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Sample records for compact pmn-pt modulator

  1. Electric-field-modulated nonvolatile resistance switching in VO₂/PMN-PT(111) heterostructures.

    PubMed

    Zhi, Bowen; Gao, Guanyin; Xu, Haoran; Chen, Feng; Tan, Xuelian; Chen, Pingfan; Wang, Lingfei; Wu, Wenbin

    2014-04-01

    The electric-field-modulated resistance switching in VO2 thin films grown on piezoelectric (111)-0.68Pb(Mg1/3Nb2/3)O3-0.32PbTiO3 (PMN-PT) substrates has been investigated. Large relative change in resistance (10.7%) was observed in VO2/PMN-PT(111) hererostructures at room temperature. For a substrate with a given polarization direction, stable resistive states of VO2 films can be realized even when the applied electric fields are removed from the heterostructures. By sweeping electric fields across the heterostructure appropriately, multiple resistive states can be achieved. These stable resistive states result from the different stable remnant strain states of substrate, which is related to the rearrangements of ferroelectric domain structures in PMN-PT(111) substrate. The resistance switching tuned by electric field in our work may have potential applications for novel electronic devices. PMID:24634978

  2. Refractive index modulating Raman spectroscopy based on perovskite PMN-PT ceramics.

    PubMed

    Wei, Danzhu; Xu, Tian; Yuan, Li; Tian, Shu; Fang, Jinghuai; Jin, Yonglong; Wang, Chaonan; Ma, Xinxiang; Shi, Jianzhen

    2016-04-01

    A three-layer planar waveguide structure comprising a perovskite (1-x)Pb(Mg1/3Nb2/3Nb2/3)O3-xPbTiO3 (PMN-PT) ceramic sandwiched by two silver films is designed and called PMPW. Using the high sensitivity of ultrahigh-order modes, theoretical analysis is performed to calculate the effective refractive index (ERI) of the PMPW. A detailed analysis of the Raman spectrum of PMN-PT at 795  cm-1 is performed. A comparison of the numerical analysis and experimental results reveals that the nonlinear change in ERI plays a primary role in the Raman signal variation. Analysis of the Raman spectrum of a sample deposited on PMPW confirms that it is effective for modulating Raman signals. PMID:27139681

  3. Modulation of metal-insulator transitions by field-controlled strain in NdNiO3/SrTiO3/PMN-PT (001) heterostructures

    PubMed Central

    Heo, Seungyang; Oh, Chadol; Eom, Man Jin; Kim, Jun Sung; Ryu, Jungho; Son, Junwoo; Jang, Hyun Myung

    2016-01-01

    The band width control through external stress has been demonstrated as a useful knob to modulate metal-insulator transition (MIT) in RNiO3 as a prototype correlated materials. In particular, lattice mismatch strain using different substrates have been widely utilized to investigate the effect of strain on transition temperature so far but the results were inconsistent in the previous literatures. Here, we demonstrate dynamic modulation of MIT based on electric field-controlled pure strain in high-quality NdNiO3 (NNO) thin films utilizing converse-piezoelectric effect of (001)-cut - (PMN-PT) single crystal substrates. Despite the difficulty in the NNO growth on rough PMN-PT substrates, the structural quality of NNO thin films has been significantly improved by inserting SrTiO3 (STO) buffer layers. Interestingly, the MIT temperature in NNO is downward shifted by ~3.3 K in response of 0.25% in-plane compressive strain, which indicates less effective TMI modulation of field-induced strain than substrate-induced strain. This study provides not only scientific insights on band-width control of correlated materials using pure strain but also potentials for energy-efficient electronic devices. PMID:26916618

  4. Modulation of metal-insulator transitions by field-controlled strain in NdNiO3/SrTiO3/PMN-PT (001) heterostructures

    NASA Astrophysics Data System (ADS)

    Heo, Seungyang; Oh, Chadol; Eom, Man Jin; Kim, Jun Sung; Ryu, Jungho; Son, Junwoo; Jang, Hyun Myung

    2016-02-01

    The band width control through external stress has been demonstrated as a useful knob to modulate metal-insulator transition (MIT) in RNiO3 as a prototype correlated materials. In particular, lattice mismatch strain using different substrates have been widely utilized to investigate the effect of strain on transition temperature so far but the results were inconsistent in the previous literatures. Here, we demonstrate dynamic modulation of MIT based on electric field-controlled pure strain in high-quality NdNiO3 (NNO) thin films utilizing converse-piezoelectric effect of (001)-cut - (PMN-PT) single crystal substrates. Despite the difficulty in the NNO growth on rough PMN-PT substrates, the structural quality of NNO thin films has been significantly improved by inserting SrTiO3 (STO) buffer layers. Interestingly, the MIT temperature in NNO is downward shifted by ~3.3 K in response of 0.25% in-plane compressive strain, which indicates less effective TMI modulation of field-induced strain than substrate-induced strain. This study provides not only scientific insights on band-width control of correlated materials using pure strain but also potentials for energy-efficient electronic devices.

  5. Modulation of metal-insulator transitions by field-controlled strain in NdNiO3/SrTiO3/PMN-PT (001) heterostructures.

    PubMed

    Heo, Seungyang; Oh, Chadol; Eom, Man Jin; Kim, Jun Sung; Ryu, Jungho; Son, Junwoo; Jang, Hyun Myung

    2016-01-01

    The band width control through external stress has been demonstrated as a useful knob to modulate metal-insulator transition (MIT) in RNiO3 as a prototype correlated materials. In particular, lattice mismatch strain using different substrates have been widely utilized to investigate the effect of strain on transition temperature so far but the results were inconsistent in the previous literatures. Here, we demonstrate dynamic modulation of MIT based on electric field-controlled pure strain in high-quality NdNiO3 (NNO) thin films utilizing converse-piezoelectric effect of (001)-cut Pb(Mg(1/3)Nb(2/3)O3-(PbTiO3) (PMN-PT) single crystal substrates. Despite the difficulty in the NNO growth on rough PMN-PT substrates, the structural quality of NNO thin films has been significantly improved by inserting SrTiO3 (STO) buffer layers. Interestingly, the MIT temperature in NNO is downward shifted by ~3.3 K in response of 0.25% in-plane compressive strain, which indicates less effective TMI modulation of field-induced strain than substrate-induced strain. This study provides not only scientific insights on band-width control of correlated materials using pure strain but also potentials for energy-efficient electronic devices. PMID:26916618

  6. Misfit strain phase diagrams of epitaxial PMN-PT films

    NASA Astrophysics Data System (ADS)

    Khakpash, N.; Khassaf, H.; Rossetti, G. A.; Alpay, S. P.

