetic industrial diamond are provided. The outlook for the industrial diamond market is also considered.

  13. Diamond-based MEMS devices for biosensing based on electrochemical and gravimetric

    NASA Astrophysics Data System (ADS)

    Carlisle, John

    2005-03-01

    Diamond offers several potential advantages as a platform material for bioinorganic interfaces, including chemical and bio-inertness, electrochemistry, and high acoustic velocity. Ultrananocrystalline diamond (UNCD), with a unique combination of physical, chemical and electrical properties, is attractive for a variety of biochemical/biomedical applications such as hermetic bio-inert coatings, MEMS compatible biosensors, and electrochemical biointerfaces. Over the past several years we have worked on both the fundamental and applied science related to enabling UNCD-based bioMEMS devices, which has encompassed both the development of UNCD surface functionalization strategies that allow fine control of surface hydrophobicity and bioactivity, as well as the development of material integration strategies and surface micromachining techniques to enable the microfabrication of UNCD structural layers (e.g. cantilevers) that incorporate these functionalized surfaces into MEMS devices which are back-end compatible with CMOS electronics. These devices could thus combine the electrochemical and gravimetric transduction of the selective adsorption of target analytes in MEMS structures fabricated directly on top of a silicon microchip.. In the past year we have successfully demonstrated the use of conducting UNCD thin films as electrochemical biointerfaces, via the successful attachment of a redox enzyme onto the UNCD surface, Glucose oxidase (GOD). The procedure to achieve GOD immobilization involved the electrochemical immobilization of nitrophenyl groups to the UNCD surface and transformation of nitrophenyl to aminophenyl groups and the covalent bonding of GOD to the carboxyl groups using the diisopropylcarbodiimide/ N-hydroxysuccinimide (DCC/NHS) as the catalyst. After immobilization, the activity of the enzyme was demonstrated via the direct electrochemical detection of hydrogen peroxide. We have also developed CMOS-compatible UNCD MEMS cantilevers and fixed-fixed beam structures, using both traditional photolithography and e-beam lithography techniques.

  14. Method and article of manufacture corresponding to a composite comprised of ultra nonacrystalline diamond, metal, and other nanocarbons useful for thermoelectric and other applications

    DOEpatents

    Gruen, Dieter M.

    2010-05-18

    One provides (101) disperse ultra-nanocrystalline diamond powder material that comprises a plurality of substantially ordered crystallites that are each sized no larger than about 10 nanometers. One then reacts (102) these crystallites with a metallic component. The resultant nanowire is then able to exhibit a desired increase with respect to its ability to conduct electricity while also substantially preserving the thermal conductivity behavior of the disperse ultra-nanocrystalline diamond powder material. The reaction process can comprise combining (201) the crystallites with one or more metal salts in an aqueous solution and then heating (203) that aqueous solution to remove the water. This heating can occur in a reducing atmosphere (comprising, for example, hydrogen and/or methane) to also reduce the salt to metal.

  15. Isotope analysis of diamond-surface passivation effect of high-temperature H2O-grown atomic layer deposition-Al2O3 films

    NASA Astrophysics Data System (ADS)

    Hiraiwa, Atsushi; Saito, Tatsuya; Matsumura, Daisuke; Kawarada, Hiroshi

    2015-06-01

    The Al2O3 film formed using an atomic layer deposition (ALD) method with trimethylaluminum as Al precursor and H2O as oxidant at a high temperature (450 °C) effectively passivates the p-type surface conduction (SC) layer specific to a hydrogen-terminated diamond surface, leading to a successful operation of diamond SC field-effect transistors at 400 °C. In order to investigate this excellent passivation effect, we carried out an isotope analysis using D2O instead of H2O in the ALD and found that the Al2O3 film formed at a conventional temperature (100 °C) incorporates 50 times more CH3 groups than the high-temperature film. This CH3 is supposed to dissociate from the film when heated afterwards at a higher temperature (550 °C) and causes peeling patterns on the H-terminated surface. The high-temperature film is free from this problem and has the largest mass density and dielectric constant among those investigated in this study. The isotope analysis also unveiled a relatively active H-exchange reaction between the diamond H-termination and H2O oxidant during the high-temperature ALD, the SC still being kept intact. This dynamic and yet steady H termination is realized by the suppressed oxidation due to the endothermic reaction with H2O. Additionally, we not only observed the kinetic isotope effect in the form of reduced growth rate of D2O-oxidant ALD but found that the mass density and dielectric constant of D2O-grown Al2O3 films are smaller than those of H2O-grown films. This is a new type of isotope effect, which is not caused by the presence of isotopes in the films unlike the traditional isotope effects that originate from the presence of isotopes itself. Hence, the high-temperature ALD is very effective in forming Al2O3 films as a passivation and/or gate-insulation layer of high-temperature-operation diamond SC devices, and the knowledge of the aforementioned new isotope effect will be a basis for further enhancing ALD technologies in general.

  16. Diamond-based capacitive micromachined ultrasonic transducers in immersion.

    PubMed

    Cetin, Ahmet M; Bayram, Baris

    2013-02-01

    Diamond is a superior membrane material for capacitive micromachined ultrasonic transducers (CMUTs). By using ultrananocrystalline diamond (UNCD) membrane and plasma-activated wafer bonding technology, a single diamond-based circular CMUT is demonstrated and operated in immersion for the first time. The diamond-based CMUT, biased at 100 V, is excited with a 10-cycle burst of 36 V(p-p) sine signal at 3.5 MHz. Pressure generated on a 2-D plane coincident with the normal of the CMUT is measured using a broadband hydrophone. Peak-to-peak hydrophone voltage measurements along the scan area clearly indicate the main lobe and the side lobes, as theoretically predicted by our directivity function calculations. The peak-to-peak hydrophone voltage on the axial direction of the CMUT is found to be in agreement with our theoretical calculations in the Fraunhofer region (-45 mm diamond-based CMUT is measured for a dc bias of 100 V, and ac excitation with 30-cycle bursts of 9, 36, and 54 V(p-p) sine signal. A peak response at 5.6 MHz is measured for all ac amplitudes. Overall, diamond is shown to be an applicable membrane for CMUT devices and applications. PMID:23357916

  17. Nanocrystalline Diamond Films for Biosensor Applications

    NASA Astrophysics Data System (ADS)

    Popov, Cyril; Kulisch, Wilhelm

    Diamond is a material with quite a number of excellent properties, like extreme hardness, high elastic modulus, high wear resistance, optical transparency in a broad spectral range, resistivity controllable by the level of dopants, etc. which make it a promising candidate for different sensor applications, e.g. for X-ray detection. Due to its outstanding electrochemical properties, superior chemical inertness and biocompatibility, artificially grown diamond has been recognised as an extremely attractive material for both (bio-)chemical sensing and as an interface to biological systems. This holds for all forms of diamond: monocrystalline (natural or artificial) and poly- (PCD), nano- (NCD) and ultrananocrystalline (UNCD) films. This paper is devoted to possible biosensor application of NCD and UNCD films. The first part will briefly introduce UNCD films (composed of diamond nanocrystallites of 3-5 nm diameter embedded in an amorphous carbon matrix with a grain boundary thickness of 1.0-1.5 nm), their deposition by microwave plasma chemical vapour deposition, their growth mechanisms and the characterization of their bulk properties, comparing them with other types of diamond films. The second part deals with surface modifications of UNCD films, which is the first step towards preparation of a biosensor, including different plasma and chemical processes, the thorough characterization of the resulting surfaces by a variety of techniques (AFM, XPS, ToF-SIMS, contact angle measurements, etc.) and the possibility to pattern the surface properties. The third part will describe possible pathways for the immobilization of biomolecules (proteins, DNA) on UNCD surfaces and the techniques for the characterization of this step, including force measurements, AFM and spectroscopic analyses. In the final part, different examples of biosensors based on UNCD as well as on NCD will be demonstrated in order to reveal the potential of diamond (films) in this field.

  18. Nanofabrication of sharp diamond tips by e-beam lithography and inductively coupled plasma reactive ion etching.

    SciTech Connect

    Moldovan, N.; Divan, R.; Zeng, H.; Carlisle, J. A.; Advanced Diamond Tech.

    2009-12-07

    Ultrasharp diamond tips make excellent atomic force microscopy probes, field emitters, and abrasive articles due to diamond's outstanding physical properties, i.e., hardness, low friction coefficient, low work function, and toughness. Sharp diamond tips are currently fabricated as individual tips or arrays by three principal methods: (1) focused ion beam milling and gluing onto a cantilever of individual diamond tips, (2) coating silicon tips with diamond films, or (3) molding diamond into grooves etched in a sacrificial substrate, bonding the sacrificial substrate to another substrate or electrodepositing of a handling chip, followed by dissolution of the sacrificial substrate. The first method is tedious and serial in nature but does produce very sharp tips, the second method results in tips whose radius is limited by the thickness of the diamond coating, while the third method involves a costly bonding and release process and difficulties in thoroughly filling the high aspect ratio apex of molding grooves with diamond at the nanoscale. To overcome the difficulties with these existing methods, this article reports on the feasibility of the fabrication of sharp diamond tips by direct etching of ultrananocrystalline diamond (UNCD{reg_sign}) as a starting and structural material. The UNCD is reactive ion etched using a cap-precursor-mask scheme. An optimized etching recipe demonstrates the formation of ultrasharp diamond tips ({approx} 10 nm tip radius) with etch rates of 650 nm/min.

  19. The Design of Diamond Compton Telescope

    E-print Network

    Kinya Hibino; Toshisuke Kashiwagi; Shoji Okuno; Kaori Yajima; Yukio Uchihori; Hisashi Kitamura; Takeshi Takashima; Mamoru Yokota; Kenji Yoshida

    2007-07-23

    We have developed radiation detectors using the new synthetic diamonds. The diamond detector has an advantage for observations of "low/medium" energy gamma rays as a Compton telescope. The primary advantage of the diamond detector can reduce the photoelectric effect in the low energy range, which is background noise for tracking of the Compton recoil electron. A concept of the Diamond Compton Telescope (DCT) consists of position sensitive layers of diamond-striped detector and calorimeter layer of CdTe detector. The key part of the DCT is diamond-striped detectors with a higher positional resolution and a wider energy range from 10 keV to 10 MeV. However, the diamond-striped detector is under development. We describe the performance of prototype diamond detector and the design of a possible DCT evaluated by Monte Carlo simulations.

  20. The Design of Diamond Compton Telescope

    E-print Network

    Hibino, Kinya; Okuno, Shoji; Yajima, Kaori; Uchihori, Yukio; Kitamura, Hisashi; Takashima, Takeshi; Yokota, Mamoru; Yoshida, Kenji

    2007-01-01

    We have developed radiation detectors using the new synthetic diamonds. The diamond detector has an advantage for observations of "low/medium" energy gamma rays as a Compton telescope. The primary advantage of the diamond detector can reduce the photoelectric effect in the low energy range, which is background noise for tracking of the Compton recoil electron. A concept of the Diamond Compton Telescope (DCT) consists of position sensitive layers of diamond-striped detector and calorimeter layer of CdTe detector. The key part of the DCT is diamond-striped detectors with a higher positional resolution and a wider energy range from 10 keV to 10 MeV. However, the diamond-striped detector is under development. We describe the performance of prototype diamond detector and the design of a possible DCT evaluated by Monte Carlo simulations.

  1. Industrial diamond

    USGS Publications Warehouse

    Olson, D.W.

    2012-01-01

    Estimated 2011 world production of natural and synthetic industrial diamond was about 4.45 billion carats. During 2011, natural industrial diamonds were produced in more than 20 countries, and synthetic industrial diamond was produced in at least 13 countries. About 98 percent of the combined natural and synthetic global output was produced in China, Ireland, Japan, Russia, South Africa and the United States. China is the world's leading producer of synthetic industrial diamond followed by Russia and the United States.

  2. Industrial diamond

    USGS Publications Warehouse

    Olson, D.W.

    2011-01-01

    Estimated world production of natural and synthetic industrial diamond was about 4.44 billion carats in 2010. Natural industrial diamond deposits have been found in more than 35 countries, and synthetic industrial diamond is produced in at least 15 countries.

  3. Industrial diamond

    USGS Publications Warehouse

    Olson, D.W.

    2013-01-01

    Estimated 2012 world production of natural and synthetic industrial diamond was about 4.45 billion carats. During 2012, natural industrial diamonds were produced in at least 20 countries, and synthetic industrial diamond was produced in at least 12 countries. About 99 percent of the combined natural and synthetic global output was produced in Belarus, China, Ireland, Japan, Russia, South Africa and the United States. During 2012, China was the world’s leading producer of synthetic industrial diamond followed by the United States and Russia. In 2012, the two U.S. synthetic producers, one in Pennsylvania and the other in Ohio, had an estimated output of 103 million carats, valued at about $70.6 million. This was an estimated 43.7 million carats of synthetic diamond bort, grit, and dust and powder with a value of $14.5 million combined with an estimated 59.7 million carats of synthetic diamond stone with a value of $56.1 million. Also in 2012, nine U.S. firms manufactured polycrystalline diamond (PCD) from synthetic diamond grit and powder. The United States government does not collect or maintain data for either domestic PCD producers or domestic chemical vapor deposition (CVD) diamond producers for quantity or value of annual production. Current trade and consumption quantity data are not available for PCD or for CVD diamond. For these reasons, PCD and CVD diamond are not included in the industrial diamond quantitative data reported here.

  4. Industrial diamond

    USGS Publications Warehouse

    Olson, D.W.

    2006-01-01

    In 2005, estimated world production of natural and synthetic industrial diamond was 630 million carats. Natural industrial diamond deposits were found in more than 35 countries. Synthetic industrial diamond is produced in at least 15 countries. More than 81% of the combined natural and synthetic global output was produced in Ireland, Japan, Russia, South Africa and the United States.

  5. Industrial diamond

    USGS Publications Warehouse

    Olson, D.W.

    2000-01-01

    Part of the 1999 Industrial Minerals Review. A review of the state of the global industrial diamond industry in 1999 is presented. World consumption of industrial diamond has increased annually in recent years, with an estimated 500 million carats valued between $650 million and $800 million consumed in 1999. In 1999, the U.S. was the world's largest market for industrial diamond and was also one of the world's main producers; the others were Ireland, Russia, and South Africa. Uses of industrial diamonds are discussed, and prices of natural and synthetic industrial diamond are reported.

  6. High-reliability passivation of hydrogen-terminated diamond surface by atomic layer deposition of Al{sub 2}O{sub 3}

    SciTech Connect

    Daicho, Akira Saito, Tatsuya; Kurihara, Shinichiro; Kawarada, Hiroshi; Hiraiwa, Atsushi

    2014-06-14

    Although the two-dimensional hole gas (2DHG) of a hydrogen-terminated diamond surface provides a unique p-type conducting layer for high-performance transistors, the conductivity is highly sensitive to its environment. Therefore, the surface must be passivated to preserve the 2DHG, especially at high temperature. We passivated the surface at high temperature (450?°C) without the loss of C-H surface bonds by atomic layer deposition (ALD) and investigated the thermal reliability of the Al{sub 2}O{sub 3} film. As a result, C-H bonds were preserved, and the hole accumulation effect appeared after the Al{sub 2}O{sub 3} deposition by ALD with H{sub 2}O as an oxidant. The sheet resistivity and hole density were almost constant between room temperature and 500?°C by the passivation with thick Al{sub 2}O{sub 3} film thicker than 38?nm deposited by ALD at 450?°C. After the annealing at 550?°C in air The sheet resistivity and hole density were preserved. These results indicate the possibility of high-temperature application of the C-H surface diamond device in air. In the case of lower deposition temperatures, the sheet resistivity increased after air annealing, suggesting an insufficient protection capability of these films. Given the result of sheet resistivity after annealing, the increase in the sheet resistivity of these samples was not greatly significant. However, bubble like patterns were observed in the Al{sub 2}O{sub 3} films formed from 200 to 400?°C by air annealing at 550?°C for 1 h. On the other hand, the patterns were no longer observed at 450?°C deposition. Thus, this 450?°C deposition is the sole solution to enabling power device application, which requires high reliability at high temperatures.

  7. Nitrogen-Vacancy Centers in Diamond for Current Imaging at the Redistributive Layer Level of Integrated Circuits

    E-print Network

    Nowodzinski, Antoine; Toraille, Loïc; Jacques, Vincent; Roch, Jean-François; Debuisschert, Thierry

    2015-01-01

    We present a novel technique based on an ensemble of Nitrogen-Vacancy (NV) centers in diamond to perform Magnetic Current Imaging (MCI) on an Integrated Circuit (IC). NV centers in diamond allow measuring the three components of the magnetic fields generated by a mA range current in an IC structure over a field of 50 x 200 {\\mu}m^2 with sub-micron resolution. Vector measurements allow using a more robust algorithm than those used for MCI using Giant Magneto Resistance (GMR) or Superconducting Quantum Interference Device (SQUID) sensors and it is opening new current reconstruction prospects. Calculated MCI from these measurements shows a very good agreement with theoretical current path. Acquisition time is around 10 sec, which is much faster than scanning measurements using SQUID or GMR. The experimental set-up relies on a standard optical microscope, and the measurements can be performed at room temperature and atmospheric pressure. These early experiments, not optimized for IC, show that NV centers in diamo...

  8. Process for buried metallization in diamond film

    SciTech Connect

    Lake, M.L.; Ting, J.; Lagounov, A.; Tang, C.

    1996-03-01

    The objective of this research was to investigate methods of combining chemical vapor deposition diamond growth techniques with state-of-the-art physical vapor deposition or ion beam enhanced deposition to produce buried metallization of polycrystalline diamond films. The mechanical and electrical integrity of both the insulating and conducting elements following metallization and diamond overgrowth was shown. Both methods were shown to have bonding strength sufficient to withstand tape lift-off, which is regarded to be a good indication of strength needed for die attachment and wire bonding. Diamond overgrowth was also shown, thus enabling buried metallized layers to be created. Electrical resistivity property measurements on metallized layers and between metallization separated by diamond films were shown to be sufficient to allow the use of diamond as an insulating inter-layer material for multi-layer circuit boards. {copyright} {ital 1996 American Institute of Physics.}

  9. Diamond detector - material science, design and application

    NASA Astrophysics Data System (ADS)

    Gaowei, Mengjia

    Modern synchrotrons, such as the NSLS-II, will enable unprecedented science by having extremely high brightness and flux with exceptional beam stability. These capabilities create a harsh and demanding environment for measuring the characteristics of the x-ray beam. In many cases, existing measurement techniques fail completely, requiring the development of new detectors which can meet the demands of the synchrotron. The combination of diamond properties ranked diamond an appealing candidate in the field of radiation detection in extreme conditions and it has been used as x-ray sensor material for decades. However, only until the development of chemical vapor deposition (CVD) process in the synthesis of diamond that has it been considered for wider applications in the state-of-art synchrotron light sources as part of beamline diagnostics, including the detection of x-ray beam flux and position. While defects and dislocations in CVD grown single crystal diamonds are inevitable, there are solutions in other aspects of a device fabrication to compensate this technological downside, including improving device performance in engineering diamond surface electrode materials and patterns and slicing and polishing diamond plates into thinner pieces. The content of this dissertation summarizes our effort in addressing several problems we encounter in the process of design and fabrication of single crystal CVD diamond based electronic devices. In order to study the generation of post-anneal photoconductive gain in our devices we have discussed in section 3 and 4 the two criteria for the observation of photoconductive current. In section 3 we reveal the correlation between structural defects in diamond and the post-anneal photoconductive regions. Section 4 introduces the measurements of hard x-ray photoelectron spectroscopy (HAXPES) we applied to investigate the diamond-metal Schottky barrier height for several metals and diamond surface terminations. The position of the diamond valence-band maximum was determined by theoretically calculating the diamond density of states and applying cross section corrections. The diamond-platinum Schottky barrier height was lowered by 0.2 eV after thermal annealing, indicating annealing may increase carrier injection in diamond devices leading to photoconductive gain. In order to adapt our device to soft x-ray applications, efforts are made to develop a thin diamond position monitor for lowering device absorption. In section 5 we have discussed the fabrication and testing of thin diamond x-ray monitors made from diamond plates with nominal thickness of 30microm, which is 1/10th of the thickness of the diamonds we previously used. Calibration results of this detector are presented and discussed in comparison with thicker diamond sensors. Section 6 introduces our effort on the investigation of carrier loss mechanism in diamond detectors. Near edge responsivity in diamond x-ray detectors has been used to confirm the carrier loss mechanism as recombination due to diffusion into the incident electrode. We present a detailed study of the bias dependence of the diamond responsivity across the carbon k-edge. The carrier loss is modeled by incorporating a characteristic recombination length into the absorption model and is shown to agree well with Monte Carlo simulated carrier losses. In addition, nitrogen doped ultrananocrystalline diamond (nUNCD) grown on the surface of a CVD single crystal diamond as an alternative contact to metal is tested in the similar measurements as the metal contact diamond. nUNCD has a much lower x-ray absorption than metal contacts and is designed to improve the performance of our device. This diamond is calibrated over a wide photon energy range from 0.2 keV to 28 keV, and compared with platinum coated diamond. Results of these studies will be presented and discussed in section 7. Future work has been proposed in the last section in improving the design and fabrication of diamond based electronics as well as in the investigation to enhance our understanding of its material and

  10. Extreme ultraviolet transmission of a synthetic diamond thin film

    NASA Technical Reports Server (NTRS)

    Vallerga, John V.; Gibson, J. L.; Knowles, J. L.

    1991-01-01

    Measurements are presented of a thin film of synthetic diamond at various wavelengths in the extreme ultraviolet. The synthetic diamond combines the transmission properties of carbon with the strength, density, and ruggedness of a natural diamond. The Extreme Ultraviolet Transmission (EUV) of a film of the synthetic diamond has shown the existence of a thin surface layer of silicon, probably in the form of silicon carbide, which is not a contaminant layer.

  11. AlTiN layer effect on mechanical properties of Ti-doped diamond-like carbon composite coatings

    E-print Network

    Volinsky, Alex A.

    transparency in the visible and infrared regions, high electrical and thermal conductivities, high wear by magnetron sputtering on W18Cr4V high speed steel substrates. The effect of the AlTiN support layer and thermal expansion mismatch when grown on substrates such as high speed and stainless steels, has

  12. A novel radial anode layer ion source for inner wall pipe coating and materials modification—Hydrogenated diamond-like carbon coatings from butane gas

    NASA Astrophysics Data System (ADS)

    Murmu, Peter P.; Markwitz, Andreas; Suschke, Konrad; Futter, John

    2014-08-01

    We report a new ion source development for inner wall pipe coating and materials modification. The ion source deposits coatings simultaneously in a 360° radial geometry and can be used to coat inner walls of pipelines by simply moving the ion source in the pipe. Rotating parts are not required, making the source ideal for rough environments and minimizing maintenance and replacements of parts. First results are reported for diamond-like carbon (DLC) coatings on Si and stainless steel substrates deposited using a novel 360° ion source design. The ion source operates with permanent magnets and uses a single power supply for the anode voltage and ion acceleration up to 10 kV. Butane (C4H10) gas is used to coat the inner wall of pipes with smooth and homogeneous DLC coatings with thicknesses up to 5 ?m in a short time using a deposition rate of 70 ± 10 nm min-1. Rutherford backscattering spectrometry results showed that DLC coatings contain hydrogen up to 30 ± 3% indicating deposition of hydrogenated DLC (a-C:H) coatings. Coatings with good adhesion are achieved when using a multiple energy implantation regime. Raman spectroscopy results suggest slightly larger disordered DLC layers when using low ion energy, indicating higher sp3 bonds in DLC coatings. The results show that commercially interesting coatings can be achieved in short time.

  13. Diamond Coatings

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Advances in materials technology have demonstrated that it is possible to get the advantages of diamond in a number of applications without the cost penalty, by coating and chemically bonding an inexpensive substrate with a thin film of diamond-like carbon (DLC). Diamond films offer tremendous technical and economic potential in such advances as chemically inert protective coatings; machine tools and parts capable of resisting wear 10 times longer; ball bearings and metal cutting tools; a broad variety of optical instruments and systems; and consumer products. Among the American companies engaged in DLC commercialization is Diamonex, Inc., a diamond coating spinoff of Air Products and Chemicals, Inc. Along with its own proprietary technology for both polycrystalline diamond and DLC coatings, Diamonex is using, under an exclusive license, NASA technology for depositing DLC on a substrate. Diamonex is developing, and offering commercially, under the trade name Diamond Aegis, a line of polycrystalline diamond-coated products that can be custom tailored for optical, electronic and engineering applications. Diamonex's initial focus is on optical products and the first commercial product is expected in late 1990. Other target applications include electronic heat sink substrates, x-ray lithography masks, metal cutting tools and bearings.

  14. Industrial diamond

    USGS Publications Warehouse

    Olson, D.W.

    2007-01-01

    World production of natural and synthetic industrial diamond was about 648 million carats in 2006, with 79 percent of the production coming from Ireland, Japan, Russia, South Africa, and the U.S. U.S. consumption was was an estimated 602 million carats, imports were over 391 million carats, and exports were about 83 million carats. About 87 percent of the industrial diamonds market uses synthetic diamonds, which are expected to become less expensive as technology improves and competition from low-cost producers increases.

  15. Industrial diamond

    USGS Publications Warehouse

    Olson, D.W.

    2004-01-01

    Part of the 2003 industrial minerals review. Supply and demand data for industrial diamond are provided. Topics discussed are consumption, prices, imports and exports, government stockpiles, and the outlook for 2004.

  16. Diamond Nanophotonics

    E-print Network

    Aharonovich, Igor

    2014-01-01

    The burgeoning field of nanophotonics has grown to be a major research area, primarily because of the ability to control and manipulate single quantum systems (emitters) and single photons on demand. For many years studying nanophotonic phenomena was limited to traditional semiconductors (including silicon and GaAs) and experiments were carried out predominantly at cryogenic temperatures. In the last decade, however, diamond has emerged as a new contender to study photonic phenomena at the nanoscale. Offering plethora of quantum emitters that are optically active at room temperature and ambient conditions, diamond has been exploited to demonstrate super-resolution microscopy and realize entanglement, Purcell enhancement and other quantum and classical nanophotonic effects. Elucidating the importance of diamond as a material, this review will highlight the recent achievements in the field of diamond nanophotonics, and convey a roadmap for future experiments and technological advancements.

  17. Diamond nanophotonics

    PubMed Central

    Beha, Katja; Wolfer, Marco; Becker, Merle C; Siyushev, Petr; Jamali, Mohammad; Batalov, Anton; Hinz, Christopher; Hees, Jakob; Kirste, Lutz; Obloh, Harald; Gheeraert, Etienne; Naydenov, Boris; Jakobi, Ingmar; Dolde, Florian; Pezzagna, Sébastien; Twittchen, Daniel; Markham, Matthew; Dregely, Daniel; Giessen, Harald; Meijer, Jan; Jelezko, Fedor; Nebel, Christoph E; Bratschitsch, Rudolf; Leitenstorfer, Alfred; Wrachtrup, Jörg

    2012-01-01

    Summary We demonstrate the coupling of single color centers in diamond to plasmonic and dielectric photonic structures to realize novel nanophotonic devices. Nanometer spatial control in the creation of single color centers in diamond is achieved by implantation of nitrogen atoms through high-aspect-ratio channels in a mica mask. Enhanced broadband single-photon emission is demonstrated by coupling nitrogen–vacancy centers to plasmonic resonators, such as metallic nanoantennas. Improved photon-collection efficiency and directed emission is demonstrated by solid immersion lenses and micropillar cavities. Thereafter, the coupling of diamond nanocrystals to the guided modes of micropillar resonators is discussed along with experimental results. Finally, we present a gas-phase-doping approach to incorporate color centers based on nickel and tungsten, in situ into diamond using microwave-plasma-enhanced chemical vapor deposition. The fabrication of silicon–vacancy centers in nanodiamonds by microwave-plasma-enhanced chemical vapor deposition is discussed in addition. PMID:23365803

  18. Diamond nanophotonics.

    PubMed

    Beha, Katja; Fedder, Helmut; Wolfer, Marco; Becker, Merle C; Siyushev, Petr; Jamali, Mohammad; Batalov, Anton; Hinz, Christopher; Hees, Jakob; Kirste, Lutz; Obloh, Harald; Gheeraert, Etienne; Naydenov, Boris; Jakobi, Ingmar; Dolde, Florian; Pezzagna, Sébastien; Twittchen, Daniel; Markham, Matthew; Dregely, Daniel; Giessen, Harald; Meijer, Jan; Jelezko, Fedor; Nebel, Christoph E; Bratschitsch, Rudolf; Leitenstorfer, Alfred; Wrachtrup, Jörg

    2012-01-01

    We demonstrate the coupling of single color centers in diamond to plasmonic and dielectric photonic structures to realize novel nanophotonic devices. Nanometer spatial control in the creation of single color centers in diamond is achieved by implantation of nitrogen atoms through high-aspect-ratio channels in a mica mask. Enhanced broadband single-photon emission is demonstrated by coupling nitrogen-vacancy centers to plasmonic resonators, such as metallic nanoantennas. Improved photon-collection efficiency and directed emission is demonstrated by solid immersion lenses and micropillar cavities. Thereafter, the coupling of diamond nanocrystals to the guided modes of micropillar resonators is discussed along with experimental results. Finally, we present a gas-phase-doping approach to incorporate color centers based on nickel and tungsten, in situ into diamond using microwave-plasma-enhanced chemical vapor deposition. The fabrication of silicon-vacancy centers in nanodiamonds by microwave-plasma-enhanced chemical vapor deposition is discussed in addition. PMID:23365803

  19. Diamond fiber field emitters

    DOEpatents

    Blanchet-Fincher, Graciela B. (Wilmington, DE); Coates, Don M. (Santa Fe, NM); Devlin, David J. (Los Alamos, NM); Eaton, David F. (Wilmington, DE); Silzars, Aris K. (Landenburg, PA); Valone, Steven M. (Santa Fe, NM)

    1996-01-01

    A field emission electron emitter comprising an electrode formed of at least one diamond, diamond-like carbon or glassy carbon composite fiber, said composite fiber having a non-diamond core and a diamond, diamond-like carbon or glassy carbon coating on said non-diamond core, and electronic devices employing such a field emission electron emitter.

  20. Advanced Diamond Anvil Techniques (Customized Diamond Anvils)

    SciTech Connect

    Weir, S

    2009-02-11

    A complete set of diamond-based fabrication tools now exists for making a wide range of different types of diamond anvils which are tailored for various high-P applications. Current tools include: CVD diamond deposition (making diamond); Diamond polishing, laser drilling, plasma etching (removal of diamond); and Lithography, 3D laser pantography (patterning features onto diamond); - Metal deposition (putting electrical circuits and metal masks onto diamond). Current applications include the following: Electrical Conductivity; Magnetic Susceptibility; and High-P/High-T. Future applications may include: NMR; Hall Effect; de Haas - Shubnikov (Fermi surface topology); Calorimetry; and thermal conductivity.

  1. 'Diamond' in 3-D

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This 3-D, microscopic imager mosaic of a target area on a rock called 'Diamond Jenness' was taken after NASA's Mars Exploration Rover Opportunity ground into the surface with its rock abrasion tool for a second time.

    Opportunity has bored nearly a dozen holes into the inner walls of 'Endurance Crater.' On sols 177 and 178 (July 23 and July 24, 2004), the rover worked double-duty on Diamond Jenness. Surface debris and the bumpy shape of the rock resulted in a shallow and irregular hole, only about 2 millimeters (0.08 inch) deep. The final depth was not enough to remove all the bumps and leave a neat hole with a smooth floor. This extremely shallow depression was then examined by the rover's alpha particle X-ray spectrometer.

    On Sol 178, Opportunity's 'robotic rodent' dined on Diamond Jenness once again, grinding almost an additional 5 millimeters (about 0.2 inch). The rover then applied its Moessbauer spectrometer to the deepened hole. This double dose of Diamond Jenness enabled the science team to examine the rock at varying layers. Results from those grindings are currently being analyzed.

    The image mosaic is about 6 centimeters (2.4 inches) across.

  2. Amorphous-diamond electron emitter

    DOEpatents

    Falabella, Steven (Livermore, CA)

    2001-01-01

    An electron emitter comprising a textured silicon wafer overcoated with a thin (200 .ANG.) layer of nitrogen-doped, amorphous-diamond (a:D-N), which lowers the field below 20 volts/micrometer have been demonstrated using this emitter compared to uncoated or diamond coated emitters wherein the emission is at fields of nearly 60 volts/micrometer. The silicon/nitrogen-doped, amorphous-diamond (Si/a:D-N) emitter may be produced by overcoating a textured silicon wafer with amorphous-diamond (a:D) in a nitrogen atmosphere using a filtered cathodic-arc system. The enhanced performance of the Si/a:D-N emitter lowers the voltages required to the point where field-emission displays are practical. Thus, this emitter can be used, for example, in flat-panel emission displays (FEDs), and cold-cathode vacuum electronics.

  3. Superconducting nanowire single photon detector on diamond

    SciTech Connect

    Atikian, Haig A.; Burek, Michael J.; Choy, Jennifer T.; Lon?ar, Marko; Eftekharian, Amin; Jafari Salim, A.; Hamed Majedi, A.

    2014-03-24

    Superconducting nanowire single photon detectors are fabricated directly on diamond substrates and their optical and electrical properties are characterized. Dark count performance and photon count rates are measured at varying temperatures for 1310?nm and 632?nm photons. A multi-step diamond surface polishing procedure is reported, involving iterative reactive ion etching and mechanical polishing to create a suitable diamond surface for the deposition and patterning of thin film superconducting layers. Using this approach, diamond substrates with less than 300?pm Root Mean Square surface roughness are obtained.

  4. Epitaxial growth of europium monoxide on diamond

    SciTech Connect

    Melville, A.; Heeg, T.; Mairoser, T.; Schmehl, A.; Fischer, M.; Gsell, S.; Schreck, M.; Awschalom, D. D.; Holländer, B.; Schubert, J.; Schlom, D. G.; Kavli Institute at Cornell for Nanoscale Science, Ithaca, New York 14853

    2013-11-25

    We report the epitaxial integration of phase-pure EuO on both single-crystal diamond and on epitaxial diamond films grown on silicon utilizing reactive molecular-beam epitaxy. The epitaxial orientation relationship is (001) EuO ? (001) diamond and [110] EuO ?[100] diamond. The EuO layer is nominally unstrained and ferromagnetic with a transition temperature of 68 ± 2 K and a saturation magnetization of 5.5 ± 0.1 Bohr magnetons per europium ion on the single-crystal diamond, and a transition temperature of 67 ± 2 K and a saturation magnetization of 2.1 ± 0.1 Bohr magnetons per europium ion on the epitaxial diamond film.

  5. Method to grow carbon thin films consisting entirely of diamond grains 3-5 nm in size and high-energy grain boundaries

    DOEpatents

    Carlisle, John A.; Auciello, Orlando; Birrell, James

    2006-10-31

    An ultrananocrystalline diamond (UNCD) having an average grain size between 3 and 5 nanometers (nm) with not more than about 8% by volume diamond having an average grain size larger than 10 nm. A method of manufacturing UNCD film is also disclosed in which a vapor of acetylene and hydrogen in an inert gas other than He wherein the volume ratio of acetylene to hydrogen is greater than 0.35 and less than 0.85, with the balance being an inert gas, is subjected to a suitable amount of energy to fragment at least some of the acetylene to form a UNCD film having an average grain size of 3 to 5 nm with not more than about 8% by volume diamond having an average grain size larger than 10 nm.

  6. Homoepitaxial Boron Doped Diamond Anvil as Heating Element in a Diamond Anvil Cell

    NASA Astrophysics Data System (ADS)

    Montgomery, Jeffrey; Samudrala, Gopi; Vohra, Yogesh

    2012-02-01

    Recent advances in designer-diamond technology have allowed for the use of electrically and thermally conducting homoepitaxially-grown layers of boron-doped diamond (grown at 1200 C with a 2% mixture of CH4 in H, resulting in extremely high doping levels ˜ 10^20/cm^3) to be used as heating elements in a diamond anvil cell (DAC). These diamonds allow for precise control of the temperature inside of the diamond anvil itself, particularly when coupled with a cryostat. Furthermore, the unmatched thermally conducting nature of diamond ensures that no significant spatial gradient in temperature occurs across the culet area. Since a thermocouple can easily be attached anywhere on the diamond surface, we can also measure diamond temperatures directly. With two such heaters, one can raise sample temperatures uniformly, or with any desired gradient along the pressure axis while preserving optical access. In our initial experiments with these diamond anvils we report on the measurement of the thermal conductivity of copper-beryllium using a single diamond heater and two thermocouples. We augment these measurements with measurements of sample pressure via ruby fluorescence and electrical resistance of the sample and diamond heater.

  7. Microstructural Evolution of Nanocrystalline Diamond Films Due to CH4/Ar/H2 Plasma Post-Treatment Process.

    PubMed

    Lin, Sheng-Chang; Yeh, Chien-Jui; Manoharan, Divinah; Leou, Keh-Chyang; Lin, I-Nan

    2015-10-01

    Plasma post-treatment process was observed to markedly enhance the electron field emission (EFE) properties of ultrananocrystalline diamond (UNCD) films. TEM examinations reveal that the prime factor which improves the EFE properties of these films is the coalescence of ultrasmall diamond grains (?5 nm) forming large diamond grains about hundreds of nanometers accompanied by the formation of nanographitic clusters along the grain boundaries due to the plasma post-treatment process. OES studies reveal the presence of large proportion of atomic hydrogen and C2 (or CH) species, which are the main ingredients that altered the granular structure of the UNCD films. In the post-treatment process, the plasma interacts with the diamond films by a diffusion process. The recrystallization of diamond grains started at the surface region of the material, and the interaction zone increased with the post-treatment period. The entire diamond film can be converted into a nanocrystalline granular structure when post-treated for a sufficient length of time. PMID:26372852

  8. Isotope analysis of diamond-surface passivation effect of high-temperature H{sub 2}O-grown atomic layer deposition-Al{sub 2}O{sub 3} films

    SciTech Connect

    Hiraiwa, Atsushi E-mail: qs4a-hriw@asahi-net.or.jp; Saito, Tatsuya; Matsumura, Daisuke; Kawarada, Hiroshi

    2015-06-07

    The Al{sub 2}O{sub 3} film formed using an atomic layer deposition (ALD) method with trimethylaluminum as Al precursor and H{sub 2}O as oxidant at a high temperature (450?°C) effectively passivates the p-type surface conduction (SC) layer specific to a hydrogen-terminated diamond surface, leading to a successful operation of diamond SC field-effect transistors at 400?°C. In order to investigate this excellent passivation effect, we carried out an isotope analysis using D{sub 2}O instead of H{sub 2}O in the ALD and found that the Al{sub 2}O{sub 3} film formed at a conventional temperature (100?°C) incorporates 50 times more CH{sub 3} groups than the high-temperature film. This CH{sub 3} is supposed to dissociate from the film when heated afterwards at a higher temperature (550?°C) and causes peeling patterns on the H-terminated surface. The high-temperature film is free from this problem and has the largest mass density and dielectric constant among those investigated in this study. The isotope analysis also unveiled a relatively active H-exchange reaction between the diamond H-termination and H{sub 2}O oxidant during the high-temperature ALD, the SC still being kept intact. This dynamic and yet steady H termination is realized by the suppressed oxidation due to the endothermic reaction with H{sub 2}O. Additionally, we not only observed the kinetic isotope effect in the form of reduced growth rate of D{sub 2}O-oxidant ALD but found that the mass density and dielectric constant of D{sub 2}O-grown Al{sub 2}O{sub 3} films are smaller than those of H{sub 2}O-grown films. This is a new type of isotope effect, which is not caused by the presence of isotopes in the films unlike the traditional isotope effects that originate from the presence of isotopes itself. Hence, the high-temperature ALD is very effective in forming Al{sub 2}O{sub 3} films as a passivation and/or gate-insulation layer of high-temperature-operation diamond SC devices, and the knowledge of the aforementioned new isotope effect will be a basis for further enhancing ALD technologies in general.

  9. Study of diamond film growth and properties

    NASA Technical Reports Server (NTRS)

    Albin, Sacharial

    1990-01-01

    The objective was to study diamond film growth and its properties in order to enhance the laser damage threshold of substrate materials. Calculations were performed to evaluate laser induced thermal stress parameter, R(sub T) of diamond. It is found that diamond has several orders of magnitude higher in value for R(sub T) compared to other materials. Thus, the laser induced damage threshold (LIDT) of diamond is much higher. Diamond films were grown using a microwave plasma enhanced chemical vapor deposition (MPECVD) system at various conditions of gas composition, pressure, temperature, and substrate materials. A 0.5 percent CH4 in H2 at 20 torr were ideal conditions for growing of high quality diamond films on substrates maintained at 900 C. The diamond films were polycrystalline which were characterized by scanning electron microscopy (SEM) and Raman scattering spectroscopy. The top surface of the growing film is always rough due to the facets of polycrystalline film while the back surface of the film replicates the substrate surface. An analytical model based on two dimensional periodic heat flow was developed to calculate the effective in-plane (face parallel) diffusivity of a two layer system. The effective diffusivity of diamond/silicon samples was measured using a laser pulse technique. The thermal conductivity of the films was measured to be 13.5 W/cm K, which is better than that of a type Ia natural diamond. Laser induced damage experiments were performed on bare Si substrates, diamond film coated Si, and diamond film windows. Significant improvements in the LIDT were obtained for diamond film coated Si compared to the bare Si.

  10. Diamond Tours

    NASA Technical Reports Server (NTRS)

    2007-01-01

    On April 24, a group traveling with Diamond Tours visited StenniSphere, the visitor center at NASA John C. Stennis Space Center in South Mississippi. The trip marked Diamond Tours' return to StenniSphere since Hurricane Katrina struck the Gulf Coast on Aug. 29, 2005. About 25 business professionals from Georgia enjoyed the day's tour of America's largest rocket engine test complex, along with the many displays and exhibits at the museum. Before Hurricane Katrina, the nationwide company brought more than 1,000 visitors to StenniSphere each month. That contributed to more than 100,000 visitors from around the world touring the space center each year. In past years StenniSphere's visitor relations specialists booked Diamond Tours two or three times a week, averaging 40 to 50 people per visit. SSC was established in the 1960s to test the huge engines for the Saturn V moon rockets. Now 40 years later, the center tests every main engine for the space shuttle. SSC will soon begin testing the rocket engines that will power spacecraft carrying Americans back to the moon and on to Mars. For more information or to book a tour, visit http://www.nasa.gov/centers/stennis/home/index.html and click on the StenniSphere logo; or call 800-237-1821 or 228-688-2370.

  11. Plasma spraying method for forming diamond and diamond-like coatings

    DOEpatents

    Holcombe, C.E.; Seals, R.D.; Price, R.E.

    1997-06-03

    A method and composition is disclosed for the deposition of a thick layer of diamond or diamond-like material. The method includes high temperature processing wherein a selected composition including at least glassy carbon is heated in a direct current plasma arc device to a selected temperature above the softening point, in an inert atmosphere, and is propelled to quickly quenched on a selected substrate. The softened or molten composition crystallizes on the substrate to form a thick deposition layer comprising at least a diamond or diamond-like material. The selected composition includes at least glassy carbon as a primary constituent and may include at least one secondary constituent. Preferably, the secondary constituents are selected from the group consisting of at least diamond powder, boron carbide (B{sub 4}C) powder and mixtures thereof. 9 figs.