    2015-02-01

    Misfit strain-temperature phase diagrams of three compositions of (001) pseudocubic (1 - x).Pb (Mgl/3Nb2/3)O3 - x.PbTiO3 (PMN-PT) thin films are computed using a phenomenological model. Two (x = 0.30, 0.42) are located near the morphotropic phase boundary (MPB) of bulk PMN-PT at room temperature (RT) and one (x = 0.70) is located far from the MPB. The results show that it is possible to stabilize an adaptive monoclinic phase over a wide range of misfit strains. At RT, the stability region of this phase is much larger for PMN-PT compared to barium strontium titanate and lead zirconate titanate films.

  7. Design and fabrication of PIN-PMN-PT single-crystal high-frequency ultrasound transducers.

    PubMed

    Sun, Ping; Zhou, Qifa; Zhu, Benpeng; Wu, Dawei; Hu, Changhong; Cannata, Jonathan M; Tian, Jin; Han, Pengdi; Wang, Gaofeng; Shung, K Kirk

    2009-12-01

    High-frequency PIN-PMN-PT single crystal ultrasound transducers at center frequencies of 35 MHz and 60 MHz were successfully fabricated using lead indium niobate-lead magnesium niobate-lead titanate (0.23PIN- 0.5PMN-0.27PT) single crystal. The new PIN-PMN-PT single crystal has higher coercivity (6.0 kV/cm) and higher Curie temperature (160 degrees C) than PMN-PT crystal. Experimental results showed that the PIN-PMN-PT transducers have similar performance but better thermal stability compared with the PMN-PT transducers. PMID:20040413

  8. Frequency dependence of PMN-PT ceramics under electrical bias

    NASA Astrophysics Data System (ADS)

    Robinson, Harold C.; McLaughlin, Elizabeth A.

    2002-07-01

    It is a well-known fact that electrostrictive materials, such as lead magnesium niobate-lead titanate (PMN-PT) ceramics, exhibit significant frequency dispersion in their small signal dielectric constant below their dielectric maximum temperature Tm. The frequency dispersion in several PMN-PT compositions will be examined in this study using two independent measurement methods: dc biased resonance and large signal quasistatic measurements conducted on NUWC Division Newport's SDECS. From these measurements, the coupling factor, piezoelectric constant and Young's modulus are compared as a function of the applied bias and frequency. Both the DC biased and SDECS measurements were performed on the same 3:1 aspect ratio samples. Finite element calculations will show that the error in determining the Young's modulus and piezoelectric constant from resonance using these samples is less than 5 percent. It will be shown that when frequency dispersion exists it remains even with the application of dc bias, and that the degree of deviation between these quantities increases the further below Tm the temperature drops. It will also be shown that, like the dielectric constant, the coupling factor, piezoelectric constant and Young's modulus in PMN-PT ceramics above Tm are non-dispersive.

  9. Four-state memory based on a giant and non-volatile converse magnetoelectric effect in FeAl/PIN-PMN-PT structure

    NASA Astrophysics Data System (ADS)

    Wei, Yanping; Gao, Cunxu; Chen, Zhendong; Xi, Shibo; Shao, Weixia; Zhang, Peng; Chen, Guilin; Li, Jiangong

    2016-07-01

    We report a stable, tunable and non-volatile converse magnetoelectric effect (ME) in a new type of FeAl/PIN-PMN-PT heterostructure at room temperature, with a giant electrical modulation of magnetization for which the maximum relative magnetization change (ΔM/M) is up to 66%. The 109° ferroelastic domain switching in the PIN-PMN-PT and coupling with the ferromagnetic (FM) film via uniaxial anisotropy originating from the PIN-PMN-PT (011) surface are the key roles in converse ME effect. We also propose here a new, four-state memory through which it is possible to modify the remanent magnetism state by adjusting the electric field. This work represents a helpful approach to securing electric-writing magnetic-reading with low energy consumption for future high-density information storage applications.

  10. Four-state memory based on a giant and non-volatile converse magnetoelectric effect in FeAl/PIN-PMN-PT structure

    PubMed Central

    Wei, Yanping; Gao, Cunxu; Chen, Zhendong; Xi, Shibo; Shao, Weixia; Zhang, Peng; Chen, Guilin; Li, Jiangong

    2016-01-01

    We report a stable, tunable and non-volatile converse magnetoelectric effect (ME) in a new type of FeAl/PIN-PMN-PT heterostructure at room temperature, with a giant electrical modulation of magnetization for which the maximum relative magnetization change (ΔM/M) is up to 66%. The 109° ferroelastic domain switching in the PIN-PMN-PT and coupling with the ferromagnetic (FM) film via uniaxial anisotropy originating from the PIN-PMN-PT (011) surface are the key roles in converse ME effect. We also propose here a new, four-state memory through which it is possible to modify the remanent magnetism state by adjusting the electric field. This work represents a helpful approach to securing electric-writing magnetic-reading with low energy consumption for future high-density information storage applications. PMID:27417902

  11. Four-state memory based on a giant and non-volatile converse magnetoelectric effect in FeAl/PIN-PMN-PT structure.

    PubMed

    Wei, Yanping; Gao, Cunxu; Chen, Zhendong; Xi, Shibo; Shao, Weixia; Zhang, Peng; Chen, Guilin; Li, Jiangong

    2016-01-01

    We report a stable, tunable and non-volatile converse magnetoelectric effect (ME) in a new type of FeAl/PIN-PMN-PT heterostructure at room temperature, with a giant electrical modulation of magnetization for which the maximum relative magnetization change (ΔM/M) is up to 66%. The 109° ferroelastic domain switching in the PIN-PMN-PT and coupling with the ferromagnetic (FM) film via uniaxial anisotropy originating from the PIN-PMN-PT (011) surface are the key roles in converse ME effect. We also propose here a new, four-state memory through which it is possible to modify the remanent magnetism state by adjusting the electric field. This work represents a helpful approach to securing electric-writing magnetic-reading with low energy consumption for future high-density information storage applications. PMID:27417902

  12. Microscopic evidence of strain-mediated magnetoelectric coupling in Co/Pt multilayers/PMN-PT(011) heterostructures

    NASA Astrophysics Data System (ADS)

    Sun, Ying; Wang, Wenbo; Wu, Weida; Zheng, Xiaoli; Cai, Jianwang; Zhao, Yonggang; Liu, Ming

    A promising way to control magnetization(M) via an electric field(E-field) is using magnetoelectric(ME) effect in FM/FE heterostructures. We use magnetic(electric) force microscopy(M(e)FM) to study the strain-mediated E-field modulation of M in (Co/Pt)n with perpendicular magnetic anisotropy(PMA) or in-plane anisotropy on PMN-PT(011) substrates. MFM were performed on (Co/Pt)n with an DC E-field applied to PMN-PT. In MeFM, we superimpose an AC modulation on a DC one and utilize lock-in technique to detect weak ME effect. For (Co/Pt)n with PMA, MFM images show stripe domains with no obvious changes at varied DC E-fields. However, MeFM shows interesting structures and the image contrast reverses sign at opposite strain slopes of the PMN-PT substrate. For sample with in-plane anisotropy, both MFM and MeFM images show dipole-like domains. Interestingly, the MeFM image contrast reverses sign at opposite strain slopes of the substrate. The sign reversal of MeFM contrast indicates that features revealed by MeFM are intrinsic local ME effect. Our MeFM data are consistent with the ferromagnetic resonance results showing that strain-induced anisotropy change will cause part of M switching to the in-plane direction. Possible scenarios will be discussed.

  13. Design, production and testing of PMN-PT electrostrictive transducers.

    PubMed

    Coutte, J; Dubus, B; Debus, J C; Granger, C; Jones, D

    2002-05-01

    Lead magnesium niobate ceramics (PMN) are promising materials for application in the field of high power transducers. The advantage of PMN materials are the large strains generated under moderate electric field and the low hysteresis. The electrostrictive effect is non-linear, the corresponding physical constants depend on temperature and frequency and a DC electrical bias is required. These difficulties must be considered at the design stage. A finite element model has been developed and validated in the ATILA code for non-linear static and time-domain analyses. These numerical modelings are used to design and test two Langevin-type electrostrictive transducers. The first transducer is made of PMN-PT-La (90-10-1%) ceramics (TRS Ceramics), the second one of ESCI ceramics (Morgan Matroc). For given static mechanical prestresses, resonance frequencies and effective coupling coefficients are measured at different DC electric fields and temperatures. PMID:12160063

  14. Intrinsically tunable bulk acoustic wave resonators based on sol-gel grown PMN-PT films

    NASA Astrophysics Data System (ADS)

    Vorobiev, A.; Spreitzer, M.; Veber, A.; Suvorov, D.; Gevorgian, S.

    2014-08-01

    Intrinsically tunable bulk acoustic wave resonators, based on sol-gel 0.70Pb(Mg1/3Nb2/3)O3-0.30PbTiO3 (PMN-PT) thin films, with high effective electromechanical coupling coefficient of 13% and tunability of the series resonance frequency up to 4.0% are fabricated and characterized. The enhanced electroacoustic properties of the PMN-PT resonators are attributed to the mechanism of polarization rotation occurring in the region of the morphotropic phase boundary. Electroacoustic performance of the PMN-PT resonators is analyzed using the theory of dc field-induced piezoelectric effect in ferroelectrics. Extrinsic acoustic loss in the PMN-PT resonators is analyzed using the model of the wave scattering at reflections from rough interfaces. Mechanical Q-factor of the resonators is up to 70 at 4.1 GHz and limited mainly by losses in the PMN-PT film.

  15. Machining induced defects in Relaxor ferroelectric PMN-PT crystals

    NASA Astrophysics Data System (ADS)

    Deng, Cheng

    The superior piezoelectric and dielectric properties of the relaxor based piezoelectric single crystals (PMN-PT) render them as prime candidates for Navy sonar detectors as well as in broad band medical ultrasonic imaging devices. Production of phased array probes utilizing these types of high performance ceramics requires dicing these crystals to arrays with pitches of less than the desired wavelength, ranging from tens to hundreds of micrometers. However, the relaxor based single crystals are very brittle with fracture toughness of about a third to a half that of typical PZT ceramics (0.4-0.8 MPa m ). Excessive chipping and cracking, either during the cutting or poling process, have been reported as major hurdles in processing, leading to spurious resonance and degradation of the distance resolution. In addition, residual stress from the cutting process could be major reliability degradation if it is not well quantified and minimized. In this work, we experimentally analyzed the machining induced damage in a group of Lead Magnesium Niobate-Lead Titanate solid solution single crystal {(1-x)[Pb(Mg1/3Nb2/3)O3]-x[PbTiO3] (PMN-PT)} under simulated process parameters for cutting speeds and down feeds. The machined surfaces are examined by non-contact optical profilometer for planarity and roughness, scanning electron microscopy for subsurface damage, and by micro-raman spectroscopic analysis and X-ray diffraction analysis to uncover machining induced phase transformations. The analysis reveals the preferred process parameters for minimal machining induced damages.

  16. Surfactant-Assisted Hydrothermal Synthesis of PMN-PT Nanorods.

    PubMed

    Li, Chuan; Liu, Xingzhao; Luo, Wenbo; Xu, Dong; He, Kai

    2016-12-01

    The effects of surfactant polyacrylate acid (PAA) on shape evolution of 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 (0.7PMN-0.3PT) nanorods were studied. The results revealed that the polyacrylic acid content had great influence on the morphology of 0.7PMN-0.3PT. With increasing PAA concentration from 0.45 to 0.82 g/ml, the ratio of perovskite phase (PMN-PT nanorod) increased, while the ratio of pyrochlore phase decreased. When the PAA concentration was 0.82 g/ml, pure 0.7PMN-0.3PT nanorods were obtained. However, when PAA concentration was higher than 0.82 g/ml, the excess of PAA would hindered their [100] orientation growth. The piezoelectric coefficient d 33 of 0.7PMN-0.3PT nanorod was obtained by linear fitting, and the d 33 value was 409 pm/V. PMID:26831687

  17. Surfactant-Assisted Hydrothermal Synthesis of PMN-PT Nanorods

    NASA Astrophysics Data System (ADS)

    Li, Chuan; Liu, Xingzhao; Luo, Wenbo; Xu, Dong; He, Kai

    2016-02-01

    The effects of surfactant polyacrylate acid (PAA) on shape evolution of 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 (0.7PMN-0.3PT) nanorods were studied. The results revealed that the polyacrylic acid content had great influence on the morphology of 0.7PMN-0.3PT. With increasing PAA concentration from 0.45 to 0.82 g/ml, the ratio of perovskite phase (PMN-PT nanorod) increased, while the ratio of pyrochlore phase decreased. When the PAA concentration was 0.82 g/ml, pure 0.7PMN-0.3PT nanorods were obtained. However, when PAA concentration was higher than 0.82 g/ml, the excess of PAA would hindered their [100] orientation growth. The piezoelectric coefficient d 33 of 0.7PMN-0.3PT nanorod was obtained by linear fitting, and the d 33 value was 409 pm/V.

  18. Anisotropic modulation of magnetic properties and the memory effect in a wide-band (011)-Pr0.7Sr0.3MnO3/PMN-PT heterostructure.