  12. Plasma spraying method for forming diamond and diamond-like coatings

    DOEpatents

    Holcombe, Cressie E. (Farragut, TN); Seals, Roland D. (Oak Ridge, TN); Price, R. Eugene (Knoxville, TN)

    1997-01-01

    A method and composition for the deposition of a thick layer (10) of diamond or diamond-like material. The method includes high temperature processing wherein a selected composition (12) including at least glassy carbon is heated in a direct current plasma arc device to a selected temperature above the softening point, in an inert atmosphere, and is propelled to quickly quenched on a selected substrate (20). The softened or molten composition (18) crystallizes on the substrate (20) to form a thick deposition layer (10) comprising at least a diamond or diamond-like material. The selected composition (12) includes at least glassy carbon as a primary constituent (14) and may include at least one secondary constituent (16). Preferably, the secondary constituents (16) are selected from the group consisting of at least diamond powder, boron carbide (B.sub.4 C) powder and mixtures thereof.

  13. Research on the diamond MISFET

    NASA Astrophysics Data System (ADS)

    Jianjun, Zhou; Song, Bai; Cen, Kong; Xijiao, Geng; Haiyan, Lu; Yuechan, Kong; Tangsheng, Chen

    2013-03-01

    Based on the hydrogen-terminated surface channel diamond material, a 1 ?m gate length diamond metal—insulator—semiconductor field-effect transistor (MISFET) was fabricated. The gate dielectric A12O3 was formed by naturally oxidated thin Al metal layer, and a less than 2 pA gate leakage current was obtained at gate bias between -4 V and 4 V. The DC characteristic of the diamond MISFET showed a drain-current density of 80 mA/mm at drain voltage of -5 V, and a maximum transconductance of 22 mS/mm at gate—source voltage of -3 V. With the small signal measurement, a current gain cutoff frequency of 2.1 GHz was also obtained.

  14. The mechanical properties of various chemical vapor deposition diamond structures compared to the ideal single crystal

    NASA Astrophysics Data System (ADS)

    Hess, Peter

    2012-03-01

    The structural and electronic properties of the diamond lattice, leading to its outstanding mechanical properties, are discussed. These include the highest elastic moduli and fracture strength of any known material. Its extreme hardness is strongly connected with the extreme shear modulus, which even exceeds the large bulk modulus, revealing that diamond is more resistant to shear deformation than to volume changes. These unique features protect the ideal diamond lattice also against mechanical failure and fracture. Besides fast heat conduction, the fast vibrational movement of carbon atoms results in an extreme speed of sound and propagation of crack tips with comparable velocity. The ideal mechanical properties are compared with those of real diamond films, plates, and crystals, such as ultrananocrystalline (UNC), nanocrystalline, microcrystalline, and homo- and heteroepitaxial single-crystal chemical vapor deposition (CVD) diamond, produced by metastable synthesis using CVD. Ultrasonic methods have played and continue to play a dominant role in the determination of the linear elastic properties, such as elastic moduli of crystals or the Young's modulus of thin films with substantially varying impurity levels and morphologies. A surprising result of these extensive measurements is that even UNC diamond may approach the extreme Young's modulus of single-crystal diamond under optimized deposition conditions. The physical reasons for why the stiffness often deviates by no more than a factor of two from the ideal value are discussed, keeping in mind the large variety of diamond materials grown by various deposition conditions. Diamond is also known for its extreme hardness and fracture strength, despite its brittle nature. However, even for the best natural and synthetic diamond crystals, the measured critical fracture stress is one to two orders of magnitude smaller than the ideal value obtained by ab initio calculations for the ideal cubic lattice. Currently, fracture is studied mainly by indentation or mechanical breaking of freestanding films, e.g., by bending or bursting. It is very difficult to study the fracture mechanism, discriminating between tensile, shear, and tearing stress components (mode I-III fracture) with these partly semiquantitative methods. A novel ultrasonic laser-based technique using short nonlinear surface acoustic wave pulses, developing shock fronts during propagation, has recently been employed to study mode-resolved fractures of single-crystal silicon. This method allows the generation of finite cracks and the evaluation of the fracture strength for well-defined crystallographic configurations. Laser ultrasonics reaches the critical stress at which real diamond fails and therefore can be employed as a new tool for mechanistic studies of the fracture behavior of CVD diamond in the future.

  15. Attempts to p-Dope Ultrananocrystalline Diamond Films in a Hot Filament Reactor Paul William May and Matthew Hannaway

    E-print Network

    Bristol, University of

    hydrolysed to boric acid on exposure to air. These results are rationalised using a model for UNCD growth. With 40,000 ppm of B2H6, crystals of boric oxide were found on the substrate surface, which slowly

  16. Wear-resistant diamond nanoprobe tips with integrated silicon heater for tip-based nanomanufacturing.

    PubMed

    Fletcher, Patrick C; Felts, Jonathan R; Dai, Zhenting; Jacobs, Tevis D; Zeng, Hongjun; Lee, Woo; Sheehan, Paul E; Carlisle, John A; Carpick, Robert W; King, William P

    2010-06-22

    We report exceptional nanoscale wear and fouling resistance of ultrananocrystalline diamond (UNCD) tips integrated with doped silicon atomic force microscope (AFM) cantilevers. The resistively heated probe can reach temperatures above 600 degrees C. The batch fabrication process produces UNCD tips with radii as small as 15 nm, with average radius 50 nm across the entire wafer. Wear tests were performed on substrates of quartz, silicon carbide, silicon, or UNCD. Tips were scanned for more than 1 m at a scan speed of 25 mum s(-1) at temperatures ranging from 25 to 400 degrees C under loads up to 200 nN. Under these conditions, silicon tips are partially or completely destroyed, while the UNCD tips exhibit little or no wear, no signs of delamination, and exceptional fouling resistance. We demonstrate nanomanufacturing of more than 5000 polymer nanostructures with no deterioration in the tip. PMID:20481445

  17. Bioimaging Applications Using Color Centers in Diamond

    NASA Astrophysics Data System (ADS)

    Glenn, David; Zhang, Huiliang; Benado, Anat; Kasthuri, Narayanan; Schalek, Richard; Lichtman, Jeff; Walsworth, Ronald

    2012-06-01

    Color centers in diamond offer significant opportunities for the development of new techniques in bioimaging. We present recent work on the application of various color centers in nanodiamond as cathodoluminescent probes for efficient correlative microscopy. We also discuss progress on the use of bulk diamond samples with surface-implanted nitrogen-vacancy (NV) layers for magnetic field sensing, with the specific goal of making sensitive, spatially-localized measurements of free radical concentrations in biological systems.

  18. Toward deep blue nano hope diamonds: heavily boron-doped diamond nanoparticles.

    PubMed

    Heyer, Steffen; Janssen, Wiebke; Turner, Stuart; Lu, Ying-Gang; Yeap, Weng Siang; Verbeeck, Jo; Haenen, Ken; Krueger, Anke

    2014-06-24

    The production of boron-doped diamond nanoparticles enables the application of this material for a broad range of fields, such as electrochemistry, thermal management, and fundamental superconductivity research. Here we present the production of highly boron-doped diamond nanoparticles using boron-doped CVD diamond films as a starting material. In a multistep milling process followed by purification and surface oxidation we obtained diamond nanoparticles of 10-60 nm with a boron content of approximately 2.3 × 10(21) cm(-3). Aberration-corrected HRTEM reveals the presence of defects within individual diamond grains, as well as a very thin nondiamond carbon layer at the particle surface. The boron K-edge electron energy-loss near-edge fine structure demonstrates that the B atoms are tetrahedrally embedded into the diamond lattice. The boron-doped diamond nanoparticles have been used to nucleate growth of a boron-doped diamond film by CVD that does not contain an insulating seeding layer. PMID:24738731

  19. Physical and Tribological Characteristics of Ion-Implanted Diamond Films

    NASA Technical Reports Server (NTRS)

    Miyoshi, K.; Heidger, S.; Korenyi-Both, A. L.; Jayne, D. T.; Herrera-Fierro, P.; Shogrin, B.; Wilbur, P. J.; Wu, R. L. C.; Garscadden, A.; Barnes, P. N.

    1994-01-01

    Unidirectional sliding friction experiments were conducted with a natural, polished diamond pin in contact with both as-deposited and carbon-ion-implanted diamond films in ultrahigh vacuum. Diamond films were deposited on silicon, silicon carbide, and silicon nitride by microwave-plasma-assisted chemical vapor deposition. The as-deposited diamond films were impacted with carbon ions at an accelerating energy of 60 keV and a current density of 50 micron A/cm(exp 2) for approximately 6 min, resulting in a dose of 1.2 x 10(exp 17) carbon ions/cm(exp 2). The results indicate that the carbon ion implantation produced a thin surface layer of amorphous, nondiamond carbon. The nondiamond carbon greatly decreased both friction and wear of the diamond films. The coefficients of friction for the carbon-ion-implanted, fine-grain diamond films were less than 0.1, factors of 20 to 30 lower than those for the as-deposited, fine-grain diamond films. The coefficients of friction for the carbon-ion-implanted, coarse-grain diamond films were approximately 0.35, a factor of five lower than those for the as-deposited, coarse-grain diamond films. The wear rates for the carbon-ion-implanted, diamond films were on the order of 10(exp -6) mm(exp 3)/Nm, factors of 30 to 80 lower than that for the as-deposited diamond films, regardless of grain size. The friction of the carbon-ion-implanted diamond films was greatly reduced because the amorphous, nondiamond carbon, which had a low shear strength, was restricted to the surface layers (less than 0.1 micron thick) and because the underlying diamond materials retained their high hardness. In conclusion, the carbon-ion-implanted, fine-grain diamond films can be used effectively as wear resistant, self-lubricating coatings for ceramics, such as silicon nitride and silicon carbide, in ultrahigh vacuum.

  20. One step deposition of highly adhesive diamond films on cemented carbide substrates via diamond/?-SiC composite interlayers

    NASA Astrophysics Data System (ADS)

    Wang, Tao; Zhuang, Hao; Jiang, Xin

    2015-12-01

    Deposition of adherent diamond films on cobalt-cemented tungsten carbide substrates has been realized by application of diamond/beta-silicon carbide composite interlayers. Diamond top layers and the interlayers were deposited in one single process by hot filament chemical vapor deposition technique. Two different kinds of interlayers have been employed, namely, gradient interlayer and interlayer with constant composition. The distribution of diamond and beta-silicon carbide phases was precisely controlled by manipulating the gas phase composition. X-ray diffraction and Raman spectroscopy were employed to determine the existence of diamond, beta-silicon carbide and cobalt silicides (Co2Si, CoSi) phases, as well as the quality of diamond crystal and the residual stress in the films. Rockwell-C indentation tests were carried out to evaluate the film adhesion. It is revealed that the adhesion of the diamond film is drastically improved by employing the interlayer. This is mainly influenced by the residual stress in the diamond top layer, which is induced by the different thermal expansion coefficient of the film and the substrate. It is even possible to further suppress the stress by manipulating the distribution of diamond and beta-silicon carbide in the interlayer. The most adhesive diamond film on cemented carbide is thus obtained by employing a gradient composite interlayer.

  1. Effects of high energy Au-ion irradiation on the microstructure of diamond films

    SciTech Connect

    Chen, Shih-Show; Chen, Huang-Chin; Wang, Wei-Cheng; Lin, I-Nan; Chang, Ching-Lin; Lee, Chi-Young; Guo Jinghua

    2013-03-21

    The effects of 2.245 GeV Au-ion irradiation and subsequent annealing processes on the evolution of microstructure of diamond films with microcrystalline (MCD) or ultra-nanocrystalline (UNCD) granular structure were investigated, using near edge x-ray absorption fine structure and electron energy loss spectroscopy in transmission electron microscopy. For MCD films, the Au-ion irradiation disintegrated some of the diamond grains, resulting in the formation of nano-sized carbon clusters embedded in a matrix of amorphous carbon (a-C). The annealing process recrystallized the diamond grains and converted the a-C into nano-sized graphite particulates and, at the same time, induced the formation of nano-sized i-carbon clusters, the bcc structured carbon with a{sub 0} = 0.432 nm. In contrast, for UNCD films, the Au-ion irradiation transformed the grain boundary phase into nano-sized graphite, but insignificantly altered the crystallinity of the grains of the UNCD films. The annealing process recrystallized the materials. In some of the regions, the residual a-C phases were transformed into nano-sized graphites, whereas in other regions i-carbon nanoclusters were formed. The difference in irradiation-induced microstructural transformation behavior between the MCD and the UNCD films is ascribed to the different granular structures of the two types of films.

  2. Effects of high energy Au-ion irradiation on the microstructure of diamond films

    NASA Astrophysics Data System (ADS)

    Chen, Shih-Show; Chen, Huang-Chin; Wang, Wei-Cheng; Lee, Chi-Young; Lin, I.-Nan; Guo, Jinghua; Chang, Ching-Lin

    2013-03-01

    The effects of 2.245 GeV Au-ion irradiation and subsequent annealing processes on the evolution of microstructure of diamond films with microcrystalline (MCD) or ultra-nanocrystalline (UNCD) granular structure were investigated, using near edge x-ray absorption fine structure and electron energy loss spectroscopy in transmission electron microscopy. For MCD films, the Au-ion irradiation disintegrated some of the diamond grains, resulting in the formation of nano-sized carbon clusters embedded in a matrix of amorphous carbon (a-C). The annealing process recrystallized the diamond grains and converted the a-C into nano-sized graphite particulates and, at the same time, induced the formation of nano-sized i-carbon clusters, the bcc structured carbon with a0 = 0.432 nm. In contrast, for UNCD films, the Au-ion irradiation transformed the grain boundary phase into nano-sized graphite, but insignificantly altered the crystallinity of the grains of the UNCD films. The annealing process recrystallized the materials. In some of the regions, the residual a-C phases were transformed into nano-sized graphites, whereas in other regions i-carbon nanoclusters were formed. The difference in irradiation-induced microstructural transformation behavior between the MCD and the UNCD films is ascribed to the different granular structures of the two types of films.

  3. Electronic properties of graphene-single crystal diamond heterostructures

    SciTech Connect

    Zhao, Fang; Thuong Nguyen, Thuong; Golsharifi, Mohammad; Amakubo, Suguru; Jackman, Richard B.; Loh, K. P.

    2013-08-07

    Single crystal diamond has been used as a substrate to support single layer graphene grown by chemical vapor deposition methods. It is possible to chemically functionalise the diamond surface, and in the present case H-, F-, O-, and N-group have been purposefully added prior to graphene deposition. The electronic properties of the resultant heterostructures vary strongly; a p-type layer with good mobility and a band gap of ?0.7?eV is created when H-terminated diamond layers are used, whilst a layer with more metallic-like character (high carrier density and low carrier mobility) arises when N(O)-terminations are introduced. Since it is relatively easy to pattern these functional groups on the diamond surface, this suggests that this approach may offer an exciting route to 2D device structures on single layer graphene sheets.

  4. Diamond Sheet: A new diamond tool material

    NASA Technical Reports Server (NTRS)

    Mackey, C. R.

    1982-01-01

    Diamond sheet is termed a diamond tool material because it is not a cutting tool, but rather a new material from which a variety of different tools may be fabricated. In appearance and properties, it resembles a sheet of copper alloy with diamond abrasive dispersed throughout it. It is capable of being cut, formed, and joined by conventional methods, and subsequently used for cutting as a metal bonded diamond tool. Diamond sheet is normally made with industrial diamond as the abrasive material. The metal matrix in diamond sheet is a medium hard copper alloy which has performed well in most applications. This alloy has the capability of being made harder or softer if specific cutting conditions require it. Other alloys have also been used including a precipitation hardened aluminum alloy with very free cutting characteristics. The material is suitable for use in a variety of cutting, surfacing, and ring type tools, as well as in such mundane items as files and sandpaper. It can also be used as a bearing surface (diamond to diamond) and in wear resistant surfaces.

  5. 'Diamond Jenness': After the Grind

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This microscopic imager mosaic taken by NASA's Mars Exploration Rover Opportunity shows the rock dubbed 'Diamond Jenness.' It was taken on sol 177 (July 23, 2004) after the rover first ground into the rock with its rock abrasion tool, or 'Rat.' The rover later ground into the rock a second time. A sliced spherule, or 'blueberry,' is visible in the upper left corner of the hole.

    Opportunity has bored nearly a dozen holes into the inner walls of 'Endurance Crater.' On sols 177 and 178 (July 23 and July 24, 2004), the rover worked double-duty on Diamond Jenness. Surface debris and the bumpy shape of the rock resulted in a shallow and irregular hole, only about 2 millimeters (0.08 inch) deep. The final depth was not enough to remove all the bumps and leave a neat hole with a smooth floor. This extremely shallow depression was then examined by the rover's alpha particle X-ray spectrometer.

    On Sol 178, Opportunity's 'robotic rodent' dined on Diamond Jenness once again, grinding almost an additional 5 millimeters (about 0.2 inch). The rover then applied its Moessbauer spectrometer to the deepened hole. This double dose of Diamond Jenness enabled the science team to examine the rock at varying layers. Results from those grindings are currently being analyzed.

    The image mosaic is about 6 centimeters (2.4 inches) across.

  6. 'Diamond Jenness': Before the Grind

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This microscopic imager mosaic of the rock called 'Diamond Jenness' was snapped on sol 177 before NASA's Mars Exploration Rover Opportunity ground into the surface with its rock abrasion tool, or 'Rat.'

    Opportunity has bored nearly a dozen holes into the inner walls of 'Endurance Crater.' On sols 177 and 178 (July 23 and July 24, 2004), the rover worked double-duty on Diamond Jenness. Surface debris and the bumpy shape of the rock resulted in a shallow and irregular hole, only about 2 millimeters (0.08 inch) deep. The final depth was not enough to remove all the bumps and leave a neat hole with a smooth floor. This extremely shallow depression was then examined by the rover's alpha particle X-ray spectrometer. On Sol 178, Opportunity's 'robotic rodent' dined on Diamond Jenness once again, grinding almost an additional 5 millimeters (about 0.2 inch). The rover then applied its Moessbauer spectrometer to the deepened hole. This double dose of Diamond Jenness enabled the science team to examine the rock at varying layers. Results from those grindings are currently being analyzed.

    The image mosaic is about 6 centimeters (2.4 inches) across.

  7. 'Diamond Jenness': A Tough Grind

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This microscopic imager mosaic of the target area called 'Diamond Jenness' was taken after NASA's Mars Exploration Rover Opportunity ground into the surface with its rock abrasion tool for a second time.

    Opportunity has bored nearly a dozen holes into the inner walls of 'Endurance Crater.' On sols 177 and 178 (July 23 and July 24, 2004), the rover worked double-duty on Diamond Jenness. Surface debris and the bumpy shape of the rock resulted in a shallow and irregular hole, only about 2 millimeters (0.08 inch) deep. The final depth was not enough to remove all the bumps and leave a neat hole with a smooth floor. This extremely shallow depression was then examined by the rover's alpha particle X-ray spectrometer.

    On Sol 178, Opportunity's 'robotic rodent' dined on Diamond Jenness once again, grinding almost an additional 5 millimeters (about 0.2 inch). The rover then applied its Moessbauer spectrometer to the deepened hole. This double dose of Diamond Jenness enabled the science team to examine the rock at varying layers. Results from those grindings are currently being analyzed.

    The image mosaic is about 6 centimeters (2.4 inches) across.

  8. Germanium: a new catalyst for diamond synthesis and a new optically active impurity in diamond.

    PubMed

    Palyanov, Yuri N; Kupriyanov, Igor N; Borzdov, Yuri M; Surovtsev, Nikolay V

    2015-01-01

    Diamond attracts considerable attention as a versatile and technologically useful material. For many demanding applications, such as recently emerged quantum optics and sensing, it is important to develop new routes for fabrication of diamond containing defects with specific optical, electronic and magnetic properties. Here we report on successful synthesis of diamond from a germanium-carbon system at conditions of 7 GPa and 1,500-1,800 °C. Both spontaneously nucleated diamond crystals and diamond growth layers on seeds were produced in experiments with reaction time up to 60 h. We found that diamonds synthesized in the Ge-C system contain a new optical centre with a ZPL system at 2.059 eV, which is assigned to germanium impurities. Photoluminescence from this centre is dominated by zero-phonon optical transitions even at room temperature. Our results have widened the family of non-metallic elemental catalysts for diamond synthesis and demonstrated the creation of germanium-related optical centres in diamond. PMID:26435400

  9. Germanium: a new catalyst for diamond synthesis and a new optically active impurity in diamond

    NASA Astrophysics Data System (ADS)

    Palyanov, Yuri N.; Kupriyanov, Igor N.; Borzdov, Yuri M.; Surovtsev, Nikolay V.

    2015-10-01

    Diamond attracts considerable attention as a versatile and technologically useful material. For many demanding applications, such as recently emerged quantum optics and sensing, it is important to develop new routes for fabrication of diamond containing defects with specific optical, electronic and magnetic properties. Here we report on successful synthesis of diamond from a germanium-carbon system at conditions of 7?GPa and 1,500-1,800?°C. Both spontaneously nucleated diamond crystals and diamond growth layers on seeds were produced in experiments with reaction time up to 60?h. We found that diamonds synthesized in the Ge-C system contain a new optical centre with a ZPL system at 2.059?eV, which is assigned to germanium impurities. Photoluminescence from this centre is dominated by zero-phonon optical transitions even at room temperature. Our results have widened the family of non-metallic elemental catalysts for diamond synthesis and demonstrated the creation of germanium-related optical centres in diamond.

  10. Germanium: a new catalyst for diamond synthesis and a new optically active impurity in diamond

    PubMed Central

    Palyanov, Yuri N.; Kupriyanov, Igor N.; Borzdov, Yuri M.; Surovtsev, Nikolay V.

    2015-01-01

    Diamond attracts considerable attention as a versatile and technologically useful material. For many demanding applications, such as recently emerged quantum optics and sensing, it is important to develop new routes for fabrication of diamond containing defects with specific optical, electronic and magnetic properties. Here we report on successful synthesis of diamond from a germanium-carbon system at conditions of 7?GPa and 1,500–1,800?°C. Both spontaneously nucleated diamond crystals and diamond growth layers on seeds were produced in experiments with reaction time up to 60?h. We found that diamonds synthesized in the Ge-C system contain a new optical centre with a ZPL system at 2.059?eV, which is assigned to germanium impurities. Photoluminescence from this centre is dominated by zero-phonon optical transitions even at room temperature. Our results have widened the family of non-metallic elemental catalysts for diamond synthesis and demonstrated the creation of germanium-related optical centres in diamond. PMID:26435400

  11. California: Diamond Valley

    Atmospheric Science Data Center

    2014-05-15

    ...     View Larger Image The new Diamond Valley Lake Reservoir near the city of Hemet in Riverside County is ... storage capacity. In addition to routine water management, Diamond Valley Lake is designed to provide protection against drought and a ...

  12. Diamond/aluminium nitride composites for efficient thermal management applications

    SciTech Connect

    Cervenka, J.; Dontschuk, N.; Prawer, S.; Ladouceur, F.; Duvall, S. G.

    2012-07-30

    Synthetic diamond/AlN composite materials have been fabricated by a combination of microwave plasma-assisted chemical vapor deposition and molecular beam epitaxy. These wide band gap semiconductor heterojunctions show promises for many applications, including thermal management, deep ultraviolet light emitting devices, and high power and high temperature electronics. Here, we report results of an interface study of polycrystalline diamond layers grown on single crystal AlN(0001). High resolution transmission microscopy revealed atomically sharp interfaces between diamond and AlN. Temperature dependent Raman spectroscopy measurements showed reduced thermal resistance on diamond-coated AlN substrates compared to uncoated AlN at temperatures above 330 K.

  13. Fabrication of thin, luminescent, single-crystal diamond membranes

    NASA Astrophysics Data System (ADS)

    Magyar, Andrew P.; Lee, Jonathan C.; Limarga, Andi M.; Aharonovich, Igor; Rol, Fabian; Clarke, David R.; Huang, Mengbing; Hu, Evelyn L.

    2011-08-01

    The formation of single-crystal diamond membranes is an important prerequisite for the fabrication of high-quality optical cavities in this material. Diamond membranes fabricated using lift-off processes involving the creation of a damaged layer through ion implantation often suffer from residual ion damage, which severely limits their usefulness for photonic structures. The current work demonstrates that strategic etch removal of the most highly defective material yields thin, single-crystal diamond membranes with strong photoluminescence and a Raman signature approaching that of single-crystal bulk diamond. These optically active membranes can form the starting point for fabrication of high-quality optical resonators.

  14. Electrically conductive diamond electrodes

    DOEpatents

    Swain, Greg (East Lansing, MI); Fischer, Anne (Arlington, VA),; Bennett, Jason (Lansing, MI); Lowe, Michael (Holt, MI)

    2009-05-19

    An electrically conductive diamond electrode and process for preparation thereof is described. The electrode comprises diamond particles coated with electrically conductive doped diamond preferably by chemical vapor deposition which are held together with a binder. The electrodes are useful for oxidation reduction in gas, such as hydrogen generation by electrolysis.

  15. Protein-modified nanocrystalline diamond thin films for biosensor applications

    NASA Astrophysics Data System (ADS)

    Härtl, Andreas; Schmich, Evelyn; Garrido, Jose A.; Hernando, Jorge; Catharino, Silvia C. R.; Walter, Stefan; Feulner, Peter; Kromka, Alexander; Steinmüller, Doris; Stutzmann, Martin

    2004-10-01

    Diamond exhibits several special properties, for example good biocompatibility and a large electrochemical potential window, that make it particularly suitable for biofunctionalization and biosensing. Here we show that proteins can be attached covalently to nanocrystalline diamond thin films. Moreover, we show that, although the biomolecules are immobilized at the surface, they are still fully functional and active. Hydrogen-terminated nanocrystalline diamond films were modified by using a photochemical process to generate a surface layer of amino groups, to which proteins were covalently attached. We used green fluorescent protein to reveal the successful coupling directly. After functionalization of nanocrystalline diamond electrodes with the enzyme catalase, a direct electron transfer between the enzyme's redox centre and the diamond electrode was detected. Moreover, the modified electrode was found to be sensitive to hydrogen peroxide. Because of its dual role as a substrate for biofunctionalization and as an electrode, nanocrystalline diamond is a very promising candidate for future biosensor applications.

  16. Diamond particle detectors systems in high energy physics

    NASA Astrophysics Data System (ADS)

    Oh, A.

    2015-04-01

    With the first three years of the LHC running complete, ATLAS and CMS are planning to upgrade their innermost tracking layers with more radiation hard technologies. Chemical Vapor Deposition (CVD) diamond is one such technology. CVD diamond has been used extensively in beam condition monitors as the innermost detectors in the highest radiation areas of BaBar, Belle, CDF and all LHC experiments. The lessons learned in constructing the ATLAS Beam Conditions Monitor (BCM), Diamond Beam Monitor (DBM) and the CMS Pixel Luminosity Telescope (PLT) all of which are based on CVD diamond with the goal of elucidating the issues that should be addressed for future diamond based detector systems. The first beam test results of prototype diamond devices with 3D detector geometry should further enhance the radiation tolerance of this material.

  17. Diamond bio electronics.

    PubMed

    Linares, Robert; Doering, Patrick; Linares, Bryant

    2009-01-01

    The use of diamond for advanced applications has been the dream of mankind for centuries. Until recently this dream has been realized only in the use of diamond for gemstones and abrasive applications where tons of diamonds are used on an annual basis. Diamond is the material system of choice for many applications, but its use has historically been limited due to the small size, high cost, and inconsistent (and typically poor) quality of available diamond materials until recently. The recent development of high quality, single crystal diamond crystal growth via the Chemical Vapor Deposition (CVD) process has allowed physcists and increasingly scientists in the life science area to think beyond these limitations and envision how diamond may be used in advanced applications ranging from quantum computing, to power generation and molecular imaging, and eventually even diamond nano-bots. Because of diamond's unique properties as a bio-compatible material, better understanding of diamond's quantum effects and a convergence of mass production, semiconductor-like fabrication process, diamond now promises a unique and powerful key to the realization of the bio-electronic devices being envisioned for the new era of medical science. The combination of robust in-the-body diamond based sensors, coupled with smart bio-functionalized diamond devices may lead to diamond being the platform of choice for bio-electronics. This generation of diamond based bio-electronic devices would contribute substantially to ushering in a paradigm shift for medical science, leading to vastly improved patient diagnosis, decrease of drug development costs and risks, and improved effectiveness of drug delivery and gene therapy programs through better timed and more customized solutions. PMID:19745488

  18. Layers

    NASA Astrophysics Data System (ADS)

    Hong, K. J.; Jeong, T. S.; Youn, C. J.

    2014-09-01

    The temperature-dependent photoresponse characteristics of MnAl2S4 layers have been investigated, for the first time, by use of photocurrent (PC) spectroscopy. Three peaks were observed at all temperatures. The electronic origin of these peaks was associated with band-to-band transitions from the valence-band states ?4( z), ?5( x), and ?5( y) to the conduction-band state ?1( s). On the basis of the relationship between PC-peak energy and temperature, the optical band gap could be well expressed by the expression E g( T) = E g(0) - 2.80 × 10-4 T 2/(287 + T), where E g(0) was estimated to be 3.7920 eV, 3.7955 eV, and 3.8354 eV for the valence-band states ?4( z), ?5( x), and ?5( y), respectively. Results from PC spectroscopy revealed the crystal-field and spin-orbit splitting were 3.5 meV and 39.9 meV. The gradual decrease of PC intensity with decreasing temperature can be explained on the basis of trapping centers associated with native defects in the MnAl2S4 layers. Plots of log J ph, the PC current density, against 1/ T, revealed a dominant trap level in the high-temperature region. By comparing PC and the Hall effect results, we confirmed that this trap level is a shallow donor 18.9 meV below the conduction band.

  19. Diamond Synthesis Employing Nanoparticle Seeds

    NASA Technical Reports Server (NTRS)

    Uppireddi, Kishore (Inventor); Morell, Gerardo (Inventor); Weiner, Brad R. (Inventor)

    2014-01-01

    Iron nanoparticles were employed to induce the synthesis of diamond on molybdenum, silicon, and quartz substrates. Diamond films were grown using conventional conditions for diamond synthesis by hot filament chemical vapor deposition, except that dispersed iron oxide nanoparticles replaced the seeding. This approach to diamond induction can be combined with dip pen nanolithography for the selective deposition of diamond and diamond patterning while avoiding surface damage associated to diamond-seeding methods.

  20. Space-time diamonds

    E-print Network

    Daiqin Su; T. C. Ralph

    2015-07-02

    We show that the particle number distribution of diamond modes, modes that are localised in a finite space-time region, are thermal for the Minkowski vacuum state of a massless scalar field, an analogue to the Unruh effect. The temperature of the diamond is inversely proportional to its size. An inertial observer can detect this thermal radiation by coupling to the diamond modes using an appropriate energy scaled detector. We further investigate the correlations between various diamonds and find that entanglement between adjacent diamonds dominates.

  1. Diamonds for beam instrumentation

    SciTech Connect

    Griesmayer, Erich

    2013-04-19

    Diamond is perhaps the most versatile, efficient and radiation tolerant material available for use in beam detectors with a correspondingly wide range of applications in beam instrumentation. Numerous practical applications have demonstrated and exploited the sensitivity of diamond to charged particles, photons and neutrons. In this paper, a brief description of a generic diamond detector is given and the interaction of the CVD diamond detector material with protons, electrons, photons and neutrons is presented. Latest results of the interaction of sCVD diamond with 14 MeV mono-energetic neutrons are shown.

  2. A micro-scale hot wire anemometer based on low stress (Ni/W) multi-layers deposited on nano-crystalline diamond for air flow sensing

    NASA Astrophysics Data System (ADS)

    Talbi, A.; Gimeno, L.; Gerbedoen, J.-C.; Viard, R.; Soltani, A.; Mortet, V.; Preobrazhensky, V.; Merlen, A.; Pernod, P.

    2015-12-01

    A linear array of microscale thermal anemometers has been designed, fabricated and characterized. The sensitive element consists of a self-compensated-stress multilayer (Ni/W) patterned to form a wire with length, width, and thickness close to 200 ?m, 5 ?m and 2 ?m respectively. The wire is deposited and supported by prongs made of nano-crystalline diamond (NCD) of about 2 ?m in thickness. Due to its high Young’s modulus, NCD allows a very high mechanical toughness without the need for thicker support for the hot wire. Also, depending on grain size, the NCD is able to present thermal conductivity smaller than 10?W mK?1, providing good thermal insulation from the substrate and less conductive end losses to the prongs. The sensor was characterized experimentally. Its electrical and thermal properties were obtained first in the absence of fluid flow. The results confirm the effectiveness of thermal insulation and the mechanical robustness of the structure. The fluidic characterizations were performed and analysed in the case of an airflow with velocities of up to 30 m s?1.

  3. Diamond and Polycrystalline Diamond for MEMS Applications: Simulations and Experiments

    E-print Network

    Çagin, Tahir

    Diamond and Polycrystalline Diamond for MEMS Applications: Simulations and Experiments Tahir C¸ a on Silicon and polycrystalline diamond show that this rapid wear is caused by a variety of factors, related processes on diamond surfaces. We studied the atomic friction of diamond (100)­surface employing an extended

  4. Diamond anvils with integrated diamond-encapsulated microprobes for high-pressure electrical transport experiments

    SciTech Connect

    Akella, J; Catledge, S A; Vohra, Y K; Weir, S

    1999-07-21

    We have fabricated diamond anvils specially designed for use in ultra-high pressure electrical transport experiments. These anvils, which we refer to as ''designer anvils'', feature thin-film metal microprobes which are encased in a layer of high-quality, epitaxial, chemically vapor deposited (CVD) diamond. The synthetic diamond film ensures that the microprobes are survivable to Mbar pressures, and also serves to electrically insulate the microprobes from the high-pressure gasket. High-pressure resistivity experiments were performed on KI and FeO to pressures of approximately 1.8 and 1.7 Mbars, respectively. Future possible applications of designer anvils are also discussed. [electrical conductivity, synthetic diamond, band overlap, metallization, designer anvils

  5. Diamond tool machining of materials which react with diamond

    DOEpatents

    Lundin, Ralph L. (Los Alamos, NM); Stewart, Delbert D. (Los Alamos, NM); Evans, Christopher J. (Gaithersburg, MD)

    1992-01-01

    Apparatus for the diamond machining of materials which detrimentally react with diamond cutting tools in which the cutting tool and the workpiece are chilled to very low temperatures. This chilling halts or retards the chemical reaction between the workpiece and the diamond cutting tool so that wear rates of the diamond tool on previously detrimental materials are comparable with the diamond turning of materials which do not react with diamond.

  6. Diamond tool machining of materials which react with diamond

    DOEpatents

    Lundin, R.L.; Stewart, D.D.; Evans, C.J.

    1992-04-14

    An apparatus is described for the diamond machining of materials which detrimentally react with diamond cutting tools in which the cutting tool and the workpiece are chilled to very low temperatures. This chilling halts or retards the chemical reaction between the workpiece and the diamond cutting tool so that wear rates of the diamond tool on previously detrimental materials are comparable with the diamond turning of materials which do not react with diamond. 1 figs.

  7. Diamond tool machining of materials which react with diamond

    SciTech Connect

    Lundin, R.L.; Stewart, D.D.; Evans, C.J.

    1991-04-01

    This invention is comprised of an apparatus for the diamond machining of materials which detrimentally react with diamond cutting tools in which the cutting tool and the workpiece are chilled to very low temperatures. This chilling halts or retards the chemical reaction between the workpiece and the diamond cutting tool so that wear rates of the diamond tool on previously detrimental materials are comparable with the diamond turning of materials which do not react with diamond.

  8. DiamondLink Security Policy

    E-print Network

    ............................................................................................................. 17 5. DEFINITION OF SECURITY RELEVANT DATA ITEMS (SRDI) .............................. 21 6TM DiamondPak DiamondLink DiamondVPN FIPS 140-1 Security Policy Version 1.75 October 7, 2002..................................................................................................... 6 2. SECURITY LEVEL

  9. DiamondLink Security Policy

    E-print Network

    ........................................................................................................14 5. DEFINITION OF SECURITY RELEVANT DATA ITEMS (SRDI) ...........................18 6. DEFINITIONSTM DiamondNIC DiamondPak DiamondLink FIPS 140-1 Security Policy April 10, 2002 Copyright © 2001.................................................................................................5 2. SECURITY LEVEL

  10. Characterization of diamond thin films: Diamond phase identification, surface morphology, and defect structures

    SciTech Connect

    Williams, B.E.; Glass, J.T.

    1989-03-01

    Thin carbon films grown from a low pressure methane-hydrogen gas mixture by microwave plasma enhanced CVD have been examined by Auger electron spectroscopy, secondary ion mass spectrometry, electron and x-ray diffraction, electron energy loss spectroscopy, and electron microscopy. They were determined to be similar to natural diamond in terms of composition, structure, and bonding. The surface morphology of the diamond films was a function of position on the sample surface and the methane concentration in the feedgas. Well-faceted diamond crystals were observed near the center of the sample whereas a less faceted, cauliflower texture was observed near the edge of the sample, presumably due to variations in temperature across the surface of the sample. Regarding methane concentration effects, threefold /111/ faceted diamond crystals were predominant on a film grown at 0.3% CH/sub 4/ in H/sub 2/ while fourfold /100/ facets were observed on films grown in 1.0% and 2.0% CH/sub 4/ in H/sub 2/. Transmission electron microscopy of the diamond films has shown that the majority of diamond crystals have a very high defect density comprised of /111/ twins, /111/ stacking faults, and dislocations. In addition, cross-sectional TEM has revealed a 50 A epitaxial layer of ..beta..--SiC at the diamond-silicon interface of a film grown with 0.3% CH/sub 4/ in H/sub 2/ while no such layer was observed on a diamond film grown in 2.0% CH/sub 4/ in H/sub 2/.

  11. Diamond anvil technology

    NASA Astrophysics Data System (ADS)

    Seal, Michael

    This paper is largely a review of the techniques used in making diamond anvils and the constraints these put on the shapes of anvil. Techniques available for shaping diamonds include cleaving, sawing, polishing, laser cutting, and bruting. At present the shapes most commonly used for anvils are a modification of the brilliant cut derived from the gem industry, and a design based on an octagonal prism with truncated pyramidal top and base, known as the "Drukker standard design". Diamond orientation and material selection are considered as are future possibilities for the attainment of still higher pressures through modifications of the diamond anvil material or design.

  12. Raman Characterisation of Diamond Coatings Using Different Laser Wavelengths

    NASA Astrophysics Data System (ADS)

    Haubner, Roland; Rudigier, Moritz

    Diamond layers can show different morphologies, i.e. well-facetted, fine-grained and ballas diamond. Additionally, the types NCD (nanocrystalline diamond), UNCD (ultra nanocrystalline diamond) and various types of amorphous carbon (a- C, a-CH …) are known. To characterise the various carbon deposits Raman spectroscopy is most common, because this technique is simple to handle. With a modern Raman spectrometer, provided with three different laser units (wavelengths 472,681 nm/ blue, 532,1 nm/ green, 632,81 nm/ red), the same spot of a sample can be measured several times. A set of diamond coatings, representing the different morphologies, and moreover, boron doped levels were selected for Raman characterisation. Varying the laser wavelength, highly different Raman spectra were obtained and their interpretation is quite difficult.

  13. All-diamond microelectrode array device.

    PubMed

    Pagels, Markus; Hall, Clive E; Lawrence, Nathan S; Meredith, Andrew; Jones, Timothy G J; Godfried, Herman P; Pickles, C S James; Wilman, Jonathan; Banks, Craig E; Compton, Richard G; Jiang, Li

    2005-06-01

    We report the development of all-diamond microelectrochemical devices, namely, a microelectrode array (MEA), in which a periodic array structure with well-defined diameters, distance, and hexagonal unit cell pattern is micromachined using a combination of state-of-the-art microwave-induced plasma growth and laser ablation shaping techniques to prepare and coat a patterned boron-doped diamond (BDD) substrate with an intrinsic diamond insulating layer. The active BDD element can be tuned to between 10 and 50 microm in diameter with a 10 times diameter center-to-center distance between two adjacent conducting elements, which are exactly coplanar to the dielectric surroundings. This type of device should enable applications in harsh conditions such as high temperature, high pressure, and resistive media under dynamic flow regimes. PMID:15924409

  14. Raman and conductivity studies of boron-doped microcrystalline diamond, facetted nanocrystalline diamond and cauliflower diamond films

    E-print Network

    Bristol, University of

    diamond and cauliflower diamond films P.W. May a,, W.J. Ludlow a , M. Hannaway a , P.J. Heard b , J (MCD), faceted nanocrystalline diamond (f-NCD) and `cauliflower' diamond (c-NCD). For the same B spectroscopy; CVD diamond; nanodiamond; Cauliflower diamond; Boron doping 1. Introduction Diamond films

  15. Diamond Nucleation Using Polyethene

    NASA Technical Reports Server (NTRS)

    Morell, Gerardo (Inventor); Makarov, Vladimir (Inventor); Varshney, Deepak (Inventor); Weiner, Brad (Inventor)

    2013-01-01

    The invention presents a simple, non-destructive and non-abrasive method of diamond nucleation using polyethene. It particularly describes the nucleation of diamond on an electrically viable substrate surface using polyethene via chemical vapor deposition (CVD) technique in a gaseous environment.

  16. Diamond nucleation using polyethene

    DOEpatents

    Morell, Gerardo; Makarov, Vladimir; Varshney, Deepak; Weiner, Brad

    2013-07-23

    The invention presents a simple, non-destructive and non-abrasive method of diamond nucleation using polyethene. It particularly describes the nucleation of diamond on an electrically viable substrate surface using polyethene via chemical vapor deposition (CVD) technique in a gaseous environment.

  17. Diamond films: Historical perspective

    SciTech Connect

    Messier, R.

    1993-01-01

    This section is a compilation of notes and published international articles about the development of methods of depositing diamond films. Vapor deposition articles are included from American, Russian, and Japanese publications. The international competition to develop new deposition methodologies is stressed. The current status of chemical vapor deposition of diamond is assessed.

  18. Diamond and diamond-like carbon films for advanced electronic applications

    SciTech Connect

    Siegal, M.P.; Friedmann, T.A.; Sullivan, J.P.

    1996-03-01

    Aim of this laboratory-directed research and development (LDRD) project was to develop diamond and/or diamond-like carbon (DLC) films for electronic applications. Quality of diamond and DLC films grown by chemical vapor deposition (CVD) is not adequate for electronic applications. Nucleation of diamond grains during growth typically results in coarse films that must be very thick in order to be physically continuous. DLC films grown by CVD are heavily hydrogenated and are stable to temperatures {le} 400{degrees}C. However, diamond and DLC`s exceptional electronic properties make them candidates for integration into a variety of microelectronic structures. This work studied new techniques for the growth of both materials. Template layers have been developed for the growth of CVD diamond films resulting in a significantly higher nucleation density on unscratched or unprepared Si surfaces. Hydrogen-free DLC with temperature stability {le} 800{degrees}C has been developed using energetic growth methods such as high-energy pulsed-laser deposition. Applications with the largest system impact include electron-emitting materials for flat-panel displays, dielectrics for interconnects, diffusion barriers, encapsulants, and nonvolatile memories, and tribological coatings that reduce wear and friction in integrated micro-electro-mechanical devices.