    PubMed

    Zhao, Ying-Ying; Wang, Jing; Kuang, Hao; Hu, Feng-Xia; Liu, Yao; Wu, Rong-Rong; Zhang, Xi-Xiang; Sun, Ji-Rong; Shen, Bao-Gen

    2015-01-01

    Memory effect of electric-field control on magnetic behavior in magnetoelectric composite heterostructures has been a topic of interest for a long time. Although the piezostrain and its transfer across the interface of ferroelectric/ferromagnetic films are known to be important in realizing magnetoelectric coupling, the underlying mechanism for nonvolatile modulation of magnetic behaviors remains a challenge. Here, we report on the electric-field control of magnetic properties in wide-band (011)-Pr0.7Sr0.3MnO3/0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 heterostructures. By introducing an electric-field-induced in-plane anisotropic strain field during the cooling process from room temperature, we observe an in-plane anisotropic, nonvolatile modulation of magnetic properties in a wide-band Pr0.7Sr0.3MnO3 film at low temperatures. We attribute this anisotropic memory effect to the preferential seeding and growth of ferromagnetic (FM) domains under the anisotropic strain field. In addition, we find that the anisotropic, nonvolatile modulation of magnetic properties gradually diminishes as the temperature approaches FM transition, indicating that the nonvolatile memory effect is temperature dependent. By taking into account the competition between thermal energy and the potential barrier of the metastable magnetic state induced by the anisotropic strain field, this distinct memory effect is well explained, which provides a promising approach for designing novel electric-writing magnetic memories. PMID:25909177

  19. Anisotropic modulation of magnetic properties and the memory effect in a wide-band (011)-Pr0.7Sr0.3MnO3/PMN-PT heterostructure

    NASA Astrophysics Data System (ADS)

    Zhao, Ying-Ying; Wang, Jing; Kuang, Hao; Hu, Feng-Xia; Liu, Yao; Wu, Rong-Rong; Zhang, Xi-Xiang; Sun, Ji-Rong; Shen, Bao-Gen

    2015-04-01

    Memory effect of electric-field control on magnetic behavior in magnetoelectric composite heterostructures has been a topic of interest for a long time. Although the piezostrain and its transfer across the interface of ferroelectric/ferromagnetic films are known to be important in realizing magnetoelectric coupling, the underlying mechanism for nonvolatile modulation of magnetic behaviors remains a challenge. Here, we report on the electric-field control of magnetic properties in wide-band (011)-Pr0.7Sr0.3MnO3/0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 heterostructures. By introducing an electric-field-induced in-plane anisotropic strain field during the cooling process from room temperature, we observe an in-plane anisotropic, nonvolatile modulation of magnetic properties in a wide-band Pr0.7Sr0.3MnO3 film at low temperatures. We attribute this anisotropic memory effect to the preferential seeding and growth of ferromagnetic (FM) domains under the anisotropic strain field. In addition, we find that the anisotropic, nonvolatile modulation of magnetic properties gradually diminishes as the temperature approaches FM transition, indicating that the nonvolatile memory effect is temperature dependent. By taking into account the competition between thermal energy and the potential barrier of the metastable magnetic state induced by the anisotropic strain field, this distinct memory effect is well explained, which provides a promising approach for designing novel electric-writing magnetic memories.

  20. Energy scavenging based on a single-crystal PMN-PT nanobelt

    NASA Astrophysics Data System (ADS)

    Wu, Fan; Cai, Wei; Yeh, Yao-Wen; Xu, Shiyou; Yao, Nan

    2016-03-01

    Self-powered nanodevices scavenging mechanical energy require piezoelectric nanostructures with high piezoelectric coefficients. Here we report the fabrication of a single-crystal (1 - x)Pb(Mg1/3Nb2/3)O3 - xPbTiO3 (PMN-PT) nanobelt with a superior piezoelectric constant (d33 = ~550 pm/V), which is approximately ~150%, 430%, and 2100% of the largest reported values for previous PMN-PT, PZT and ZnO nanostructures, respectively. The high d33 of the single-crystalline PMN-PT nanobelt results from the precise orientation control during its fabrication. As a demonstration of its application in energy scavenging, a piezoelectric nanogenerator (PNG) is built on the single PMN-PT nanobelt, generating a maximum output voltage of ~1.2 V. This value is ~4 times higher than that of a single-CdTe PNG, ~13 times higher than that of a single-ZnSnO3 PNG, and ~26 times higher than that of a single-ZnO PNG. The profoundly increased output voltage of a lateral PNG built on a single PMN-PT nanobelt demonstrates the potential application of PMN-PT nanostructures in energy harvesting, thus enriching the material choices for PNGs.

  1. Broadband ultrasonic linear array using ternary PIN-PMN-PT single crystal.

    PubMed

    Wang, Wei; Zhao, Xiangyong; Or, Siu Wing; Leung, Chung Ming; Zhang, Yaoyao; Jiao, Jie; Luo, Haosu

    2012-09-01

    Ternary Pb(In(1/2)Nb(1/2))O(3)-Pb(Mg(1/3)Nb(2/3))O(3)-PbTiO(3) (PIN-PMN-PT) single crystal was investigated for potential application in ultrasonic linear array. Orientation and temperature dependences of height extensional electromechanical coupling coefficient k'(33) for PIN-PMN-PT single crystal were studied. It was found that the [001] poled PIN-PMN-PT diced along the [100] direction would achieve a maximum k'(33) (~87%) and the service temperature was up to 110 °C. Ultrasonic linear arrays using PIN-PMN-PT single crystal and PZT ceramic were fabricated and compared. The bandwidth at -6 dB, two-way insertion loss and pulse length of the PIN-PMN-PT array were 98.6%, -45.1 dB, and 0.28 μs, respectively, which were about 25% broader, 3.7dB higher, and 0.08 μs shorter than those of the PZT array. The experimental results agreed well with the theoretical simulation. These superior performances were attributable to the excellent piezoelectric properties of PIN-PMN-PT single crystal. PMID:23020406

  2. Energy scavenging based on a single-crystal PMN-PT nanobelt.

    PubMed

    Wu, Fan; Cai, Wei; Yeh, Yao-Wen; Xu, Shiyou; Yao, Nan

    2016-01-01

    Self-powered nanodevices scavenging mechanical energy require piezoelectric nanostructures with high piezoelectric coefficients. Here we report the fabrication of a single-crystal (1 - x)Pb(Mg1/3Nb2/3)O3 - xPbTiO3 (PMN-PT) nanobelt with a superior piezoelectric constant (d33 = ~550 pm/V), which is approximately ~150%, 430%, and 2100% of the largest reported values for previous PMN-PT, PZT and ZnO nanostructures, respectively. The high d33 of the single-crystalline PMN-PT nanobelt results from the precise orientation control during its fabrication. As a demonstration of its application in energy scavenging, a piezoelectric nanogenerator (PNG) is built on the single PMN-PT nanobelt, generating a maximum output voltage of ~1.2 V. This value is ~4 times higher than that of a single-CdTe PNG, ~13 times higher than that of a single-ZnSnO3 PNG, and ~26 times higher than that of a single-ZnO PNG. The profoundly increased output voltage of a lateral PNG built on a single PMN-PT nanobelt demonstrates the potential application of PMN-PT nanostructures in energy harvesting, thus enriching the material choices for PNGs. PMID:26928788

  3. Micromachined PIN-PMN-PT Crystal Composite Transducer for High-Frequency Intravascular Ultrasound (IVUS) Imaging

    PubMed Central

    Li, Xiang; Ma, Teng; Tian, Jian; Han, Pengdi; Zhou, Qifa; Shung, K. Kirk

    2015-01-01

    In this paper, we report the use of micromachined PbIn1/2Nb1/2O3–PbMg1/3Nb2/3O3–PbTiO3 (PIN-PMN-PT) single crystal 1–3 composite material for intravascular ultrasound (IVUS) imaging application. The effective electromechanical coupling coefficient kt(eff) of the composite was measured to be 0.75 to 0.78. Acoustic impedance was estimated to be 20 MRayl. Based on the composite, needle-type and flexible-type IVUS transducers were fabricated. The composite transducer achieved an 86% bandwidth at the center frequency of 41 MHz, which resulted in a 43 μm axial resolution. Ex vivo IVUS imaging was conducted to demonstrate the improvement of axial resolution. The composite transducer was capable of identifying the three layers of a cadaver coronary artery specimen with high resolution. The PIN-PMN-PT-based composite has superior piezoelectric properties comparable to PMN-PT-based composite and its thermal stability is higher than PMN-PT. PIN-PMN-PT crystal can be an alternative approach for fabricating high-frequency composite, instead of using PMN-PT. PMID:24960706

  4. Energy scavenging based on a single-crystal PMN-PT nanobelt

    PubMed Central

    Wu, Fan; Cai, Wei; Yeh, Yao-Wen; Xu, Shiyou; Yao, Nan

    2016-01-01

    Self-powered nanodevices scavenging mechanical energy require piezoelectric nanostructures with high piezoelectric coefficients. Here we report the fabrication of a single-crystal (1 − x)Pb(Mg1/3Nb2/3)O3 − xPbTiO3 (PMN-PT) nanobelt with a superior piezoelectric constant (d33 = ~550 pm/V), which is approximately ~150%, 430%, and 2100% of the largest reported values for previous PMN-PT, PZT and ZnO nanostructures, respectively. The high d33 of the single-crystalline PMN-PT nanobelt results from the precise orientation control during its fabrication. As a demonstration of its application in energy scavenging, a piezoelectric nanogenerator (PNG) is built on the single PMN-PT nanobelt, generating a maximum output voltage of ~1.2 V. This value is ~4 times higher than that of a single-CdTe PNG, ~13 times higher than that of a single-ZnSnO3 PNG, and ~26 times higher than that of a single-ZnO PNG. The profoundly increased output voltage of a lateral PNG built on a single PMN-PT nanobelt demonstrates the potential application of PMN-PT nanostructures in energy harvesting, thus enriching the material choices for PNGs. PMID:26928788

  5. Effect of biaxial strain induced by piezoelectric PMN-PT on the upconversion photoluminescence of BaTiO₃:Yb/Er thin films.

    PubMed

    Wu, Zhenping; Zhang, Yang; Bai, Gongxun; Tang, Weihua; Gao, Ju; Hao, Jianhua

    2014-11-17

    Thin films of Yb3+/Er3+ co-doped BaTiO3 (BTO:Yb/Er) have been epitaxially grown on piezoelectric Pb(Mg1/3Nb2/3)0.7Ti0.3O3 (PMN-PT) substrates. Biaxial strain can be effectively controlled by applying electric field on PMN-PT substrate. A reversible, in situ and dynamic modification of upconversion photoluminescence in BTO:Yb/Er film was observed via converse piezoelectric effect. Detailed analysis and in situ X-ray diffraction indicate that such modulations are possibly due to the change in the lattice deformation of the thin films. This result suggests an alternative method to rationally tune the upconversion emissions via strain engineering. PMID:25402140

  6. Flexible piezoelectric PMN-PT nanowire-based nanocomposite and device.

    PubMed

    Xu, Shiyou; Yeh, Yao-wen; Poirier, Gerald; McAlpine, Michael C; Register, Richard A; Yao, Nan

    2013-06-12

    Piezoelectric nanocomposites represent a unique class of materials that synergize the advantageous features of polymers and piezoelectric nanostructures and have attracted extensive attention for the applications of energy harvesting and self-powered sensing recently. Currently, most of the piezoelectric nanocomposites were synthesized using piezoelectric nanostructures with relatively low piezoelectric constants, resulting in lower output currents and lower output voltages. Here, we report a synthesis of piezoelectric (1 - x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-PT) nanowire-based nanocomposite with significantly improved performances for energy harvesting and self-powered sensing. With the high piezoelectric constant (d33) and the unique hierarchical structure of the PMN-PT nanowires, the PMN-PT nanowire-based nanocomposite demonstrated an output voltage up to 7.8 V and an output current up to 2.29 μA (current density of 4.58 μA/cm(2)); this output voltage is more than double that of other reported piezoelectric nanocomposites, and the output current is at least 6 times greater. The PMN-PT nanowire-based nanocomposite also showed a linear relationship of output voltage versus strain with a high sensitivity. The enhanced performance and the flexibility of the PMN-PT nanowire-based nanocomposite make it a promising building block for energy harvesting and self-powered sensing applications. PMID:23634729

  7. Micromachined PIN-PMN-PT crystal composite transducer for high-frequency intravascular ultrasound (IVUS) imaging.

    PubMed

    Li, Xiang; Ma, Teng; Tian, Jian; Han, Pengdi; Zhou, Qifa; Shung, K Kirk

    2014-07-01

    In this paper, we report the use of micromachined PbIn1/2Nb1/2O3-PbMg1/3Nb2/3O3-PbTiO 3 (PIN-PMNPT) single crystal 1-3 composite material for intravascular ultrasound (IVUS) imaging application. The effective electromechanical coupling coefficient kt(eff) of the composite was measured to be 0.75 to 0.78. Acoustic impedance was estimated to be 20 MRayl. Based on the composite, needle-type and flexible-type IVUS transducers were fabricated. The composite transducer achieved an 86% bandwidth at the center frequency of 41 MHz, which resulted in a 43 μm axial resolution. Ex vivo IVUS imaging was conducted to demonstrate the improvement of axial resolution. The composite transducer was capable of identifying the three layers of a cadaver coronary artery specimen with high resolution. The PIN-PMN-PT-based composite has superior piezoelectric properties comparable to PMN-PT-based composite and its thermal stability is higher than PMN-PT. PIN-PMN-PT crystal can be an alternative approach for fabricating high-frequency composite, instead of using PMN-PT. PMID:24960706

  8. Simultaneous measurement of electro-optical and converse-piezoelectric coefficients of PMN-PT ceramics.

    PubMed

    Xiao, Pingping; Wang, Xianping; Sun, Jingjing; Huang, Meizhen; Chen, Xianfeng; Cao, Zhuangqi