  19. Mechanical stresses and amorphization of ion-implanted diamond

    NASA Astrophysics Data System (ADS)

    Khmelnitsky, R. A.; Dravin, V. A.; Tal, A. A.; Latushko, M. I.; Khomich, A. A.; Khomich, A. V.; Trushin, A. S.; Alekseev, A. A.; Terentiev, S. A.

    2013-06-01

    Scanning white light interferometry and Raman spectroscopy were used to investigate the mechanical stresses and structural changes in ion-implanted natural diamonds with different impurity content. The uniform distribution of radiation defects in implanted area was obtained by the regime of multiple-energy implantation of keV He+ ions. A modification of Bosia's et al. (Nucl. Instrum. Meth. B 268 (2010) 2991) method for determining the internal stresses and the density variation in an ion-implanted diamond layer was proposed that suggests measuring, in addition to the surface swelling of a diamond plate, the radius of curvature of the plate. It is shown that, under multiple-energy implantation of He+, mechanical stresses in the implanted layer may be as high as 12 GPa. It is shown that radiation damage reaches saturation for the implantation fluence characteristic of amorphization of diamond but is appreciably lower than the graphitization threshold.

  20. Software optimization for electrical conductivity imaging in polycrystalline diamond cutters

    SciTech Connect

    Bogdanov, G.; Ludwig, R.; Wiggins, J.; Bertagnolli, K.

    2014-02-18

    We previously reported on an electrical conductivity imaging instrument developed for measurements on polycrystalline diamond cutters. These cylindrical cutters for oil and gas drilling feature a thick polycrystalline diamond layer on a tungsten carbide substrate. The instrument uses electrical impedance tomography to profile the conductivity in the diamond table. Conductivity images must be acquired quickly, on the order of 5 sec per cutter, to be useful in the manufacturing process. This paper reports on successful efforts to optimize the conductivity reconstruction routine, porting major portions of it to NVIDIA GPUs, including a custom CUDA kernel for Jacobian computation.

  1. Software optimization for electrical conductivity imaging in polycrystalline diamond cutters

    NASA Astrophysics Data System (ADS)

    Bogdanov, G.; Wiggins, J.; Bertagnolli, K.; Ludwig, R.

    2014-02-01

    We previously reported on an electrical conductivity imaging instrument developed for measurements on polycrystalline diamond cutters. These cylindrical cutters for oil and gas drilling feature a thick polycrystalline diamond layer on a tungsten carbide substrate. The instrument uses electrical impedance tomography to profile the conductivity in the diamond table. Conductivity images must be acquired quickly, on the order of 5 sec per cutter, to be useful in the manufacturing process. This paper reports on successful efforts to optimize the conductivity reconstruction routine, porting major portions of it to NVIDIA GPUs, including a custom CUDA kernel for Jacobian computation.

  2. Instrumentation development for electrical conductivity imaging in polycrystalline diamond cutters

    NASA Astrophysics Data System (ADS)

    Bogdanov, G.; Wiggins, J.; Rhodes, J.; Bertagnolli, K.; Ludwig, R.

    2013-01-01

    We previously reported on an electrical conductivity non-destructive inspection methodology for polycrystalline diamond cutters. These cylindrical cutters for oil and gas drilling feature a thick polycrystalline diamond layer on a tungsten carbide substrate. We use electrical impedance tomography to image the conductivity in the diamond table. In this paper we report on progress in preparing this instrument for factory deployment. Instrument enhancements include an adjustable part holder, a field-swappable sensor and GPU-enabled software capable of rapidly acquiring images.

  3. Metal oxide semiconductor structure using oxygen-terminated diamond

    NASA Astrophysics Data System (ADS)

    Chicot, G.; Maréchal, A.; Motte, R.; Muret, P.; Gheeraert, E.; Pernot, J.

    2013-06-01

    Metal-oxide-semiconductor structures with aluminum oxide as insulator and p-type (100) mono-crystalline diamond as semiconductor have been fabricated and investigated by capacitance versus voltage and current versus voltage measurements. The aluminum oxide dielectric was deposited using low temperature atomic layer deposition on an oxygenated diamond surface. The capacitance voltage measurements demonstrate that accumulation, depletion, and deep depletion regimes can be controlled by the bias voltage, opening the route for diamond metal-oxide-semiconductor field effect transistor. A band diagram is proposed and discussed.

  4. High temperature light emitting diodes on insulating diamonds

    SciTech Connect

    Melnikov, A.A.; Varichenko, V.S.; Fahrner, W.R.

    1995-12-31

    Electrical and optical properties of diamond based light emitting p-i-n diodes have been studied up to 500{degrees}C. Bulk and planar structures have been fabricated on natural and synthetic single crystal substrates by ion implantation. Electroluminescence (EL) in blue, green and orange spectral ranges has been observed from the insulating i-layer of the diodes. The EL emission is due to electron-hole recombination through the optical centers in the diamond substrate.

  5. Diamond Ranch High School.

    ERIC Educational Resources Information Center

    Betsky, Aaron

    2000-01-01

    Highlights award-winning Diamond Ranch High School (California) that was designed and built on a steep site around Los Angeles considered unsatisfactory for building due to its unstable soils. Building organization is discussed, and photos are provided. (GR)

  6. Quantum Engineering in Diamond 

    E-print Network

    Chen, Jeson

    2015-08-06

    Solid-state technologies for quantum mechanical application require delicate materials that can operate stably with a long coherence time. Nitrogen vacancy (NV) centers in diamond is one of the most promising candidates for quantum physics...

  7. Amorphous diamond films

    DOEpatents

    Falabella, S.

    1998-06-09

    Amorphous diamond films having a significant reduction in intrinsic stress are prepared by biasing a substrate to be coated and depositing carbon ions thereon under controlled temperature conditions. 1 fig.

  8. Diamond nanobeam waveguide optomechanics

    E-print Network

    Khanaliloo, Behzad; Hryciw, Aaron C; Lake, David P; Kaviani, Hamidreza; Barclay, Paul E

    2015-01-01

    Optomechanical devices sensitively transduce and actuate motion of nanomechanical structures using light, and are central to many recent fundamental studies and technological advances. Single--crystal diamond promises to improve the performance of optomechanical devices, while also providing opportunities to interface nanomechanics with diamond color center spins and related quantum technologies. Here we demonstrate measurement of diamond nanobeam resonators with a sensitivity of 9.5 fm/Hz^0.5 and bandwidth >120 nm through dissipative waveguide--optomechanical coupling. Nanobeams are fabricated from bulk single--crystal diamond using a scalable quasi--isotropic oxygen plasma undercut etching process, and support mechanical resonances with quality factor of 2.5 x 10^5 at room temperature, and 7.2 x 10^5 in cryogenic conditions (5K). Mechanical self--oscillations, resulting from interplay between optomechanical coupling and the photothermal response of nanobeams in a buckled state, are observed with amplitude e...

  9. 31 CFR 592.310 - Rough diamond.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Rough diamond. 592.310 Section 592.310 ...DEPARTMENT OF THE TREASURY ROUGH DIAMONDS CONTROL REGULATIONS General Definitions § 592.310 Rough diamond. The term rough diamond means...

  10. 31 CFR 592.310 - Rough diamond.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Rough diamond. 592.310 Section 592.310 ...DEPARTMENT OF THE TREASURY ROUGH DIAMONDS CONTROL REGULATIONS General Definitions § 592.310 Rough diamond. The term rough diamond means...

  11. 31 CFR 592.310 - Rough diamond.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Rough diamond. 592.310 Section 592.310 ...DEPARTMENT OF THE TREASURY ROUGH DIAMONDS CONTROL REGULATIONS General Definitions § 592.310 Rough diamond. The term rough diamond means...

  12. 31 CFR 592.310 - Rough diamond.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Rough diamond. 592.310 Section 592.310 ...DEPARTMENT OF THE TREASURY ROUGH DIAMONDS CONTROL REGULATIONS General Definitions § 592.310 Rough diamond. The term rough diamond means...

  13. 31 CFR 592.310 - Rough diamond.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Rough diamond. 592.310 Section 592.310 ...DEPARTMENT OF THE TREASURY ROUGH DIAMONDS CONTROL REGULATIONS General Definitions § 592.310 Rough diamond. The term rough diamond means...

  14. Hybrid Group IV Nanophotonic Structures Incorporating Diamond Silicon-Vacancy Color Centers

    E-print Network

    Jingyuan Linda Zhang; Hitoshi Ishiwata; Thomas M. Babinec; Marina Radulaski; Kai Müller; Konstantinos G. Lagoudakis; Constantin Dory; Jeremy Dahl; Robert Edgington; Veronique Soulière; Gabriel Ferro; Andrey A. Fokin; Peter R. Schreiner; Zhi-Xun Shen; Nicholas A. Melosh; Jelena Vu?kovi?

    2015-10-26

    We demonstrate a new approach for engineering group IV semiconductor-based quantum photonic structures containing negatively charged silicon-vacancy (SiV$^-$) color centers in diamond as quantum emitters. Hybrid SiC/diamond structures are realized by combining the growth of nanoand micro-diamonds on silicon carbide (3C or 4H polytype) substrates, with the subsequent use of these diamond crystals as a hard mask for pattern transfer. SiV$^-$ color centers are incorporated in diamond during its synthesis from molecular diamond seeds (diamondoids), with no need for ionimplantation or annealing. We show that the same growth technique can be used to grow a diamond layer controllably doped with SiV$^-$ on top of a high purity bulk diamond, in which we subsequently fabricate nanopillar arrays containing high quality SiV$^-$ centers. Scanning confocal photoluminescence measurements reveal optically active SiV$^-$ lines both at room temperature and low temperature (5 K) from all fabricated structures, and, in particular, very narrow linewidths and small inhomogeneous broadening of SiV$^-$ lines from all-diamond nano-pillar arrays, which is a critical requirement for quantum computation. At low temperatures (5 K) we observe in these structures the signature typical of SiV$^-$ centers in bulk diamond, consistent with a double lambda. These results indicate that high quality color centers can be incorporated into nanophotonic structures synthetically with properties equivalent to those in bulk diamond, thereby opening opportunities for applications in classical and quantum information processing.

  15. High-mobility diamond

    NASA Astrophysics Data System (ADS)

    Landstrass, Maurice I.

    1994-04-01

    Recent improvements in the CVD diamond deposition process have made possible the fabrication of diamond photoconductive diodes with carrier mobility and lifetime exceeding the values typical of natural gemstones. One of the more surprising recent results is that the best room-temperature carrier properties have been measured on polycrystalline diamond films. The combined electron- hole mobility, as measured by transient photoconductivity at low carrier densities, is 4000 square centimeters per volt per second at electric field of 200 volts per centimeter and is comparable to that of the best single-crystal IIa natural diamonds. Carrier lifetimes measured under the same conditions are 150 picoseconds for the CVD diamond films. The collection distance within the diamond films, at the highest applied fields, is comparable to the average film grain size, indicative of little or no carrier scattering at grain boundaries. A comparison of SIMS measurements with electrical results suggest that impurity incorporation in the near grain boundary regions are responsible for controlling the carrier mobility.

  16. Fundamentals and technology for monolithically integrated RF MEMS switches with ultra-nanocrystaline diamond dielectric/CMOS devices.

    SciTech Connect

    Auciello, O.; Sumant, A.; Goldsmith, C.; O'Brien, S.; Sampath, S.; Gudeman, C; Wang, W.; Hwang, J.; Swonger, J.; Carlisle, J.; Balachandran, S.; MEMtronics Corp.; Innovative Micro Technology; Lehigh Univ.; Peregrine Semiconductor; Advanced Diamond Technologies

    2010-01-01

    Most current capacitive RF-MEMS switch technology is based on conventional dielectric materials such as SiO{sub 2} and Si{sub 3}N{sub 4}. However, they suffer not only from charging problems but also stiction problems leading to premature failure of an RF-MEMS switch. Ultrananocrystalline diamond (UNCD{sup (R)}) (2-5 nm grains) and nanocrystalline diamond (NCD) (10-100 nm grains) films exhibit one of the highest Young's modulus ({approx} 980-1100 GPa) and demonstrated MEMS resonators with the highest quality factor (Q {ge} 10,000 in air for NCD) today, they also exhibit the lowest force of adhesion among MEMS/NEMS materials ({approx}10 mJ/m{sup 2}-close to van der Waals attractive force for UNCD) demonstrated today. Finally, UNCD exhibits dielectric properties (fast discharge) superior to those of Si and SiO{sub 2}, as shown in this paper. Thus, UNCD and NCD films provide promising platform materials beyond Si for a new generation of important classes of high-performance MEMS/NEMS devices.

  17. Effect of Metal Matrix Alloying on Mechanical Strength of Diamond Particle-Reinforced Aluminum Composites

    NASA Astrophysics Data System (ADS)

    Zhang, Hailong; Wu, Jianhua; Zhang, Yang; Li, Jianwei; Wang, Xitao

    2015-06-01

    Diamond particle-reinforced Al matrix (Al/diamond) composites were produced by a gas pressure infiltration method, where 0.5-4.0 wt.% Ti was added to Al matrix. An interfacial TiC layer of about 2 ?m thickness was formed between Al and diamond at 4.0 wt.% Ti addition. The mechanical properties of the Al/diamond composites were enhanced by both the formation of interfacial layer and the strengthening of the matrix. The mechanical strength increased with increasing alloying Ti content, and a tensile strength of 153 MPa was obtained at 4.0 wt.% Ti addition. The tensile flow stress of the composites was found to be in broad agreement with the prediction of the Mori-Tanaka model. The effect of interfacial layer on mechanical properties provides guideline for the production of mechanically reliable Al/diamond composites.

  18. Laser Patterning of Diamond. Part II. Surface Nondiamond Carbon Formation and its Removal

    SciTech Connect

    Smedley, J.; Jaye, C; Bohon, J; Rao, T; Fischer, D

    2009-01-01

    As diamond becomes more prevalent for electronic and research applications, methods of patterning diamond will be required. One such method, laser ablation, has been investigated in a related work. We report on the formation of surface nondiamond carbon during laser ablation of both polycrystalline and single-crystal synthetic diamonds. Near edge x-ray absorption fine structure spectroscopy was used to confirm that the nondiamond carbon layer formed during the ablation was amorphous, and Fourier transform infrared absorption spectroscopy (FTIR) was used to estimate the thickness of this layer to be {approx} 60 nm. Ozone cleaning was used to remove the nondiamond carbon layer.

  19. Laser patterning of diamond. Part II. Surface nondiamond carbon formation and its removal

    NASA Astrophysics Data System (ADS)

    Smedley, John; Jaye, Cherno; Bohon, Jen; Rao, Triveni; Fischer, Daniel A.

    2009-06-01

    As diamond becomes more prevalent for electronic and research applications, methods of patterning diamond will be required. One such method, laser ablation, has been investigated in a related work. We report on the formation of surface nondiamond carbon during laser ablation of both polycrystalline and single-crystal synthetic diamonds. Near edge x-ray absorption fine structure spectroscopy was used to confirm that the nondiamond carbon layer formed during the ablation was amorphous, and Fourier transform infrared absorption spectroscopy (FTIR) was used to estimate the thickness of this layer to be ˜60 nm. Ozone cleaning was used to remove the nondiamond carbon layer.

  20. Ion-Implanted Diamond Films and Their Tribological Properties

    NASA Technical Reports Server (NTRS)

    Wu, Richard L. C.; Miyoshi, Kazuhisa; Korenyi-Both, Andras L.; Garscadden, Alan; Barnes, Paul N.

    1993-01-01

    This paper reports the physical characterization and tribological evaluation of ion-implanted diamond films. Diamond films were produced by microwave plasma, chemical vapor deposition technique. Diamond films with various grain sizes (0.3 and 3 microns) and roughness (9.1 and 92.1 nm r.m.s. respectively) were implanted with C(+) (m/e = 12) at an ion energy of 160 eV and a fluence of 6.72 x 10(exp 17) ions/sq cm. Unidirectional sliding friction experiments were conducted in ultrahigh vacuum (6.6 x 10(exp -7)Pa), dry nitrogen and humid air (40% RH) environments. The effects of C(+) ion bombardment on fine and coarse-grained diamond films are as follows: the surface morphology of the diamond films did not change; the surface roughness increased (16.3 and 135.3 nm r.m.s.); the diamond structures were damaged and formed a thin layer of amorphous non-diamond carbon; the friction coefficients dramatically decreased in the ultrahigh vacuum (0.1 and 0.4); the friction coefficients decreased slightly in the dry nitrogen and humid air environments.

  1. Photo-stimulated low electron temperature high current diamond film field emission cathode

    DOEpatents

    Shurter; Roger Philips (Los Alamos, NM), Devlin; David James (Santa Fe, NM), Moody; Nathan Andrew (Los Alamos, NM), Taccetti; Jose Martin (Santa Fe, NM), Russell; Steven John (Los Alamos, NM)

    2012-07-24

    An electron source includes a back contact surface having a means for attaching a power source to the back contact surface. The electron source also includes a layer comprising platinum in direct contact with the back contact surface, a composite layer of single-walled carbon nanotubes embedded in platinum in direct contact with the layer comprising platinum. The electron source also includes a nanocrystalline diamond layer in direct contact with the composite layer. The nanocrystalline diamond layer is doped with boron. A portion of the back contact surface is removed to reveal the underlying platinum. The electron source is contained in an evacuable container.

  2. A kinetic model of diamond nucleation and silicon carbide interlayer formation during chemical vapor deposition

    E-print Network

    Dandy, David

    A kinetic model of diamond nucleation and silicon carbide interlayer formation during chemical February 2005 Available online 7 April 2005 Abstract The presence of thin silicon carbide intermediate of carbon atoms into the silicon carbide layer and the morphology and orientation of the diamond film

  3. Diamond/AlN Thin Films for Optical Applications

    SciTech Connect

    Knoebber, F.; Bludau, O.; Williams, O. A.; Sah, R. E.; Kirste, L.; Baeumler, M.; Nebel, C. E.; Ambacher, O.; Cimalla, V.; Lebedev, V.; Leopold, S.; Paetz, D.

    2010-11-01

    In this work we report on membranes made of nanocrystalline diamond (NCD) and AlN for the use in tunable micro-optics. For the growth of the AlN and NCD thin films, magnetron sputtering and chemical vapor deposition techniques have been used, respectively. A chemical-mechanical polishing process of NCD layers has been introduced, which is crucial for the growth of c-oriented, fiber textured AlN films. AlN layers deposited on as grown and polished nanocrystalline diamond along with free standing membranes have been compared by studying microstructure, surface morphology, piezoelectrical response as well as optical properties.

  4. Facts about Diamond Blackfan Anemia

    MedlinePLUS

    ... Form Controls NCBDDD Cancel Submit Search The CDC Diamond Blackfan Anemia (DBA) Note: Javascript is disabled or ... Español (Spanish) Recommend on Facebook Tweet Share Compartir Diamond Blackfan anemia (DBA) is a rare blood disorder ...

  5. Peculiarities of boron distribution in as-grown boron-doped diamond

    NASA Astrophysics Data System (ADS)

    Blank, V. D.; Kulnitskiy, B. A.; Perezhogin, I. A.; Terentiev, S. A.; Nosukhin, S. A.; Kuznetsov, M. S.

    2014-09-01

    Boron doped diamond (BDD) single crystals have been grown under conditions of high isostatic pressure by the temperature gradient method. Numerous equilateral triangles were found on the fluorescence images of {111}-diamond facets. Structural peculiarities of BDD were investigated by JEM-2010 transmission electron microscope with GIF Quantum attachment for electron energy loss spectroscopy (EELS). High resolution image of diamond lattice revealed some distorted {111}-layers. EELS testifies the presence of boron in distorted regions of diamond lattice. The crystallographic features of BDD and their connection with the superconductivity are discussed.

  6. Improvements in the Formation of Boron-Doped Diamond Coatings on Platinum Wires Using the Novel Nucleation Process (NNP)

    PubMed Central

    Fhaner, Mathew; Zhao, Hong; Bian, Xiaochun; Galligan, James J.; Swain, Greg M.

    2010-01-01

    In order to increase the initial nucleation density for the growth of boron-doped diamond on platinum wires, we employed the novel nucleation process (NNP) originally developed by Rotter et al. and discussed by others [1–3]. This pretreatment method involves (i) the initial formation of a thin carbon layer over the substrate followed by (ii) ultrasonic seeding of this “soft” carbon layer with nanoscale particles of diamond. This two-step pretreatment is followed by the deposition of boron-doped diamond by microwave plasma-assisted CVD. Both the diamond seed particles and sites on the carbon layer itself function as the initial nucleation zones for diamond growth from an H2-rich source gas mixture. We report herein on the characterization of the pre-growth carbon layer formed on Pt as well as boron-doped films grown for 2, 4 and 6 h post NNP pretreatment. Results from scanning electron microscopy, Raman spectroscopy and electrochemical studies are reported. The NNP method increases the initial nucleation density on Pt and leads to the formation of a continuous diamond film in a shorter deposition time than is typical for wires pretreated by conventional ultrasonic seeding. The results indicate that the pregrowth layer itself consists of nanoscopic domains of diamond and functions well to enhance the initial nucleation of diamond without any diamond powder seeding. PMID:21617759

  7. Experimental study of diamond resorption during mantle metasomatism

    NASA Astrophysics Data System (ADS)

    Fedorchuk, Yana; Schmidt, Max W.; Liebske, Christian

    2014-05-01

    Many of kimberlite-derived diamonds are partially dissolved to various degree but show similar resorption style. This resorption style has been observed in experiments with aqueous fluid at the conditions corresponding to kimberlite emplacement (1-2 GPa). At the same time, each diamond population has more than ten percent of diamond crystals with several drastically different resorption styles, which have not been observed in experiments, and may represent partial dissolution of diamonds during metasomatism in different mantle domains. Metasomatic processes modify the composition of subcratonic mantle, may trigger the formation of kimberlite magma, and result in the growth and partial dissolution of diamonds. Composition of metasomatic agents as constrained from studies of the reaction rims on mantle minerals (garnet, clinopyroxene) and experimental studies vary between carbonatitic melt, aqueous silicate melt, and CHO fluid. However, complex chemical pattern of mantle minerals and estimates of redox regime in subcratonic mantle allow different interpretations. Here we explore diamond dissolution morphology as an indicator of the composition of mantle metasomatic agents. Towards this end we examine diamond dissolution morphologies developed in experiments at the conditions of mantle metasomatism in different reacting media and compare them to the mantle-derived dissolution features of natural diamonds. The experiments were conducted in multi-anvil (Walker-Type) apparatus at 6 GPa and 1200-1500oC. Dissolution morphology of natural octahedral diamond crystals (0.5 mg) was examined in various compositions in synthetic system MgO-CaO- SiO2-CO2-H2O. The runs had the following phases present: solid crystals with fluid (various ratio of H2O-CO2-SiO2, and in the air), carbonate melt, carbonate-silicate melt, and carbonate melt with CHO fluid. Experiments produced three different styles of diamond resorption. In the presence of a fluid phase with variable proportions of H2O and CO2 diamond crystals develop ditrigonal outline of {111} faces, striation or hillocks along the edges, and shallow negatively oriented trigonal etch pits with flat or pointed bottom. Presence of SiO2 in the fluid resulted in multi-corner morphology, layering and / or more intensive etching of {111} faces. Dissolution in carbonate melt in the absence of water produced deep stepped-wall hexagonal and trigonal etch pits with negative orientation. The three resorption styles show strong resemblance to the secondary morphology of natural diamonds. This suggests that CHO fluid, aqueous silicate melt, and carbonatatitic melt are metasomatic agents reacting with natural diamonds in subcratonic mantle. The comparison of the experimentally-induced resorption styles to those on natural diamonds show that mantle metasomatism induced by CHO fluid develop morphologies similar to those developed in kimberlite magma. This indicates that significant proportion of kimberlite-hosted diamonds may show resorption features of mantle origin. Aqueous silicate melt induces step-faced multi-corner resorption morphology, similar to natural diamonds with nitrogen aggregation corresponding to eclogitic diamonds. Dissolution in carbonatitic melt results in complex morphologies with deep hexagonal pits similar to natural diamonds with nitrogen data corresponding to peridotitic diamonds.

  8. Diamond collecting in northern Colorado.

    USGS Publications Warehouse

    Collins, D.S.

    1982-01-01

    The discovery of numerous diamond-bearing kimberlite diatremes in the N Front Range of Colorado and Wyoming is of both scientific and economic interest. Species recovered from heavy-mineral concentrates include Cr-diopside, spinel, Mg-ilmenite, pyrope and diamond. A nodule tentatively identified as a graphite-diamond eclogite was also found. -G.W.R.

  9. MUTUAL DIAMOND Sy D. Friedman

    E-print Network

    MUTUAL DIAMOND Sy D. Friedman Department of Mathematics Massachusetts Institute of Technology Zoran Spasojevi´c Department of Mathematics Massachusetts Institute of Technology ABSTRACT: We formulate a diamond that P is not + -saturated unless = = 1. We use it here to formulate a diamond-like principle

  10. Making Diamond in the Laboratory

    ERIC Educational Resources Information Center

    Strong, Herbert

    1975-01-01

    Discusses the graphite to diamond transformation and a phase diagram for carbon. Describes high temperature-higher pressure experimental apparatus and growth of diamonds from seed crystals. Reviews properties of the diamond which suggest uses for the synthetic product. Illustrations with text. (GH)

  11. A multilayer innovative solution to improve the adhesion of nanocrystalline diamond coatings

    NASA Astrophysics Data System (ADS)

    Poulon-Quintin, A.; Faure, C.; Teulé-Gay, L.; Manaud, J. P.

    2015-03-01

    Nano-crystalline diamond (NCD) films grown under negative biased substrates by chemical vapor deposition (CVD) are widely used as surface overlay coating onto cermet WC-Co cutting tools to get better performances. To improve the diamond adhesion to the cermet substrate, suitable multi-layer systems have been added. They are composed of a cobalt diffusion barrier close to the substrate (single and sequenced nitrides layers) coated with a nucleation extra layer to improve the nucleus density of diamond during CVD processing. For all systems, before and after diamond deposition, transmission electron microscopy (TEM) has been performed for a better understanding of the diffusion phenomena occurring at the interfaces and to evaluate the presence of graphitic species at the interface with the diamond. Innovative multilayer system dedicated to the regulation of cobalt diffusion coated with a bilayer system optimized for the carbon diffusion control, is shown as an efficient solution to significantly reduce the graphite layer formation at the interface with the diamond down to 10 nm thick and to increase the adhesion of NCD diamond layer as scratch-tests confirm.

  12. Development of Designer Diamond Anvils for High Pressure-High-Temperature Experiments in Support of the Stockpile Stewardship Program

    SciTech Connect

    Yogesh K. Vohra

    2005-05-12

    The focus of this program at the University of Alabama at Birmingham (UAB) is to develop the next generation of designer diamond anvils that can perform simultaneous joule heating and temperature profile measurements in a diamond anvil cell. A series of tungsten-rhenium thermocouples will be fabricated onto to the anvil and encapsulated by a chemical vapor deposited diamond layer to allow for a complete temperature profile measurement across the anvil. The tip of the diamond anvil will be engineered to reduce the thermal conductivity so that the tungsten-heating coils can be deposited on top of this layer. Several different approaches will be investigated to engineer the tip of the diamond anvil for reduction in thermal conductivity (a) isotopic mixture of 12C and 13C in the diamond layer, (b) doping of diamond with impurities (nitrogen and/or boron), and (c) growing diamond in a higher concentration of methane in hydrogen plasma. Under this academic alliance with Lawrence Livermore National Laboratory (LLNL), PI and his graduate students will use the lithographic and diamond polishing facility at LLNL. This proposed next generation of designer diamond anvils will allow multi-tasking capability with the ability to measure electrical, magnetic, structural and thermal data on actinide materials with unparallel sensitivity in support of the stockpile stewardship program.

  13. Diamonds in HD 97048

    E-print Network

    E. Habart; L. Testi; A. Natta; M. Carbillet

    2004-09-27

    We present adaptive optics high angular resolution ($\\sim0\\farcs$1) spectroscopic observations in the 3 $\\mu$m region of the Herbig Ae/Be star HD 97048. For the first time, we spatially resolve the emission in the diamond features at 3.43 and 3.53 $\\mu$m and in the adjacent continuum. Using both the intensity profiles along the slit and reconstructed two-dimensional images of the object, we derive full-width at half-maximum sizes consistent with the predictions for a circumstellar disk seen pole-on. The diamond emission originates in the inner region ($R \\lesssim 15$ AU) of the disk.

  14. Process for making diamonds

    NASA Technical Reports Server (NTRS)

    Rasquin, J. R.; Estes, M. F. (inventors)

    1973-01-01

    A description is given of a device and process for making industrial diamonds. The device is composed of an exponential horn tapering from a large end to a small end, with a copper plate against the large end. A magnetic hammer abuts the copper plate. The copper plate and magnetic hammer function together to create a shock wave at the large end of the horn. As the wave propagates to the small end, the extreme pressure and temperature caused by the wave transforms the graphite, present in an anvil pocket at the small end, into diamonds.

  15. Diamond Measuring Machine

    SciTech Connect

    Krstulic, J.F.

    2000-01-27

    The fundamental goal of this project was to develop additional capabilities to the diamond measuring prototype, work out technical difficulties associated with the original device, and perform automated measurements which are accurate and repeatable. For this project, FM and T was responsible for the overall system design, edge extraction, and defect extraction and identification. AccuGem provided a lab and computer equipment in Lawrence, 3D modeling, industry expertise, and sets of diamonds for testing. The system executive software which controls stone positioning, lighting, focusing, report generation, and data acquisition was written in Microsoft Visual Basic 6, while data analysis and modeling were compiled in C/C++ DLLs. All scanning parameters and extracted data are stored in a central database and available for automated analysis and reporting. The Phase 1 study showed that data can be extracted and measured from diamond scans, but most of the information had to be manually extracted. In this Phase 2 project, all data required for geometric modeling and defect identification were automatically extracted and passed to a 3D modeling module for analysis. Algorithms were developed which automatically adjusted both light levels and stone focus positioning for each diamond-under-test. After a diamond is analyzed and measurements are completed, a report is printed for the customer which shows carat weight, summarizes stone geometry information, lists defects and their size, displays a picture of the diamond, and shows a plot of defects on a top view drawing of the stone. Initial emphasis of defect extraction was on identification of feathers, pinpoints, and crystals. Defects were plotted color-coded by industry standards for inclusions (red), blemishes (green), and unknown defects (blue). Diamonds with a wide variety of cut quality, size, and number of defects were tested in the machine. Edge extraction, defect extraction, and modeling code were tested for multiple runs of each stone. Although there were problems with a few stones, the machine automatically completed measurements on a majority of the stones tested. A demo was performed in Lawrence for AccuGem stockholders and potential investors. The demo successfully demonstrated our technology on a random stone brought by an attendee. In conclusion, the project was successful in development of the basic technology required for a diamond measuring machine. Continued improvements in lighting control, edge and defect extraction, and an increased image depth-of-field will increase the reliability and consistency of measurements. Although additional work is needed to make the machine a commercial product, there are no foreseeable technical roadblocks in that process.

  16. Fluidized bed deposition of diamond

    DOEpatents

    Laia, Jr., Joseph R. (Los Alamos, NM); Carroll, David W. (Los Alamos, NM); Trkula, Mitchell (Los Alamos, NM); Anderson, Wallace E. (Los Alamos, NM); Valone, Steven M. (Santa Fe, NM)

    1998-01-01

    A process for coating a substrate with diamond or diamond-like material including maintaining a substrate within a bed of particles capable of being fluidized, the particles having substantially uniform dimensions and the substrate characterized as having different dimensions than the bed particles, fluidizing the bed of particles, and depositing a coating of diamond or diamond-like material upon the substrate by chemical vapor deposition of a carbon-containing precursor gas mixture, the precursor gas mixture introduced into the fluidized bed under conditions resulting in excitation mechanisms sufficient to form the diamond coating.

  17. A charge transport study in diamond, surface passivated by high-k dielectric oxides

    SciTech Connect

    Kovi, Kiran Kumar Majdi, Saman; Gabrysch, Markus; Isberg, Jan

    2014-11-17

    The recent progress in the growth of high-quality single-crystalline diamond films has sparked interest in the realization of efficient diamond power electronic devices. However, finding a suitable passivation is essential to improve the reliability and electrical performance of devices. In the current work, high-k dielectric materials such as aluminum oxide and hafnium oxide were deposited by atomic layer deposition on intrinsic diamond as a surface passivation layer. The hole transport properties in the diamond films were evaluated and compared to unpassivated films using the lateral time-of-flight technique. An enhancement of the near surface hole mobility in diamond films of up to 27% is observed when using aluminum oxide passivation.

  18. Topomineralogy of the Siberian diamonds

    NASA Astrophysics Data System (ADS)

    Afanasyev, Valentin; Lobanov, Sergey; Vasiliy, Koptil; Bogdan, Pomazanskiy; Alexander, Gerasimchuk; Nikolay, Pokhilenko

    2010-05-01

    Diamond placers are widespread in the modern alluvial deposits and ancient sedimentary collectors of the Siberian craton and can be divided into two major types: 1) related with the rich and famous kimberlites such as Mir and International pipe and 2) with unidentified root source. The lattert are wide spread, industrially significant and in use in the north-east of the Siberian craton. Yet, kimberlites known in the north-east of the Siberian craton have poor diamond concentrations or non-diamondiferous at all. A contradiction occur between high alluvial and extremely-low host diamond content of this region. Detailed studies of this problem led to the fact that diamonds from the alluvial deposits of the Siberian craton, as well as other diamondiferous regions, show broader spectrum of typomorphic features than diamonds from the known kimberlites. Moreover, some diamond groups are not typical for the phanerozoic kimberlites of Siberia, or do not occur in significant amounts. The foregoing suggests that diamonds from the unknown host rock type occur in the diamond placers of the Siberian craton along with typical kimberlite diamonds. Based on the detailed studies of the typomorphic features of the alluvial diamonds from Siberian craton 5 parasteresis groups, probably related to different host rock types, were distinguished. Parasteresis is a regular spatial mineral association which are united by single geological process, such as kimberlite indicator minerals and diamonds from kimberlites which differ in genesis but united by the whole kimberlitic process. Parasteresis 1 (kimberlite-type) involves diamonds which are common for the phanerozoic kimberlites. Parasteresis 2 (supposed to be lamproitic) includes roundish (cryptolaminar) diamonds of dodecahedron habit, the so called "brazilian" or "ural" types. In Siberian phanerozoic industrial kimberlites the part of such diamonds does not exceed 15%. That is the diamonds which dominate in the placers of the Urals and nearby Eastern Sayan (south-west of the Siberian craton). Parasteresis 3 (unknown host rock type) includes yellow-orange cuboids (II type according to Orlov's classification), which occur in kimberlites in small quantities, but most common in the north-east placers of the Siberian craton. Parasteresis 4 (unknown host rock type) includes diamonds of V and VII types according to Orlov, which are entirely absent in kimberlites. Parasteresis 5 involves the so called yacutites - microcrystalline substance with the add of lonsdaleite phase, typical for diamonds from impact craters. Comparison of yacutites with diamonds from Popigay astrobleme showed up their complete similarity. This fact is evident for the relation of yacutites to the Popigay astrobleme. Thus, in the placers of the Siberian craton there are at least three groups of diamonds with the unknown host rock type. The distribution of the discriminated types of diamonds among the craton is higly uneven. Diamonds of 2,3,4 and 5 parasteresis type (supposed to be from lamprophyres, unknown sources and yacutites) predominate in the north-eastern placers of the Siberian craton, whereas the part of the kimberlitic diamonds is less then a half, in some areas they are completely absent. Early- carboniferous deposits of the Kjutungdinskij graben is the only area where kimberlitic diamonds strongly predominate. That was the case to predict mid-paleozoic kimberlitic field there. In the central part of the province the major role goes to the kimberlitic diamonds associated with the mid-paleozoic kimberlites. Roundish diamonds of the second parasteresis type are in lead on the south of the Siberian craton, and may probably associate with the lamprophyres such as Ingash complex. Mapping of distribution of the distinguished diamond parasteresises among the Siberian craton reveals the tendency of diamonds hypothetically from lamprophyres and unknown sources to associate with the precambrian protrusions - Anabar shield, Olenek rise and Eastern Sayan. This allows us to suggest that the diamonds supply of the

  19. REMEDIATION OF OIL CONTAMINATED GROUND AND SURFACE WATER USING SULFATE NANOFILTRATION COMBINED WITH HIGH EFFICIENCY ON-SITE GENERATION OF PEROXODISULFATE USING ULTRANANOCRYSTALLINE DIAMOND ELECTRODES - PHASE I

    EPA Science Inventory

    This Small Business Innovation Research (SBIR) project will employ nanofiltration to generate sulfate ion feedstocks and high current density on-site generation (synthesis) of the powerful oxidant...

  20. Surface Design and Engineering Toward Wear-Resistant, Self-Lubricant Diamond Films and Coatings. Chapter 10

    NASA Technical Reports Server (NTRS)

    Miyoshi, Kazuhisa

    1999-01-01

    This chapter describes three studies on the surface design, surface engineering, and tribology of chemical-vapor-deposited (CVD) diamond films and coatings toward wear-resistant, self-lubricating diamond films and coatings. Friction mechanisms and solid lubrication mechanisms of CVD diamond are stated. Effects of an amorphous hydrogenated carbon on CVD diamond, an amorphous, nondiamond carbon surface layer formed on CVD diamond by carbon and nitrogen ion implantation, and a materials combination of cubic boron nitride and CVD diamond on the adhesion, friction, and wear behaviors of CVD diamond in ultrahigh vacuum are described. How surface modification and the selected materials couple improved the tribological functionality of coatings, giving low coefficient of friction and good wear resistance, is explained.

  1. DIAMOND AMPLIFIED PHOTOCATHODES.

    SciTech Connect

    SMEDLEY,J.; BEN-ZVI, I.; BOHON, J.; CHANG, X.; GROVER, R.; ISAKOVIC, A.; RAO, T.; WU, Q.

    2007-11-26

    High-average-current linear electron accelerators require photoinjectors capable of delivering tens to hundreds of mA average current, with peak currents of hundreds of amps. Standard photocathodes face significant challenges in meeting these requirements, and often have short operational lifetimes in an accelerator environment. We report on recent progress toward development of secondary emission amplifiers for photocathodes, which are intended to increase the achievable average current while protecting the cathode from the accelerator. The amplifier is a thin diamond wafer which converts energetic (few keV) primary electrons into hundreds of electron-hole pairs via secondary electron emission. The electrons drift through the diamond under an external bias and are emitted into vacuum via a hydrogen-terminated surface with negative electron affinity (NEA). Secondary emission gain of over 200 has been achieved. Two methods of patterning diamond, laser ablation and reactive-ion etching (RIE), are being developed to produce the required geometry. A variety of diagnostic techniques, including FTIR, SEM and AFM, have been used to characterize the diamonds.

  2. Multiplying Electrons With Diamond

    NASA Technical Reports Server (NTRS)

    2003-01-01

    As researchers in the Space Communications Division of NASA s Glenn Research Center in 1992, Dr. Gerald Mearini, Dr. Isay Krainsky, and Dr. James Dayton made a secondary electron emission discovery that became the foundation for Mearini s company, GENVAC AeroSpace Corporation. Even after Mearini departed Glenn, then known as Lewis Research Center, his contact with NASA remained strong as he was awarded Small Business Innovation Research (SBIR) contracts to further develop his work. Mearini s work for NASA began with the investigation of diamond as a material for the suppression of secondary electron emissions. The results of his research were the opposite of what was expected diamond proved to be an excellent emitter rather than absorber. Mearini, Krainsky, and Dayton discovered that laboratory-grown diamond films can produce up to 45 electrons from a single incident electron. Having built an electron multiplier prototype at NASA, Mearini decided to start his own company to develop diamond structures usable in electron beam devices.

  3. ELECTRON AMPLIFICATION IN DIAMOND.

    SciTech Connect

    SMEDLEY, J.; BEN-ZVI, I.; BURRILL, A.; CHANG, X.; GRIMES, J.; RAO, T.; SEGALOV, Z.; WU, Q.

    2006-07-10

    We report on recent progress toward development of secondary emission ''amplifiers'' for photocathodes. Secondary emission gain of over 300 has been achieved in transmission mode and emission mode for a variety of diamond samples. Techniques of sample preparation, including hydrogenation to achieve negative electron affinity (NEA), have been adapted to this application.

  4. CVD diamond - fundamental phenomena

    SciTech Connect

    Yarbrough, W.A.

    1993-01-01

    This compilation of figures and diagrams addresses the basic physical processes involved in the chemical vapor deposition of diamond. Different methods of deposition are illustrated. For each method, observations are made of the prominent advantages and disadvantages of the technique. Chemical mechanisms of nucleation are introduced.

  5. Lower pressure synthesis of diamond material

    DOEpatents

    Lueking, Angela (State College, PA); Gutierrez, Humberto (State College, PA); Narayanan, Deepa (Redmond, WA); Burgess Clifford, Caroline E. (State College, PA); Jain, Puja (King Of Prussia, PA)

    2010-07-13

    Methods of synthesizing a diamond material, particularly nanocrystalline diamond, diamond-like carbon and bucky diamond are provided. In particular embodiments, a composition including a carbon source, such as coal, is subjected to addition of energy, such as high energy reactive milling, producing a milling product enriched in hydrogenated tetrahedral amorphous diamond-like carbon compared to the coal. A milling product is treated with heat, acid and/or base to produce nanocrystalline diamond and/or crystalline diamond-like carbon. Energy is added to produced crystalline diamond-like carbon in particular embodiments to produce bucky diamonds.

  6. Diamondization of Graphene and Graphene-BN Bilayers: Chemical Functionalization and Electronic Structure Engineering

    E-print Network

    Yuan, Long; Yang, Jinlong; Hou, Jian Guo

    2011-01-01

    In this article, based on first-principles calculations, we systematically study functionalization induced diamonization of graphene bilayer and graphene-BN hybrid bilayer. With single-side functionalization, the diamondized structures are magnetic semiconductor. Interestingly, if both sides of the bilayer are functionalized, diamondization becomes spontaneous without a barrier. On the other hand, when the bottom layer of the bilayer graphene is replaced by a single hexagonal BN layer, the diamondized structure becomes nonmagnetic metal. The tunable electronic and magnetic properties pave new avenues to construct graphene-based electronics and spintronics devices.

  7. Catalytic effect of ultrananocrystalline Fe3O4 on algal bio-crude production via HTL process

    NASA Astrophysics Data System (ADS)

    Rojas-Pérez, Arnulfo; Diaz-Diestra, Daysi; Frias-Flores, Cecilia B.; Beltran-Huarac, Juan; Das, K. C.; Weiner, Brad R.; Morell, Gerardo; Díaz-Vázquez, Liz M.

    2015-10-01

    We report a comprehensive quantitative study of the production of refined bio-crudes via a controlled hydrothermal liquefaction (HTL) process using Ulva fasciata macroalgae (UFMA) as biomass and ultrananocrystalline Fe3O4 (UNCFO) as catalyst. X-ray diffraction and electron microscopy were applied to elucidate the formation of the high-quality nanocatalysts. Gas chromatography-mass spectroscopy (GC-MS) and CHNS analyses showed that the bio-crude yield and carbon/oxygen ratios increase as the amount of UNCFO increases, reaching a peak value of 32% at 1.25 wt% (a 9% increase when compared to the catalyst-free yield). The bio-crude is mainly composed of fatty acids, alcohols, ketones, phenol and benzene derivatives, and hydrocarbons. Their relative abundance changes as a function of catalyst concentration. FTIR spectroscopy and vibrating sample magnetometry revealed that the as-produced bio-crudes are free of iron species, which accumulate in the generated bio-chars. Our findings also indicate that the energy recovery values via the HTL process are sensitive to the catalyst loading, with a threshold loading of 1.25 wt%. GC-MS studies show that the UNCFO not only influences the chemical nature of the resulting bio-crudes and bio-chars, but also the amount of fixed carbons in the solid residues. The detailed molecular characterization of the bio-crudes and bio-chars catalyzed by UNCFO represents the first systematic study reported using UFMA. This study brings forth new avenues to advance the highly-pure bio-crude production employing active, heterogeneous catalyst materials that are recoverable and recyclable for continuous thermochemical reactions.We report a comprehensive quantitative study of the production of refined bio-crudes via a controlled hydrothermal liquefaction (HTL) process using Ulva fasciata macroalgae (UFMA) as biomass and ultrananocrystalline Fe3O4 (UNCFO) as catalyst. X-ray diffraction and electron microscopy were applied to elucidate the formation of the high-quality nanocatalysts. Gas chromatography-mass spectroscopy (GC-MS) and CHNS analyses showed that the bio-crude yield and carbon/oxygen ratios increase as the amount of UNCFO increases, reaching a peak value of 32% at 1.25 wt% (a 9% increase when compared to the catalyst-free yield). The bio-crude is mainly composed of fatty acids, alcohols, ketones, phenol and benzene derivatives, and hydrocarbons. Their relative abundance changes as a function of catalyst concentration. FTIR spectroscopy and vibrating sample magnetometry revealed that the as-produced bio-crudes are free of iron species, which accumulate in the generated bio-chars. Our findings also indicate that the energy recovery values via the HTL process are sensitive to the catalyst loading, with a threshold loading of 1.25 wt%. GC-MS studies show that the UNCFO not only influences the chemical nature of the resulting bio-crudes and bio-chars, but also the amount of fixed carbons in the solid residues. The detailed molecular characterization of the bio-crudes and bio-chars catalyzed by UNCFO represents the first systematic study reported using UFMA. This study brings forth new avenues to advance the highly-pure bio-crude production employing active, heterogeneous catalyst materials that are recoverable and recyclable for continuous thermochemical reactions. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr04404a

  8. South Africa, Namibia Diamond Deposits

    NASA Technical Reports Server (NTRS)

    1998-01-01

    This radar image covers a portion of the Richtersveld National Park and Orange River (top of image) in the Northern Cape Province of the Republic of South Africa. The Orange River marks the boundary between South Africa to the south and Namibia to the north. This is an area of active mining for diamonds, which were washed downstream from the famous Kimberley Diamond Area, millions of years ago when the river was much larger. The mining is focused on ancient drainages of the Orange River which are currently buried by think layers of sand and gravel. Scientists are investigating whether these ancient drainages can be seen with the radar's ability to penetrate sand cover in extremely dry regions. A mine, shown in yellow, is on the southern bank of the river in an abandoned bend which is known as an 'oxbow.' The small bright circular areas (left edge of image) west of the mine circles are fields of a large ostrich farm that are being watered with pivot irrigation. The large dark area in the center of the image is the Kubus Pluton, a body of granite rock that broke through the surrounding rocks about 550 million years ago. North is toward the upper right. The area shown is about 55 by 60 kilometers (34 by 37 miles) centered at 28.4 degrees south latitude, 16.8 degrees east longitude. Colors are assigned to different radar frequencies and polarizations as follows: red is L-band horizontally transmitted and horizontally received; green is L-band horizontally transmitted and vertically received; blue is C-band horizontally transmitted and vertically received. The image was acquired on April 18, 1994 by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture (SIR-C/X-SAR) imaging radar when it flew aboard the space shuttle Endeavour. SIR-C/X-SAR is a joint mission of the U.S./German and Italian space agencies.

  9. 31 CFR 592.310 - Rough diamond.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance:Treasury 3 2013-07-01 2013-07-01 false Rough diamond. 592.310 Section 592.310... ASSETS CONTROL, DEPARTMENT OF THE TREASURY ROUGH DIAMONDS CONTROL REGULATIONS General Definitions § 592.310 Rough diamond. The term rough diamond means any diamond that is unworked or simply sawn,...

  10. 31 CFR 592.310 - Rough diamond.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 31 Money and Finance:Treasury 3 2012-07-01 2012-07-01 false Rough diamond. 592.310 Section 592.310... ASSETS CONTROL, DEPARTMENT OF THE TREASURY ROUGH DIAMONDS CONTROL REGULATIONS General Definitions § 592.310 Rough diamond. The term rough diamond means any diamond that is unworked or simply sawn,...

  11. 31 CFR 592.310 - Rough diamond.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 Money and Finance:Treasury 3 2014-07-01 2014-07-01 false Rough diamond. 592.310 Section 592.310... ASSETS CONTROL, DEPARTMENT OF THE TREASURY ROUGH DIAMONDS CONTROL REGULATIONS General Definitions § 592.310 Rough diamond. The term rough diamond means any diamond that is unworked or simply sawn,...

  12. 31 CFR 592.310 - Rough diamond.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false Rough diamond. 592.310 Section 592.310... ASSETS CONTROL, DEPARTMENT OF THE TREASURY ROUGH DIAMONDS CONTROL REGULATIONS General Definitions § 592.310 Rough diamond. The term rough diamond means any diamond that is unworked or simply sawn,...

  13. 31 CFR 592.310 - Rough diamond.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Rough diamond. 592.310 Section 592... FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY ROUGH DIAMONDS CONTROL REGULATIONS General Definitions § 592.310 Rough diamond. The term rough diamond means any diamond that is unworked or simply...

  14. Catalytic effect of ultrananocrystalline Fe3O4 on algal bio-crude production via HTL process.

    PubMed

    Rojas-Pérez, Arnulfo; Diaz-Diestra, Daysi; Frias-Flores, Cecilia B; Beltran-Huarac, Juan; Das, K C; Weiner, Brad R; Morell, Gerardo; Díaz-Vázquez, Liz M

    2015-11-14

    We report a comprehensive quantitative study of the production of refined bio-crudes via a controlled hydrothermal liquefaction (HTL) process using Ulva fasciata macroalgae (UFMA) as biomass and ultrananocrystalline Fe3O4 (UNCFO) as catalyst. X-ray diffraction and electron microscopy were applied to elucidate the formation of the high-quality nanocatalysts. Gas chromatography-mass spectroscopy (GC-MS) and CHNS analyses showed that the bio-crude yield and carbon/oxygen ratios increase as the amount of UNCFO increases, reaching a peak value of 32% at 1.25 wt% (a 9% increase when compared to the catalyst-free yield). The bio-crude is mainly composed of fatty acids, alcohols, ketones, phenol and benzene derivatives, and hydrocarbons. Their relative abundance changes as a function of catalyst concentration. FTIR spectroscopy and vibrating sample magnetometry revealed that the as-produced bio-crudes are free of iron species, which accumulate in the generated bio-chars. Our findings also indicate that the energy recovery values via the HTL process are sensitive to the catalyst loading, with a threshold loading of 1.25 wt%. GC-MS studies show that the UNCFO not only influences the chemical nature of the resulting bio-crudes and bio-chars, but also the amount of fixed carbons in the solid residues. The detailed molecular characterization of the bio-crudes and bio-chars catalyzed by UNCFO represents the first systematic study reported using UFMA. This study brings forth new avenues to advance the highly-pure bio-crude production employing active, heterogeneous catalyst materials that are recoverable and recyclable for continuous thermochemical reactions. PMID:26465090

  15. GaN heterostructures with diamond and , G Tsiakatouras2

    E-print Network

    Dunin-Borkowski, Rafal E.

    graphene oxide in light- emitting diodes (LEDs) [6]; transferable GaN layers deposited on ZnO with their superior thermal conductivities (2000 Wm-1 K-1 for diamond and 5000 Wm-1 K-1 for gra- phene). A review

  16. Metastable carbon allotropes in picosecond-laser-modified diamond

    NASA Astrophysics Data System (ADS)

    Pimenov, Sergei M.; Khomich, Andrey A.; Vlasov, Igor I.; Zavedeev, Evgeny V.; Khomich, Alexander V.; Neuenschwander, Beat; Jäggi, Beat; Romano, Valerio

    2014-08-01

    In this paper, we report on the bulk modifications of type IIa single-crystal diamond with visible 10-ps pulses (at ? = 532 nm) and microstructural changes characterized by the appearance of several `unidentifiable' vibrational modes in the frequency range of 1000-1400 cm-1 in the Raman spectra of laser-modified diamond. It is found that the new Raman modes are strongly pronounced in the spectra of high-stress regions in immediate proximity to the bulk microstructures in the absence of the G mode at ~1580 cm-1 characteristic of the sp2 phase. The high internal stresses are determined from the splitting of the triply degenerate diamond Raman line. The revealed structure transformation is localized within a narrow bulk layer near the bulk microstructures formed, and the stress relaxation is found to result in disappearance of the detected vibrational modes in the spectra. It is suggested that the formation of bulk regions with a sp3 carbon structure consisting of Z-carbon and hexagonal diamond is responsible for the appearance of new Raman modes in the spectra of laser-modified diamond. These findings evidence that the stress-assisted formation of novel metastable carbon phases or defect structures occur in the course of bulk modification of diamond with ps-laser pulses. In addition, we report the results of simulations of internal stresses in the system `graphitized cylinder-in-diamond' to show (1) the effect of the mechanical properties of laser-modified diamond on the resulting stresses and (2) formation of bulk microscopic regions with high stresses of >10 GPa, i.e., the conditions at which various sp3 carbon allotropes and defect structures become more stable than graphite.

  17. Raman investigation of diamond films

    SciTech Connect

    Feng, Li-Ming

    1993-12-31

    Extensive Raman investigations were conducted on a wide range of diamond films whose structures were dilineated by optical and confocal microscopy. The Raman Spectra from one extreme of this range indicates a very intense 1331 cm{sup {minus}1} line diagnostic of bulk crystalline diamond. Microscopy of the corresponding film shows the presence of many large true diamond crystallite. The 1331 cm{sup {minus}1} Raman line at the other extreme of the range, however, is virtually absent. It is replaced, at this extreme, by a very broad Raman contour whose maxima occur near 1355 cm{sup {minus}1} and 1575 cm{sup {minus}1}. Optical microscopy now reveals a complete lack of diamond crystallites. The ratio of the integrated Raman intensity of the 1331 cm{sup {minus}1} diamond line to the integral of the entire broad contour extending from {approx}1200 cm{sup {minus}1} to 1800 cm{sup {minus}1}, with maxima near 1355 cm{sup {minus}1} and 1575 cm{sup {minus}1}, was determined. This ratio rises with increasing diamond crystallite size, and it decreases as true diamond crystallites are replaced by diamond-like, but amorphous, hard carbon, which produces the broad Raman contour. The measured intensity ratio was analyzed in terms of a differential equation related to phonon coupling. The increase of the intensity ratio of the 1331 cm{sup {minus}1} diagnostic diamond peak is due to phono-phonon coupling between the diamond crystallites, as the concentration of the amorphous diamond-like carbon decreases. Confocal microscopy indicates many amorphous-like regions interspersed between diamond crystallites which account for the intensity loss, and agree with the Raman intensity measurements. These Raman measurements crystallinity versus amorphous hard-carbon character of thin diamond film.

  18. Low Temperature Growth of Nanostructured Diamond Films on Metals

    NASA Technical Reports Server (NTRS)

    Baker, Paul A.; Catledge, Shane A.; Vohra, Yogesh K.

    2001-01-01

    The field of nanocrystalline diamond and tetrahedral amorphous carbon films has been the focus of intense experimental activity in the last few years for applications in field emission display devices, optical windows, and tribological coatings, The choice of substrate used in most studies has typically been silicon. For metals, however, the thermal expansion mismatch between the diamond film and substrate gives rise to thermal stress that often results in delamination of the film. To avoid this problem in conventional CVD deposition low substrate temperatures (less than 700 C) have been used, often with the incorporation of oxygen or carbon monoxide to the feedgas mixture. Conventionally grown CVD diamond films are also rough and would require post-deposition polishing for most applications. Therefore, there is an obvious need to develop techniques for deposition of well-adhered, smooth nano-structured diamond films on metals for various tribological applications. In our work, nanostructured diamond films are grown on a titanium alloy substrate using a two-step deposition process. The first step is performed at elevated temperature (820 C) for 30 minutes using a H2/CH4/N2 gas mixture in order to grow a thin (approx. 600 nm) nanostructured diamond layer and improve film adhesion. The remainder of the deposition involves growth at low temperature (less than 600 C) in a H2/CH4/O2 gas mixture. Laser reflectance Interferometry (LRI) pattern during growth of a nanostructured diamond film on Ti-6Al-4V alloy. The first 30 minutes are at a high temperature of 820 C and the rest of the film is grown at a low temperature of 580 T. The fringe pattern is observed till the very end due to extremely low surface roughness of 40 nm. The continuation of the smooth nanostructured diamond film growth during low temperature deposition is confirmed by in-situ laser reflectance interferometry and by post-deposition micro-Raman spectroscopy and surface profilometry. Similar experiments performed without the starting nanostructured diamond layer resulted in poorly adhered films with a more crystalline appearance and a higher surface roughness. This low temperature deposition of nanostructured diamond films on metals offers advantages in cases where high residual thermal stress leads to delamination at high temperatures.

  19. Structure and properties of diamond and diamond-like films

    SciTech Connect

    Clausing, R.E.

    1993-01-01

    This section is broken into four parts: (1) introduction, (2) natural IIa diamond, (3) importance of structure and composition, and (4) control of structure and properties. Conclusions of this discussion are that properties of chemical vapor deposited diamond films can compare favorably with natural diamond, that properties are anisotropic and are a strong function of structure and crystal perfection, that crystal perfection and morphology are functions of growth conditions and can be controlled, and that the manipulation of texture and thereby surface morphology and internal crystal perfection is an important step in optimizing chemically deposited diamond films for applications.

  20. Surface and pseudo-surface acoustic waves piezoelectrically excited in diamond-based structures

    NASA Astrophysics Data System (ADS)

    Glushkov, Evgeny; Glushkova, Natalia; Zhang, Chuanzeng

    2012-09-01

    Surface and pseudo-surface acoustic plane waves generated in two- and three-layer AlN/Diamond and AlN/Diamond/? -TiAl structures by a point electric source are analyzed in the mathematical framework based on the Green's matrix integral representation and guided wave asymptotics derived using the residue technique. The attention is focused on the effect of pseudo-surface-to-surface wave degeneration at certain discrete values of h /? (h is the thickness of the piezoelectric layer and ? is the wave-length). Earlier such optimal ratios were discovered and experimentally verified for the first pseudo-surface (Sezawa) wave mode in the AlN/Diamond structure. The present research reveals this effect for higher modes as well as examines its manifestation for three-layer structures with different diamond-to-AlN thickness ratios H/h.

  1. CZ: Multiple Inheritance Without Diamonds Donna Malayeri

    E-print Network

    Aldrich, Jonathan

    CZ: Multiple Inheritance Without Diamonds Donna Malayeri Carnegie Mellon University donna, such as mixins and traits. Instead, we ad- dress the diamond problem directly, considering two diffi- culties approach: supporting multiple inheritance but forbidding diamond inheritance. Expressiveness is retained

  2. Conversion of fullerenes to diamond

    DOEpatents

    Gruen, Dieter M. (1324 59th St., Downers Grove, IL 60515)

    1994-01-01

    A method of forming synthetic diamond on a substrate. The method involves providing a substrate surface covered with a fullerene or diamond coating, positioning a fullerene in an ionization source, creating a fullerene vapor, ionizing fullerene molecules, accelerating the fullerene ions to energies above 250 eV to form a fullerene ion beam, impinging the fullerene ion beam on the substrate surface and continuing these steps to obtain a diamond film thickness on the substrate.

  3. Conversion of fullerenes to diamond

    DOEpatents

    Gruen, Dieter M. (1324 59th St., Downers Grove, IL 60515)

    1993-01-01

    A method of forming synthetic diamond on a substrate is disclosed. The method involves providing a substrate surface covered with a fullerene or diamond coating, positioning a fullerene in an ionization source, creating a fullerene vapor, ionizing fullerene molecules, accelerating the fullerene ions to energies above 250 eV to form a fullerene ion beam, impinging the fullerene ion beam on the substrate surface and continuing these steps to obtain a diamond thickness on the substrate.

  4. Diamond films for laser hardening

    NASA Technical Reports Server (NTRS)

    Albin, S.; Watkins, L.; Ravi, K.; Yokota, S.

    1989-01-01

    Laser-damage experiments were performed on free-standing polycrystalline diamond films prepared by plasma-enhanced CVD. The high laser-induced stress resistance found for this material makes it useful for thin-film coatings for laser optics. Results for diamond-coated silicon substrates demonstrate the enhanced damage threshold imparted by diamond thin-film coatings to materials susceptible to laser damage.

  5. Stable metallization for diamond and other materials

    NASA Technical Reports Server (NTRS)

    Bachli, Andreas (Inventor); Kolawa, Elzbieta (Inventor); Nicolet, Marc-Aurele (Inventor); Vandersande, Jan W. (Inventor)

    2000-01-01

    An adherent and metallurgically stable metallization system for diamond is presented. The big improvement in metallurgical stability is attributed to the use of a ternary, amorphous Ti--Si--N diffusion barrier. No diffusion between the layers and no delamination of the metallization was observed after annealing the schemes at 400.degree. C. for 100 hours and at 900.degree. C. for 30 minutes. Thermal cycling experiments in air from -65 to 155.degree. C. and adhesion tests were performed. Various embodiments are disclosed.

  6. Extended defects in diamond: The interstitial platelet

    NASA Astrophysics Data System (ADS)

    Goss, J. P.; Coomer, B. J.; Jones, R.; Fall, C. J.; Briddon, P. R.; Öberg, S.

    2003-04-01

    The structure and properties of the {001} planar platelet in diamond are investigated using ab initio theory. We find that a carbonaceous model, based on a layer of self-interstitials, satisfies the requirements of transmission electron microscopy, infrared absorption data, and energetic considerations. The energetics of self-interstitial production during nitrogen aggregation are considered. It is found that the growth mechanism of the platelet involves a thermally activated release of vacancies from platelets. The role of vacant sites and platelet nitrogen are also investigated and it is shown that these defects embedded within the platelet could account for the observed optical activity.

  7. Boron-doped superlattices and Bragg mirrors in diamond

    SciTech Connect

    Fiori, A.; Bousquet, J.; Eon, D.; Omnès, F.; Bustarret, E.; Bellet-Amalric, E.

    2014-08-25

    A periodic modulation of the boron doping level of single crystal diamond multilayers over more than three orders of magnitude during epitaxial growth by microwave plasma-enhanced chemical vapor deposition is shown to yield Bragg mirrors in the visible. The thicknesses and doping level of the individual layers were controlled by in situ spectroscopic ellipsometry, enabling to tune the reflectance peak to the wavelength range of diamond color centers, such as NV{sup 0} or NV{sup ?}. The crystalline quality, periodicity, and sharpness of the doping transitions in these doping superlattices over tens of periods were confirmed by high resolution X-ray diffraction.

  8. Boron-doped superlattices and Bragg mirrors in diamond

    NASA Astrophysics Data System (ADS)

    Fiori, A.; Bousquet, J.; Eon, D.; Omnès, F.; Bellet-Amalric, E.; Bustarret, E.

    2014-08-01

    A periodic modulation of the boron doping level of single crystal diamond multilayers over more than three orders of magnitude during epitaxial growth by microwave plasma-enhanced chemical vapor deposition is shown to yield Bragg mirrors in the visible. The thicknesses and doping level of the individual layers were controlled by in situ spectroscopic ellipsometry, enabling to tune the reflectance peak to the wavelength range of diamond color centers, such as NV0 or NV-. The crystalline quality, periodicity, and sharpness of the doping transitions in these doping superlattices over tens of periods were confirmed by high resolution X-ray diffraction.

  9. DIAMOND PEAK WILDERNESS, OREGON.

    USGS Publications Warehouse

    Sherrod, David R.; Moyle, Phillip R.

    1984-01-01

    No metallic mineral resources were identified during a mineral survey of the Diamond Peak Wilderness in Oregon. Cinder cones within the wilderness contain substantial cinder resources, but similar deposits that are more accessible occur outside the wilderness. The area could have geothermal resources, but available data are insufficient to evaluate their potential. Several deep holes could be drilled in areas of the High Cascades outside the wilderness, from which extrapolations of the geothermal potential of the several Cascade wilderness could be made.

  10. DIAMOND SECONDARY EMITTER

    SciTech Connect

    BEN-ZVI, I.; RAO, T.; BURRILL, A.; CHANG, X.; GRIMES, J.; RANK, J.; SEGALOV, Z.; SMEDLEY, J.

    2005-10-09

    We present the design and experimental progress on the diamond secondary emitter as an electron source for high average power injectors. The design criteria for average currents up to 1 A and charge up to 20 nC are established. Secondary Electron Yield (SEY) exceeding 200 in transmission mode and 50 in emission mode have been measured. Preliminary results on the design and fabrication of the self contained capsule with primary electron source and secondary electron emitter will also be presented.

  11. Diamond turning of glass

    SciTech Connect

    Blackley, W.S.; Scattergood, R.O.

    1988-12-01

    A new research initiative will be undertaken to investigate the critical cutting depth concepts for single point diamond turning of brittle, amorphous materials. Inorganic glasses and a brittle, thermoset polymer (organic glass) are the principal candidate materials. Interrupted cutting tests similar to those done in earlier research are Ge and Si crystals will be made to obtain critical depth values as a function of machining parameters. The results will provide systematic data with which to assess machining performance on glasses and amorphous materials

  12. Conversion of p-type to n-type diamond by exposure to a deuterium plasma

    SciTech Connect

    Kalish, R.; Saguy, C.; Cytermann, C.; Chevallier, J.; Teukam, Z.; Jomard, F.; Kociniewski, T.; Ballutaud, D.; Butler, J.E.; Baron, C.; Deneuville, A.

    2004-12-15

    The lack of a shallow donor in diamond with reasonable room temperature conductivity has been a major obstacle, until now, for the realization of many diamond based electronic devices. Most recently it has been shown that exposure of p-type (B doped) homoepitaxial diamond layers to a deuterium plasma can result in the formation of n-type diamond with a shallow donor state (E{sub a}=0.34 eV) and high room temperature mobility (430 cm{sup 2}/V s) [Z. Teukam et al., Nat. Mater. 2, 482 (2003); C. Saguy et al., Diamond Relat. Mater. 13, 700 (2004)]. Experimental results, based on the comparison of secondary ion mass spectrometry profiles of B and D and Hall effect measurements at different temperatures are presented. They confirm the previous speculation that some deuterium related complex is responsible for the donor activity in diamond. These donors are shown to be formed in a two-step process. First, deuterium diffuses into the entire B containing layer rather slowly, being trapped by the boron acceptors and passivating them. Once all B have formed complexes, further exposure to a D plasma results in the formation of a layer that contains about twice as many D atoms as the B content. This step is the one that gives rise to the excellent n-type features observed. The most recent theoretical attempts to explain the donor state by simulations of various boron-hydrogen complexes in diamond are reviewed.

  13. Conversion of fullerenes to diamonds

    DOEpatents

    Gruen, Dieter M. (1324 59th St., Downers Grove, IL 60515)

    1995-01-01

    A method of forming synthetic diamond or diamond-like films on a substrate surface. The method involves the steps of providing a vapor selected from the group of fullerene molecules or an inert gas/fullerene molecule mixture, providing energy to the fullerene molecules consisting of carbon-carbon bonds, the energized fullerene molecules breaking down to form fragments of fullerene molecules including C.sub.2 molecules and depositing the energized fullerene molecules with C.sub.2 fragments onto the substrate with farther fragmentation occurring and forming a thickness of diamond or diamond-like films on the substrate surface.

  14. Diamonds in ophiolites: Contamination or a new diamond growth environment?

    NASA Astrophysics Data System (ADS)

    Howell, D.; Griffin, W. L.; Yang, J.; Gain, S.; Stern, R. A.; Huang, J.-X.; Jacob, D. E.; Xu, X.; Stokes, A. J.; O'Reilly, S. Y.; Pearson, N. J.

    2015-11-01

    For more than 20 years, the reported occurrence of diamonds in the chromites and peridotites of the Luobusa massif in Tibet (a complex described as an ophiolite) has been widely ignored by the diamond research community. This skepticism has persisted because the diamonds are similar in many respects to high-pressure high-temperature (HPHT) synthetic/industrial diamonds (grown from metal solvents), and the finding previously has not been independently replicated. We present a detailed examination of the Luobusa diamonds (recovered from both peridotites and chromitites), including morphology, size, color, impurity characteristics (by infrared spectroscopy), internal growth structures, trace-element patterns, and C and N isotopes. A detailed comparison with synthetic industrial diamonds shows many similarities. Cubo-octahedral morphology, yellow color due to unaggregated nitrogen (C centres only, Type Ib), metal-alloy inclusions and highly negative ?13C values are present in both sets of diamonds. The Tibetan diamonds (n = 3) show an exceptionally large range in ?15N (-5.6 to + 28.7 ‰) within individual crystals, and inconsistent fractionation between {111} and {100} growth sectors. This in contrast to large synthetic HPHT diamonds grown by the temperature gradient method, which have with ?15N = 0 ‰ in {111} sectors and + 30 ‰ in {100} sectors, as reported in the literature. This comparison is limited by the small sample set combined with the fact the diamonds probably grew by different processes. However, the Tibetan diamonds do have generally higher concentrations and different ratios of trace elements; most inclusions are a NiMnCo alloy, but there are also some small REE-rich phases never seen in HPHT synthetics. These characteristics indicate that the Tibetan diamonds grew in contact with a C-saturated Ni-Mn-Co-rich melt in a highly reduced environment. The stable isotopes indicate a major subduction-related contribution to the chemical environment. The unaggregated nitrogen, combined with the lack of evidence for resorption or plastic deformation, suggests a short (geologically speaking) residence in the mantle. Previously published models to explain the occurrence of the diamonds, and other phases indicative of highly reduced conditions and very high pressures, have failed to take into account the characteristics of the diamonds and the implications for their formation. For these diamonds to be seriously considered as the result of a natural growth environment requires a new understanding of mantle conditions that could produce them.

  15. Monolithic diamond Raman laser.

    PubMed

    Reilly, Sean; Savitski, Vasili G; Liu, Hangyu; Gu, Erdan; Dawson, Martin D; Kemp, Alan J

    2015-03-15

    A monolithic diamond Raman laser is reported. It utilizes a 13-mm radius of curvature lens etched onto the diamond surface and dielectric mirror coatings to form a stable resonator. The performance is compared to that of a monolithic diamond Raman laser operating in a plane-plane cavity. On pumping with a compact Q-switched laser at 532 nm (16 ?J pulse energy; 1.5 ns pulse duration; 10 kHz repetition-rate; M2<1.5), laser action was observed at the first, second, and third Stokes wavelengths (573 nm, 620 nm and 676 nm, respectively) in both cases. For the microlens cavity, a conversion efficiency of 84% was achieved from the pump to the total Raman output power, with a slope efficiency of 88%. This compares to a conversion efficiency of 59% and a slope efficiency of 74% for the plane-plane case. Total Raman output powers of 134 and 96 mW were achieved for the microlens and plane-plane cavities, respectively. PMID:25768149

  16. DIAMOND AMPLIFIER FOR PHOTOCATHODES.

    SciTech Connect

    RAO,T.; BEN-ZVI,I.; BURRILL,A.; CHANG,X.; HULBERT,S.; JOHNSON,P.D.; KEWISCH,J.

    2004-06-21

    We report a new approach to the generation of high-current, high-brightness electron beams. Primary electrons are produced by a photocathode (or other means) and are accelerated to a few thousand electron-volts, then strike a specially prepared diamond window. The large Secondary Electron Yield (SEY) provides a multiplication of the number of electrons by about two orders of magnitude. The secondary electrons drift through the diamond under an electric field and emerge into the accelerating proper of the ''gun'' through a Negative Electron Affinity surface of the diamond. The advantages of the new approach include the following: (1) Reduction of the number of primary electrons by the large SEY, i.e. a very low laser power in a photocathode producing the primaries. (2) Low thermal emittance due to the NEA surface and the rapid thermalization of the electrons. (3) Protection of the cathode from possible contamination from the gun, allowing the use of large quantum efficiency but sensitive cathodes. (4) Protection of the gun from possible contamination by the cathode, allowing the use of superconducting gun cavities. (5) Production of high average currents, up to ampere class. (6) Encapsulated design, making the ''load-lock'' systems unnecessary. This paper presents the criteria that need to be taken into account in designing the amplifier.

  17. Influence of diamond surface termination on thermal boundary conductance between Al and diamond

    SciTech Connect

    Monachon, Christian; Weber, Ludger

    2013-05-14

    The effect of diamond surface treatment on the Thermal Boundary Conductance (TBC) between Al and diamond is investigated. The treatments consist in either of the following: exposition to a plasma of pure Ar, Ar:H and Ar:O, and HNO{sub 3}:H{sub 2}SO{sub 4} acid dip for various times. The surface of diamond after treatment is analyzed by X-ray Photoelectron Spectroscopy, revealing hydrogen termination for the as-received and Ar:H plasma treated samples, pure sp{sup 2} termination for Ar treated ones and oxygen (keton-like) termination for the other treatments. At ambient, all the specific treatments improve the TBC between Al and diamond from 23 {+-} 2 MW m{sup -2} K{sup -1} for the as-received to 65 {+-} 5, 125 {+-} 20, 150 {+-} 20, 180 {+-} 20 MW m{sup -2} K{sup -1} for the ones treated by Ar:H plasma, acid, pure Ar plasma, and Ar:O plasma with an evaporated Al layer on top, respectively. The effect of these treatments on temperature dependence are also observed and compared with the most common models available in the literature as well as experimental values in the same system. The results obtained show that the values measured for an Ar:O plasma treated diamond with Al sputtered on top stay consistently higher than the values existing in the literature over a temperature range from 78 to 290 K, probably due a lower sample surface roughness. Around ambient, the TBC values measured lay close to or even somewhat above the radiation limit, suggesting that inelastic or electronic processes may influence the transfer of heat at this metal/dielectric interface.

  18. Influence of diamond surface termination on thermal boundary conductance between Al and diamond

    NASA Astrophysics Data System (ADS)

    Monachon, Christian; Weber, Ludger

    2013-05-01

    The effect of diamond surface treatment on the Thermal Boundary Conductance (TBC) between Al and diamond is investigated. The treatments consist in either of the following: exposition to a plasma of pure Ar, Ar:H and Ar:O, and HNO3:H2SO4 acid dip for various times. The surface of diamond after treatment is analyzed by X-ray Photoelectron Spectroscopy, revealing hydrogen termination for the as-received and Ar:H plasma treated samples, pure sp2 termination for Ar treated ones and oxygen (keton-like) termination for the other treatments. At ambient, all the specific treatments improve the TBC between Al and diamond from 23 ± 2 MW m-2 K-1 for the as-received to 65 ± 5, 125 ± 20, 150 ± 20, 180 ± 20 MW m-2 K-1 for the ones treated by Ar:H plasma, acid, pure Ar plasma, and Ar:O plasma with an evaporated Al layer on top, respectively. The effect of these treatments on temperature dependence are also observed and compared with the most common models available in the literature as well as experimental values in the same system. The results obtained show that the values measured for an Ar:O plasma treated diamond with Al sputtered on top stay consistently higher than the values existing in the literature over a temperature range from 78 to 290 K, probably due a lower sample surface roughness. Around ambient, the TBC values measured lay close to or even somewhat above the radiation limit, suggesting that inelastic or electronic processes may influence the transfer of heat at this metal/dielectric interface.

  19. IEEE ELECTRON DEVICE LETTERS, VOL. 32, NO. 5, MAY 2011 599 Scaling of Hydrogen-Terminated Diamond FETs

    E-print Network

    Bristol, University of

    created in a 1-kW microwave plasma. The process flow used for device realization is similar-state device solution. The high-frequency performance of diamond FETs has seen continuous improve- ment through was achieved by exposure of the diamond surface to oxygen plasma after removal of the Au layer by KI wet etch

  20. Friction and Wear Properties of As-Deposited and Carbon Ion-Implanted Diamond Films

    NASA Technical Reports Server (NTRS)

    Miyoshi, Kazuhisa

    1996-01-01

    Recent work on the friction and wear properties of as-deposited and carbon ion-implanted diamond films was reviewed. Diamond films were produced by the microwave plasma chemical vapor deposition (CVD) technique. Diamond films with various grain sizes and surface roughnesses were implanted with carbon ions at 60 keV ion energy, resulting in a dose of 1.2 x 10(exp 17) carbon ions per cm(exp 2). Various analytical techniques, including Raman spectroscopy, proton recoil analysis, Rutherford backscattering, transmission and scanning electron microscopy, X-ray photoelectron spectroscopy, and X-ray diffraction, were utilized to characterize the diamond films. Sliding friction experiments were conducted with a polished natural diamond pin in contact with diamond films in the three environments: humid air (40% relative humidity), dry nitrogen (less than 1 percent relative humidity), and ultrahigh vacuum (10(exp -7) Pa). The CVD diamond films indeed have friction and wear properties similar to those of natural diamond in the three environments. The as-deposited, fine-grain diamond films can be effectively used as self-lubricating, wear-resistant coatings that have low coefficients of friction (0.02 to 0.04) and low wear rates (10(exp -7) to lO(exp -8) mm(exp 3) N(exp -1) m(exp -1)) in both humid air and dry nitrogen. However, they have high coefficients of friction (1.5 to 1.7) and a high wear rate (10(exp -4) mm(exp 7) N(exp -1) m(exp -1)) in ultrahigh vacuum. The carbon ion implantation produced a thin surficial layer (less than 0.1 micron thick) of amorphous, non-diamond carbon on the diamond films. In humid air and dry nitrogen, the ion-implanted, fine and coarse-grain diamond films have a low coefficient of friction (around 0.1) and a low wear rate (10(exp -7) mm(exp 3) N(exp -1) m(exp-1)). Even in ultrahigh vacuum, the presence of the non-diamond carbon layer reduced the coefficient of friction of fine-grain diamond films to 0.1 or lower and the wear rate to 10(exp -6) mm(exp 3) N(exp -1) m(exp -1). Thus, the carbon ion-implanted, fine-grain diamond films can be effectively used as wear-resistant, self-lubricating coatings not only in air and dry nitrogen, but also in ultrahigh vacuum.

  1. Raman and conductivity studies of boron doped microcrystalline diamond, facetted nanocrystalline diamond and cauliflower diamond films

    NASA Astrophysics Data System (ADS)

    May, P. W.; Ludlow, W. J.; Hannaway, M.; Heard, P. J.; Smith, J. A.; Rosser, K. N.

    2007-09-01

    We present data showing how the electrical conductivity and Raman spectra of boron-doped CVD diamond films vary with both B content and crystallite size, for microcrystalline diamond (MCD), facetted nanocrystalline diamond (f-NCD) and 'cauliflower' diamond (c-NCD). The position of the Lorentzian contribution to the 500 cm -1 Raman feature was used to estimate the B content. This underestimated the SIMS concentration of B by a factor of ˜5 for the f-NCD and c-NCD films, but remained reasonably accurate for MCD films. One explanation for this is that most of the B incorporates at the grain boundaries and not in substitutional sites.

  2. Improving nanocrystalline diamond coatings for micro end mills

    NASA Astrophysics Data System (ADS)

    Heaney, Patrick J.

    A new method is presented for coating 300 mum diameter tungsten carbide (WC) micro end mills with diamond using a hot filament chemical vapor deposition (HF-CVD) method. This method has been developed to create uniform, conformal and continuous diamond coatings. Initial work is shown to prove the feasibility and concept of the project. This was the first work known to coat and evaluate the machining performance WC micro end mills. The performance of uncoated and coated micro end mills was evaluated by dry machining channels in 6061-T6 aluminum. The test results showed a 75% and 90% decrease in both cutting and trust forces for machining, respectfully. The coated tools produced a more predictable surface finish with no burring. These improved results are due to the superior tribological properties of diamond against aluminum. Initial results indicated severe problems with coating delamination causing complete tool failure. After proving the initial concept, new methods for optimizing the coating and improving performance were studied. Each optimization step is monitored through surface analysis techniques to monitor changes in coating morphology and diamond quality. Nucleation density was increased by improving the seed method, using ultra dispersed diamond (UDD) seed. The increase in nucleation density allowed the synthesis of coatings as thin as 60 nm. The adhesion of the coating to the tool was improved through carbon ion implantation (CII). CII is a different surface preparation technique that deactivates the effect of Co, while not weakening the tool. CII also creates a great nucleation layer which diamond can directly grow from, allowing the diamond coating to chemically bond to the substrate improving adhesion and eliminating the need for a seed layer. These thin coatings were shown to be of high quality sp3 trigonaly bonded diamond that resulted in lower machining forces with less delamination. The 90% reduction in machining forces that thin conformal diamond coatings can achieve for micro end mills directly influences the accuracy of parts and the speed with which they can be made. A 50% reduction in forces could be used to double the material removal rate, cutting the part machining cost in half.

  3. Fabrication of UV Photodetector on TiO2/Diamond Film.

    PubMed

    Liu, Zhangcheng; Li, Fengnan; Li, Shuoye; Hu, Chao; Wang, Wei; Wang, Fei; Lin, Fang; Wang, Hongxing

    2015-01-01

    The properties of ultraviolet (UV) photodetector fabricated on TiO2/diamond film were investigated. Single crystal diamond layer was grown on high-pressure-high-temperature Ib-type diamond substrate by microwave plasma chemical vapor deposition method, upon which TiO2 film was prepared directly using radio frequency magnetron sputtering technique in Ar and O2 mixing atmosphere. Tungsten was used as electrode material to fabricate metal-semiconductor-metal UV photodetector. The dark current is measured to be 1.12?pA at 30?V. The photo response of the device displays an obvious selectivity between UV and visible light, and the UV-to-visible rejection ratio can reach 2 orders of magnitude. Compared with that directly on diamond film, photodetector on TiO2/diamond film shows higher responsivity. PMID:26399514

  4. Fabrication of UV Photodetector on TiO2/Diamond Film

    PubMed Central

    Liu, Zhangcheng; Li, Fengnan; Li, Shuoye; Hu, Chao; Wang, Wei; Wang, Fei; Lin, Fang; Wang, Hongxing

    2015-01-01

    The properties of ultraviolet (UV) photodetector fabricated on TiO2/diamond film were investigated. Single crystal diamond layer was grown on high-pressure-high-temperature Ib-type diamond substrate by microwave plasma chemical vapor deposition method, upon which TiO2 film was prepared directly using radio frequency magnetron sputtering technique in Ar and O2 mixing atmosphere. Tungsten was used as electrode material to fabricate metal-semiconductor-metal UV photodetector. The dark current is measured to be 1.12?pA at 30?V. The photo response of the device displays an obvious selectivity between UV and visible light, and the UV-to-visible rejection ratio can reach 2 orders of magnitude. Compared with that directly on diamond film, photodetector on TiO2/diamond film shows higher responsivity. PMID:26399514

  5. Fabrication of UV Photodetector on TiO2/Diamond Film

    NASA Astrophysics Data System (ADS)

    Liu, Zhangcheng; Li, Fengnan; Li, Shuoye; Hu, Chao; Wang, Wei; Wang, Fei; Lin, Fang; Wang, Hongxing

    2015-09-01

    The properties of ultraviolet (UV) photodetector fabricated on TiO2/diamond film were investigated. Single crystal diamond layer was grown on high-pressure-high-temperature Ib-type diamond substrate by microwave plasma chemical vapor deposition method, upon which TiO2 film was prepared directly using radio frequency magnetron sputtering technique in Ar and O2 mixing atmosphere. Tungsten was used as electrode material to fabricate metal-semiconductor-metal UV photodetector. The dark current is measured to be 1.12?pA at 30?V. The photo response of the device displays an obvious selectivity between UV and visible light, and the UV-to-visible rejection ratio can reach 2 orders of magnitude. Compared with that directly on diamond film, photodetector on TiO2/diamond film shows higher responsivity.

  6. Ab initio structure determination of n-diamond

    PubMed Central

    Li, Da; Tian, Fubo; Chu, Binhua; Duan, Defang; Sha, Xiaojing; Lv, Yunzhou; Zhang, Huadi; Lu, Nan; Liu, Bingbing; Cui, Tian

    2015-01-01

    A systematic computational study on the crystal structure of n-diamond has been performed using first-principle methods. A novel carbon allotrope with hexagonal symmetry R32 space group has been predicted. We name it as HR-carbon. HR-carbon composed of lonsdaleite layers and unique C3 isosceles triangle rings, is stable over graphite phase above 14.2?GPa. The simulated x-ray diffraction pattern, Raman, and energy-loss near-edge spectrum can match the experimental results very well, indicating that HR-carbon is a likely candidate structure for n-diamond. HR-carbon has an incompressible atomic arrangement because of unique C3 isosceles triangle rings. The hardness and bulk modulus of HR-carbon are calculated to be 80?GPa and 427?GPa, respectively, which are comparable to those of diamond. C3 isosceles triangle rings are very important for the stability and hardness of HR-carbon. PMID:26299905

  7. Ab initio structure determination of n-diamond

    NASA Astrophysics Data System (ADS)

    Li, Da; Tian, Fubo; Chu, Binhua; Duan, Defang; Sha, Xiaojing; Lv, Yunzhou; Zhang, Huadi; Lu, Nan; Liu, Bingbing; Cui, Tian

    2015-08-01

    A systematic computational study on the crystal structure of n-diamond has been performed using first-principle methods. A novel carbon allotrope with hexagonal symmetry R32 space group has been predicted. We name it as HR-carbon. HR-carbon composed of lonsdaleite layers and unique C3 isosceles triangle rings, is stable over graphite phase above 14.2?GPa. The simulated x-ray diffraction pattern, Raman, and energy-loss near-edge spectrum can match the experimental results very well, indicating that HR-carbon is a likely candidate structure for n-diamond. HR-carbon has an incompressible atomic arrangement because of unique C3 isosceles triangle rings. The hardness and bulk modulus of HR-carbon are calculated to be 80?GPa and 427?GPa, respectively, which are comparable to those of diamond. C3 isosceles triangle rings are very important for the stability and hardness of HR-carbon.

  8. Deuterium-induced passivation of boron acceptors in polycrystalline diamond

    NASA Astrophysics Data System (ADS)

    Habka, N.; Chikoidze, E.; Jomard, F.; Dumont, Y.; Chevallier, J.; Barjon, J.; Mer, C.; Bergonzo, P.