    2012-06-18

    A new scheme is proposed to measure the electro-optical (EO) and converse-piezoelectric (CPE) coefficients of the PMN-PT ceramics simultaneously, in which the PMN-PT ceramics acts as the guiding layer of a symmetrical metal-cladding waveguide. As the applied electric field exerts on the waveguide, the effective refractive index (RI) (or synchronous angle) can be effectively tuned from a selected mode to another adjacent mode owing to the high sensitivity and the small spacing of the ultra-high order modes. Subsequently, a correlation between EO and CPE coefficients is established. With this correlation and the measurement of the effective RI change to the applied voltage, the quadratic EO and CPE coefficients of PMN-PT ceramics are obtained simultaneously. The obtained results are further checked by fitting the variations of effective RI to a quadratic function. Our measurement method can be extended to a wide range of other materials. PMID:22714448

  9. Tuning of near-infrared luminescence of SrTiO3:Ni2+ thin films grown on piezoelectric PMN-PT via strain engineering

    PubMed Central

    Bai, Gongxun; Zhang, Yang; Hao, Jianhua

    2014-01-01

    We report the tunable near-infrared luminescence of Ni2+ doped SrTiO3 (STO:Ni) thin film grown on piezoelectric Pb(Mg1/3Nb2/3)0.7Ti0.3O3 (PMN-PT) substrate via strain engineering differing from conventional chemical approach. Through controlling the thickness of STO:Ni film, the luminescent properties of the films including emission wavelength and bandwidth, as well as lifetime can be effectively tuned. The observed phenomena can be explained by the variation in the crystal field around Ni2+ ions caused by strain due to the lattice mismatch. Moreover, the modulation of strain can be controlled under an external electric field via converse piezoelectric effect of PMN-PT used in this work. Consequently, controllable emission of the STO:Ni thin film is demonstrated in a reversible and real-time way, arising from the biaxial strain produced by piezoelectric PMN-PT. Physical mechanism behind the observation is discussed. This work will open a door for not only investigating the luminescent properties of the phosphors via piezoelectric platform, but also potentially developing novel planar light sources. PMID:25030046

  10. Tuning of near-infrared luminescence of SrTiO3:Ni2+ thin films grown on piezoelectric PMN-PT via strain engineering

    NASA Astrophysics Data System (ADS)

    Bai, Gongxun; Zhang, Yang; Hao, Jianhua

    2014-07-01

    We report the tunable near-infrared luminescence of Ni2+ doped SrTiO3 (STO:Ni) thin film grown on piezoelectric Pb(Mg1/3Nb2/3)0.7Ti0.3O3 (PMN-PT) substrate via strain engineering differing from conventional chemical approach. Through controlling the thickness of STO:Ni film, the luminescent properties of the films including emission wavelength and bandwidth, as well as lifetime can be effectively tuned. The observed phenomena can be explained by the variation in the crystal field around Ni2+ ions caused by strain due to the lattice mismatch. Moreover, the modulation of strain can be controlled under an external electric field via converse piezoelectric effect of PMN-PT used in this work. Consequently, controllable emission of the STO:Ni thin film is demonstrated in a reversible and real-time way, arising from the biaxial strain produced by piezoelectric PMN-PT. Physical mechanism behind the observation is discussed. This work will open a door for not only investigating the luminescent properties of the phosphors via piezoelectric platform, but also potentially developing novel planar light sources.

  11. Tuning of near-infrared luminescence of SrTiO3:Ni2+ thin films grown on piezoelectric PMN-PT via strain engineering.

    PubMed

    Bai, Gongxun; Zhang, Yang; Hao, Jianhua

    2014-01-01

    We report the tunable near-infrared luminescence of Ni(2+) doped SrTiO3 (STO:Ni) thin film grown on piezoelectric Pb(Mg(1/3)Nb(2/3))(0.7)Ti(0.3)O3 (PMN-PT) substrate via strain engineering differing from conventional chemical approach. Through controlling the thickness of STO:Ni film, the luminescent properties of the films including emission wavelength and bandwidth, as well as lifetime can be effectively tuned. The observed phenomena can be explained by the variation in the crystal field around Ni(2+) ions caused by strain due to the lattice mismatch. Moreover, the modulation of strain can be controlled under an external electric field via converse piezoelectric effect of PMN-PT used in this work. Consequently, controllable emission of the STO:Ni thin film is demonstrated in a reversible and real-time way, arising from the biaxial strain produced by piezoelectric PMN-PT. Physical mechanism behind the observation is discussed. This work will open a door for not only investigating the luminescent properties of the phosphors via piezoelectric platform, but also potentially developing novel planar light sources. PMID:25030046

  12. Characterization of PMN-PT piezoelectric single crystal and PMN-PT 1-3 composite at elevated temperatures by electrical impedance resonance analysis.

    PubMed

    Wu, Zhengbin; Xi, Kui

    2014-07-01

    In this paper, lead magnesium niobate-lead titanate (PMN-PT) piezoelectric single crystal and its 1-3 composite counterpart were characterized and analyzed under different stable temperatures using both a Simulated Annealing (SA) optimization algorithm and the commercial software PRAP (Piezoelectric Resonance Analysis Program). Electrical impedance resonance characteristics of the two material samples over the range 25-125 °C were measured. The correlation between experimental data and numerical fits derived from both SA and PRAP is considered. Calculation of the determination coefficient (R1(2)) between numerically fitted and measured results is above 95% for both methods. Furthermore, variations in the number of data values used for the fit introduced no more than 3.1% uncertainty on the calculated material parameters. It is found that the complex material parameters of PMN-PT composite are more dependent on temperature than the single crystal. The phase transition of the PMN-PT, which is close to 90 °C, has an effect on the high temperature material characteristics of both piezoelectric materials. These calculated complex material parameters can be used for the design of ultrasonic transducers for elevated temperature applications. PMID:24495996

  13. Recent Developments on High Curie Temperature PIN-PMN-PT Ferroelectric Crystals

    PubMed Central

    Zhang, Shujun; Li, Fei; Sherlock, Nevin P.; Luo, Jun; Lee, Hyeong Jae; Xia, Ru; Meyer, Richard J.; Hackenberger, Wesley; Shrout, Thomas R.