    2010-12-01

    In monocrystalline boron-doped diamond (BDD), the diffusion of deuterium induces an electrical passivation of acceptors by the formation of (B,D) complexes. However, device applications based on this process are presently limited by the small size of available monocrystalline substrates. In this work, we show that the grain size of polycrystalline diamond is a key parameter in order to achieve efficient deuterium diffusion by trapping on boron atoms. As a result, we present the first clear evidences of the electrical passivation of boron acceptors in the case of polycrystalline diamond layers with an average grain size of 50 ?m. We show that, for a boron concentration of 2×1019 cm-3, the room temperature hole mobility increases from 70 to 120 cm2 V-1 s-1 after deuteration. More surprisingly, the compensation ratio keeps the same order of magnitude which suggests a passivation effect on both acceptors and donors.

  9. GaN heterostructures with diamond and graphene

    NASA Astrophysics Data System (ADS)

    Pécz, B.; Tóth, L.; Tsiakatouras, G.; Adikimenakis, A.; Kovács, A.; Duchamp, M.; Dunin-Borkowski, R. E.; Yakimova, R.; Neumann, P. L.; Behmenburg, H.; Foltynski, B.; Giesen, C.; Heuken, M.; Georgakilas, A.

    2015-11-01

    The full performance of GaN devices for high power applications is not exploited due to their self-heating. Possible solutions are the integration of materials with high heat conductivity i.e., single crystalline diamond and graphene layers. We report the growth of single crystalline (0001)-oriented GaN thin films on (100), (110) and (111) diamond single crystals studied by transmission electron microscopy (TEM) in cross-sections. As for graphene, we show a high quality GaN layer that was deposited on patterned graphene layers and 6H-SiC. The atomic structures of the interfaces in the heterostructure are studied using aberration-corrected scanning TEM combined with energy dispersive x-ray and electron energy-loss spectroscopy.

  10. Microwave plasma enhanced chemical vapor deposition of nanocrystalline diamond films by bias-enhanced nucleation and bias-enhanced growth

    SciTech Connect

    Chu, Yueh-Chieh; Tzeng, Yonhua; Auciello, Orlando

    2014-01-14

    Effects of biasing voltage-current relationship on microwave plasma enhanced chemical vapor deposition of ultrananocrystalline diamond (UNCD) films on (100) silicon in hydrogen diluted methane by bias-enhanced nucleation and bias-enhanced growth processes are reported. Three biasing methods are applied to study their effects on nucleation, growth, and microstructures of deposited UNCD films. Method A employs 320?mA constant biasing current and a negative biasing voltage decreasing from ?490?V to ?375?V for silicon substrates pre-heated to 800?°C. Method B employs 400?mA constant biasing current and a decreasing negative biasing voltage from ?375?V to ?390?V for silicon pre-heated to 900?°C. Method C employs ?350?V constant biasing voltage and an increasing biasing current up to 400?mA for silicon pre-heated to 800?°C. UNCD nanopillars, merged clusters, and dense films with smooth surface morphology are deposited by the biasing methods A, B, and C, respectively. Effects of ion energy and flux controlled by the biasing voltage and current, respectively, on nucleation, growth, microstructures, surface morphologies, and UNCD contents are confirmed by scanning electron microscopy, high-resolution transmission-electron-microscopy, and UV Raman scattering.

  11. Chemical Vapor-Deposited (CVD) Diamond Films for Electronic Applications

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Diamond films have a variety of useful applications as electron emitters in devices such as magnetrons, electron multipliers, displays, and sensors. Secondary electron emission is the effect in which electrons are emitted from the near surface of a material because of energetic incident electrons. The total secondary yield coefficient, which is the ratio of the number of secondary electrons to the number of incident electrons, generally ranges from 2 to 4 for most materials used in such applications. It was discovered recently at the NASA Lewis Research Center that chemical vapor-deposited (CVD) diamond films have very high secondary electron yields, particularly when they are coated with thin layers of CsI. For CsI-coated diamond films, the total secondary yield coefficient can exceed 60. In addition, diamond films exhibit field emission at fields orders of magnitude lower than for existing state-of-the-art emitters. Present state-of-the-art microfabricated field emitters generally require applied fields above 5x10^7 V/cm. Research on field emission from CVD diamond and high-pressure, high-temperature diamond has shown that field emission can be obtained at fields as low as 2x10^4 V/cm. It has also been shown that thin layers of metals, such as gold, and of alkali halides, such as CsI, can significantly increase field emission and stability. Emitters with nanometer-scale lithography will be able to obtain high-current densities with voltages on the order of only 10 to 15 V.

  12. Diamond detectors in particle physics

    NASA Astrophysics Data System (ADS)

    Tapper, R. J.

    2000-08-01

    Particle detectors made from artificial diamond have great promise for future experiments in particle physics because they are far less vulnerable to radiation damage than any other detector type. We review the history of diamond detectors and describe their current state of development. We also discuss the evidence which proves the resistance of these detectors to damage by various forms of incident radiation.

  13. Theoretical investigation of the electronic structure and quantum transport in the graphene-C(111) diamond surface system

    NASA Astrophysics Data System (ADS)

    Selli, Daniele; Baburin, Igor; Leoni, Stefano; Zhu, Zhen; Tománek, David; Seifert, Gotthard

    2013-10-01

    We investigate the interaction of a graphene monolayer with the C(111) diamond surface using ab initio density functional theory. To accommodate the lattice mismatch between graphene and diamond, the overlayer deforms into a wavy structure that binds strongly to the diamond substrate. The detached ridges of the wavy graphene overlayer behave electronically as free-standing polyacetylene chains with delocalized ? electrons, separated by regions containing only sp3 carbon atoms covalently bonded to the (111) diamond surface. We performed quantum transport calculations for different geometries of the system to study how the buckling of the graphene layer and the associated bonding to the diamond substrate affect the transport properties. The system displays high carrier mobility along the ridges and a wide transport gap in the direction normal to the ridges. These intriguing, strongly anisotropic transport properties qualify the hybrid graphene-diamond system as a viable candidate for electronic nanodevices.

  14. Theoretical investigation of the electronic structure and quantum transport in the graphene-C(111) diamond surface system.

    PubMed

    Selli, Daniele; Baburin, Igor; Leoni, Stefano; Zhu, Zhen; Tománek, David; Seifert, Gotthard

    2013-10-30

    We investigate the interaction of a graphene monolayer with the C(111) diamond surface using ab initio density functional theory. To accommodate the lattice mismatch between graphene and diamond, the overlayer deforms into a wavy structure that binds strongly to the diamond substrate. The detached ridges of the wavy graphene overlayer behave electronically as free-standing polyacetylene chains with delocalized ? electrons, separated by regions containing only sp(3) carbon atoms covalently bonded to the (111) diamond surface. We performed quantum transport calculations for different geometries of the system to study how the buckling of the graphene layer and the associated bonding to the diamond substrate affect the transport properties. The system displays high carrier mobility along the ridges and a wide transport gap in the direction normal to the ridges. These intriguing, strongly anisotropic transport properties qualify the hybrid graphene-diamond system as a viable candidate for electronic nanodevices. PMID:24096938

  15. Friction and Wear Properties of As-deposited and Carbon Ion-implanted Diamond Films

    NASA Technical Reports Server (NTRS)

    Miyoshi, Kazuhisa

    1994-01-01

    Recent work on the friction and wear properties of as-deposited and carbon ion-implanted diamond films was reviewed. Diamond films were produced by the microwave plasma chemical vapor deposition (CVD) technique. Diamond films with various grain sizes and surface roughnesses were implanted with carbon ions at 60 ke V ion energy, resulting in a dose of 1.2310(exp 17) carbon ions/cm(exp 2). Various analytical techniques, including Raman spectroscopy, proton recoil analysis, Rutherford backscattering, transmission and scanning electron microscopy, x-ray photoelectron spectroscopy, and x-ray diffraction, were utilized to characterize the diamond films. Sliding friction experiments were conducted with a polished natural diamond pin in contact with diamond films in the three environments: humid air (40 percent relative humidity), dry nitrogen (less than 1 percent relative humidity), and ultrahigh vacuum (10(exp -7) Pa). The CVD diamond films indeed have friction and were properties similar to those of natural diamond in the three environments. The as-deposited, fine-grain diamond films can be effectively used as self-lubricating, wear-resistant coatings that have low coefficients of friction (0.02 to 0.04) and low wear rates (10(exp -7) to 10(exp -8)mm(exp 3)/N-m) in both humid air and dry nitrogen. However, they have high coefficients of friction (1.5 to 1.7) and a high wear rate (10(exp -4)mm(exp 3/N-m) in ultrahigh vacuum. The carbon ion implanation produced a thin surficial layer (less than 0.1 micron thick) of amorphous, nondiamond carbon on the diamond films. In humid air and dry nitrogen, the ion-implanted, fine- and coarse-grain diamond films have a low coefficient of friction (around 0.1) and a low wear rate (10(exp -7)mm(exp 3/N-m). Even in ultrahigh vacuum, the presence of the nondiamond carbon layer reduced the coefficient of friction of fine-grain diamond films to 0.1 or lower and the wear rate to 10(exp -6)mm(exp 3)/N-m. Thus, the carbon ion-implanted, fine-grain diamond films can be effectively used as wear-resistant, self-lubricating coatings not only in air and dry nitrogen, but also in ultrahigh vacuum. The wear mechanism of diamond films is that of small fragments chipping off the surface. The size of wear particles is related to the extent of wear rates.

  16. Diamonds in particle by Thibaut Mueller

    E-print Network

    Budker, Dmitry

    Diamonds in particle detectors by Thibaut Mueller Physics H190, March 30th 2011 1 #12;2 Overview" readout, rebuild tracks 6 #12;Diamonds have properties that make them advantageous for detectors · currently use silicon strips/ pixel · plans to replace with diamonds for sLHC upgrade · use of diamonds

  17. Comparisons of Scintillating Fiber, Diamond Particle Detector

    E-print Network

    McDonald, Kirk

    Comparisons of Scintillating Fiber, Diamond Particle Detector and Beam Current Transformer T. Tsang TP #12;Diamond particle detector Shot # 17017 Shot # 17006 typical diamond detector signal trace from Marcus Palm #12;Nov. 11, 2007, 17000 series data Red: x, diamond particle detector signal @ left 20o

  18. Hybrid Group IV Nanophotonic Structures Incorporating Diamond Silicon-Vacancy Color Centers

    E-print Network

    Zhang, Jingyuan Linda; Babinec, Thomas M; Radulaski, Marina; Müller, Kai; Lagoudakis, Konstantinos G; Dahl, Jeremy; Edgington, Robert; Soulière, Veronique; Ferro, Gabriel; Fokin, Andrey A; Schreiner, Peter R; Shen, Zhi-Xun; Melosh, Nicholas A; Vu?kovi?, Jelena

    2015-01-01

    We demonstrate a new approach for engineering group IV semiconductor-based quantum photonic structures containing negatively charged silicon-vacancy (SiV$^-$) color centers in diamond as quantum emitters. Hybrid SiC/diamond structures are realized by combining the growth of nanoand micro-diamonds on silicon carbide (3C or 4H polytype) substrates, with the subsequent use of these diamond crystals as a hard mask for pattern transfer. SiV$^-$ color centers are incorporated in diamond during its synthesis from molecular diamond seeds (diamondoids), with no need for ionimplantation or annealing. We show that the same growth technique can be used to grow a diamond layer controllably doped with SiV$^-$ on top of a high purity bulk diamond, in which we subsequently fabricate nanopillar arrays containing high quality SiV$^-$ centers. Scanning confocal photoluminescence measurements reveal optically active SiV$^-$ lines both at room temperature and low temperature (5 K) from all fabricated structures, and, in particula...

  19. Electrochemically grafted polypyrrole changes photoluminescence of electronic states inside nanocrystalline diamond

    SciTech Connect

    Galá?, P. Malý, P.; ?ermák, J.; Kromka, A.; Rezek, B.

    2014-12-14

    Hybrid diamond-organic interfaces are considered attractive for diverse applications ranging from electronics and energy conversion to medicine. Here we use time-resolved and time-integrated photoluminescence spectroscopy in visible spectral range (380–700?nm) to study electronic processes in H-terminated nanocrystalline diamond films (NCD) with 150?nm thin, electrochemically deposited polypyrrole (PPy) layer. We observe changes in dynamics of NCD photoluminescence as well as in its time-integrated spectra after polymer deposition. The effect is reversible. We propose a model where the PPy layer on the NCD surface promotes spatial separation of photo-generated charge carriers both in non-diamond carbon phase and in bulk diamond. By comparing different NCD thicknesses we show that the effect goes as much as 200?nm deep inside the NCD film.

  20. Investigation of nucleation and growth processes of diamond films by atomic force microscopy

    NASA Technical Reports Server (NTRS)

    George, M. A.; Burger, A.; Collins, Warren E.; Hu, Z.

    1995-01-01

    The nucleation and growth of plasma enhanced chemical vapor deposited (PECVD) polycrystalline diamond films were studied using atomic force microscopy (AFM). AFM images were obtained for: (1) nucleated diamond films produced from depositions that were terminated during the initial stages of growth, (2) the silicon substrate-diamond film interface side of diamond films (1-4 micrometers thick) removed from the original surface of the substrate, and (3) cross-sectional fracture surface of the film, including the Si/diamond interface. Pronounced tip effects were observed for early-stage diamond nucleation attributed to tip convolution in the AFM images. AFM images of the films cross-section and interface however were not affected by tip convolution, and the images indicate that the surface of the silicon substrate is initially covered by small grained polycrystalline-like film and the formation of this precursor film is followed by nucleation of the diamond film on top of this layer. X-ray photoelectron spectroscoy (XPS) spectra indicates that some silicon carbide is present in the precursor layer.

  1. Investigation of nucleation and growth processes of diamond films by atomic force microscopy

    NASA Technical Reports Server (NTRS)

    George, M. A.; Burger, A.; Collins, W. E.; Davidson, J. L.; Barnes, A. V.; Tolk, N. H.

    1994-01-01

    The nucleation and growth of plasma-enhanced chemical-vapor deposited polycrystalline diamond films were studied using atomic force microscopy (AFM). AFM images were obtained for (1) nucleated diamond films produced from depositions that were terminated during the initial stages of growth, (2) the silicon substrate-diamond film interface side of diamond films (1-4 micrometers thick) removed from the original surface of the substrate, and (3) the cross-sectional fracture surface of the film, including the Si/diamond interface. Pronounced tip effects were observed for early-stage diamond nucleation attributed to tip convolution in the AFM images. AFM images of the film's cross section and interface, however, were not highly affected by tip convolution, and the images indicate that the surface of the silicon substrate is initially covered by a small grained polycrystalline-like film and the formation of this precursor film is followed by nucleation of the diamond film on top of this layer. X-ray photoelectron spectroscopy spectra indicate that some silicon carbide is present in the precursor layer.

  2. Electron energy loss spectrometry of interstellar diamonds

    NASA Technical Reports Server (NTRS)

    Bernatowicz, Thomas J.; Gibbons, Patrick C.; Lewis, Roy S.

    1990-01-01

    The results are reported of electron energy loss spectra (EELS) measurements on diamond residues from carbonaceous meteorites designed to elucidate the structure and composition of interstellar diamonds. Dynamic effective medium theory is used to model the dielectric properties of the diamonds and in particular to synthesize the observed spectra as mixtures of diamond and various pi-bonded carbons. The results are shown to be quantitatively consistent with the idea that diamonds and their surfaces are the only contributors to the electron energy loss spectra of the diamond residues and that these peculiar spectra are the result of the exceptionally small grain size and large specific surface area of the interstellar diamonds.

  3. Subpicotesla Diamond Magnetometry

    NASA Astrophysics Data System (ADS)

    Wolf, Thomas; Neumann, Philipp; Nakamura, Kazuo; Sumiya, Hitoshi; Ohshima, Takeshi; Isoya, Junichi; Wrachtrup, Jörg

    2015-10-01

    Nitrogen-vacancy (NV) defect centers in diamond are promising solid-state magnetometers. Single centers allow for high-spatial-resolution field imaging but are limited in their magnetic field sensitivity. Using defect-center ensembles, sensitivity can be scaled with ?{N } when N is the number of defects. In the present work, we use an ensemble of N ˜1011 defect centers within an effective sensor volume of 8.5 ×10-4 mm3 for sensing at room temperature. By carefully eliminating noise sources and using high-quality diamonds with large NV concentrations, we demonstrate, for such sensors, a sensitivity scaling as 1 /?{t } , where t is the total measurement time. The associated photon-shot-noise-limited magnetic-field sensitivity for ac signals of f =20 kHz is 0.9 pT /?{Hz } . For a total measurement time of 100 s, we reach a standard deviation of about 100 fT. Further improvements using decoupling sequences and material optimization could lead to fT /?{Hz } sensitivity.

  4. A subpicotesla diamond magnetometer

    E-print Network

    Thomas Wolf; Philipp Neumann; Kazuo Nakamura; Hitoshi Sumiya; Junichi Isoya; Jörg Wrachtrup

    2014-12-19

    Diamond defect centers are promising solid state magnetometers. Single centers allow for high spatial resolution field imaging but are limited in their magnetic field sensitivity to around 10 nT/Hz^(1/2) at room-temperature. Using defect center ensembles sensitivity can be scaled as N^(1/2) when N is the number of defects. In the present work we use an ensemble of 1e11 defect centers for sensing. By carefully eliminating all noise sources like laser intensity fluctuations, microwave amplitude and phase noise we achieve a photon shot noise limited field sensitivity of 0.9 pT/Hz^(1/2) at room-temperature with an effective sensor volume of 8.5e-4 mm^3. The smallest field we measured with our device is 100 fT. While this denotes the best diamond magnetometer sensitivity so far, further improvements using decoupling sequences and material optimization could lead to fT/Hz^(1/2) sensitivity.

  5. Status review of the science and technology of Ultrananoscrystalline Diamond (UNCD (sup {trademark}) films and application to multifunctional devices.

    SciTech Connect

    Auciello, O.; Sumant, A. V.

    2010-07-01

    This review focuses on a status report on the science and technology of ultrananocrystalline diamond (UNCD) films developed and patented at Argonne National Laboratory. The UNCD material has been developed in thin film form and exhibit multifunctionalities applicable to a broad range of macro to nanoscale multifunctional devices. UNCD thin films are grown by microwave plasma chemical vapor deposition (MPCVD) or hot filament chemical vapor deposition (HFCVD) using new patented Ar-rich/CH4 or H2/CH4 plasma chemistries. UNCD films exhibit a unique nanostructure with 2-5 nm grain size (thus the trade name UNCD) and grain boundaries of 0.4-0.6 nm for plain films, and grain sizes of 7-10 nm and grain boundaries of 2-4 nm when grown with nitrogen introduced in the Ar-rich/CH4 chemistry, to produce UNCD films incorporated with nitrogen, which exhibit electrical conductivity up to semi-metallic level. This review provides a status report on the synthesis of UNCD films via MPCVD and integration with dissimilar materials like oxides for piezoactuated MEMS/NEMS, metal films for contacts, and biological matter for a new generation of biomedical devices and biosensors. A broad range of applications from macro to nanoscale multifunctional devices is reviewed, such as coatings for mechanical pumps seals, field-emission cold cathodes, RF MEMS/NEMS resonators and switches for wireless communications and radar systems, NEMS devices, biomedical devices, biosensors, and UNCD as a platform for developmental biology, involving biological cells growth on the surface. Comparisons with nanocrystalline diamond films and technology are made when appropriate.

  6. Building Diamond-free Posets Aaron Dutle

    E-print Network

    Biro, Csaba

    Building Diamond-free Posets Aaron Dutle AMS Southeastern Sectional October 5, 2013 Joint with ´Eva Czabarka, Travis Johnston, and L´aszl´o Sz´ekely Dutle Building Diamond-free Posets #12;The Diamond Johnston, and L´aszl´o Sz´ekely Dutle The Diamond Conjecture is False #12;#12;Building Diamond-free Posets

  7. Chemical-Vapor-Deposited Diamond Film

    NASA Technical Reports Server (NTRS)

    Miyoshi, Kazuhisa

    1999-01-01

    This chapter describes the nature of clean and contaminated diamond surfaces, Chemical-vapor-deposited (CVD) diamond film deposition technology, analytical techniques and the results of research on CVD diamond films, and the general properties of CVD diamond films. Further, it describes the friction and wear properties of CVD diamond films in the atmosphere, in a controlled nitrogen environment, and in an ultra-high-vacuum environment.

  8. Recent Development in Diamond Synthesis

    NASA Astrophysics Data System (ADS)

    Chen, Changle; Chen, Qianwang

    The high pressure-high temperature (HPHT) method led to wide applications of artificial diamonds in industry. Low temperature coating of diamonds has been studied for some time, and chemical vapor deposition has been developed. In this contribution, we will focus on the most recent developments in diamond synthesis, and especially the important progress upon hydrothermal synthesis and the reduction of carbide (HSRC), which has attracted more and more attention due to its great commercial potential. Especially, we will discuss the synthesis of colorless, large diamond crystals from the reduction of carbon dioxide or carbonates. In addition, some recent progress on the theoretical studies of the metastable nucleation and growth of diamonds will also be reviewed. Finally, theories about the genesis of natural diamond were briefly reviewed, and a new theory based on our experimental results was proposed, which suggests that diamond within the Earth could be produced from carbon dioxide wherever carbon dioxide existed and the conditions (e.g., temperature, pressure, and reducing environment) are satisfied.

  9. Toward a Universal Anti-Stick Layer for Nanoimprint Lithography Imprinters: Ultra-Thin F-DLC

    E-print Network

    Krchnavek, Robert R.

    Toward a Universal Anti-Stick Layer for Nanoimprint Lithography Imprinters: Ultra-Thin F-DLC Ryan W of the nanoscale pattern. Previous work on thick (>100 nm) diamond-like carbon (DLC) layers indicates fluorinated diamond-like carbon (F-DLC) provides a durable anti-wear, anti-stick layer. In this work, a process

  10. Thermal and fast neutron detection in chemical vapor deposition single-crystal diamond detectors

    SciTech Connect

    Almaviva, S.; Marinelli, M.; Milani, E.; Prestopino, G.; Tucciarone, A.; Verona, C.; Verona-Rinati, G.; Angelone, M.; Lattanzi, D.; Pillon, M.; Montereali, R. M.; Vincenti, M. A.

    2008-03-01

    Recently, a compact solid-state neutron detector capable of simultaneously detecting thermal and fast neutrons was proposed [M. Marinelli et al., Appl. Phys. Lett. 89, 143509 (2006)]. Its design is based on a p-type/intrinsic/metal layered structure obtained by Microwave Plasma Chemical Vapor Deposition (CVD) of homoepitaxial diamond followed by thermal evaporation of an Al contact and a {sup 6}LiF converting layer. Fast neutrons are directly detected in the CVD diamond bulk, since they have enough energy to produce the {sup 12}C(n,{alpha}){sup 9}Be reaction in diamond. Thermal neutrons are instead converted into charged particles in the {sup 6}LiF layer through the {sup 6}Li(n,{alpha})T nuclear reaction. These charged particles are then detected in the diamond layer. The thickness of the {sup 6}LiF converting layer and the CVD diamond sensing layer affect the counting efficiency and energy resolution of the detector both for low- (thermal) and high-energy neutrons. An analysis is carried out on the dynamics of the {sup 6}Li(n,{alpha})T and the {sup 12}C(n,{alpha}){sup 9}Be reactions products, and the distribution of the energy released inside the sensitive layer is calculated. The detector counting efficiency and energy resolution were accordingly derived as a function of the thickness of the {sup 6}LiF and CVD diamond layers, both for thermal and fast neutrons, thus allowing us to choose the optimum detector design for any particular application. Comparison with experimental results is also reported.

  11. All-Diamond Microelectrodes as Solid State Probes for Localized Electrochemical Sensing.

    PubMed

    Silva, Eduardo L; Gouvêa, Cristol P; Quevedo, Marcela C; Neto, Miguel A; Archanjo, Braulio S; Fernandes, António J S; Achete, Carlos A; Silva, Rui F; Zheludkevich, Mikhail L; Oliveira, Filipe J

    2015-07-01

    The fabrication of an all-diamond microprobe is demonstrated for the first time. This ME (microelectrode) assembly consists of an inner boron doped diamond (BDD) layer and an outer undoped diamond layer. Both layers were grown on a sharp tungsten tip by chemical vapor deposition (CVD) in a stepwise manner within a single deposition run. BDD is a material with proven potential as an electrochemical sensor. Undoped CVD diamond is an insulating material with superior chemical stability in comparison to conventional insulators. Focused ion beam (FIB) cutting of the apex of the ME was used to expose an electroactive BDD disk. By cyclic voltammetry, the redox reaction of ferrocenemethanol was shown to take place at the BDD microdisk surface. In order to ensure that the outer layer was nonelectrically conductive, a diffusion barrier for boron atoms was established seeking the formation of boron-hydrogen complexes at the interface between the doped and the undoped diamond layers. The applicability of the microelectrodes in localized corrosion was demonstrated by scanning amperometric measurements of oxygen distribution above an Al-Cu-CFRP (Carbon Fiber Reinforced Polymer) galvanic corrosion cell. PMID:26057348

  12. Conversion of fullerenes to diamond

    DOEpatents

    Gruen, Dieter M. (1324 59th St., Downers Grove, IL 60515)

    1994-01-01

    A method of forming synthetic hydrogen defect free diamond or diamond like films on a substrate. The method involves providing vapor containing fullerene molecules with or without an inert gas, providing a device to impart energy to the fullerene molecules, fragmenting at least in part some of the fullerene molecules in the vapor or energizing the molecules to incipient fragmentation, ionizing the fullerene molecules, impinging ionized fullerene molecules on the substrate to assist in causing fullerene fragmentation to obtain a thickness of diamond on the substrate.

  13. Tailoring nanocrystalline diamond film properties

    DOEpatents

    Gruen, Dieter M. (Downers Grove, IL); McCauley, Thomas G. (Somerville, MA); Zhou, Dan (Orlando, FL); Krauss, Alan R. (Naperville, IL)

    2003-07-15

    A method for controlling the crystallite size and growth rate of plasma-deposited diamond films. A plasma is established at a pressure in excess of about 55 Torr with controlled concentrations of hydrogen up to about 98% by volume, of unsubstituted hydrocarbons up to about 3% by volume and an inert gas of one or more of the noble gases and nitrogen up to about 98% by volume. The volume ratio of inert gas to hydrogen is preferably maintained at greater than about 4, to deposit a diamond film on a suitable substrate. The diamond film is deposited with a predetermined crystallite size and at a predetermined growth rate.

  14. CVD diamond cost analysis update

    NASA Astrophysics Data System (ADS)

    Progress for IBIS Associates in the fourth quarter of 1994 includes discussion with 3M and Research Triangle Institute regarding their radio frequency (RF) CVD diamond deposition technology. Although modeling this technology has not been accomplished, the non-disclosure agreements have been taken care of. IBIS awaits feedback on the schedules of 3M and RTI contacts for modeling to proceed. Also accomplished in the fourth quarter of 1994 was initial discussion with Torch Temed (Arava, Israel) concerning the economics of their DC arcjet CVD diamond deposition technology. IBIS intends to follow up with 3M and RF and analyze the economics of their CVD diamond process.

  15. CVD Diamond Dielectric Accelerating Structures

    SciTech Connect

    Schoessow, P.; Kanareykin, A.; Gat, R.

    2009-01-22

    The electrical and mechanical properties of diamond make it an ideal candidate material for use in dielectric accelerating structures: high RF breakdown field, extremely low dielectric losses and the highest available thermoconductive coefficient. Using chemical vapor deposition (CVD) cylindrical diamond structures have been manufactured with dimensions corresponding to fundamental TM{sub 01} mode frequencies in the GHz to THz range. Surface treatments are being developed to reduce the secondary electron emission (SEE) coefficient below unity to reduce the possibility of multipactor. The diamond CVD cylindrical waveguide technology developed here can be applied to a variety of other high frequency, large-signal applications.

  16. Diamond and Diamond-Like Materials as Hydrogen Isotope Barriers

    SciTech Connect

    Foreman, L.R.; Barbero, R.S.; Carroll, D.W.; Archuleta, T.; Baker, J.; Devlin, D.; Duke, J.; Loemier, D.; Trukla, M.

    1999-07-10

    This is the final report of a two-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The purpose of this project was to develop diamond and diamond-like thin-films as hydrogen isotope permeation barriers. Hydrogen embrittlement limits the life of boost systems which otherwise might be increased to 25 years with a successful non-reactive barrier. Applications in tritium processing such as bottle filling processes, tritium recovery processes, and target filling processes could benefit from an effective barrier. Diamond-like films used for low permeability shells for ICF and HEDP targets were also investigated. Unacceptable high permeabilities for hydrogen were obtained for plasma-CVD diamond-like-carbon films.

  17. Growth of twin-free heteroepitaxial diamond on Ir/YSZ/Si(111)

    SciTech Connect

    Fischer, M.; Brescia, R.; Gsell, S.; Schreck, M.; Stritzker, B.; Brugger, T.; Greber, T.; Osterwalder, J.

    2008-12-15

    Heteroepitaxial nucleation and growth of twin-free diamond on Ir(111) is reported. The bias enhanced nucleation (BEN) technique was applied in a microwave plasma chemical vapor deposition setup to induce diamond nucleation on the new multilayer stack Ir/YSZ/Si(111). We demonstrate that the gathering of the diamond nuclei in so-called 'domains', a pattern formation process unique for diamond nucleation on iridium, is also present on Ir(111). The 1-2 nm thick carbon layer deposited by BEN does not show any crystalline diamond structures in electron diffraction and high resolution lattice imaging microscopy. In contrast, x-ray photoelectron diffraction (XPD) measurements yield C 1s diffractograms with clear threefold symmetry. The main features are comparable to measurements on diamond (111) single crystal surfaces. The weaker fine structure in the XPD patterns of the BEN layers is attributed to some disorder due to the harsh ion bombardment. However, this ion bombardment did not induce any measurable amount of twinning as deduced from the threefold symmetry. After 3 h diamond growth, the signal due to twins in the x-ray diffraction pole figures is still below the noise level of {approx}1%. Negligible twinning and the low mosaic spread of 0.96 deg. (tilt) and 1.85 deg. (twist) indicate that these films mark a breakthrough toward heteroepitaxial diamond films with (111) orientation. They provide interesting growth substrates, e.g., for phosphorous doped diamond or for the formation of heterojunction devices by deposition of wurtzite-type wide band gap semiconductor materials.

  18. Surface Design and Engineering Toward Wear-Resistant, Self-Lubricating Diamond Films and Coatings

    NASA Technical Reports Server (NTRS)

    Miyoshi, Kazuhisa

    1999-01-01

    The tribological properties of chemical-vapor-deposited (CVD) diamond films vary with the environment, possessing a Jekyll-and-Hyde character. CVD diamond has low coefficient of friction and high wear resistance in air but high coefficient of friction and low wear resistance in vacuum. Improving the tribological functionality of materials (such as achieving low friction and good wear resistance) was an aim of this investigation. Three studies on the surface design, surface engineering, and tribology of CVD diamond have shown that its friction and wear are significantly reduced in ultrahigh vacuum. The main criteria for judging whether diamond films are an effective wear-resistant, self-lubricating material were coefficient of friction and wear rate, which must be less than 0.1 and on the order of 10(exp 6) cu mm/N(dot)m, respectively. In the first study the presence of a thin film (less than 1 micron thick) of amorphous, nondiamond carbon (hydrogenated carbon, also called diamondlike carbon or DLC) on CVD diamond greatly decreased the coefficient of friction and the wear rate. Therefore, a thin DLC film on CVD diamond can be an effective wear-resistant, lubricating coating in ultrahigh vacuum. In the second study the presence of an amorphous, nondiamond carbon surface layer formed on CVD diamond by ion implantation significantly reduced the coefficient of friction and the wear rate in ultrahigh vacuum. Therefore, such surface layers are acceptable for effective self-lubricating, wear-resistant applications of CVD diamond. In the third study CVD diamond in contact with cubic boron nitride exhibited low coefficient of friction in ultra high vacuum. Therefore, this materials combination can provide an effective self-lubricating, wear-resistant couple in ultrahigh vacuum.

  19. Electron microscopy of gallium nitride growth on polycrystalline diamond

    NASA Astrophysics Data System (ADS)

    Webster, R. F.; Cherns, D.; Kuball, M.; Jiang, Q.; Allsopp, D.

    2015-11-01

    Transmission and scanning electron microscopy were used to examine the growth of gallium nitride (GaN) on polycrystalline diamond substrates grown by metalorganic vapour phase epitaxy with a low-temperature aluminium nitride (AlN) nucleation layer. Growth on unmasked substrates was in the (0001) orientation with threading dislocation densities ?7 × 109 cm-2. An epitaxial layer overgrowth technique was used to reduce the dislocation densities further, by depositing silicon nitride stripes on the surface and etching the unmasked regions down to the diamond substrate. A re-growth was then performed on the exposed side walls of the original GaN growth, reducing the threading dislocation density in the overgrown regions by two orders of magnitude. The resulting microstructures and the mechanisms of dislocation reduction are discussed.

  20. 3D neutron and X-ray imaging of diamondiferous eclogites, Siberia: Evidence for the secondary origin of diamonds

    NASA Astrophysics Data System (ADS)

    Howarth, G. H.; Pernet-Fisher, J. F.; Sobolev, N. V.; Penumadu, D.; Puplampu, S.; Ketcham, R. A.; Maisano, J. A.; Taylor, D.; Taylor, L. A.

    2013-12-01

    Non-destructive, 3D tomography of diamondiferous eclogites (Siberia) has effectively imaged diamonds and their spatial and textural relationships in situ. A rare suite of 17 diamondiferous eclogites have been analyzed, representing the largest collection outside of Siberia. New innovations in X-ray imaging, in combination with the first effective use of neutron imaging techniques, allow for the identification of secondary metasomatic minerals and the delineation of metasomatic pathways through the eclogites. Combining observations from both imaging techniques provides first-order characterizations and textural descriptions critical for understanding diamond genesis that has heretofore been absent in the literature. Eclogitic diamonds are generally octahedral in morphology, but dodecahedral diamonds are also observed, completely enclosed within the eclogites, implying in situ resorption. Diamonds are never observed in contact with primary minerals - i.e., always surrounded by secondary phases. Primary garnet and clinopyroxene show varying degrees of alteration, discerning the delineation of metasomatic pathways. In general, such pathways are observed as interconnected networks of veinlets, commonly cross-cutting the eclogites. Furthermore, clinopyroxene-rich layers observed show higher degrees of alteration, relative to garnet-rich layers within the same sample, highlighting clinopyroxene as more susceptible to metasomatic alteration than garnet. Diamonds are always observed within such metasomatic pathways. For example, eclogite U-112 contains ~22 macro-diamonds, all of which are contained within an altered clinopyroxene-rich layer. In addition, no spatial relationship is observed between diamonds and sulfide phases. The ubiquitous association of diamonds with metasomatic minerals and pathways provides compelling evidence for the secondary origin of diamonds, in agreement with current interpretations on the origin of diamonds [1,2]. However, diamonds are generally believed to be ancient (1-3 Ga) [3], whereas the metasomatic mineral assemblages observed within eclogites are interpreted to have formed much later, perhaps just prior to incorporation into the rising kimberlite magma [4]. This age dichotomy indicates that either the metasomatic pathways have remained open for billions of years or that diamond growth is significantly younger than previously believed. We suggest that diamond growth may be related to metasomatic fluids circulating just prior to kimberlite emplacement and that diamonds may be significantly younger than previously believed. [1] T. Stachel, J.W. Harris, Ore. Geol. Rev. 34, 5 (2008). [2] Y. Liu et al., Lithos 112S, 1014 (2009). [3] S.B. Shirey, S.H. Richardson, Science 333, 434 (2011). [4] K.C. Misra et al., Contrib. Mineral. Petrol. 146, 696 (2004).

  1. Method of dehalogenation using diamonds

    DOEpatents

    Farcasiu, Malvina (Roslyn Harbor, NY); Kaufman, Phillip B. (Lafayette, LA); Ladner, Edward P. (Pittsburgh, PA); Anderson, Richard R. (Brownsville, PA)

    2000-01-01

    A method for preparing olefins and halogenated olefins is provided comprising contacting halogenated compounds with diamonds for a sufficient time and at a sufficient temperature to convert the halogenated compounds to olefins and halogenated olefins via elimination reactions.

  2. Fabrication of amorphous diamond films

    DOEpatents

    Falabella, S.

    1995-12-12

    Amorphous diamond films having a significant reduction in intrinsic stress are prepared by biasing a substrate to be coated and depositing carbon ions thereon under controlled temperature conditions. 1 fig.

  3. Method of Dehalogenation using Diamonds

    SciTech Connect

    Farcasiu, Malvina; Kaufman, Phillip B.; Ladner, Edward P.; Anderson, Richard R.

    1999-02-26

    A method for preparing olefins and halogenated olefins is provided comprising contacting halogenated compounds with diamonds for a sufficient time and at a sufficient temperature to convert the halogenated compounds to olefins and halogenated olefins via elimination reactions.

  4. 16 CFR 23.13 - Disclosure of treatments to diamonds

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 false Disclosure of treatments to diamonds 23.13 Section 23.13 Commercial Practices...INDUSTRIES § 23.13 Disclosure of treatments to diamonds A diamond is a gemstone product. Treatments to diamonds...

  5. 16 CFR 23.13 - Disclosure of treatments to diamonds

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 false Disclosure of treatments to diamonds 23.13 Section 23.13 Commercial Practices...INDUSTRIES § 23.13 Disclosure of treatments to diamonds A diamond is a gemstone product. Treatments to diamonds...

  6. Diamond octahedra and curie principle

    NASA Astrophysics Data System (ADS)

    Rakin, V. I.

    2015-09-01

    A numerical Monte Carlo simulation of the growth forms of octahedral crystals is performed and occurrence rates of 14 possible forms of simple polyhedra are obtained. Conclusions based on theoretical suggestions are compared with the results of studying artificial diamonds. The phenomenon of dissymmetrization of forms is established, which is consistent with the Curie principle. The conclusions drawn can be used to analyze the growth conditions of natural flat-face diamond octahedra.

  7. Evolution of the morphology of diamond particles and mechanism of their growth during the synthesis by chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Feoktistov, N. A.; Grudinkin, S. A.; Golubev, V. G.; Baranov, M. A.; Bogdanov, K. V.; Kukushkin, S. A.

    2015-11-01

    The evolution of the surface morphology of diamond particles synthesized by chemical vapor deposition (CVD) on silicon substrates has been investigated. It has been found that, when the diamond particles reach a critical size of less than 800 nm, the surface of the diamond faces is transformed. Particles with sizes of no more than 100-300 nm have a well-faceted surface covered by the {100} and {111} faces. An increase in the size of diamond particles leads to a change in the structure of their surface. The surface is covered by the {100} faces surrounded by a disordered phase. With a further increase in the particle size (up to ˜2000 nm), the {100} faces disappear and the diamond particles are covered by high-index faces. A model explaining the evolution of the surface morphology of diamond particles has been proposed. According to this model, during the evolution of diamond particles with an increase in their size, the mechanism of layer-bylayer growth changes to normal growth, which leads to a significant transformation of the entire surface of the diamond particles. The critical size of a two-dimensional nucleus formed on the {100} and {111} faces, at which the change in the growth mechanism begins to occur, has been calculated. A method has been proposed for controlling the morphology of diamond particles during their synthesis.

  8. 33 CFR 110.6 - Portland Harbor, Portland, Maine (between Little Diamond Island and Great Diamond Island).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Portland Harbor, Portland, Maine (between Little Diamond Island and Great Diamond Island). 110.6 Section 110.6 Navigation...Portland Harbor, Portland, Maine (between Little Diamond Island and Great Diamond Island)....

  9. 33 CFR 110.6 - Portland Harbor, Portland, Maine (between Little Diamond Island and Great Diamond Island).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Portland Harbor, Portland, Maine (between Little Diamond Island and Great Diamond Island). 110.6 Section 110.6 Navigation...Portland Harbor, Portland, Maine (between Little Diamond Island and Great Diamond Island)....

  10. 33 CFR 110.6 - Portland Harbor, Portland, Maine (between Little Diamond Island and Great Diamond Island).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Portland Harbor, Portland, Maine (between Little Diamond Island and Great Diamond Island). 110.6 Section 110.6 Navigation...Portland Harbor, Portland, Maine (between Little Diamond Island and Great Diamond Island)....

  11. 33 CFR 110.6 - Portland Harbor, Portland, Maine (between Little Diamond Island and Great Diamond Island).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...Portland Harbor, Portland, Maine (between Little Diamond Island and Great Diamond Island). 110.6 Section 110.6 Navigation...Portland Harbor, Portland, Maine (between Little Diamond Island and Great Diamond Island)....

  12. 33 CFR 110.6 - Portland Harbor, Portland, Maine (between Little Diamond Island and Great Diamond Island).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Portland Harbor, Portland, Maine (between Little Diamond Island and Great Diamond Island). 110.6 Section 110.6 Navigation...Portland Harbor, Portland, Maine (between Little Diamond Island and Great Diamond Island)....

  13. Stiff diamond/buckypaper carbon hybrids.

    PubMed

    Holz, T; Mata, D; Santos, N F; Bdikin, I; Fernandes, A J S; Costa, F M

    2014-12-24

    Given the specific properties of each carbon allotrope such as high electrical/thermal conductivity of multiwall carbon nanotubes (MWCNT) and extreme hardness and high inertness of nanocrystalline diamond (NCD), the integration of both carbon phases is highly desirable. Therefore, in the present work, buckypapers were produced from MWCNT suspensions and were used as free-standing substrates to be coated with NCD by microwave plasma chemical vapor deposition (MPCVD). The integration of both allotropes was successfully achieved, the CNTs being preserved after diamond growth as confirmed by ?-Raman spectroscopy and scanning electron microscopy (SEM). Additionally, a good linkage was observed, the CNTs remaining embedded within the NCD matrix, thus reinforcing the interface of the resulting hybrid structure. This was corroborated by bending tests in a modified nanohardness tester. The increase of the Young's modulus from 0.3 to 300 GPa after NCD growth enables the use of this material in a wide range of applications including microelectromechanical systems (MEMS). Additionally, a highly anisotropic electrical resistivity behavior was confirmed: low in-plane values were found for the CNT layer (1.39 × 10(-2) ?.cm), while high transverse ones were measured for both the NCD coated and uncoated CNT buckypapers (8.13 × 10(5) and 6.18 × 10(2) ?.cm, respectively). PMID:25412196

  14. Tensile properties of amorphous diamond films

    SciTech Connect

    Lavan, D.A.; Hohlfelder, R.J.; Sullivan, J.P.; Friedmann, T.A.; Mitchell, M.A.; Ashby, C.I.