    2011-01-01

    Pb(In0.5Nb0.5)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) ferroelectric crystals attracted extensive attentions in last couple years, due to their higher usage temperatures range (> 30°C) and coercive fields (~5kV/cm), meanwhile maintaining similar electromechanical couplings (k33> 90%) and piezoelectric coefficients (d33~1500pC/N), when compared to their binary counterpart Pb(Mg1/3Nb2/3)O3-PbTiO3. In this article, we reviewed recent developments on the PIN-PMN-PT single crystals, including the Bridgman crystal growth, dielectric, electromechanical, piezoelectric and ferroelectric behaviors as function of temperature and dc bias. Mechanical quality factor Q was studied as function of orientation and phase. Of particular interest is the dynamic strain, which related to the Q and d33, was found to be improved when compared to binary system, exhibiting the potential usage of PIN-PMN-PT in high power application. Furthermore, PIN-PMN-PT crystals exhibit improved thickness dependent properties, due to their small domain size, being on the order of 1μm. Finally, the manganese acceptor dopant in the ternary crystals was investigated and discussed briefly in this paper. PMID:21516190

  14. Electric field modification of magnetotransport in Ni thin films on (011) PMN-PT piezosubstrates

    NASA Astrophysics Data System (ADS)

    Tkach, Alexander; Kehlberger, Andreas; Büttner, Felix; Jakob, Gerhard; Eisebitt, Stefan; Kläui, Mathias

    2015-02-01

    This study reports the magnetotransport and magnetic properties of 20 nm-thick polycrystalline Ni films deposited by magnetron sputtering on unpoled piezoelectric (011) [PbMg1/3Nb2/3O3]0.68-[PbTiO3]0.32 (PMN-PT) substrates. The longitudinal magnetoresistance (MR) of the Ni films on (011) PMN-PT, measured at room temperature in the magnetic field range of -0.3 T < μ0H < 0.3 T, is found to depend on the crystallographic direction and polarization state of piezosubstrate. Upon poling the PMN-PT substrate, which results in a transfer of strain to the Ni film, the MR value decreases by factor of 20 for the current along [100] of PMN-PT and slightly increases for the [ 01 1 ¯ ] current direction. Simultaneously, a strong increase (decrease) in the field value, where the MR saturates, is observed for the [ 01 1 ¯ ] ([100]) current direction. The anisotropic magnetoresistance is also strongly affected by the remanent strain induced by the electric field pulses applied to the PMN-PT in the non-linear regime revealing a large (132 mT) magnetic anisotropy field. Applying a critical electric field of 2.4 kV/cm, the anisotropy field value changes back to the original value, opening a path to voltage-tuned magnetic field sensor or storage devices. This strain mediated voltage control of the MR and its dependence on the crystallographic direction is correlated with the results of magnetization reversal measurements.

  15. Tip-bias-induced domain evolution in PMN-PT transparent ceramics via piezoresponse force microscopy

    NASA Astrophysics Data System (ADS)

    Zhao, K. Y.; Zhao, W.; Zeng, H. R.; Yu, H. Z.; Ruan, W.; Xu, K. Q.; Li, G. R.

    2015-05-01

    Piezoresponse force microscopy (PFM) was employed to investigate ferroelectric domain structures and their dynamic behavior of lead magnesium niobate-lead titanate [Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-PT)] transparent ceramics under an tip-bias-induced electric field. A remarkable effect of fluctuation of PT content on the domain configurations and domain dynamic response in PMN-PT transparent ferroelectric ceramics were found by PFM. Comparing with PMN-10%PT and PMN-20%PT, the reversed polarization of macrodomain area in PMN-35%PT and PMN-25%PT exhibits a relatively higher response behavior and better polarization retention performance under the PFM tip-bias-induced electric field, which correspond to their unique macroscopic electro-optic properties.

  16. Design of a slim-type optical pick-up actuator using PMN-PT bimorphs

    NASA Astrophysics Data System (ADS)

    Ko, Byeongsik; Jung, Jung-Sub; Lee, Seung-Yop

    2006-12-01

    In this paper, a new optical pick-up actuator is proposed using PMN-PT (lead magnesium niobate-lead titanate) bimorphs for slim and small form factor optical disk drives. We suggest a novel structure enabling both tracking and focusing motions by changing the moving directions of the two parallel bimorphs. A cymbal-type flextensional structure is used as a displacement amplifier in order to meet the stroke requirement for optical pick-up actuators. We have performed the theoretical analyses for the bimorph actuator and displacement amplifier to predict the resultant force and displacement. The proposed actuator based on PMN-PT bimorphs and displacement amplifier has been manufactured, and the experimental results are compared to the analytical predictions. Experimental results agree well with the analytical predictions, showing that the cymbal structure amplifies the displacement twice and the focusing stroke is 52 µm at 10 V.

  17. High-power characterization of a microcutter actuated by PMN-PT piezocrystals.

    PubMed

    Kuang, Yang; Sadiq, Muhammad; Cochran, Sandy; Huang, Zhihong

    2015-11-01

    An ultrasonic microcutter is an alternative approach to conventional ultrasonic instruments actuated by sandwich piezoelectric transducers for surgery. This paper reports high-power behavior of a microcutter actuated by the piezocrystal lead magnesium niobate-lead titanate (PMN-PT), defining its practical performance and the feasibility of PMNPT actuation for surgical applications. The microcutter was driven at resonance with constant current amplitudes, either unloaded or loaded by poultry breast tissue, until its behavior achieved a steady state. During this driving process, its electric impedance, resonant frequency, and vibration velocity, along with the temperature increase of the PMN-PT, were recorded in real time. The microcutter produced a maximum vibration velocity >2.8 m/s with an excitation current of 0.11 A(rms). The mechanical loss increased significantly with current amplitude, resulting in a maximum temperature increase approaching 50°C around the interface between the PMN-PT and the blade, where they were bonded together with epoxy. Because of the low phase-transition temperature of PMN-PT, this temperature rise prevented the microcutter from working at higher current amplitudes. Along with the high vibration velocity, it also caused a frequency shift downward by 3 kHz at the same current amplitude. During tests with poultry breast tissue, radiation reactance increased the resonant frequency and the radiation resistance increased the loss of the microcutter. However, the loss did not further increase the temperature of the piezoelectric material. The maximum force and the overall work required to penetrate the microcutter into poultry breast tissue were reduced by 47.1 ± 8% and 53.5 ± 6%, respectively, when the microcutter was actuated at a current of 0.07 A(rms). PMID:26559625

  18. Self-powered cardiac pacemaker enabled by flexible single crystalline PMN-PT piezoelectric energy harvester.

    PubMed

    Hwang, Geon-Tae; Park, Hyewon; Lee, Jeong-Ho; Oh, SeKwon; Park, Kwi-Il; Byun, Myunghwan; Park, Hyelim; Ahn, Gun; Jeong, Chang Kyu; No, Kwangsoo; Kwon, HyukSang; Lee, Sang-Goo; Joung, Boyoung; Lee, Keon Jae

    2014-07-23

    A flexible single-crystalline PMN-PT piezoelectric energy harvester is demonstrated to achieve a self-powered artificial cardiac pacemaker. The energy-harvesting device generates a short-circuit current of 0.223 mA and an open-circuit voltage of 8.2 V, which are enough not only to meet the standard for charging commercial batteries but also for stimulating the heart without an external power source. PMID:24740465

  19. PMN-PT single-crystal high-frequency kerfless phased array.

    PubMed

    Chen, Ruimin; Cabrera-Munoz, Nestor E; Lam, Kwok Ho; Hsu, Hsiu-sheng; Zheng, Fan; Zhou, Qifa; Shung, K Kirk