    1999-12-02

    The strength and modulus of amorphous diamond, a new material for surface micromachined MEMS and sensors, was tested in uniaxial tension by pulling laterally with a flat tipped diamond in a nanoindenter. Several sample designs were attempted. Of those, only the single layer specimen with a 1 by 2 {micro}m gage cross section and a fixed end rigidly attached to the substrate was successful. Tensile load was calculated by resolving the measured lateral and normal forces into the applied tensile force and frictional losses. Displacement was corrected for machine compliance using the differential stiffness method. Post-mortem examination of the samples was performed to document the failure mode. The load-displacement data from those samples that failed in the gage section was converted to stress-strain curves using carefully measured gage cross section dimensions. Mean fracture strength was found to be 8.5 {+-} 1.4 GPa and the modulus was 831 {+-} 94 GPa. Tensile results are compared to hardness and modulus measurements made using a nanoindenter.

  15. A procedure for diamond turning KDP crystals

    SciTech Connect

    Montesanti, R.C.; Thompson, S.L.

    1995-07-07

    A procedure and the equipment necessary for single-point diamond flycutting (loosely referred to as diamond turning) potassium di-hydrogen phosphate (KDP) crystals are described. It is based on current KDP diamond turning activities at the Lawrence Livermore National Laboratory (LLNL), drawing upon knowledge from the Nova crystal finishing development during the 1980`s and incorporating refinements from our efforts during 1995. In addition to describing a step-by-step process for diamond turning KDP, specific discussions are included on the necessary diamond tool geometry and edge sharpness, cutting fluid, and crystal preparation, handling, cleaning, and inspection. The authors presuppose that the reader is already familiar with diamond turning practices.

  16. Wear mechanism of diamond coated cutting tools

    SciTech Connect

    Leyendecker, T.; Lemmer, O.; Esser, S.

    1995-12-31

    Since Diamond Coatings were introduced into the market in 1989, five years experience in industrial applications of diamond coated cutting tools enables to present an overview of tool life and wear behavior of diamond coated cutting tools due to different cutting conditions and workpiece-materials. Machining reinforced plastics, presintered ceramic compacts, aluminum alloys, metal-matrix composites and graphite, different wear behavior occurs at the cutting edges of diamond coated tools. Having a good adhesion fatigue and chemical wear of Diamond coatings determines life time of the tools. By a profound pretreatment procedure CVD Diamond coated tools can compete with conventional PCD-tools.

  17. Electron microscopic evidence for a tribologically induced phase transformation as the origin of wear in diamond

    SciTech Connect

    Zhang, Xinyi; Schneider, Reinhard; Müller, Erich; Gerthsen, Dagmar; Mee, Manuel; Meier, Sven; Gumbsch, Peter

    2014-02-14

    Tribological testing of a coarse-grained diamond layer, deposited by plasma-enhanced chemical vapor deposition, was performed on a ring-on-ring tribometer with a diamond counterpart. The origin of the wear of diamond and of the low friction coefficient of 0.15 was studied by analyzing the microstructure of worn and unworn regions by transmission and scanning electron microscopy. In the worn regions, the formation of an amorphous carbon layer with a thickness below 100?nm is observed. Electron energy loss spectroscopy of the C-K ionization edge reveals the transition from sp{sup 3}-hybridized C-atoms in crystalline diamond to a high fraction of sp{sup 2}-hybridized C-atoms in the tribo-induced amorphous C-layer within a transition region of less than 5?nm thickness. The mechanically induced phase transformation from diamond to the amorphous phase is found to be highly anisotropic which is clearly seen at a grain boundary, where the thickness of the amorphous layer above the two differently oriented grains abruptly changes.

  18. A new method for fabrication of diamond-dust blocking filters

    NASA Technical Reports Server (NTRS)

    Collard, H. R.; Hogan, R. C.

    1986-01-01

    Thermal embedding of diamond dust onto a polyethylene-coated Al plate has been used to make a blocking filter for FIR applications. The Al plate is sandwiched between two Mylar 'blankets' and the air between the layers is removed by means of a small vacuum pump. After the polyethylene is heated and softened, the diamond dust is applied to the polyethylene coating using a brush. The optimum diamond dust grain sizes corresponding to polyethylene layer thicknesses of 9-12 microns are given in a table, and the application of the blocking filter to spectrometric measurements in the FIR is described. An exploded view diagram of the layered structure of the blocking filter is provided.

  19. Thermionic energy conversion and particle detection using diamond and diamond-like carbon surfaces

    NASA Astrophysics Data System (ADS)

    Smith, Joshua Ryan

    The potential for diamond films were considered for a vacuum thermionic energy conversion device application. First, the effect of field enhancement structures located on the emitter on the output current characteristic was considered. The structures result in Schottky barrier lowering due to enhanced field at the tips and therefore an improved current. Three dimensional simulations were generated and the finite element method was used to calculate the electrostatic potential within the interelectrode space. From these calculations, Schottky barrier lowering enhanced current was determined. The output current was enhanced via two mechanisms: first, the Schottky barrier lowering increased emission at the tips of the structures. Second, an increased surface area contributed to increased emission. These two effects compete with one another to increase the output current, therefore an optimization of the geometric configuration is necessary to maximize output current. A theory was developed to model the electron transport across a vacuum thermionic energy conversion device employing a negative electron affinity material as the emitter electrode. Two specific systems were considered: nitrogen doped diamond with a barrier height of 1.4eV and phosphorus doped diamond with a barrier height of 0.6eV. Results from these calculations were compared against calculations from an ideal model of electron transport where the negative space charge effect is ignored, and a more complete model that included space charge effects. It was shown that, in general, the NEA device outperforms the Langmuir device because the negative electron affinity lowers the boundary condition at the emitter, resulting in electrons emitted with nonzero kinetic energy. It was also shown that for a value of Richardson's constant equal to the theoretical value of 120 Acm-2K-2, the nitrogen doped diamond device outperforms the phosphorus doped diamond device at an interelectrode spacing of 10microm because the phosphorus doped diamond device operates deep in the space charge limited mode. For values of Richardson's constant equal to 10Acm-2K -2 and 1Acm-2K -2, the phosphorus doped diamond device outperforms the phosphorus doped diamond device. It was shown that for certain sets of parameters, it is possible for a TEC to avoid the space charge limited mode and perform equivalent to an ideal device. The Interstellar Boundary Explorer (IBEX) is a satellite which detects energetic neutral atoms in space. The IBEX-Lo detector features a tetrahedral amorphous carbon conversion surface. A procedure was developed to hydrogen terminate the facets making up the conversion surface such that the root mean square roughness did not exceed 0.5nm per 1micro m x 1microm surface area. A remote plasma electron cyclotron resonance chemical vapor deposition technique was used for the hydrogen termination, and ultraviolet photoemission spectroscopy, x-ray photoemission spectroscopy, and atomic force microscopy were used to characterize the surface. After the H-termination, the oxygen peak in the XPS spectrum was not detectable, indicating removal of the adsorbed oxygen layer. Additionally, the vacuum cutoff of the UPS spectrum was lowered, and a large peak appeared near the vacuum cutoff, indicating a negative electron affinity and the presence of hydrogen.

  20. Diamonds: Exploration, mines and marketing

    NASA Astrophysics Data System (ADS)

    Read, George H.; Janse, A. J. A. (Bram)

    2009-11-01

    The beauty, value and mystique of exceptional quality diamonds such as the 603 carat Lesotho Promise, recovered from the Letseng Mine in 2006, help to drive a multi-billion dollar diamond exploration, mining and marketing industry that operates in some 45 countries across the globe. Five countries, Botswana, Russia, Canada, South Africa and Angola account for 83% by value and 65% by weight of annual diamond production, which is mainly produced by four major companies, De Beers, Alrosa, Rio Tinto and BHP Billiton (BHPB), which together account for 78% by value and 72% by weight of annual diamond production for 2007. During the last twelve years 16 new diamond mines commenced production and 4 re-opened. In addition, 11 projects are in advanced evaluation and may begin operations within the next five years. Exploration for diamondiferous kimberlites was still energetic up to the last quarter of 2008 with most work carried out in Canada, Angola, Democratic Republic of the Congo (DRC) and Botswana. Many kimberlites were discovered but no new economic deposits were outlined as a result of this work, except for the discovery and possible development of the Bunder project by Rio Tinto in India. Exploration methods have benefitted greatly from improved techniques of high resolution geophysical aerial surveying, new research into the geochemistry of indicator minerals and further insights into the formation of diamonds and the relation to tectonic/structural events in the crust and mantle. Recent trends in diamond marketing indicate that prices for rough diamonds and polished goods were still rising up to the last quarter of 2008 and subsequently abruptly sank in line with the worldwide financial crisis. Most analysts predict that prices will rise again in the long term as the gap between supply and demand will widen because no new economic diamond discoveries have been made recently. The disparity between high rough and polished prices and low share prices of publicly traded diamond companies may be due to investors losing patience with the slow pace or absence of new promising discoveries and switching into shares of base metals and fertilizers for agriculture (potash and phosphates).

  1. Nanodiamonds in the Younger Dryas boundary sediment layer.

    PubMed

    Kennett, D J; Kennett, J P; West, A; Mercer, C; Hee, S S Que; Bement, L; Bunch, T E; Sellers, M; Wolbach, W S

    2009-01-01

    We report abundant nanodiamonds in sediments dating to 12.9 +/- 0.1 thousand calendar years before the present at multiple locations across North America. Selected area electron diffraction patterns reveal two diamond allotropes in this boundary layer but not above or below that interval. Cubic diamonds form under high temperature-pressure regimes, and n-diamonds also require extraordinary conditions, well outside the range of Earth's typical surficial processes but common to cosmic impacts. N-diamond concentrations range from approximately 10 to 3700 parts per billion by weight, comparable to amounts found in known impact layers. These diamonds provide strong evidence for Earth's collision with a rare swarm of carbonaceous chondrites or comets at the onset of the Younger Dryas cool interval, producing multiple airbursts and possible surface impacts, with severe repercussions for plants, animals, and humans in North America. PMID:19119227

  2. Multivariable study on homoepitaxial growth of diamond on planar and non-planar substrates

    NASA Astrophysics Data System (ADS)

    Samudrala, Gopi Krishna

    In this dissertation research, the roles of three basic parameters in homoepitaxial diamond growth by microwave plasma chemical vapor deposition on planar (type Ib yellow diamond plates) and non-planar (type Ia brilliant cut natural diamonds) substrates have been investigated. Isotopically enriched carbon-13 methane gas has been utilized in the experiments as the source of carbon to clearly distinguish the grown diamond layer from the underlying substrate using Raman spectroscopy. Nitrogen showed a catalytic effect in the growth of diamond on diamond anvil substrates. In the standard H2/O2/N2/ 13CH4 feed gas mixture, when nitrogen was varied between 0 to 3500 parts per million (ppm), an optimum value of 1250 ppm nitrogen resulted in the highest growth rate and smoothest surface morphology. This particular chemistry resulted in 100% success rate during the fabrication of designer diamond anvils. No such optimum value in nitrogen concentration was found for planar substrates indicating a strong dependence of diamond growth rate on the substrate geometry. On planar substrates, the effects of nitrogen concentration, methane concentration and substrate temperatures were studied independently by varying each parameter carefully over a broad range. Dramatic changes in surface morphologies and growth rates were observed by optical and atomic force microscopy. The nitrogen incorporation in carbon-13 diamond layers was monitored through photoluminescence spectroscopy of nitrogen--vacancy complexes. A twentyfold increase in growth rate has been reported as a result of this research. An optimum substrate temperature of 1050 C resulted in the highest growth rate when 2% CH 4/H2 was used in feed gas mixture. Use of high methane concentration in the feed gas mixture resulted in diamond films where twinning on the surface was completely absent. Aggressive incorporation of nitrogen in CVD diamond has been observed at substrate temperatures above 1050 C indicating that species such as HCN, CN and NHX play an active role on the surface at those temperatures. The optimum temperature has been observed to shift to higher values as the C/N ratio in the feed gas mixture increased. The roles of various growth parameters in high growth rate and high quality homoepitaxial diamond growth are discussed in this thesis.

  3. Diamonds are a Sun's Best Friend: Examining the Photoconductive Properties of Diamond to Improve TEC Efficiency

    E-print Network

    Diamonds are a Sun's Best Friend: Examining the Photoconductive Properties of Diamond to Improve or diffuse creating current. · Diamond is one of the most efficient electron emitting materials and the effect of temperature on a boron doped diamond film deposited via MPCVD on a molybdenum substrate

  4. Prof. Peter A. Diamond Dr. Peter A. Diamond, one of the world's leading economists,

    E-print Network

    Çetin, Müjdat

    Prof. Peter A. Diamond Dr. Peter A. Diamond, one of the world's leading economists, is an Institute model with overlapping generations has been very widely used. Professor Diamond has won the Nobel Prize, 1997, Professor Diamond was named an Institute Professor, the highest honor the MIT faculty can bestow

  5. Welcome to Diamond Light Source Parking Visitors can park outside Diamond

    E-print Network

    Crowther, Paul

    Welcome to Diamond Light Source Parking ­ Visitors can park outside Diamond House, or if that is full, in the Visitor car park. Users should park around the ring. On Arrival ­ Diamond does not have 8500). Then take a seat 2 and wait for your Diamond contact to collect you. Users ­ Fast track users

  6. Combined single-crystalline and polycrystalline CVD diamond substrates for diamond electronics

    SciTech Connect

    Vikharev, A. L. Gorbachev, A. M.; Dukhnovsky, M. P.; Muchnikov, A. B.; Ratnikova, A. K.; Fedorov, Yu. Yu.

    2012-02-15

    The fabrication of diamond substrates in which single-crystalline and polycrystalline CVD diamond form a single wafer, and the epitaxial growth of diamond films on such combined substrates containing polycrystalline and (100) single-crystalline CVD diamond regions are studied.

  7. Diamond photodiodes for x-ray application

    SciTech Connect

    Distel, James R; Smedley, John; Keister, Jeffrey W; Muller, Erik; Jordan - Sweet, Jean; Bohon, Jen; Dong, Bin

    2009-01-01

    Single crystal high purity CVD diamonds have been metallized and calibrated as photodiodes at the National Synchrotron Light Source (NSLS). Current mode responsivity measurements have been made over a wide range (0.2-28 keV) of photon energies across several beamlines. Linear response has been achieved over ten orders of magnitude of incident flux, along with uniform spatial response. A simple model of responsivity has been used to describe the results, yielding a value of 13.3 {+-} 0.5 eV for the mean pair creation energy. The responsivity vs. photon energy data show a dip for photon energies near the carbon edge (284 eV), indicating incomplete charge collection for carriers created less than one micron from the metallized layer.

  8. Genesis of Diamond-bearing and Diamond-free Podiform Chromitites in the Luobusa Ophiolite, Tibet

    NASA Astrophysics Data System (ADS)

    Yang, J.; Xiong, F.; Xu, X.; Robinson, P. T.; Dilek, Y.; Griffin, W. L.

    2014-12-01

    Micro-diamonds, moissanite and many highly reduced minerals, such as native Fe, Cr, Ni, Si, Al, and metallic alloys, have been reported previously from podiform chromitites and peridotites of the Luobusa ophiolite in the eastern segment of the Yarlung-Zangbo suture of southern Tibet.. Similar mineral associations have now been confirmed in mantle peridotites or chromitites of 11 other ophiolites in 5 orogenic belts, in Tibet, Myanmar, North China and the Polar Urals. However, detailed studies of the Luobusa ophiolite show that not all chromitites contain these UHP and highly reduced minerals. Diamond-bearing chromitites are chiefly massive bodies composed of over 95 modal% magnesiochromite with Cr#s [100Cr/(Cr+Al)] of 77-83 and Mg#s [100Mg/(Mg+Fe)] of 71-82. Most of these bodies have sharp contacts with the host harzburgites and are only rarely enclosed in dunite envelopes. Many magnesiochromite grains in the massive chromitites contain inclusions of forsterite and pyroxene. Forsterite inclusions have Fo numbers of 97-99 and NiO contents of 1.11-1.29 wt%. Mg#s of clinopyroxene inclusions are 96-98 and those of orthopyroxene are 96-97. X-ray studies show that the olivine inclusions have very small unit cells and short cation-oxygen bond distances, suggesting crystallization at high pressure. In contrast, diamond-free chromitites typically occur as layers within thick dunite sequences or as irregular patches surrounded by dunite envelopes. They consist of variable proportions of magnesiochromite (Cr# = 76-78; Mg# = 58-61) and olivine, and have banded, nodular and disseminated textures. The dunite envelopes consist chiefly of granular olivine with a few relatively large, amoeboidal grains of magnesiochromite, and typically grade into the host peridotites with increasing pyroxene. Unlike those in the massive ores, magnesiochromite grains in nodular and disseminated chromitites lack pyroxene inclusions, and their olivine inclusions have relatively low Fo (94-96) and NiO (0.35-0.58 wt%). We propose that the diamond-bearing chromitite ores formed within the deeper parts of the upper mantle and were emplaced at an oceanic spreading ridge, whereas the diamond-free chromitites formed at shallow levels by melt/rock reaction, most likely in a SSZ environment.

  9. YBa2Cu3O7 thin films on nanocrystalline diamond films for HTSC bolometer

    NASA Technical Reports Server (NTRS)

    Cui, G.; Beetz, C. P., Jr.; Boerstler, R.; Steinbeck, J.

    1993-01-01

    Superconducting YBa2Cu3O(7-x) films on nanocrystalline diamond thin films have been fabricated. A composite buffer layer system consisting of diamond/Si3N4/YSZ/YBCO was explored for this purpose. The as-deposited YBCO films were superconducting with Tc of about 84 K and a relatively narrow transition width of about 8 K. SEM cross sections of the films showed very sharp interfaces between diamond/Si3N4 and between Si3N4/YSZ. The deposited YBCO film had a surface roughness of about 1000 A, which is suitable for high-temperature superconductive (HTSC) bolometer fabrication. It was also found that preannealing of the nanocrystalline diamond thin films at high temperature was very important for obtaining high-quality YBCO films.

  10. Diamond Composite Films for Protective Coatings on Metals and Method of Formation

    NASA Technical Reports Server (NTRS)

    Ong, Tiong P. (Inventor); Shing, Yuh-Han (Inventor)

    1997-01-01

    Composite films consisting of diamond crystallites and hard amorphous films such as diamond-like carbon, titanium nitride, and titanium oxide are provided as protective coatings for metal substrates against extremely harsh environments. A composite layer having diamond crystallites and a hard amorphous film is affixed to a metal substrate via an interlayer including a bottom metal silicide film and a top silicon carbide film. The interlayer is formed either by depositing metal silicide and silicon carbide directly onto the metal substrate, or by first depositing an amorphous silicon film, then allowing top and bottom portions of the amorphous silicon to react during deposition of the diamond crystallites, to yield the desired interlayer structure.

  11. Molecular orientation of lead phthalocyanine on (100) oriented single crystal diamond surfaces.

    PubMed

    Dexters, Wim; Bourgeois, Emilie; Nesládek, Milos; D'Haen, Jan; Goovaerts, Etienne; Haenen, Ken

    2015-04-21

    Lead phthalocyanine (PbPc) thin films of 5 and 50 nm have been deposited on hydrogen and oxygen terminated single crystal diamond (SCD) using organic molecular beam deposition. Atomic force microscopy and X-ray diffraction (XRD) studies showed that PbPc grown on the hydrogen terminated SCD forms layers with a high degree of crystallinity, dominated by the monoclinic (320) orientation parallel to the diamond surface. The oxygen terminated diamond led to a randomly oriented PbPc film. Absorption and photocurrent measurements indicated the presence of both polymorphs of PbPc, however, the ratio differed depending on the termination of the SCD. Finally, polarized Raman spectroscopy was used to determine the orientation of the molecules of the thin film. The results confirmed the random orientation on the O-terminated diamond. On SCD:H, the PbPc molecules are lying down in accordance with the XRD results. PMID:25779759

  12. Spectroscopic ellipsometry of homoepitaxial diamond multilayers and delta-doped structures

    SciTech Connect

    Bousquet, J.; Chicot, G.; Eon, D.; Bustarret, E.

    2014-01-13

    The optimization of diamond-based unipolar electronic devices such as pseudo-vertical Schottky diodes or delta-doped field effect transistors relies in part on the sequential growth of nominally undoped (p{sup –}) and heavily boron doped (p{sup ++}) layers with well-controlled thicknesses and steep interfaces. Optical ellipsometry offers a swift and contactless method to characterize the thickness, roughness, and electronic properties of semiconducting and metallic diamond layers. We report ellipsometric studies carried out on delta-doped structures and other epitaxial multilayers with various boron concentrations and thicknesses (down to the nanometer range). The results are compared with Secondary Ion Mass Spectroscopy and transport measurements.

  13. Confocal luminescence study of nitrogen-vacancy distribution within nitrogen-rich single crystal CVD diamond

    NASA Astrophysics Data System (ADS)

    Shershulin, V. A.; Samoylenko, S. R.; Kudryavtsev, O. S.; Bolshakov, A. P.; Ashkinazi, E. E.; Yurov, V. Yu; Ralchenko, V. G.; Konov, V. I.; Vlasov, I. I.

    2016-01-01

    Confocal photoluminescence (PL) microscopy was used to study a distribution of negatively charged nitrogen-vacancy (NV?) defects within a surface and in a cross section of a homoepitaxial chemical vapor deposition (CVD) diamond layer intentionally grown with a nitrogen concentration close to the solubility limit. A variation in the PL intensity within the whole sample was found to exceed no more than 30% of the intensity maximum. The diamond layers with densely packed NV? arrays are a promising material platform for the design of highly sensitive magnetic field and temperature sensors, as well as for using this material in quantum optics and informatics technologies based on NV? spins.

  14. Effective placement of detectors at diamond interchanges 

    E-print Network

    Prabhakar, Dayakar

    1994-01-01

    . Further, the signal designer usually does not have published guidelines on the optimal location of detectors at diamond interchanges based on traffic conditions. Therefore, application guidelines on the placement of detectors at diamond interchanges...

  15. Diamond Blackfan Anemia, Genetics, and You

    MedlinePLUS

    Diamond Blackfan Anemia, Genetics, and You Q0 Is Diamond Blackfan Anemia (DBA) a genetic disorder? A Yes, ... A The body’s failure to make enough red blood cells has been linked to genetic mutations in ...

  16. Development of Designer Diamond Technology for High Pressure High Temperature Experiments in Support of Stockpile Stewardship Program

    SciTech Connect

    Vohra, Yogesh, K.

    2009-10-28

    The role of nitrogen in the fabrication of designer diamond was systematically investigated by adding controlled amount of nitrogen in hydrogen/methane/oxygen plasma. This has led to a successful recipe for reproducible fabrication of designer diamond anvils for high-pressure high-temperature research in support of stockpile stewardship program. In the three-year support period, several designer diamonds fabricated with this new growth chemistry were utilized in high-pressure experiments at UAB and Lawrence Livermore National Laboratory. The designer diamond anvils were utilized in high-pressure studies on heavy rare earth metals, high pressure melting studies on metals, and electrical resistance measurements on iron-based layered superconductors under high pressures. The growth chemistry developed under NNSA support can be adapted for commercial production of designer diamonds.

  17. Design and fabrication of nano-scale single crystal diamond cutting tool by focused ion beam (FIB) milling

    NASA Astrophysics Data System (ADS)

    Baek, Seung-Yub

    2015-07-01

    Micro/nanoscale diamond cutting tools used in ultra-precision machining can be fabricated by precision grinding, but it is hard to fabricate a tool with a nanometric cutting edge and complex configurations. High-precision geometry accuracy and special shapes for microcutting tools with sharp edges can be achieved by FIB milling. Because the FIB milling method induces much smaller machining stress compared with conventional precision grinding methods. In this study, the FIB milling characteristics of single-crystal diamond were investigated, along with methods for decreasing the FIB-induced damage on diamond tools. Lift-off process method and Pt(Platinum) coating process method with FIB milling were investigated to reduce the damage layer on diamond substrate and quadrilateral-shaped single-crystal diamond cutting tool with cutting edge width under 500 nm were obtained.

  18. Modular dynamics in diamonds

    E-print Network

    Romeo Brunetti; Valter Moretti

    2010-09-25

    We investigate the relation between the actions of Tomita-Takesaki modular operators for local von Neumann algebras in the vacuum for free massive and massless bosons in four dimensional Minkowskian spacetime. In particular, we prove a long-standing conjecture that says that the generators of the mentioned actions differ by a pseudo-differential operator of order zero. To get that, one needs a careful analysis of the interplay of the theories in the bulk and at the boundary of double cones (a.k.a. diamonds). After introducing some technicalities, we prove the crucial result that the vacuum state for massive bosons in the bulk of a double cone restricts to a KMS state at its boundary, and that the restriction of the algebra at the boundary does not depend anymore on the mass. The origin of such result lies in a careful treatment of classical Cauchy and Goursat problems for the Klein-Gordon equation as well as the application of known general mathematical techniques, concerning the interplay of algebraic structures related with the bulk and algebraic structures related with the boundary of the double cone, arising from quantum field theories in curved spacetime. Our procedure gives explicit formulas for the modular group and its generator in terms of integral operators acting on symplectic space of solutions of massive Klein-Gordon Cauchy problem.

  19. Nanocrystalline diamond synthesized from C60

    SciTech Connect

    Dubrovinskaia, N.; Dubrovinsky, L.; Langehorst, F.; Jacobsen, S.; Liebske, C.

    2010-11-30

    A bulk sample of nanocrystalline cubic diamond with crystallite sizes of 5-12 nm was synthesized from fullerene C{sub 60} at 20(1) GPa and 2000 C using a multi-anvil apparatus. The new material is at least as hard as single crystal diamond. It was found that nanocrystalline diamond at high temperature and ambient pressure kinetically is more stable with respect to graphitization than usual diamonds.

  20. Ultimate Atomic Bling: Nanotechnology of Diamonds

    SciTech Connect

    Dahl, Jeremy

    2010-05-25

    Diamonds exist in all sizes, from the Hope Diamond to minuscule crystals only a few atoms across. The smallest of these diamonds are created naturally by the same processes that make petroleum. Recently, researchers discovered that these 'diamondoids' are formed in many different structural shapes, and that these shapes can be used like LEGO blocks for nanotechnology. This talk will discuss the discovery of these nano-size diamonds and highlight current SLAC/Stanford research into their applications in electronics and medicine.

  1. Multimegabar pressures using synthetic diamond anvils

    SciTech Connect

    Ruoff, A. L.; Vohra, Y. K.

    1989-07-17

    Synthetic type 1/ital B/ yellow diamonds containing nitrogen in single substitutional form, with extremely low birefringence, were used as anvils in a diamond anvil cell. The diamonds were well characterized by infrared and visible absorption spectra. Sensitive spectroscopic methods along with mechanical chopping techniques were used to record ruby fluorescence to 250--300 GPa, a pressure equal to or exceeding that attained with natural diamonds. Nitrogen platelets are /ital not/ essential to attaining multimegabar pressures.

  2. Diamond-integrated optomechanical circuits.

    PubMed

    Rath, Patrik; Khasminskaya, Svetlana; Nebel, Christoph; Wild, Christoph; Pernice, Wolfram H P

    2013-01-01

    Diamond offers unique material advantages for the realization of micro- and nanomechanical resonators because of its high Young's modulus, compatibility with harsh environments and superior thermal properties. At the same time, the wide electronic bandgap of 5.45 eV makes diamond a suitable material for integrated optics because of broadband transparency and the absence of free-carrier absorption commonly encountered in silicon photonics. Here we take advantage of both to engineer full-scale optomechanical circuits in diamond thin films. We show that polycrystalline diamond films fabricated by chemical vapour deposition provide a convenient wafer-scale substrate for the realization of high-quality nanophotonic devices. Using free-standing nanomechanical resonators embedded in on-chip Mach-Zehnder interferometers, we demonstrate efficient optomechanical transduction via gradient optical forces. Fabricated diamond resonators reproducibly show high mechanical quality factors up to 11,200. Our low cost, wideband, carrier-free photonic circuits hold promise for all-optical sensing and optomechanical signal processing at ultra-high frequencies. PMID:23575694

  3. Ohmic contacts to semiconducting diamond

    NASA Astrophysics Data System (ADS)

    Zeidler, James R.; Taylor, M. J.; Zeisse, Carl R.; Hewett, C. A.; Delahoussaye, Paul R.

    1990-10-01

    Work was carried out to improve the electron beam evaporation system in order to achieve better deposited films. The basic system is an ion pumped vacuum chamber, with a three-hearth, single-gun e-beam evaporator. Four improvements were made to the system. The system was thoroughly cleaned and new ion pump elements, an e-gun beam adjust unit, and a more accurate crystal monitor were installed. The system now has a base pressure of 3 X 10(exp -9) Torr, and can easily deposit high-melting-temperature metals such as Ta with an accurately controlled thickness. Improved shadow masks were also fabricated for better alignment and control of corner contacts for electrical transport measurements. Appendices include: A Thermally Activated Solid State Reaction Process for Fabricating Ohmic Contacts to Semiconducting Diamond; Tantalum Ohmic Contacts to Diamond by a Solid State Reaction Process; Metallization of Semiconducting Diamond: Mo, Mo/Au, and Mo/Ni/Au; Specific Contact Resistance Measurements of Ohmic Contracts to Diamond; and Electrical Activation of Boron Implanted into Diamond.

  4. Diamond and diamond-like films for transportation applications

    SciTech Connect

    Perez, J.M.

    1993-01-01

    This section is a compilation of transparency templates which describe the goals of the Office of Transportation Materials (OTM) Tribology Program. The positions of personnel on the OTM are listed. The role and mission of the OTM is reviewed. The purpose of the Tribology Program is stated to be `to obtain industry input on program(s) in tribology/advanced lubricants areas of interest`. The objective addressed here is to identify opportunities for cost effective application of diamond and diamond-like carbon in transportation systems.

  5. 46 CFR 45.33 - Diamond.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Diamond. 45.33 Section 45.33 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) LOAD LINES GREAT LAKES LOAD LINES Load Line Marks § 45.33 Diamond. (a) Each vessel must be marked with the diamond mark described in figure 2 of § 45.35 amidships...

  6. Diamond Surfaces: Interactions with Hydrogen and Halogens

    E-print Network

    Goddard III, William A.

    Diamond Surfaces: Interactions with Hydrogen and Halogens Thesis by M. Susan Melnik In Partial­ knowledge my co­advisor Prof. David G. Goodwin for introducing me to the fascinat­ ing subject of diamond and providing me with an office. GRR, thanks for several useful and enjoyable discussions about diamond, IR

  7. 46 CFR 45.33 - Diamond.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Diamond. 45.33 Section 45.33 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) LOAD LINES GREAT LAKES LOAD LINES Load Line Marks § 45.33 Diamond. (a) Each vessel must be marked with the diamond mark described in figure 2 of § 45.35 amidships...

  8. 46 CFR 45.33 - Diamond.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Diamond. 45.33 Section 45.33 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) LOAD LINES GREAT LAKES LOAD LINES Load Line Marks § 45.33 Diamond. (a) Each vessel must be marked with the diamond mark described in figure 2 of § 45.35 amidships...

  9. Pro-Q Diamond Phosphoprotein Gel Stain

    E-print Network

    Lebendiker, Mario

    Pro-Q Diamond Phosphoprotein Gel Stain In-gel Detection Technology for Protein Phosphorylation and phosphoproteomics, the Pro-Q Diamond phos- phoprotein gel stain is a breakthrough technology that provides a simple phosphoproteins, the Pro-Q Diamond signal is linear over three orders of magnitude and the strength of the signal

  10. Diamond-free Families Jerrold R. Griggs

    E-print Network

    Griggs, Jerrold R.

    Diamond-free Families Jerrold R. Griggs Wei-Tian Li Linyuan Lu August 28, 2011 Abstract Given. For k 2 let Dk denote the k-diamond poset {A that continues to stymie all interested researchers is the diamond poset on four elements. We present a better

  11. 46 CFR 45.33 - Diamond.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Diamond. 45.33 Section 45.33 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) LOAD LINES GREAT LAKES LOAD LINES Load Line Marks § 45.33 Diamond. (a) Each vessel must be marked with the diamond mark described in figure 2 of § 45.35 amidships...

  12. Jared M. Diamond: physiologist, ornithologist, geographer, ecologist

    E-print Network

    Harms, Kyle E.

    Jared M. Diamond: physiologist, ornithologist, geographer, ecologist John C. Mittermeier Louisiana State University, BIOL 7083 April 3, 2014 #12;Why Jared Diamond? #12;#12;1937 1961 1966 1964 #12;In Diamond's words, he divides his time between four things 1. Teaching undergraduate geography 2. Field

  13. Traditionally configured prawn trawls contain small diamond-

    E-print Network

    434 Traditionally configured prawn trawls contain small diamond- shaped meshes in the codend, and small diamond-mesh sections. A strategically located panel of 85-mm netting was inserted on the bar with a conventional diamond-mesh codend (control) showed that both square-mesh designs significantly re- duced

  14. 46 CFR 45.33 - Diamond.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Diamond. 45.33 Section 45.33 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) LOAD LINES GREAT LAKES LOAD LINES Load Line Marks § 45.33 Diamond. (a) Each vessel must be marked with the diamond mark described in figure 2 of § 45.35 amidships...

  15. June 4, 2014 Diamond particle detectors systems

    E-print Network

    Gan, K. K.

    TIPP2014 1 June 4, 2014 K.K. Gan Diamond particle detectors systems in high energy physics K.K. Gan for the RD42 Collaboration #12;K.K. Gan TIPP2014 2 Outline Why diamond? ATLAS Diamond Beam Monitor (DBM) CMS Pixel Luminosity Telescope (PLT) Summary #12;K.K. Gan Curse

  16. Diamond Drilling Specification Manual and Course Outline.

    ERIC Educational Resources Information Center

    British Columbia Dept. of Education, Victoria.

    This publication presents the standards required of a person practicing diamond drilling in western Canada and provides an outline for teaching the skills and knowledge. It is divided into two parts. The Diamond Drilling Specification Manual establishes the levels of skill and knowledge required in the four certified levels of diamond drilling.…

  17. Ultratough single crystal boron-doped diamond

    DOEpatents

    Hemley, Russell J [Carnegie Inst. for Science, Washington, DC (United States); Mao, Ho-Kwang [Carnegie Inst. for Science, Washington, DC (United States); Yan, Chih-Shiue [Carnegie Inst. for Science, Washington, DC (United States); Liang, Qi [Carnegie Inst. for Science, Washington, DC (United States)

    2015-05-05

    The invention relates to a single crystal boron doped CVD diamond that has a toughness of at least about 22 MPa m.sup.1/2. The invention further relates to a method of manufacturing single crystal boron doped CVD diamond. The growth rate of the diamond can be from about 20-100 .mu.m/h.

  18. High-fluence Si-implanted diamond: Optimum implantation temperature for SiC formation

    SciTech Connect

    Weishart, H.; Eichhorn, F.; Heera, V.; Pecz, B.; Barna, A.; Skorupa, W.

    2005-08-15

    In this paper the authors investigate the effect of implantation temperature on the structural properties of diamond implanted with high fluences of Si between 5.3x10{sup 17} Si cm{sup -2} and 1x10{sup 18} Si cm{sup -2}. In order to reduce radiation-induced damage and to enhance SiC formation the implantations were performed at elevated temperatures in the range from 900 to 1200 deg. C. Subsequently, all samples were annealed for 10 min at 1500 deg. C in a rf-heated furnace. X-ray diffraction revealed the formation of cubic SiC nanocrystallites in a buried layer inside the implanted diamond. The implantation-induced damage was assessed by analyzing graphitization of the surface-near layer using Raman spectroscopy. With increasing Si fluence the implantation-induced damage rises and the nearly perfect alignment of the formed SiC crystallites within the host diamond lattice deteriorates. However, raising the implantation temperature from 900 to 1000 deg. C reduces the damage in the diamond and increases the amount, size, and epitaxial alignment of the crystalline SiC precipitates. Further increase of the implantation temperature gives no improvement in the quality of the SiC-rich layer. Instead, the damaged diamond converts into graphite and the formation of SiC crystallites is obstructed.

  19. Diamond-silicon carbide composite

    DOEpatents

    Qian, Jiang; Zhao, Yusheng

    2006-06-13

    Fully dense, diamond-silicon carbide composites are prepared from ball-milled microcrystalline diamond/amorphous silicon powder mixture. The ball-milled powder is sintered (P=5–8 GPa, T=1400K–2300K) to form composites having high fracture toughness. A composite made at 5 GPa/1673K had a measured fracture toughness of 12 MPa.dot.m1/2. By contrast, liquid infiltration of silicon into diamond powder at 5 GPa/1673K produces a composite with higher hardness but lower fracture toughness. X-ray diffraction patterns and Raman spectra indicate that amorphous silicon is partially transformed into nanocrystalline silicon at 5 GPa/873K, and nanocrystalline silicon carbide forms at higher temperatures.

  20. Diamond-structured photonic crystals.

    PubMed

    Maldovan, Martin; Thomas, Edwin L

    2004-09-01

    Certain periodic dielectric structures can prohibit the propagation of light for all directions within a frequency range. These 'photonic crystals' allow researchers to modify the interaction between electromagnetic fields and dielectric media from radio to optical wavelengths. Their technological potential, such as the inhibition of spontaneous emission, enhancement of semiconductor lasers, and integration and miniaturization of optical components, makes the search for an easy-to-craft photonic crystal with a large bandgap a major field of study. This progress article surveys a collection of robust complete three-dimensional dielectric photonic-bandgap structures for the visible and near-infrared regimes based on the diamond morphology together with their specific fabrication techniques. The basic origin of the complete photonic bandgap for the 'champion' diamond morphology is described in terms of dielectric modulations along principal directions. Progress in three-dimensional interference lithography for fabrication of near-champion diamond-based structures is also discussed. PMID:15343291

  1. Friction and wear performance of boron doped, undoped microcrystalline and fine grained composite diamond films

    NASA Astrophysics Data System (ADS)

    Wang, Xinchang; Wang, Liang; Shen, Bin; Sun, Fanghong

    2015-01-01

    Chemical vapor deposition (CVD) diamond films have attracted more attentions due to their excellent mechanical properties. Whereas as-fabricated traditional diamond films in the previous studies don't have enough adhesion or surface smoothness, which seriously impact their friction and wear performance, and thus limit their applications under extremely harsh conditions. A boron doped, undoped microcrystalline and fine grained composite diamond (BD-UM-FGCD) film is fabricated by a three-step method adopting hot filament CVD (HFCVD) method in the present study, presenting outstanding comprehensive performance, including the good adhesion between the substrate and the underlying boron doped diamond (BDD) layer, the extremely high hardness of the middle undoped microcrystalline diamond (UMCD) layer, as well as the low surface roughness and favorable polished convenience of the surface fine grained diamond (FGD) layer. The friction and wear behavior of this composite film sliding against low-carbon steel and silicon nitride balls are studied on a ball-on-plate rotational friction tester. Besides, its wear rate is further evaluated under a severer condition using an inner-hole polishing apparatus, with low-carbon steel wire as the counterpart. The test results show that the BD-UM-FGCD film performs very small friction coefficient and great friction behavior owing to its high surface smoothness, and meanwhile it also has excellent wear resistance because of the relatively high hardness of the surface FGD film and the extremely high hardness of the middle UMCD film. Moreover, under the industrial conditions for producing low-carbon steel wires, this composite film can sufficiently prolong the working lifetime of the drawing dies and improve their application effects. This research develops a novel composite diamond films owning great comprehensive properties, which have great potentials as protecting coatings on working surfaces of the wear-resistant and anti-frictional components.

  2. Superconductivity in CVD Diamond Films

    NASA Astrophysics Data System (ADS)

    Takano, Yoshihiko

    2005-03-01

    The recent news of superconductivity 2.3K in heavily boron-doped diamond synthesized by high pressure sintering was received with considerable surprise (1). Opening up new possibilities for diamond-based electrical devices, a systematic investigation of these phenomena clearly needs to be achieved. Application of diamond to actual devices requires it to be made into the form of wafers or thin films. We show unambiguous evidence for superconductivity in a heavily boron-doped diamond thin film deposited by the microwave plasma assisted chemical vapor deposition (MPCVD) method (2). An advantage of the MPCVD deposited diamond is that it can control boron concentration in its wider range, particularly in (111) oriented films. The temperature dependence of resistivity for (111) and (100) homoepitaxial thin films were measured under several magnetic fields. Superconducting transition temperatures of (111) homoepitaxial film are determined to be 11.4K for Tc onset and 7.2K for zero resistivity. And the upper critical field is estimated to be about 8T. These values are 2-3 times higher than these ever reported (1,3). On other hand, for (100) homoepitaxial film, Tc onset and Tc zero resistivity were estimated to be 6.3 and 3.2K respectively. The superconductivity in (100) film was strongly suppressed even at the same boron concentration. These differences of superconductivity in film orientation will be discussed. These findings established the superconductivity as a universal property of boron-doped diamond, demonstrating that device application is indeed a feasible challenge. 1. E. A. Ekimov et al. Nature, 428, 542 (2004). 2. Y. Takano et al., Appl. Phys. Lett. 85, 2851 (2004). 3. E. Bustarret et al., ond-mat 0408517.

  3. The boron doping of single crystal diamond for high power diode applications

    NASA Astrophysics Data System (ADS)

    Nicley, Shannon Singer

    Diamond has the potential to revolutionize the field of high power and high frequency electronic devices as a superlative electronic material. The realization of diamond electronics depends on the control of the growth process of both lightly and heavily boron doped diamond. This dissertation work is focused on furthering the state of the art of boron doped diamond (BDD) growth toward the realization of high power diamond Schottky barrier diodes (SBDs). The achievements of this work include the fabrication of a new dedicated reactor for lightly boron doped diamond deposition, the optimization of growth processes for both heavily and lightly boron doped single crystal diamond (SCD), and the proposal and realization of the corner architecture SBD. Boron doped SCD is grown in microwave plasma-assisted chemical vapor deposition (MPACVD) plasma disc bell-jar reactors, with feedgas mixtures including hydrogen, methane, carbon dioxide, and diborane. Characterization methods for the analysis of BDD are described, including Fourier-transformed infrared spectroscopy (FTIR), Secondary Ion Mass Spectroscopy (SIMS) and temperature-dependent four point probe conductivity for activation energy. The effect of adding carbon dioxide to the plasma feedgas for lightly boron doped diamond is investigated. The effect of diborane levels and other growth parameters on the incorporated boron levels are reported, and the doping efficiency is calculated over a range of boron concentrations. The presence of defects is shown to affect the doping uniformity. The substrate growth temperature dependence of the plasma gas-phase to solid-phase doping efficiency in heavily boron doped SCD deposition is investigated. The substrate temperature during growth is shown to have a significant effect on the grown sample defect morphology, and a temperature dependence of the doping efficiency is also shown. The effect of the growth rate on the doping efficiency is discussed, and the ratio of the boron concentration in the gas phase to the flux of carbon incorporated into the solid diamond phase is shown to be a more predictive measure of the resulting boron concentration than the gas phase boron to carbon ratio that is more commonly reported. The corner architecture SBD structure is proposed as an alternative vertical architecture for the realization of high power, high temperature single crystal diamond diodes. The lightly doped layer of the diode is grown in a direction perpendicular to the previous epitaxial growth of the heavily doped layer, to reduce the threading type dislocations in the active region of the fabricated diodes. The first ever corner architecture SBD is fabricated and evaluated for diode performance, using the regimes identified for high quality boron doped diamond deposition at light and heavy doping levels.

  4. Thermal conductivity of ultrathin nano-crystalline diamond films determined by Raman thermography assisted by silicon nanowires

    NASA Astrophysics Data System (ADS)

    Anaya, Julian; Rossi, Stefano; Alomari, Mohammed; Kohn, Erhard; Tóth, Lajos; Pécz, Béla; Kuball, Martin

    2015-06-01

    The thermal transport in polycrystalline diamond films near its nucleation region is still not well understood. Here, a steady-state technique to determine the thermal transport within the nano-crystalline diamond present at their nucleation site has been demonstrated. Taking advantage of silicon nanowires as surface temperature nano-sensors, and using Raman Thermography, the in-plane and cross-plane components of the thermal conductivity of ultra-thin diamond layers and their thermal barrier to the Si substrate were determined. Both components of the thermal conductivity of the nano-crystalline diamond were found to be well below the values of polycrystalline bulk diamond, with a cross-plane thermal conductivity larger than the in-plane thermal conductivity. Also a depth dependence of the lateral thermal conductivity through the diamond layer was determined. The results impact the design and integration of diamond for thermal management of AlGaN/GaN high power transistors and also show the usefulness of the nanowires as accurate nano-thermometers.

  5. Method for machining steel with diamond tools

    DOEpatents

    Casstevens, John M. (Greenville, TX)

    1986-01-01

    The present invention is directed to a method for machining optical quality inishes and contour accuracies of workpieces of carbon-containing metals such as steel with diamond tooling. The wear rate of the diamond tooling is significantly reduced by saturating the atmosphere at the interface of the workpiece and the diamond tool with a gaseous hydrocarbon during the machining operation. The presence of the gaseous hydrocarbon effectively eliminates the deterioration of the diamond tool by inhibiting or preventing the conversion of the diamond carbon to graphite carbon at the point of contact between the cutting tool and the workpiece.

  6. Diamond cutting element in a rotating bit

    SciTech Connect

    Grappendorf, R. H.

    1985-01-01

    An improved tooth for use in rotating diamond bits incorporating a generally triangular prismatic polycrystalline diamond element is devised by integrally forming an oval shaped base about the tooth or element extending from the face of the rotating bit, thereby providing a lateral reinforcing collar. The diamond element is also reinforced by a tapered trailing support having a leading surface contiguous and substantially congruous with the trailing surface of the diamond element. In one embodiment, a prepad provides reinforcement or support for the leading surface of the diamond element.

  7. Method for machining steel with diamond tools

    DOEpatents

    Casstevens, J.M.

    1984-01-01

    The present invention is directed to a method for machine optical quality finishes and contour accuracies of workpieces of carbon-containing metals such as steel with diamond tooling. The wear rate of the diamond tooling is significantly reduced by saturating the atmosphere at the interface of the workpiece and the diamond tool with a gaseous hydrocarbon during the machining operation. The presence of the gaseous hydrocarbon effectively eliminates the deterioration of the diamond tool by inhibiting or preventing the conversion of the diamond carbon to graphite carbon at the point of contact between the cutting tool and the workpiece.

  8. Electron Microscopy of Natural and Epitaxial Diamond

    NASA Technical Reports Server (NTRS)

    Posthill, J. B.; George, T.; Malta, D. P.; Humphreys, T. P.; Rudder, R. A.; Hudson, G. C.; Thomas, R. E.; Markunas, R. J.

    1993-01-01

    Semiconducting diamond films have the potential for use as a material in which to build active electronic devices capable of operating at high temperatures or in high radiation environments. Ultimately, it is preferable to use low-defect-density single crystal diamond for device fabrication. We have previously investigated polycrystalline diamond films with transmission electron microscopy (TEM) and scanning electron microscopy (SEM), and homoepitaxial films with SEM-based techniques. This contribution describes some of our most recent observations of the microstructure of natural diamond single crystals and homoepitaxial diamond thin films using TEM.

  9. A diamond (1 0 0) surface with perfect phase purity

    NASA Astrophysics Data System (ADS)

    Dyachenko, Oleksiy; Diek, Nadine; Shapiro, Yevgeniy; Tamang, Rajesh; Harneit, Wolfgang; Reichling, Michael; Borodin, Andriy

    2015-11-01

    Diamond surfaces with (1 0 0) orientation and perfect phase purity regarding the coexistence of sp3 and sp2 bonding as well as near surface nitrogen implanted layers are repeatedly produced from one sample by a cycle of nitrogen implantation, etching in oxygen and wet chemical etching. Comprehensive surface studies carried out by X-ray photoelectron spectroscopy (XPS) involving a deconvolution of the C 1s peak into contributions of C sp3, C sp2 and C sp3(N) reveal the surface and near-surface phase and stoichiometry. It is demonstrated that efficient etching of nitrogen implanted diamond occurs by high temperature annealing in oxygen and a wet chemical treatment.

  10. Zr/oxidized diamond interface for high power Schottky diodes

    SciTech Connect

    Traoré, A. Muret, P.; Fiori, A.; Eon, D.; Gheeraert, E.; Pernot, J.

    2014-02-03

    High forward current density of 10{sup 3} A/cm{sup 2} (at 6 V) and a breakdown field larger than 7.7 MV/cm for diamond diodes with a pseudo-vertical architecture, are demonstrated. The power figure of merit is above 244 MW/cm{sup 2} and the relative standard deviation of the reverse current density over 83 diodes is 10% with a mean value of 10{sup ?9} A/cm{sup 2}. These results are obtained with zirconium as Schottky contacts on the oxygenated (100) oriented surface of a stack comprising an optimized lightly boron doped diamond layer on a heavily boron doped one, epitaxially grown on a Ib substrate. The origin of such performances are discussed.

  11. CVD diamond film oxidation resistance research

    NASA Astrophysics Data System (ADS)

    Jing, Longwei; Wang, Xiaoping; Wang, Lijun; Pan, Xiufang; Sun, Yiqing; Wang, Jinye; Sun, Hongtao

    2013-12-01

    Diamond films were deposited on a silicon substrate by microwave plasma chemical vapor deposition system, and its oxidation experiments were carried out in atmospheric environmental condition by using a muffle furnace. Inatmospheric environment (the temperature is from 400°C to 900°C) the oxidation resistance of diamond thin films was investigated. The results indicate that under the atmospheric environment diamond thin film surface morphology did not change after 6 hours at 400°C. Diamond thin film surface morphology began to change after 2 hours at 600°C, and when time was extended to 4 hours, the diamond thin film surface morphology changed significantly. The surface morphology of diamond films began to change after 15 minutes at a 700°C condition and when time was extended to 6 hours diamond films were all destroyed. All the diamond films on the silicon substrate disappeared completely in 20 minutes at 900°C. The intact crystal face is the reason that natural diamond has stable chemical property. The crystal face of synthetic diamond film has a lot of defects, especially on the side. Oxidation of the diamond films begin with the grain boundary and defects.

  12. Valleytronics: Electrons dance in diamond

    NASA Astrophysics Data System (ADS)

    Nebel, Christoph E.

    2013-08-01

    In addition to manipulating the charge or spin of electrons, another way to control electric current is by using the 'valley' degree-of-freedom of electrons. The first demonstration of the generation, transport and detection of valley-polarized electrons in bulk diamond now opens up new opportunities for quantum control in electronic devices.

  13. High thermal conductivity of diamond

    NASA Technical Reports Server (NTRS)

    Stephan, Patrick M.

    1993-01-01

    The objectives of this educational exercise were to demonstrate the high rate of heat flow from a synthetic diamond coupon and to compare it to a commonly used thermal conductor, such as copper. The principles of heat transfer by conduction and convection may also be demonstrated. A list of equipment and supplies and the procedure for the experiment are presented.

  14. Diamond/diamond-like carbon coated nanotube structures for efficient electron field emission

    NASA Technical Reports Server (NTRS)

    Dimitrijevic, Steven (Inventor); Withers, James C. (Inventor); Loutfy, Raouf O. (Inventor)

    2005-01-01

    The present invention is directed to a nanotube coated with diamond or diamond-like carbon, a field emitter cathode comprising same, and a field emitter comprising the cathode. It is also directed to a method of preventing the evaporation of carbon from a field emitter comprising a cathode comprised of nanotubes by coating the nanotube with diamond or diamond-like carbon. In another aspect, the present invention is directed to a method of preventing the evaporation of carbon from an electron field emitter comprising a cathode comprised of nanotubes, which method comprises coating the nanotubes with diamond or diamond-like carbon.

  15. Diamond anvil cell for spectroscopic investigation of materials at high temperature, high pressure and shear

    DOEpatents

    Westerfield, Curtis L. (Espanola, NM); Morris, John S. (Los Alamos, NM); Agnew, Stephen F. (Los Alamos, NM)

    1997-01-01

    Diamond anvil cell for spectroscopic investigation of materials at high temperature, high pressure and shear. A cell is described which, in combination with Fourier transform IR spectroscopy, permits the spectroscopic investigation of boundary layers under conditions of high temperature, high pressure and shear.

  16. Diamond anvil cell for spectroscopic investigation of materials at high temperature, high pressure and shear

    DOEpatents

    Westerfield, C.L.; Morris, J.S.; Agnew, S.F.

    1997-01-14

    Diamond anvil cell is described for spectroscopic investigation of materials at high temperature, high pressure and shear. A cell is described which, in combination with Fourier transform IR spectroscopy, permits the spectroscopic investigation of boundary layers under conditions of high temperature, high pressure and shear. 4 figs.

  17. Transitions in morphology observed in nitrogenmethanehydrogen depositions of polycrystalline diamond films

    E-print Network

    Ayres, Virginia

    . EXPERIMENTAL APPROACH A 2.45 GHz microwave plasma cavity reactor was used to deposit polycrystalline diamond on the op- erating pressure, with minor dependence on the microwave input power, as discussed in Ref. 7 was observed for both series. 5 A layered growth and/or etched morphology at high nitrogen concentrations

  18. AlN/single crystalline diamond piezoelectric structure as a high overtone bulk acoustic resonator

    NASA Astrophysics Data System (ADS)

    Sorokin, B. P.; Kvashnin, G. M.; Volkov, A. P.; Bormashov, V. S.; Aksenenkov, V. V.; Kuznetsov, M. S.; Gordeev, G. I.; Telichko, A. V.

    2013-03-01

    First, the Al/AlN/Al/Cr/diamond single crystal piezoelectric layered structure has been developed, and its properties have been investigated up to 8 GHz. The peculiarities associated with the influence of piezoelectric film on the Q factor of high overtones of substrate have been pointed out. High Q ˜ 104 has been found at 6-7 GHz band.

  19. Multiple Diamond Anvil (MDA) apparatus using nano-polycrystalline diamond

    NASA Astrophysics Data System (ADS)

    Irifune, T.; Kunimoto, T.; Tange, Y.; Shinmei, T.; Isobe, F.; Kurio, A.; Funakoshi, K.

    2011-12-01

    Thanks to the great efforts by Dave Mao, Bill Bassett, Taro Takahashi, and their colleagues at the University of Rochester through 1960s-70s, diamond anvil cell (DAC) became a major tool to investigate the deep Earth after its invention by scientists at NBS in 1958. DAC can now cover almost the entire pressure and temperature regimes of the Earth's interior, which seems to have solved the longstanding debate on the crystal structure of iron under the P-T conditions of the Earth's inner core. In contrast, various types of static large-volume presses (LVP) have been invented, where tungsten carbide has conventionally been used as anvils. Kawai-type multianvil apparatus (MA), which utilize 6 first-stage harden steel and 8 tungsten carbide anvils, is the most successful LVP, and has been used for accurate measurements of phase transitions, physical properties, element partitioning, etc. at high pressure and temperature. However, pressures using tungsten carbide as the second-stage anvils have been limited to about 30 GPa due to significant plastic deformation of the anvils. Efforts have been made to expand this pressure limit by replacing tungsten carbide anvils with harder sintered diamond (SD) anvils over the last two decades, but the pressures available in KMA with SD anvils have still been limited to below 100 GPa. We succeeded to produce nano-polycrystalline diamond (NPD or HIME-Diamond) in 2003, which is known to have ultrahigh hardness, very high toughness and elastic stiffness, high transmittance of light, relatively low thermal conductivity. These properties are feasible for its use as anvils, and some preliminary experiments of application of NPD anvils to laser heated DAC have successfully made in the last few years. We are now able to synthesize NPD rods with about 1cm in both diameter and length using a newly constructed 6000-ton KMA at Geodynamics Research Center, Ehime University, and have just started to apply this new polycrystalline diamond as anvils for multianvil apparatus. Various versions of the Multiple Diamond Anvil (MDA) apparatus with NPD anvils (Fig.1), amalgamated forms of MA and DAC, are currently being tested for experiments under Mbar regimes without sacrificing the advantages of MA over DAC.

  20. Measurements and Studies of Secondary Electron Emission of Diamond Amplified Photocathode

    SciTech Connect

    Wu,Q.

    2008-10-01

    The Diamond Amplified Photocathode (DAP) is a novel approach to generating electrons. By following the primary electron beam, which is generated by traditional electron sources, with an amplifier, the electron beam available to the eventual application is increased by 1 to 2 orders of magnitude in current. Diamond has a very wide band gap of 5.47eV which allows for a good negative electron affinity with simple hydrogenation, diamond can hold more than 2000MV/m field before breakdown. Diamond also provides the best rigidity among all materials. These two characters offer the capability of applying high voltage across very thin diamond film to achieve high SEY and desired emission phase. The diamond amplifier also is capable of handling a large heat load by conduction and sub-nanosecond pulse input. The preparation of the diamond amplifier includes thinning and polishing, cleaning with acid etching, metallization, and hydrogenation. The best mechanical polishing available can provide high purity single crystal diamond films with no less than 100 {micro}m thickness and <15 nm Ra surface roughness. The ideal thickness for 700MHz beam is {approx}30 {micro}m, which requires further thinning with RIE or laser ablation. RIE can achieve atomic layer removal precision and roughness eventually, but the time consumption for this procedure is very significant. Laser ablation proved that with <266nm ps laser beam, the ablation process on the diamond can easily achieve removing a few microns per hour from the surface and <100nm roughness. For amplifier application, laser ablation is an adequate and efficient process to make ultra thin diamond wafers following mechanical polishing. Hydrogenation will terminate the diamond surface with monolayer of hydrogen, and form NEA so that secondary electrons in the conduction band can escape into the vacuum. The method is using hydrogen cracker to strike hydrogen atoms onto the bare diamond surface to form H-C bonds. Two independent experiments were carried out to determine the transport of the electrons within the diamond and their emission at the surface. In transmission mode measurements, the diamond amplifier was coated with metal on both sides, so results simply depend only on the electron transport within the diamond. The SEY for this mode provides one secondary electron per 20eV energy, which gives the gain of more than 200 for 4.7keV (effective energy) primary electrons under 2MV/m. Laser detrapping can help the signal maintain the gain with lops pulse and duty cycle of 1.67 x 10{sup -7}. In emission mode measurements, in which the diamond is prepared as in the actual application, the SEY is {approx}20 for 700eV (effective energy) primary electrons under 1.21MV/m. The electric field applied and the primary electron energy is limited by the experiment setup, but the results show good trend toward large gain under high field. Thermal emittance of the diamond secondary emission is critical for the beam application. A careful design is setup to measure with very fine precision and accuracy of 0.01eV.

  1. 33 CFR 110.6 - Portland Harbor, Portland, Maine (between Little Diamond Island and Great Diamond Island).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... (between Little Diamond Island and Great Diamond Island). 110.6 Section 110.6 Navigation and Navigable... Areas § 110.6 Portland Harbor, Portland, Maine (between Little Diamond Island and Great Diamond Island). Beginning at the southeasterly corner of the wharf, at the most southerly point of Great Diamond Island...

  2. 33 CFR 110.6 - Portland Harbor, Portland, Maine (between Little Diamond Island and Great Diamond Island).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... (between Little Diamond Island and Great Diamond Island). 110.6 Section 110.6 Navigation and Navigable... Areas § 110.6 Portland Harbor, Portland, Maine (between Little Diamond Island and Great Diamond Island). Beginning at the southeasterly corner of the wharf, at the most southerly point of Great Diamond Island...

  3. 33 CFR 110.6 - Portland Harbor, Portland, Maine (between Little Diamond Island and Great Diamond Island).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (between Little Diamond Island and Great Diamond Island). 110.6 Section 110.6 Navigation and Navigable... Areas § 110.6 Portland Harbor, Portland, Maine (between Little Diamond Island and Great Diamond Island). Beginning at the southeasterly corner of the wharf, at the most southerly point of Great Diamond Island...

  4. 33 CFR 110.6 - Portland Harbor, Portland, Maine (between Little Diamond Island and Great Diamond Island).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... (between Little Diamond Island and Great Diamond Island). 110.6 Section 110.6 Navigation and Navigable... Areas § 110.6 Portland Harbor, Portland, Maine (between Little Diamond Island and Great Diamond Island). Beginning at the southeasterly corner of the wharf, at the most southerly point of Great Diamond Island...

  5. 33 CFR 110.6 - Portland Harbor, Portland, Maine (between Little Diamond Island and Great Diamond Island).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (between Little Diamond Island and Great Diamond Island). 110.6 Section 110.6 Navigation and Navigable... Areas § 110.6 Portland Harbor, Portland, Maine (between Little Diamond Island and Great Diamond Island). Beginning at the southeasterly corner of the wharf, at the most southerly point of Great Diamond Island...

  6. Medical applications of diamond particles and surfaces.

    SciTech Connect

    Narayan, R. J.; Boehm, R. D.; Sumant, A. V.

    2011-04-01

    Diamond has been considered for use in several medical applications due to its unique mechanical, chemical, optical, and biological properties. In this paper, methods for preparing synthetic diamond surfaces and particles are described. In addition, recent developments involving the use of diamond in prostheses, sensing, imaging, and drug delivery applications are reviewed. These developments suggest that diamond-containing structures will provide significant improvements in the diagnosis and treatment of medical conditions over the coming years. Diamond is an allotrope of carbon that is being considered for use in several medical applications. Ramachandran determined that the crystal structure of diamond consists of two close packed interpenetrating face centered cubic lattices; one lattice is shifted with respect to the other along the elemental cube space diagonal by one-quarter of its length. If one approximates carbon atoms as equal diameter rigid spheres, the filling of this construction is 34%. Due to the carbon-carbon distance (1.54 {angstrom}), diamond crystal exhibits the highest atomic density (1.76 x 10{sup 23} cm{sup -3}) of any solid. The very high bond energy between two carbon atoms (83 kcal/mol) and the directionality of tetrahedral bonds are the main reasons for the high strength of diamond. Diamond demonstrates the highest Vickers hardness value of any material (10,000 kg/mm{sup 2}). The tribological properties of diamond are also impressive; the coefficient of friction of polished diamond is 0.07 in argon and 0.05 in humid air. Diamond is resistant to corrosion except in an oxygen atmosphere at temperatures over 800 C. In addition, type IIa diamond exhibits the highest thermal conductivity of all materials (20 W cm{sup -1} K{sup -1} at room temperature).

  7. Synthesizing Diamond from Liquid Feedstock

    NASA Technical Reports Server (NTRS)

    Tzeng, Yonhua

    2005-01-01

    A relatively economical method of chemical vapor deposition (CVD) has been developed for synthesizing diamond crystals and films. Unlike prior CVD methods for synthesizing diamond, this method does not require precisely proportioned flows of compressed gas feedstocks or the use of electrical discharges to decompose the feedstocks to obtain free radicals needed for deposition chemical reactions. Instead, the feedstocks used in this method are mixtures of common organic liquids that can be prepared in advance, and decomposition of feedstock vapors is effected simply by heating. The feedstock used in this method is a solution comprising between 90 and 99 weight percent of methanol and the balance of one or more other oxyhydrocarbons that could include ethanol, isopropanol, and/or acetone. This mixture of compounds is chosen so that dissociation of molecules results in the desired proportions of carbon-containing radicals (principally, CH3) and of OH, H, and O radicals. Undesirably, the CVD temperature and pressure conditions thermodynamically favor the growth of graphite over the growth of diamond. The H radicals are desirable because they help to stabilize the growing surface of diamond by shifting the thermodynamic balance toward favoring the growth of diamond. The OH and O radicals are desirable because they preferentially etch graphite and other non-diamond carbon, thereby helping to ensure the net deposition of pure diamond. The non-methanol compounds are included in the solution because (1) methanol contains equal numbers of C and O atoms; (2) an excess of C over O is needed to obtain net deposition of diamond; and (3) the non-methanol molecules contain multiple carbon atoms for each oxygen atom and thus supply the needed excess carbon A typical apparatus used in this method includes a reservoir containing the feedstock liquid and a partially evacuated stainless-steel reaction chamber. The reservoir is connected to the chamber via tubing and a needle valve or other suitable flow controller. When the liquid enters the low-pressure environment inside the chamber, it evaporates to form a vapor mixture of the same chemical composition. In addition to the inlet for the feedstock liquid, the chamber is fitted with an outlet connected to a vacuum pump (not shown) through a throttle valve (also not shown) that is automatically controlled to keep the pressure at or near the required value throughout the deposition process. Inside the chamber, a spiral filament made of tungsten, tantalum, graphite, or other high-melting-temperature material is electrically heated to a temperature >2,000 C high enough to cause dissociation of vapor molecules into the aforementioned radicals. A deposition substrate typically, a diamond-polished silicon wafer about 2.5 cm square is positioned about 2 cm away from the filament. The exact location of the substrate is chosen so that the substrate becomes heated by the filament to a deposition temperature in the approximate range of 800 to 1,000 C.

  8. 21 CFR 872.4535 - Dental diamond instrument.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...Surgical Devices § 872.4535 Dental diamond instrument. (a) Identification. A dental diamond instrument is an abrasive device...which is inserted into a handpiece and a head which has diamond chips imbedded into it. Rotation...

  9. 21 CFR 872.4535 - Dental diamond instrument.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...Surgical Devices § 872.4535 Dental diamond instrument. (a) Identification. A dental diamond instrument is an abrasive device...which is inserted into a handpiece and a head which has diamond chips imbedded into it. Rotation...

  10. 78 FR 57104 - Airworthiness Directives; Diamond Aircraft Industries Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-17

    ...2120-AA64 Airworthiness Directives; Diamond Aircraft Industries Airplanes AGENCY...new airworthiness directive (AD) for Diamond Aircraft Industries Model DA 40 and DA...identified in this proposed AD, contact Diamond Aircraft Industries GmbH, N.A....

  11. 76 FR 48047 - Airworthiness Directives; Diamond Aircraft Industries Powered Sailplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-08

    ...2120-AA64 Airworthiness Directives; Diamond Aircraft Industries Powered Sailplanes...new airworthiness directive (AD) for Diamond Aircraft Industries Model H-36 ``DIMONA...brake control system torsion tube on a Diamond (formerly Hoffman) H 36 powered...

  12. 76 FR 64793 - Airworthiness Directives; Diamond Aircraft Industries Powered Sailplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-19

    ...2120-AA64 Airworthiness Directives; Diamond Aircraft Industries Powered Sailplanes...new airworthiness directive (AD) for Diamond Aircraft Industries Model H-36 ``DIMONA...brake control system torsion tube on a Diamond (formerly Hoffman) H 36 powered...

  13. Network-Aware Partitioning of Computation in Diamond

    E-print Network

    Network-Aware Partitioning of Computation in Diamond Alex Nizhner1 Larry Huston2 Peter Steenkiste Pittsburgh, PA 15213 Abstract The Diamond storage architecture enables efficient interactive search efficient use of resources under dynamic conditions, Diamond adaptively partitions computation among

  14. 21 CFR 872.4535 - Dental diamond instrument.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Dental diamond instrument. 872.4535 Section 872...Surgical Devices § 872.4535 Dental diamond instrument. (a) Identification. A dental diamond instrument is an abrasive device...

  15. 21 CFR 872.4535 - Dental diamond instrument.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Dental diamond instrument. 872.4535 Section 872...Surgical Devices § 872.4535 Dental diamond instrument. (a) Identification. A dental diamond instrument is an abrasive device...

  16. 16 CFR 23.13 - Disclosure of treatments to diamonds.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 false Disclosure of treatments to diamonds. 23.13 Section 23.13 Commercial Practices...INDUSTRIES § 23.13 Disclosure of treatments to diamonds. A diamond is a gemstone product. Treatments to...

  17. 16 CFR 23.13 - Disclosure of treatments to diamonds.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 false Disclosure of treatments to diamonds. 23.13 Section 23.13 Commercial Practices...INDUSTRIES § 23.13 Disclosure of treatments to diamonds. A diamond is a gemstone product. Treatments to...

  18. 16 CFR 23.13 - Disclosure of treatments to diamonds.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 false Disclosure of treatments to diamonds. 23.13 Section 23.13 Commercial Practices...INDUSTRIES § 23.13 Disclosure of treatments to diamonds. A diamond is a gemstone product. Treatments to...

  19. 21 CFR 872.4535 - Dental diamond instrument.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Dental diamond instrument. 872.4535 Section 872...Surgical Devices § 872.4535 Dental diamond instrument. (a) Identification. A dental diamond instrument is an abrasive device...

  20. Studies of the secondary electron from diamond films

    E-print Network

    Bristol, University of

    .............................................................................1 1.2. Deposition techniques of synthetic diamond ...................................................Studies of the secondary electron emission from diamond films Raquel Maria Amaro Vaz A dissertation research was the development of an optimised secondary electron emission (SEE) diamond film to use

  1. Chemical vapor deposited diamond-on-diamond powder composites (LDRD final report)

    SciTech Connect

    Panitz, J.K.; Hsu, W.L.; Tallant, D.R.; McMaster, M.; Fox, C.; Staley, D.

    1995-12-01

    Densifying non-mined diamond powder precursors with diamond produced by chemical vapor infiltration (CVI) is an attractive approach for forming thick diamond deposits that avoids many potential manufacturability problems associated with predominantly chemical vapor deposition (CVD) processes. The authors developed techniques for forming diamond powder precursors and densified these precursors in a hot filament-assisted reactor and a microwave plasma-assisted reactor. Densification conditions were varied following a fractional factorial statistical design. A number of conclusions can be drawn as a result of this study. High density diamond powder green bodies that contain a mixture of particle sizes solidify more readily than more porous diamond powder green bodies with narrow distributions of particle sizes. No composite was completely densified although all of the deposits were densified to some degree. The hot filament-assisted reactor deposited more material below the exterior surface, in the interior of the powder deposits; in contrast, the microwave-assisted reactor tended to deposit a CVD diamond skin over the top of the powder precursors which inhibited vapor phase diamond growth in the interior of the powder deposits. There were subtle variations in diamond quality as a function of the CVI process parameters. Diamond and glassy carbon tended to form at the exterior surface of the composites directly exposed to either the hot filament or the microwave plasma. However, in the interior, e.g. the powder/substrate interface, diamond plus diamond-like-carbon formed. All of the diamond composites produced were grey and relatively opaque because they contained flawed diamond, diamond-like-carbon and glassy carbon. A large amount of flawed and non-diamond material could be removed by post-CVI oxygen heat treatments. Heat treatments in oxygen changed the color of the composites to white.

  2. Laser damage threshold of diamond films

    NASA Technical Reports Server (NTRS)

    Albin, Sacharia; Cropper, Andre D.; Watkins, Linwood C.; Byvik, Charles E.; Buoncristiani, A. Martin

    1989-01-01

    The possibility that diamond films may inhibit laser-induced damage to optical components in laser systems films was investigated by measuring laser damage thresholds of free-standing diamond film windows, diamond films deposited on silicon substrates, and bare silicon substrate. Polycrystalline diamond films were deposited using a dc plasma-enhanced CVD process. It was found that free-standing diamond films had the highest laser damage threshold at 1064 nm. For a diamond film of 630 nm, the damage threshold was found to be 7 J/sq cm, as compared to a damage threshold of 4.5 J/sq cm for bare silicon, and a low value of 1.5 J/sq cm for the film/substrate combination. The damage mechanism is considered to involve melting or dielectric breakdown induced by laser radiation. The low value of the film/substrate combination is attributed to film stress and conditions of film deposition.

  3. Diamond thermoluminescence properties of different chondrites

    NASA Technical Reports Server (NTRS)

    Fisenko, A. V.; Kashkarov, L. L.; Semjonova, L. F.; Pillinger, C. T.

    1993-01-01

    It was found that thermoluminescence (TL) glows of diamonds depend on the origin of diamonds and the chondrite metamorphism degree. The investigation of TL of diamonds was continued and the results for diamonds from Murchison CM2, Krymka LL3.0, Kainsaz CO3, and Abee E4 were considered. The diamonds synthesized by CVD-process (samples 133, 159) and by detonation from soot (DDS-B14-89) were also analyzed for comparison. Before the TL measuring samples were annealed at approximately 350 C for a few seconds and then irradiated by gamma-rays of Cs-137 up to dose approximately 200 krad. TL-measurements were performed in the air atmosphere on the standard equipment. TL data for samples are shown. TL glow for some diamonds are also presented.

  4. Raman and conductivity studies of boron doped microcrystalline diamond, facetted nanocrystalline diamond

    E-print Network

    Bristol, University of

    diamond and cauliflower diamond films P.W. May a,*, W.J. Ludlow a , M. Hannaway a , P.J. Heard b , J (f-NCD) and `cauliflower' diamond (c-NCD). The position of the Lorentzian contribution to the 500 cm

  5. Diamond and Related Materials 9 (2000) 12631269 www.elsevier.com/locate/diamond

    E-print Network

    Bristol, University of

    2000-01-01

    regions or by suppressing the formationThe patterning of the diamond will be a key process rate Selective suppression of the formation of diamond nucleidevices such as planar electron field emitter arrays for patterning synthetic diamond nano-grit ontopretreatment steps involving at some point the use of a polished

  6. Mineral resource of the month: diamond

    USGS Publications Warehouse

    Olson, Donald W.

    2009-01-01

    The article presents information on diamond, which is regarded as the world's most popular gemstone. It states that there is strength in the covalent bonding between its carbon atoms, resulting to the strength of its physical properties. The presence of colors in diamonds may be attributed to the impurities that settle in the crystal lattice. Diamonds have been used as decorative items since the ancient era.

  7. Diamond-silicon carbide composite and method

    DOEpatents

    Zhao, Yusheng (Los Alamos, NM)

    2011-06-14

    Uniformly dense, diamond-silicon carbide composites having high hardness, high fracture toughness, and high thermal stability are prepared by consolidating a powder mixture of diamond and amorphous silicon. A composite made at 5 GPa/1673K had a measured fracture toughness of 12 MPam.sup.1/2. By contrast, liquid infiltration of silicon into diamond powder at 5 GPa/1673K produces a composite with higher hardness but lower fracture toughness.

  8. Nanotwinned diamond with unprecedented hardness and stability

    NASA Astrophysics Data System (ADS)

    Huang, Quan; Yu, Dongli; Xu, Bo; Hu, Wentao; Ma, Yanming; Wang, Yanbin; Zhao, Zhisheng; Wen, Bin; He, Julong; Liu, Zhongyuan; Tian, Yongjun

    2014-06-01

    Although diamond is the hardest material for cutting tools, poor thermal stability has limited its applications, especially at high temperatures. Simultaneous improvement of the hardness and thermal stability of diamond has long been desirable. According to the Hall-Petch effect, the hardness of diamond can be enhanced by nanostructuring (by means of nanograined and nanotwinned microstructures), as shown in previous studies. However, for well-sintered nanograined diamonds, the grain sizes are technically limited to 10-30 nm (ref. 3), with degraded thermal stability compared with that of natural diamond. Recent success in synthesizing nanotwinned cubic boron nitride (nt-cBN) with a twin thickness down to ~3.8 nm makes it feasible to simultaneously achieve smaller nanosize, ultrahardness and superior thermal stability. At present, nanotwinned diamond (nt-diamond) has not been fabricated successfully through direct conversions of various carbon precursors (such as graphite, amorphous carbon, glassy carbon and C60). Here we report the direct synthesis of nt-diamond with an average twin thickness of ~5 nm, using a precursor of onion carbon nanoparticles at high pressure and high temperature, and the observation of a new monoclinic crystalline form of diamond coexisting with nt-diamond. The pure synthetic bulk nt-diamond material shows unprecedented hardness and thermal stability, with Vickers hardness up to ~200 GPa and an in-air oxidization temperature more than 200 °C higher than that of natural diamond. The creation of nanotwinned microstructures offers a general pathway for manufacturing new advanced carbon-based materials with exceptional thermal stability and mechanical properties.

  9. Method for machining steel with diamond tools

    SciTech Connect

    Casstevens, J.M.

    1986-01-07

    This patent describes a method for decreasing the wear rate of a diamond cutting tool used in machining a steel workpiece. This method consists of providing a gaseous hydrocarbon atmosphere at the interface between the cutting tool and the workpiece during the machining of the latter with the concentration of gaseous hydrocarbons being adequate to inhibit the conversion of diamond carbon to graphite carbon at the point of contact of the diamond tool with the workpiece.

  10. Nanotwinned diamond with unprecedented hardness and stability.

    PubMed

    Huang, Quan; Yu, Dongli; Xu, Bo; Hu, Wentao; Ma, Yanming; Wang, Yanbin; Zhao, Zhisheng; Wen, Bin; He, Julong; Liu, Zhongyuan; Tian, Yongjun

    2014-06-12

    Although diamond is the hardest material for cutting tools, poor thermal stability has limited its applications, especially at high temperatures. Simultaneous improvement of the hardness and thermal stability of diamond has long been desirable. According to the Hall-Petch effect, the hardness of diamond can be enhanced by nanostructuring (by means of nanograined and nanotwinned microstructures), as shown in previous studies. However, for well-sintered nanograined diamonds, the grain sizes are technically limited to 10-30?nm (ref. 3), with degraded thermal stability compared with that of natural diamond. Recent success in synthesizing nanotwinned cubic boron nitride (nt-cBN) with a twin thickness down to ?3.8?nm makes it feasible to simultaneously achieve smaller nanosize, ultrahardness and superior thermal stability. At present, nanotwinned diamond (nt-diamond) has not been fabricated successfully through direct conversions of various carbon precursors (such as graphite, amorphous carbon, glassy carbon and C60). Here we report the direct synthesis of nt-diamond with an average twin thickness of ?5?nm, using a precursor of onion carbon nanoparticles at high pressure and high temperature, and the observation of a new monoclinic crystalline form of diamond coexisting with nt-diamond. The pure synthetic bulk nt-diamond material shows unprecedented hardness and thermal stability, with Vickers hardness up to ?200?GPa and an in-air oxidization temperature more than 200?°C higher than that of natural diamond. The creation of nanotwinned microstructures offers a general pathway for manufacturing new advanced carbon-based materials with exceptional thermal stability and mechanical properties. PMID:24919919

  11. Maskless milling of diamond by a focused oxygen ion beam

    PubMed Central

    Martin, Aiden A.; Randolph, Steven; Botman, Aurelien; Toth, Milos; Aharonovich, Igor

    2015-01-01

    Recent advances in focused ion beam technology have enabled high-resolution, maskless nanofabrication using light ions. Studies with light ions to date have, however, focused on milling of materials where sub-surface ion beam damage does not inhibit device performance. Here we report on maskless milling of single crystal diamond using a focused beam of oxygen ions. Material quality is assessed by Raman and luminescence analysis, and reveals that the damage layer generated by oxygen ions can be removed by non-intrusive post-processing methods such as localised electron beam induced chemical etching. PMID:25753406

  12. Method and apparatus for making diamond-like carbon films

    DOEpatents

    Pern, Fu-Jann (Golden, CO); Touryan, Kenell J. (Indian Hills, CO); Panosyan, Zhozef Retevos (Yerevan, AM); Gippius, Aleksey Alekseyevich (Moscow, RU)

    2008-12-02

    Ion-assisted plasma enhanced deposition of diamond-like carbon (DLC) films on the surface of photovoltaic solar cells is accomplished with a method and apparatus for controlling ion energy. The quality of DLC layers is fine-tuned by a properly biased system of special electrodes and by exact control of the feed gas mixture compositions. Uniform (with degree of non-uniformity of optical parameters less than 5%) large area (more than 110 cm.sup.2) DLC films with optical parameters varied within the given range and with stability against harmful effects of the environment are achieved.

  13. Diamond turning machine controller implementation

    SciTech Connect

    Garrard, K.P.; Taylor, L.W.; Knight, B.F.; Fornaro, R.J.

    1988-12-01

    The standard controller for a Pnuemo ASG 2500 Diamond Turning Machine, an Allen Bradley 8200, has been replaced with a custom high-performance design. This controller consists of four major components. Axis position feedback information is provided by a Zygo Axiom 2/20 laser interferometer with 0.1 micro-inch resolution. Hardware interface logic couples the computers digital and analog I/O channels to the diamond turning machine`s analog motor controllers, the laser interferometer, and other machine status and control information. It also provides front panel switches for operator override of the computer controller and implement the emergency stop sequence. The remaining two components, the control computer hardware and software, are discussed in detail below.

  14. Site selective growth of heteroepitaxial diamond nanoislands containing single SiV centers

    E-print Network

    Carsten Arend; Patrick Appel; Jonas Nils Becker; Marcel Schmidt; Martin Fischer; Stefan Gsell; Matthias Schreck; Christoph Becher; Patrick Maletinsky; Elke Neu

    2015-11-11

    We demonstrate the controlled preparation of heteroepitaxial diamond nano- and microstructures on silicon wafer based iridium films as hosts for single color centers. Our approach uses electron beam lithography followed by reactive ion etching to pattern the carbon layer formed by bias enhanced nucleation on the iridium surface. In the subsequent chemical vapor deposition process, the patterned areas evolve into regular arrays of (001) oriented diamond nano-islands with diameters of <500nm and a height of approx. 60 nm. In the islands, we identify single SiV color centers with narrow zero phonon lines down to 1 nm at room temperature.

  15. Site selective growth of heteroepitaxial diamond nanoislands containing single SiV centers

    E-print Network

    Arend, Carsten; Becker, Jonas Nils; Schmidt, Marcel; Fischer, Martin; Gsell, Stefan; Schreck, Matthias; Becher, Christoph; Maletinsky, Patrick; Neu, Elke

    2015-01-01

    We demonstrate the controlled preparation of heteroepitaxial diamond nano- and microstructures on silicon wafer based iridium films as hosts for single color centers. Our approach uses electron beam lithography followed by reactive ion etching to pattern the carbon layer formed by bias enhanced nucleation on the iridium surface. In the subsequent chemical vapor deposition process, the patterned areas evolve into regular arrays of (001) oriented diamond nano-islands with diameters of <500nm and a height of approx. 60 nm. In the islands, we identify single SiV color centers with narrow zero phonon lines down to 1 nm at room temperature.

  16. The Toucan's Diamond

    NASA Astrophysics Data System (ADS)

    2006-06-01

    The Southern constellation Tucana (the Toucan) is probably best known as the home of the Small Magellanic Cloud, one of the satellite galaxies of the Milky Way. But Tucana also hosts another famous object that shines thousands of lights, like a magnificent, oversized diamond in the sky: the globular cluster 47 Tucanae. More popularly known as 47 Tuc, it is surpassed in size and brightness by only one other globular cluster, Omega Centauri. Globular clusters are gigantic families of stars, comprising several tens of thousands of stars, all thought to be born at the same time from the same cloud of gas [1]. As such, they constitute unique laboratories for the study of how stars evolve and interact. This is even more so because they are located at the same distance, so the brightness of different types of stars, at different stages in their evolution can be directly compared. The stars in globular clusters are held together by their mutual gravity which gives them their spherical shape, hence their name. Globular clusters are thought to be among the oldest objects in our Milky Way galaxy, and contain therefore mostly old, low-mass stars. ESO PR Photo 20/06 ESO PR Photo 20/06 Globular Cluster 47 Tuc 47 Tucanae is an impressive globular cluster that is visible with the unaided eye from the southern hemisphere. It was discovered in 1751 by the French astronomer Nicholas Louis de Lacaille who cataloged it in his list of southern nebulous objects. Located about 16 000 light years away, it has a total mass of about 1 million times the mass of the Sun and is 120 light years across, making it appear on the sky as big as the full moon. The colour image of 47 Tucanae presented here was taken with FORS1 on ESO's Very Large Telescope in 2001. The image covers only the densest, very central part of the cluster. The globular cluster extends in reality four times further away! As can be seen however, the density of stars rapidly drops off when moving away from the centre. The red giants, stars that have used up all the hydrogen in their core and have increased in size, are especially easy to pick out. 47 Tuc is so dense that stars are less than a tenth of a light year apart, which is about the size of the Solar System. By comparison, the closest star to our Sun, Proxima Centauri, is four light years away. This high density causes many stars to 'bump' into each other, some getting 'married' in the process, or some stars in binary systems exchanging companions. These dynamic processes are the origin of many exotic objects, to be found in the cluster. Thus, 47 Tuc contains at least twenty millisecond pulsars, i.e. neutron stars [2] rotating extremely rapidly around their axis, a few hundreds to one thousand times a second. Such peculiar objects are generally thought to have a companion from which they receive matter. The Hubble Space Telescope recently also looked at 47 Tuc to study planets orbiting very close to their parent stars. This experiment showed that such 'hot Jupiters' must be much less common in 47 Tucanae than around stars in the Sun's neighbourhood. This may tell us either that the dense cluster environment is unhealthy for even such close planets, or that planet formation is a different matter today than it was very early in our Galaxy's history. Technical information: ESO PR Photo 20/06 is based on data obtained with FORS1 on Kueyen, UT2 of the Very Large Telescope. The image, 7 arcmin wide, covers the central core of the 30 arcmin large globular cluster. The observations were taken in three different filters: U, R, and a narrow-band filter centred around 485 nm, for a total exposure time of less than 5 minutes. The data were extracted from the ESO Science Archive and processed by Rubina Kotak (ESO) and the final image processing was done by Henri Boffin (ESO). North is up and East is to the left.

  17. Very High Efficiency, Miniaturized, Long-Lived Alpha Particle Power Source Using Diamond Devices for Extreme Space Environments

    NASA Technical Reports Server (NTRS)

    Kolawa, Elizabeth A. (Inventor); Patel, Jagdishbhai U. (Inventor); Fleurial, Jean-Pierre (Inventor)

    2004-01-01

    A power source that converts a-particle energy into electricity by coulomb collision in doped diamond films is described. Alpha particle decay from curium-244 creates electron-hole pairs by free- ing electrons and holes inside the crystal lattice in N- and P-doped diamond films. Ohmic contacts provide electrical connection to an electronic device. Due to the built-in electric field at the rectifying junction across the hT- and P-doped diamond films, the free electrons are constrained to traveling in generally one direction. This one direction then supplies electrons in a manner similar to that of a battery. The radioactive curium layer may be disposed on diamond films for even distribution of a-particle radiation. The resulting power source may be mounted on a diamond substrate that serves to insulate structures below the diamond substrate from a-particle emission. Additional insulation or isolation may be provided in order to prevent damage from a-particle collision. N-doped silicon may be used instead of N-doped diamond.

  18. Diamond turning of thermoplastic polymers

    SciTech Connect

    Smith, E.; Scattergood, R.O.

    1988-12-01

    Single point diamond turning studies were made using a series of thermoplastic polymers with different glass transition temperatures. Variations in surface morphology and surface roughness were observed as a function of cutting speed. Lower glass transition temperatures facilitate smoother surface cuts and better surface finish. This can be attributed to the frictional heating that occurs during machining. Because of the very low glass transition temperatures in polymeric compared to inorganic glasses, the precision machining response can be very speed sensitive.

  19. Microwave Resonators Containing Diamond Disks

    NASA Technical Reports Server (NTRS)

    Dick, G. John; Maleki, Lutfollah; Wang, Rabi T.

    1996-01-01

    Synthetic diamond dielectric bodies proposed for use in cylindrical resonators helping to stabilize frequencies of some microwave oscillators. Acting in conjunction with metal resonator cavities in which mounted, such dielectric bodies support "whispering-gallery" waveguide modes characterized by desired frequencies of resonance and by electro-magnetic-field configurations limiting dissipation of power on metal surfaces outside dielectric bodies. Performances at room temperature might exceed those of liquid-nitrogen-cooled sapphire-based resonators.

  20. Electromagnetic Radiation Hardness of Diamond Detectors

    E-print Network

    T. Behnke; M. Doucet; N. Ghodbane; A. Imhof; C. Martinez; W. Zeuner

    2001-08-22

    The behavior of artificially grown CVD diamond films under intense electromagnetic radiation has been studied. The properties of irradiated diamond samples have been investigated using the method of thermally stimulated current and by studying their charge collection properties. Diamonds have been found to remain unaffected after doses of 6.8 MGy of 10 keV photons and 10 MGy of MeV-range photons. This observation makes diamond an attractive detector material for a calorimeter in the very forward region of the proposed TESLA detector.

  1. A diamond trilogy: superplumes, supercontinents, and supernovae.

    NASA Astrophysics Data System (ADS)

    Haggerty, S. E.

    1999-08-01

    Diamond is a remarkable mineral and has been long recognized for its unusual physical and chemical properties. This diversity is even greater than formally appreciated because diamond is recognized as an extraordinary recorder of astrophysical and geophysical events that extend from the far reaches of space to Earth's deep interior. Many diamonds are natural antiques that formed in presolar supernovae by carbon vapor deposition, in asteroidal impacts and meteorite craters by shock metamorphism, and in Earth's mantle 1 to 2 billion years after planetary accretion from fluids and melts. The carbon diamond is primordial, but there are unexplained isotopic fractionations and uncertainties in heterogeneity.

  2. Performance of a new Diamond Drill Bit

    SciTech Connect

    Ivie, C.R.; Wood, J.E.

    1984-05-01

    Early in 1984 a new type of synthetic diamond drill bit was introduced. The bits, know as ballaset diamond bits, are designed for and work well in medium to hard, moderately abrasive formations such as limestones, dolomites, hard brittle shales, and sandstones. Two years of field tests, many in the overthrust belt, have proven that ballaset diamond bits offer faster rates of penetration, longer life on bottom and overall improved performance when compared to types 3, 4, 5, and 7; tungsten carbide insert bits in medium to hard formations like the Twincreek limestone and Nugget sandstones of the Overthrust Belt. The ballaset cutting elements are polycrystalline, synthetic diamond. They differ from other polycrystalline synthetic diamonds (diamond compact) such as General Electric's Stratapax, in that they are thermally stable up to 1200/sup 0/C. Other synthetic diamonds are thermally stable up to 800/sup 0/C. Recognizing that frictional wear is a major factor limiting the hardness and abrasiveness of diamond compact drillable formations, thermally stable ballaset diamond bits can now drill these formations.

  3. Electrochemical patterning of amorphous carbon on diamond

    NASA Technical Reports Server (NTRS)

    Marchywka, Mike; Pehrsson, Pehr E.; Binari, Steven C.; Moses, Daniel

    1993-01-01

    The ability to pattern ion-implantation damaged or other nondiamond carbon on a diamond substrate is useful for fabricating a variety of devices. We accomplished such patterning by an unmasked implantation into a diamond substrate followed by photolithography and a selective electrochemical etch. The use of a high resistivity medium coupled with applied biases over 50 V permitted etching without requiring contact between the substrate and an electrode. Many electrolytes gave etches that exhibit high selectivity for nondiamond carbon over both diamond and dielectrics such as photoresist. Optical, electrical, and Raman spectroscopic measurements elucidate the effects of the etch on the implanted diamond surface.

  4. Negative Electron Affinity Mechanism for Diamond Surfaces

    NASA Technical Reports Server (NTRS)

    Krainsky, I. L.; Asnin, V. M.

    1998-01-01

    The energy distribution of the secondary electrons for chemical vacuum deposited diamond films with Negative Electron Affinity (NEA) was investigated. It was found that while for completely hydrogenated diamond surfaces the negative electron affinity peak in the energy spectrum of the secondary electrons is present for any energy of the primary electrons, for partially hydrogenated diamond surfaces there is a critical energy above which the peak is present in the spectrum. This critical energy increases sharply when hydrogen coverage of the diamond surface diminishes. This effect was explained by the change of the NEA from the true type for the completely hydrogenated surface to the effective type for the partially hydrogenated surfaces.

  5. Refractory two-dimensional hole gas on hydrogenated diamond surface

    NASA Astrophysics Data System (ADS)

    Hiraiwa, Atsushi; Daicho, Akira; Kurihara, Shinichiro; Yokoyama, Yuki; Kawarada, Hiroshi

    2012-12-01

    Use of two-dimensional hole gas (2DHG), induced on a hydrogenated diamond surface, is a solution to overcoming one of demerits of diamond, i.e., deep energy levels of impurities. This 2DHG is affected by its environment and accordingly needs a passivation film to get a stable device operation especially at high temperature. In response to this requirement, we achieved the high-reliability passivation forming an Al2O3 film on the diamond surface using an atomic-layer-deposition (ALD) method with an H2O oxidant at 450 °C. The 2DHG thus protected survived air annealing at 550 °C for an hour, establishing a stable high-temperature operation of 2DHG devices in air. In part, this achievement is based on high stability of C-H bonds up to 870 °C in vacuum and above 450 °C in an H2O-containing environment as in the ALD. Chemically, this stability is supported by the fact that both the thermal decomposition of C-H bonds and reaction between C-H bonds and H2O are endothermic processes. It makes a stark contrast to the instability of Si-H bonds, which decompose even at room temperature being exposed to atomic hydrogen. In this respect, the diamond 2DHG devices are also promising as power devices expectedly being free from many instability phenomena, such as hot carrier effect and negative-bias temperature instability, associated with Si devices. As to adsorbate, which is the other prerequisite for 2DHG, it desorbed in vacuum below 250 °C, and accordingly some new adsorbates should have adsorbed during the ALD at 450 °C. As a clue to this question, we certainly confirmed that some adsorbates, other than those at room temperature, adsorbed in air above 100 °C and remained at least up to 290 °C. The identification of these adsorbates is open for further investigation.

  6. (Chemically vapor deposited diamond films)

    SciTech Connect

    Clausing, R.E.; Heatherly, L. Jr.

    1990-09-22

    The NATO-ASI on Diamond and Diamond-Like Films and Coatings'' was an opportunity for us to learn the latest research results from ongoing programs in the leading laboratories of the world and relate them to our work. Specific examples are given in the comprehensive report which follows. The meeting format provided an ideal environment to meet and interact with our international counterparts. It is clear that our studies are well regarded, and that we have established an excellent reputation in a short time. New opportunities for collaboration were identified. A panel discussion at the end of the meeting addressed the needs and opportunities in the synthesis of CVD diamond. The key scientific needs are those related to modeling the nucleation and growth processes and to elucidation of the critical roles of atomic hydrogen and the mechanisms of carbon addition to the growing surfaces. The development and more extensive use of in situ diagnostics for both surface and gas phases are important to solving these issues. The more immediate practical questions concern the identification of the growth-rate-limiting steps, the relation of growth parameters to the resulting film structure, and the dependence of properties on structure.

  7. Diamond powders as neutron filters

    NASA Astrophysics Data System (ADS)

    Nagler, S. E.; Robertson, J. L.; Crow, M. L.; Chia, H.

    2006-11-01

    Low-energy band-pass filters are essential components for many neutron-scattering measurements, particularly cold-neutron inelastic scattering. There has been widespread use of polycrystalline Be filters for typical cutoff energies near 5 meV. The need to cool the filters to minimize thermal diffuse scattering is inconvenient for many experiments and for this reason we have investigated alternatives. Polycrystalline diamond appears to be an excellent candidate, with the large Debye temperature reducing the need for cooling, an abundant supply of inexpensive material, and a large scattering length density. Using the ORELA pulsed neutron source and the HFIR at ORNL, we have characterized the energy dependence of the room temperature neutron transmission for several commercially available powders of both natural and artificial diamond with homogeneous particle sizes ranging from single digits to hundreds of microns. Sharp cutoffs are observed near neutron energies of 5 meV. The low-energy transmission is reduced by small-angle scattering from voids, and we have begun to investigate methods of overcoming this limitation. Nevertheless, for some applications room temperature diamond powders are viable neutron filters.

  8. Formation of silicon-on-diamond by direct bonding of plasma-synthesized diamond-like carbon to silicon

    SciTech Connect

    Zhu Ming; Chu, Paul K; Shi Xuejie; Wong Man; Liu Weili; Lin Chenglu

    2004-09-27

    We propose to replace the buried SiO{sub 2} layer in silicon-on-insulator with a plasma synthesized diamond-like-carbon (DLC) thin film to mitigate the self-heating effects. The DLC films synthesized on silicon by a plasma immersion ion implantation and deposition process exhibit outstanding surface topography, and excellent insulating properties are maintained up to an annealing temperature of 900 deg. C. Hence, the degree of graphitization in our DLC materials is insignificant during thin-film transistor processing and even in most annealing steps in conventional complementary metal oxide silicon processing. Using Si/DLC direct bonding and the hydrogen-induced layer transfer method, a silicon-on-diamond structure has been fabricated. Cross-sectional high-resolution transmission electron microscopy reveals that the bonded interface is abrupt and the top Si layer exhibits nearly perfect single crystalline quality. A model is postulated to describe the reactions occurring at the interface during the annealing steps in Si-DLC wafer bonding.

  9. PREFACE: Science's gem: diamond science 2009 Science's gem: diamond science 2009

    NASA Astrophysics Data System (ADS)

    Mainwood, Alison; Newton, Mark E.; Stoneham, Marshall

    2009-09-01

    Natural diamond has been valued for its appearance and mechanical properties for at least two thousand years. As a gem stone diamond is unsurpassed. However, scientific work, especially in the last 20 years, has demonstrated that diamond has numerous surprising properties and many unique ones. Some of the extreme properties have been known for many years, but the true scale of diamond's other highly desirable features is still only coming to light as control in the synthesis of diamond, and hence material perfection, improves. The ultimate prize for man-made diamond is surely not in the synthesis of gem stones, but in delivering technological solutions enabled by diamond to the challenges facing our society today. If the special properties are to be exploited to their full potential, at least four crucial factors must be considered. First, there must be sufficient scientific understanding of diamond to make applications effective, efficient and economical. Secondly, the means of fabrication and control of properties have to be achieved so that diamond's role can be optimised. Thirdly, it is not enough that its properties are superior to existing materials: they must be so much better that it is worth initiating new technologies to exploit them. Finally, any substantial applications will have to address the society's major needs worldwide. The clear technology drivers for the 21st century come from the biomedical technologies, the demand for energy subject to global constraints, and the information technologies, where perhaps diamond will provide the major enabling technology [1]. The papers in this volume concern the solid state physics of diamond, and primarily concern the first two factors: understanding, and control of properties. They address many of the outstanding basic problems, such as the identification of existing defects, which affect the material's properties, both desirable and less so. Regarding future substantial applications, one paper discusses diamond's exceptional properties for quantum information processing [2], a topic on which there have been many recent papers, and where a diamond colour centre single photon source is already commercially available. Biomedical applications of diamond are recognised, partly tribological and partly electrochemical, but lie outside the present group of papers. Processing and controlling diamond surfaces and interfaces with other materials in their environment are critical steps en route to exploitation. Boron-doped diamond has already found application in electro-analysis and in the bulk oxidation of dissolved species in solution [3]. Energy-related applications—ranging from high-power electronics [3] to a potential first wall of fusion reactors [4]—are further exciting potential applications. Even small and ugly diamonds have value. Their mechanical properties [5] dominate, with significant niche applications such as thermal sinks. The major applications for diamond to date exploit only a fraction of diamond's special properties: visual for status diamonds, and mechanical for working diamonds. Diamond physics reaches well beyond the usual laboratory, to the geological diamond formation processes in the Earth's mantle. Characterization of natural gem diamonds [6, 7] is one part of the detective story that allows us to understand the conditions under which they formed. It was only half a century ago that the scientific and technological challenges of diamond synthesis were met systematically. Today, most of the recent research on diamond has concentrated on synthetics, whether created using high pressure, high temperature (HPHT) techniques or chemical vapour deposition (CVD). The HPHT synthesis of diamond has advanced dramatically [8, 9] to the extent that dislocation birefringence [10] can be largely eliminated. In silicon technology, the elimination of dislocations was a major step in microelectronics. Now, even diamond can be synthesised containing virtually no dislocations. The understanding of the critical processes that are involved in CVD diamond growth are

  10. Formation of diamond in the Earth's mantle.

    PubMed

    Stachel, Thomas; Harris, Jeff W

    2009-09-01

    The principal sources of natural diamonds are peridotitic (about 2/3 of diamonds) and eclogitic (1/3) domains located at 140-200 km depth in the subcratonic lithospheric mantle. There, diamonds probably form during redox reactions in the presence of melt (likely for eclogitic and lherzolitic diamonds) or under subsolidus conditions in the presence of CHO fluids (likely for harzburgitic diamonds). Co-variations of ?(13)C and the nitrogen content of diamonds suggest that two modes of formation may have been operational in peridotitic sources: (1) reduction of carbonates, that during closed system fractionation drives diamond compositions to higher ?(13)C values and lower nitrogen concentrations and (2) oxidation of methane, that in a closed system leads to a trend of decreasing ?(13)C with decreasing nitrogen. The present day redox state of subcratonic lithospheric mantle is generally too reduced to allow for methane oxidation to be a widespread process. Therefore, reduction of carbonate dissolved in melts and fluids is likely the dominant mode of diamond formation for the Phanerozoic (545 Ma-present) and Proterozoic (2.5 Ga-545 Ma). Model calculations indicate, however, that for predominantly Paleoarchean (3.6-3.2 Ga) to Mesoarchean (3.2-2.8 Ga) harzburgitic diamonds, methane reduction is the principal mode of precipitation. This suggests that the reduced present day character (oxygen fugacity below carbonate stability) of peridotitic diamond sources may be a secondary feature, possibly acquired during reducing Archean (>2.5 Ga) metasomatism. Recycling of biogenic carbonates back into the mantle through subduction only became an important process in the Paleoproterozoic (2.5-1.6 Ga) and diamonds forming during carbonate reduction, therefore, may predominantly be post-Archean in age. For eclogitic diamonds, open system fractionation processes involving separation of a CO(2) fluid appear to dominate, but in principal the same two modes of formation (methane oxidation, carbonate reduction) may have operated. Direct conversion of graphitized subducted organic matter is not considered to be an important process for the formation of eclogitic diamonds. The possible derivation of (12)C enriched carbon in eclogitic diamonds from remobilized former organic matter is, however, feasible in some cases and seems likely involved, for example, in the formation of sublithospheric eclogitic diamonds from the former Jagersfontein Mine (South Africa). PMID:21832312

  11. Diamond Growth in the Subduction Factory

    NASA Astrophysics Data System (ADS)

    Bureau, H.; Frost, D. J.; Bolfan-Casanova, N.; Leroy, C.; Estève, I.

    2014-12-01

    Natural diamonds are fabulous probes of the deep Earth Interior. They are the evidence of the deep storage of volatile elements, carbon at first, but also hydrogen and chlorine trapped as hydrous fluids in inclusions. The study of diamond growth processes in the lithosphere and mantle helps for our understanding of volatile elements cycling between deep reservoirs. We know now that inclusion-bearing diamonds similar to diamonds found in nature (i.e. polycrystalline, fibrous and coated diamonds) can grow in hydrous fluids or melts (Bureau et al., GCA 77, 202-214, 2012). Therefore, we propose that the best environment to promote such diamonds is the subduction factory, where highly hydrous fluids or melts are present. When oceanic plates are subducted in the lithosphere, they carry an oceanic crust soaked with seawater. While the slabs are traveling en route to the mantle, dehydration processes generate saline fluids highly concentrated in NaCl. In the present study we have experimentally shown that diamonds can grow from the saline fluids (up to 30 g/l NaCl in water) generated in subducted slabs. We have performed multi-anvil press experiments at 6-7 GPa and from 1300 to 1400°C during 6:00 hours to 30:00 hours. We observed large areas of new diamond grown in epitaxy on pure diamond seeds in salty hydrous carbonated melts, forming coated gems. The new rims are containing multi-component primary inclusions. Detailed characterizations of the diamonds and their inclusions have been performed and will be presented. These experimental results suggest that multi-component salty fluids of supercritical nature migrate with the slabs, down to the deep mantle. Such fluids may insure the first stage of the deep Earth's volatiles cycling (C, H, halogen elements) en route to the transition zone and the lower mantle. We suggest that the subduction factory may also be a diamond factory.

  12. Impedance analysis of Al2O3/H-terminated diamond metal-oxide-semiconductor structures

    NASA Astrophysics Data System (ADS)

    Liao, Meiyong; Liu, Jiangwei; Sang, Liwen; Coathup, David; Li, Jiangling; Imura, Masataka; Koide, Yasuo; Ye, Haitao

    2015-02-01

    Impedance spectroscopy (IS) analysis is carried out to investigate the electrical properties of the metal-oxide-semiconductor (MOS) structure fabricated on hydrogen-terminated single crystal diamond. The low-temperature atomic layer deposition Al2O3 is employed as the insulator in the MOS structure. By numerically analysing the impedance of the MOS structure at various biases, the equivalent circuit of the diamond MOS structure is derived, which is composed of two parallel capacitive and resistance pairs, in series connection with both resistance and inductance. The two capacitive components are resulted from the insulator, the hydrogenated-diamond surface, and their interface. The physical parameters such as the insulator capacitance are obtained, circumventing the series resistance and inductance effect. By comparing the IS and capacitance-voltage measurements, the frequency dispersion of the capacitance-voltage characteristic is discussed.

  13. Diamond drill bit with hemispherically shaped diamond inserts

    SciTech Connect

    Lebourgh, M.P.

    1989-08-22

    This patent describes a rotary drill bit for drilling a hole in subterranean formations. It comprises: a body portion including a matrix forming a face of the bit; means to define fluid passageways across the matrix. The means dividing the matrix into a plurality of fins; and a plurality of hemispherically shaped diamond cutting elements embedded in each of the fins. Each element having a cleaved, planar face, a portion of the planar face of each of the cutting elements which is not embedded in each fin being disposed to define a cutting surface to successively drill the formation upon rotation of the bit.

  14. Alpha-Voltaic Sources Using Diamond as Conversion Medium

    NASA Technical Reports Server (NTRS)

    Patel, Jagadish U.; Fleurial, Jean-Pierre; Kolawa, Elizabeth

    2006-01-01

    A family of proposed miniature sources of power would exploit the direct conversion of the kinetic energy of a particles into electricity in diamond semiconductor diodes. These power sources would function over a wide range of temperatures encountered in terrestrial and outer-space environments. These sources are expected to have operational lifetimes of 10 to 20 years and energy conversion efficiencies >35 percent. A power source according to the proposal would include a pair of devices like that shown in the figure. Each device would contain Schottky and p/n diode devices made from high-band-gap, radiation-hard diamond substrates. The n and p layers in the diode portion would be doped sparsely (<1014 cm-3) in order to maximize the volume of the depletion region and thereby maximize efficiency. The diode layers would be supported by an undoped diamond substrate. The source of a particles would be a thin film of 244Cm (half-life 18 years) sandwiched between the two paired devices. The sandwich arrangement would force almost every a particle to go through the active volume of at least one of the devices. Typical a particle track lengths in the devices would range from 20 to 30 microns. The a particles would be made to stop only in the undoped substrates to prevent damage to the crystalline structures of the diode portions. The overall dimensions of a typical source are expected to be about 2 by 2 by 1 mm. Assuming an initial 244Cm mass of 20 mg, the estimated initial output of the source is 20 mW (a current of 20 mA at a potential of 1 V).

  15. Continental mantle signature of Bushveld magmas and coeval diamonds.

    PubMed

    Richardson, Stephen H; Shirey, Steven B

    2008-06-12

    The emplacement of the 2.05-billion-year-old Bushveld complex, the world's largest layered intrusion and platinum-group element (PGE) repository, is a singular event in the history of the Kaapvaal craton of southern Africa, one of Earth's earliest surviving continental nuclei. In the prevailing model for the complex's mineralization, the radiogenic strontium and osmium isotope signatures of Bushveld PGE ores are attributed to continental crustal contamination of the host magmas. The scale of the intrusion and lateral homogeneity of the PGE-enriched layers, however, have long been problematical for the crustal contamination model, given the typically heterogeneous nature of continental crust. Furthermore, the distribution of Bushveld magmatism matches that of seismically anomalous underlying mantle, implying significant interaction before emplacement in the crust. Mineral samples of the ancient 200-km-deep craton keel, encapsulated in macrodiamonds and entrained by proximal kimberlites, reveal the nature of continental mantle potentially incorporated by Bushveld magmas. Here we show that sulphide inclusions in approximately 2-billion-year-old diamonds from the 0.5-billion-year-old Venetia and 1.2-billion-year-old Premier kimberlites (on opposite sides of the complex) have initial osmium isotope ratios even more radiogenic than those of Bushveld sulphide ore minerals. Sulphide Re-Os and silicate Sm-Nd and Rb-Sr isotope compositions indicate that continental mantle harzburgite and eclogite components, in addition to the original convecting mantle magma, most probably contributed to the genesis of both the diamonds and the Bushveld complex. Coeval diamonds provide key evidence that the main source of Bushveld PGEs is the mantle rather than the crust. PMID:18548068

  16. Fracture of synthetic diamond M. D. Droty

    E-print Network

    Ritchie, Robert

    Fracture of synthetic diamond M. D. Droty Ctystallume, 3506 Bassett Street, Santa Clara, California 1995) The fracture behavior of synthetic diamond has been investigated using indentation methods and by the tensile testing of pre-notched fracture-mechanics type samples. Specifically, the fracture toughness

  17. Diamond Formation: A Stable Isotope Perspective

    NASA Astrophysics Data System (ADS)

    Cartigny, Pierre; Palot, Médéric; Thomassot, Emilie; Harris, Jeff W.

    2014-05-01

    Primarily on the basis of C, N, S, and O stable isotope systematics, this article reviews recent achievements in understanding diamond formation and growth in Earth's mantle. Diamond is a metasomatic mineral that results from either the reduction or oxidation of mobile C-bearing liquids (fluids or melts) that intrude preexisting lithologies (eclogites, peridotites, and metamorphic rocks). This process seems ubiquitous, as it occurs over a large range of depths and extends through time. Diamond-forming carbon derives mainly from the convective asthenosphere. Most of its isotopic anomalies reflect fractionation processes in the lithospheric mantle, which are attributed to diamond precipitation itself and/or a mineralogical control occurring prior to diamond precipitation. Evidence for a mineralogical control would be the decoupling of the 15N/14N ratios in eclogitic diamond from other tracers of subduction in inclusions in the same diamond. C isotope anomalies related to subduction are rare and are probably best seen in diamonds from the transition zone.

  18. The World According to Jared Diamond.

    ERIC Educational Resources Information Center

    McNeil, J. R.

    2001-01-01

    Reviews the book, "Guns, Germs, and Steel: The Fates of Human Societies" (Jared Diamond). Examines the strengths of the book, focusing on its distinctive aspects, while also offering criticism. States that the final chapter is the most problematic part of Diamond's work. (CMK)

  19. Diamond film growth from fullerene precursors

    DOEpatents

    Gruen, Dieter M. (Downers Grove, IL); Liu, Shengzhong (Woodridge, IL); Krauss, Alan R. (Naperville, IL); Pan, Xianzheng (Woodridge, IL)

    1997-01-01

    A method and system for manufacturing diamond film. The method involves forming a fullerene vapor, providing a noble gas stream and combining the gas with the fullerene vapor, passing the combined fullerene vapor and noble gas carrier stream into a chamber, forming a plasma in the chamber causing fragmentation of the fullerene and deposition of a diamond film on a substrate.

  20. Double bevel construction of a diamond anvil

    DOEpatents

    Moss, William C. (San Mateo, CA)

    1988-01-01

    A double or multiple bevel culet geometry is used on a diamond anvil in a high pressure cell apparatus to provide increased sample pressure and stability for a given force applied to the diamond tables. Double or multiple bevel culet geometries can also be used for sapphire or other hard crystal anvils. Pressures up to and above 5 Megabars can be reached.

  1. Double bevel construction of a diamond anvil

    DOEpatents

    Moss, W.C.

    1988-10-11

    A double or multiple bevel culet geometry is used on a diamond anvil in a high pressure cell apparatus to provide increased sample pressure and stability for a given force applied to the diamond tables. Double or multiple bevel culet geometries can also be used for sapphire or other hard crystal anvils. Pressures up to and above 5 Megabars can be reached. 8 figs.

  2. Fluorinated diamond bonded in fluorocarbon resin

    DOEpatents

    Taylor, Gene W. (Los Alamos, NM)

    1982-01-01

    By fluorinating diamond grit, the grit may be readily bonded into a fluorocarbon resin matrix. The matrix is formed by simple hot pressing techniques. Diamond grinding wheels may advantageously be manufactured using such a matrix. Teflon fluorocarbon resins are particularly well suited for using in forming the matrix.

  3. Energy Harvesting Diamond Channel with Energy Cooperation

    E-print Network

    Ulukus, Sennur

    Energy Harvesting Diamond Channel with Energy Cooperation Berk Gurakan Sennur Ulukus Department@umd.edu Abstract--We consider the energy harvesting diamond channel, where the source and two relays harvest energy the option of wirelessly transferring some of its energy to the relays via energy cooperation. We find

  4. Genetics Home Reference: Diamond-Blackfan anemia

    MedlinePLUS

    ... function of bone marrow is to produce new blood cells. In Diamond-Blackfan anemia, the bone marrow malfunctions and fails ... of developing certain cancers, including a cancer of blood-forming tissue known ... with Diamond-Blackfan anemia have physical abnormalities. They may have ...

  5. Diamond film growth argon-carbon plasmas

    DOEpatents

    Gruen, Dieter M. (Downers Grove, IL); Krauss, Alan R. (Naperville, IL); Liu, Shengzhong (Canton, MI); Pan, Xianzheng (Wuhan Hubei, CN); Zuiker, Christopher D. (LaGrange, IL)

    1998-01-01

    A method and system for manufacturing diamond film. The method involves forming a carbonaceous vapor, providing a gas stream of argon, hydrogen and hydrocarbon and combining the gas with the carbonaceous vapor, passing the combined carbonaceous vapor and gas carrier stream into a chamber, forming a plasma in the chamber causing fragmentation of the carbonaceous and deposition of a diamond film on a substrate.

  6. Creation of deep blue light emitting nitrogen-vacancy center in nanosized diamond

    SciTech Connect

    Himics, L. Tóth, S.; Veres, M.; Koós, M.; Balogh, Z.

    2014-03-03

    This paper reports on the formation of complex defect centers related to the N3 center in nanosized diamond by employing plasma immersion and focused ion beam implantation methods. He{sup +} ion implantation into nanosized diamondlayer” was performed with the aim of creating carbon atom vacancies in the diamond structure, followed by the introduction of molecular N{sub 2}{sup +} ion and heat treatment in vacuum at 750?°C to initiate vacancy diffusion. To decrease the sp{sup 2} carbon content of nanosized diamond formed during the implantation processes, a further heat treatment at 450?°C in flowing air atmosphere was used. The modification of the bonding properties after each step of defect creation was monitored by Raman scattering measurements. The fluorescence measurements of implanted and annealed nanosized diamond showed the appearance of an intensive and narrow emission band with fine structures at 2.98?eV, 2.83?eV, and 2.71?eV photon energies.

  7. Study of diamond film nucleation by ultrasonic seeding in different solutions

    NASA Astrophysics Data System (ADS)

    Varga, Marián; Ižák, Tibor; Kromka, Alexander; Veselý, Marian; Hruška, Karel; Michalka, Miroslav

    2012-02-01

    In this study we have investigated diamond nucleation on Si substrates by ultrasonic seeding with different liquid solutions of Ultradispersed Detonation Diamond (UDD) powder in a mixture of metal nano- or microparticles (Ni, Co, Y). The influence of different solutions on nucleation efficiency was investigated. For highlighting nucleation centers and better evaluation of the nucleation process the nucleated samples were moved into a Microwave Plasma Enhanced Chemical Vapor Deposition (MW CVD) reactor and a "short-time" (10 min), then followed by a "long-time" (+1 hour), diamond deposition was performed. The morphology of samples was characterized by Scanning Electron Microscopy (SEM) and the chemical composition of grown diamond layer was investigated by Raman Spectroscopy. From the measurements we found out that microsized metal particles positively influenced nucleation and the uniformity of the deposited diamond thin film. The lowest surface roughness was achieved in the case of nanodiamond powder mixed with Co and Y metal powder. The influence of Ni, Co and Y to the nucleation and early growth stage are discussed.

  8. An insight into what superconducts in polycrystalline boron-doped diamonds based on investigations of microstructure

    PubMed Central

    Dubrovinskaia, N.; Wirth, R.; Wosnitza, J.; Papageorgiou, T.; Braun, H. F.; Miyajima, N.; Dubrovinsky, L.

    2008-01-01

    The discovery of superconductivity in polycrystalline boron-doped diamond (BDD) synthesized under high pressure and high temperatures [Ekimov, et al. (2004) Nature 428:542–545] has raised a number of questions on the origin of the superconducting state. It was suggested that the heavy boron doping of diamond eventually leads to superconductivity. To justify such statements more detailed information on the microstructure of the composite materials and on the exact boron content in the diamond grains is needed. For that we used high-resolution transmission electron microscopy and electron energy loss spectroscopy. For the studied superconducting BDD samples synthesized at high pressures and high temperatures the diamond grain sizes are ?1–2 ?m with a boron content between 0.2 (2) and 0.5 (1) at %. The grains are separated by 10- to 20-nm-thick layers and triangular-shaped pockets of predominantly (at least 95 at %) amorphous boron. These results render superconductivity caused by the heavy boron doping in diamond highly unlikely. PMID:18697937

  9. Effect of pressure on the Raman spectra of synthetic diamonds with boron impurity

    SciTech Connect

    Utyuzh, A. N. Timofeev, Yu. A.; Rakhmanina, A. V.

    2007-04-15

    The raman scattering technique is used for studying diamonds with a 0.04-0.1 at % boron impurity under a pressure up to 3 GPa in a chamber with sapphire anvils. The Raman frequency increases linearly with pressure for all samples with pressure coefficients of 2.947 cm{sup -1}/GPa for pure diamond and 3.01 cm{sup -1}/GPa for boron-doped samples. The Raman linewidths remain unchanged for pure diamond and for diamond with a boron concentration of about 0.04 at % and decrease linearly upon an increase in pressure for samples with a boron concentration of about 0.1 at %. The Raman spectra with a line profile corresponding to the Fano resonance do not change qualitatively up to a pressure of 3 GPa. In diamond samples with a boron impurity exceeding 0.1 at %, the boron concentration in the surface layer can be substantially higher than at the center of the sample.

  10. Nature and genesis of Kalimantan diamonds

    NASA Astrophysics Data System (ADS)

    Smith, Chris B.; Bulanova, Galina P.; Kohn, Simon C.; Milledge, H. Judith; Hall, Anne E.; Griffin, Brendan J.; Pearson, D. Graham

    2009-11-01

    The origin of alluvial diamonds from the four main diamond mining districts in Kalimantan was studied through characterisation of their properties, and determination of PT and age of formation of representative collections of diamonds from four localities of the island. The diamonds are mostly colourless, yellow or pale brown, shiny surfaced, dodecahedroids, octahedron/dodecahedroids, and more rarely cube combination forms. They are intensively resorbed. They have surface radiation damage and show abrasion features indicative of fluvial transportation and crustal recycling. The diamonds were polished down to expose internal structures and mineral inclusions. The majority of the diamonds are internally homogeneous or have simple octahedral zonation and show plastic deformation. Analysis by Fourier transform infra red spectroscopy of their N content and aggregation characteristics shows that many diamonds are well-aggregated type IaB implying a long-term, mantle residence time and/or high temperatures of formation. Identified inclusion parageneses are 68% peridotitic and 32% eclogitic. The peridotitic inclusions are represented by olivine, chromite, garnet, orthopyroxene and pentlandite. Olivines (Fo 92-93) belong to the dunite-harzburgite paragenesis, with one at Fo 90 identified as lherzolitic. Chromite inclusions with 65-66 wt.% Cr 2O 3 and < 1 wt.% TiO 2 are typical of chromite diamond inclusions world-wide. Two garnet inclusions identified are a subcalcic high chrome harzburgite "G10" and a mildly subcalcic type transitional between "G9" and "G10". The eclogitic inclusions are represented by omphacite, rutile, kyanite and coesite. Re/Os dating of a high Ni sulphide inclusion from one peridotitic diamond gave an Archean model age of 3.1 Ga ± 0.2 (2 sigma). In terms of their external and internal morphology, N aggregation characteristics and paragenesis the Kalimantan diamonds resemble those transported to surface by kimberlite or lamproite from sources in the subcontinental lithospheric mantle. Five distinctive genetic groups of diamond have been recognised but occur mixed in each of the four diamond mining districts due to a presumed long history of sedimentary recycling and alluvial transportation. Thermobarometry calculations from diamond inclusion chemistry (930 °C to 1250 °C; > 4.2 GPa) are consistent with a paleo-heat flow of 38 to 40 mW/m 2 and derivation from 120 to 160 km depth, i.e. subcontinental mantle lithosphere conditions similar to diamonds from African and Yakutian cratonic situations.

  11. Structures of diamond-like phases

    SciTech Connect

    Greshnyakov, V. A.; Belenkov, E. A.

    2011-07-15

    The diamond-like phases containing carbon atoms with the same degree of hybridization, which is close to sp{sup 3}, are classified. It is found that twenty such phases can exist, and ten of them are described for the first time. Molecular mechanics and semi-empirical quantum-mechanical methods are used to calculate the geometrically optimized structures of diamond-like phase clusters and to determine their structural parameters and properties, such as the density, the bulk modulus, and the sublimation energy. The difference between the properties of the diamond-like phases and those of diamond is found to be determined by the difference between the structures of these phases and diamond.

  12. Diamond as an inert substrate of graphene

    SciTech Connect

    Hu Wei; Li Zhenyu; Yang Jinlong

    2013-02-07

    Interaction between graphene and semiconducting diamond substrate has been examined with large-scale density functional theory calculations. Clean and hydrogenated diamond (100) and (111) surfaces have been studied. It turns out that weak van der Waals interactions dominate for graphene on all these surfaces. High carrier mobility of graphene is almost not affected, except for a negligible energy gap opening at the Dirac point. No charge transfer between graphene and diamond (100) surfaces is detected, while different charge-transfer complexes are formed between graphene and diamond (111) surfaces, inducing either p-type or n-type doping on graphene. Therefore, diamond can be used as an excellent substrate of graphene, which almost keeps its electronic structures at the same time providing the flexibility of charge doping.

  13. Diamond formation by thermal activation of graphite

    NASA Astrophysics Data System (ADS)

    Palnichenko, A. V.; Jonas, A. M.; Charlier, J.-C.; Aronin, A. S.; Issi, J.-P.

    1999-11-01

    Synthetic diamond is used in applications ranging from abrasives, tool coatings, bearing surfaces, microelectronics and optics to corrosion protection. The first artificial synthesis used high-pressure techniques to produce diamond as the thermodynamically stable form, but it can also be grown at low pressures as a metastable carbon phase. Here we report the production of high-purity cubic diamond microparticles (10-100µm), which form in a highly concentrated carbon-vapour phase, followed by deposition of the crystals on the substrate. The carbon-vapour phase is generated by thermal activation of graphite, and the fast initial growth-rates of diamond, in the range 100-500µms-1, are at least two orders of magnitude higher than previously reported. We expect that tuning of experimental parameters to optimize the density of the carbon-vapour phase will allow us to grow larger diamond crystals, thereby opening a wider range of potential practical applications.

  14. Engineering shallow spins in diamond with nitrogen delta-doping

    NASA Astrophysics Data System (ADS)

    Ohno, K.; Heremans, F. J.; Bassett, L. C.; Myers, B. A.; Toyli, D. M.; Bleszynski Jayich, A. C.; Palmstrom, C. J.; Awschalom, D. D.

    2013-03-01

    The excellent spin properties of diamond nitrogen-vacancy (NV) centers motivate applications from sensing to quantum information processing. Still, external electron and nuclear spin sensing are limited by weak magnetic dipole interactions, requiring NVs be within a few nm of the surface and retain long spin coherence times (T2). We report a nitrogen delta-doping technique to create artificial NVs meeting these requirements. Isotopically pure 15N2 gas is introduced to form a thin N-doped layer (1-2 nm thick) during chemical vapor deposition of a diamond film. Post growth electron irradiation creates vacancies and subsequent annealing forms NVs while mitigating crystal damage. We identified doped NVs through the hyperfine signature of the rare 15N isotope in electron spin resonance measurements. We confirm the doped NV depth dispersion is less than 4 nm by doping NVs in the 12C layer of an isotopically engineered 13C/12C/13C structure and probing the coupling between the doped NVs and the 13C nuclear spins. Furthermore, despite their surface proximity, doped NVs embedded in 12C films 5 (52) nm below the surface show T2 greater than 100 (600) ?s. This work was supported by AFSOR and DARPA.

  15. Toroidal plasma enhanced CVD of diamond films

    SciTech Connect

    Zvanya, John Cullen, Christopher Morris, Thomas Krchnavek, Robert R.; Holber, William Basnett, Andrew Basnett, Robert; Hettinger, Jeffrey

    2014-09-01

    An inductively coupled toroidal plasma source is used as an alternative to microwave plasmas for chemical vapor deposition of diamond films. The source, operating at a frequency of 400 kHz, synthesizes diamond films from a mixture of argon, methane, and hydrogen. The toroidal design has been adapted to create a highly efficient environment for diamond film deposition: high gas temperature and a short distance from the sample to the plasma core. Using a toroidal plasma geometry operating in the medium frequency band allows for efficient (?90%) coupling of AC line power to the plasma and a scalable path to high-power and large-area operation. In test runs, the source generates a high flux of atomic hydrogen over a large area, which is favorable for diamond film growth. Using a deposition temperature of 900–1050?°C and a source to sample distance of 0.1–2.0?cm, diamond films are deposited onto silicon substrates. The results showed that the deposition rate of the diamond films could be controlled using the sample temperature and source to sample spacing. The results also show the films exhibit good-quality polycrystalline diamond as verified by Raman spectroscopy, x-ray diffraction, and scanning electron microscopy. The scanning electron microscopy and x-ray diffraction results show that the samples exhibit diamond (111) and diamond (022) crystallites. The Raman results show that the sp{sup 3} peak has a narrow spectral width (FWHM 12?±?0.5?cm{sup ?1}) and that negligible amounts of the sp{sup 2} band are present, indicating good-quality diamond films.

  16. The Science of Diamonds and Their Inclusions: Can such Data be Used to Establish Diamond Provenance?

    NASA Astrophysics Data System (ADS)

    Taylor, L. A.; Sobolev, N. V.; Ghazi, M.; Anand, M.; Bodner, R. J.

    2002-05-01

    The physics and chemistry of diamonds and their mineral inclusions can be used to determine the geographic source of rough diamonds. The science of diamonds includes their morphology and external features, N aggregation states and zonations, ? 13C, ? 15N, trace-element chemistry, and the nature of their rims and coatings. The science of the diamond inclusions (DIs) includes their mineralogy and chemical/isotopic compositions, the variation of mineral chemistry between diamonds and as multiple DIs within a single diamond, and the relations of DIs to geologic locales. For example, the exotic DIs in Brazilian diamonds appear to be unique and world famous; but are they really? The ? 34S values of the sulfide DIs are yet another type of data that may prove useful for paragenetic identification, but the requisite data are not presently available. A recently attempted method for discerning the locale of a diamond's origin involves the combined use of laser-ablation, high-resolution, inductively-coupled-plasma, mass spectrometry (LA-HR-ICPMS) and Raman spectroscopy. These sophisticated instruments are combined in a study of the outermost rims of coated diamonds. The premise to this endeavor is that these coatings contain the signatures of the very latest stages of diamond formation, within the kimberlite, as the diamonds are carried to the Earth's surface. Based upon xenolith and DI studies, the mantle of the Earth at a depth of 150 km, although heterogeneous on a small scale, is actually quite similar worldwide. Diamonds grown in the mantle may also have similar characteristics worldwide. However, the chemistry of kimberlite magmas, as they traverse the upper mantle and lower crust, on their way to the surface, can pick up late-stage characteristics that differ from place to place. Some of these definitive signatures may be preserved in the outermost coated regions of the diamonds. The bottom line to the question of provenance for rough diamonds, as addressed at the website http://web.utk.edu/~pgi/research/diamond.html, is the same for all possible techniques ? new, large populations of diamonds from known localities are necessary for the gathering of sufficient statistics. Geologists have largely viewed diamond deposits as geologic curiosities, without the attainment of forensic data. The potential for the development of scientific identification techniques exists, but a detailed, well-funded, research program must be in place to specifically and successfully address the provenance of diamonds.

  17. Deposition of nanocrystalline diamond films by MW plasma CVD

    E-print Network

    Bristol, University of

    of the complex mechanisms and processes involved in diamond formation can be transferred into different diamondDeposition of nanocrystalline diamond films by MW plasma CVD & Gas-phase diagnostics using in contemporary issues concerning both the fundamental science underpinning diamond synthesis by chemical vapour

  18. 16 CFR 23.13 - Disclosure of treatments to diamonds.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 16 Commercial Practices 1 2012-01-01 2012-01-01 false Disclosure of treatments to diamonds. 23.13... JEWELRY, PRECIOUS METALS, AND PEWTER INDUSTRIES § 23.13 Disclosure of treatments to diamonds. A diamond is a gemstone product. Treatments to diamonds should be disclosed in the manner prescribed in §...

  19. Appendix A SIMS profiles of hydrogen and deuterium in diamond

    E-print Network

    Goddard III, William A.

    127 Appendix A SIMS profiles of hydrogen and deuterium in diamond A.1 Introduction A diamond sample ion­beam doping. Impurity levels were profiled as a function of depth from the diamond surface using­type reactor, consisting of a quartz tube with diamond­coated quartz substrate holder. The substrate

  20. 16 CFR 23.13 - Disclosure of treatments to diamonds.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 16 Commercial Practices 1 2013-01-01 2013-01-01 false Disclosure of treatments to diamonds. 23.13... JEWELRY, PRECIOUS METALS, AND PEWTER INDUSTRIES § 23.13 Disclosure of treatments to diamonds. A diamond is a gemstone product. Treatments to diamonds should be disclosed in the manner prescribed in §...