    2014-06-01

    This paper reports the design, fabrication, and characterization of a miniature high-frequency kerfless phased array prepared from a PMN-PT single crystal for forward-looking intravascular or endoscopic imaging applications. After lapping down to around 40 μm, the PMN-PT material was utilized to fabricate 32-element kerfless phased arrays using micromachining techniques. The aperture size of the active area was only 1.0 × 1.0 mm. The measured results showed that the array had a center frequency of 40 MHz, a bandwidth of 34% at -6 dB with a polymer matching layer, and an insertion loss of 20 dB at the center frequency. Phantom images were acquired and compared with simulated images. The results suggest that the feasibility of developing a phased array mounted at the tip of a forward-looking intravascular catheter or endoscope. The fabricated array exhibits much higher sensitivity than PZT ceramic-based arrays and demonstrates that PMN-PT is well suited for this application. PMID:24859667

  20. PMN-PT Single-Crystal High-Frequency Kerfless Phased Array

    PubMed Central

    Chen, Ruimin; Cabrera-Munoz, Nestor E.; Lam, Kwok Ho; Hsu, Hsiu-sheng; Zheng, Fan; Zhou, Qifa; Shung, K. Kirk

    2015-01-01

    This paper reports the design, fabrication, and characterization of a miniature high-frequency kerfless phased array prepared from a PMN-PT single crystal for forward-looking intravascular or endoscopic imaging applications. After lapping down to around 40 μm, the PMN-PT material was utilized to fabricate 32-element kerfless phased arrays using micromachining techniques. The aperture size of the active area was only 1.0 × 1.0 mm. The measured results showed that the array had a center frequency of 40 MHz, a bandwidth of 34% at −6 dB with a polymer matching layer, and an insertion loss of 20 dB at the center frequency. Phantom images were acquired and compared with simulated images. The results suggest that the feasibility of developing a phased array mounted at the tip of a forward-looking intravascular catheter or endoscope. The fabricated array exhibits much higher sensitivity than PZT ceramic-based arrays and demonstrates that PMN-PT is well suited for this application. PMID:24859667

  1. PMN-PT-PZT composite films for high frequency ultrasonic transducer applications.

    PubMed

    Hsu, Hsiu-Sheng; Benjauthrit, Vatcharee; Zheng, Fan; Chen, Rumin; Huang, Yuhong; Zhou, Qifa; Shung, K Kirk

    2012-06-01

    We have successfully fabricated x(0.65PMN-0.35PT)-(1 - x)PZT (xPMN-PT-(1 - x)PZT), where x is 0.1, 0.3, 0.5, 0.7 and 0.9, thick films with a thickness of approximately 9 µm on platinized silicon substrate by employing a composite sol-gel technique. X-ray diffraction analysis and scanning electron microscopy revealed that these films are dense and creak-free with well-crystallized perovskite phase in the whole composition range. The dielectric constant can be controllably adjusted by using different compositions. Higher PZT content of xPMN-PT-(1 - x)PZT films show better ferroelectric properties. A representative 0.9PMN-PT-0.1PZT thick film transducer is built. It has 200 MHz center frequency with a -6 dB bandwidth of 38% (76 MHz). The measured two-way insertion loss is 65 dB. PMID:23750072

  2. Voltage control of metal-insulator transition and non-volatile ferroelastic switching of resistance in VOx/PMN-PT heterostructures.

    PubMed

    Nan, Tianxiang; Liu, Ming; Ren, Wei; Ye, Zuo-Guang; Sun, Nian X

    2014-01-01

    The central challenge in realizing electronics based on strongly correlated electronic states, or 'Mottronics', lies in finding an energy efficient way to switch between the distinct collective phases with a control voltage in a reversible and reproducible manner. In this work, we demonstrate that a voltage-impulse-induced ferroelastic domain switching in the (011)-oriented 0.71Pb(Mg1/3Nb2/3)O3-0.29PbTiO3 (PMN-PT) substrates allows a robust non-volatile tuning of the metal-insulator transition in the VOx films deposited onto them. In such a VOx/PMN-PT heterostructure, the unique two-step electric polarization switching covers up to 90% of the entire poled area and contributes to a homogeneous in-plane anisotropic biaxial strain, which, in turn, enables the lattice changes and results in the suppression of metal-insulator transition in the mechanically coupled VOx films by 6 K with a resistance change up to 40% over a broad range of temperature. These findings provide a framework for realizing in situ and non-volatile tuning of strain-sensitive order parameters in strongly correlated materials, and demonstrate great potentials in delivering reconfigurable, compactable, and energy-efficient electronic devices. PMID:25088796

  3. Voltage Control of Metal-insulator Transition and Non-volatile Ferroelastic Switching of Resistance in VOx/PMN-PT Heterostructures

    NASA Astrophysics Data System (ADS)

    Nan, Tianxiang; Liu, Ming; Ren, Wei; Ye, Zuo-Guang; Sun, Nian X.

    2014-08-01

    The central challenge in realizing electronics based on strongly correlated electronic states, or `Mottronics', lies in finding an energy efficient way to switch between the distinct collective phases with a control voltage in a reversible and reproducible manner. In this work, we demonstrate that a voltage-impulse-induced ferroelastic domain switching in the (011)-oriented 0.71Pb(Mg1/3Nb2/3)O3-0.29PbTiO3 (PMN-PT) substrates allows a robust non-volatile tuning of the metal-insulator transition in the VOx films deposited onto them. In such a VOx/PMN-PT heterostructure, the unique two-step electric polarization switching covers up to 90% of the entire poled area and contributes to a homogeneous in-plane anisotropic biaxial strain, which, in turn, enables the lattice changes and results in the suppression of metal-insulator transition in the mechanically coupled VOx films by 6 K with a resistance change up to 40% over a broad range of temperature. These findings provide a framework for realizing in situ and non-volatile tuning of strain-sensitive order parameters in strongly correlated materials, and demonstrate great potentials in delivering reconfigurable, compactable, and energy-efficient electronic devices.

  4. Voltage Control of Metal-insulator Transition and Non-volatile Ferroelastic Switching of Resistance in VOx/PMN-PT Heterostructures

    PubMed Central

    Nan, Tianxiang; Liu, Ming; Ren, Wei; Ye, Zuo-Guang; Sun, Nian X.

    2014-01-01

    The central challenge in realizing electronics based on strongly correlated electronic states, or ‘Mottronics', lies in finding an energy efficient way to switch between the distinct collective phases with a control voltage in a reversible and reproducible manner. In this work, we demonstrate that a voltage-impulse-induced ferroelastic domain switching in the (011)-oriented 0.71Pb(Mg1/3Nb2/3)O3-0.29PbTiO3 (PMN-PT) substrates allows a robust non-volatile tuning of the metal-insulator transition in the VOx films deposited onto them. In such a VOx/PMN-PT heterostructure, the unique two-step electric polarization switching covers up to 90% of the entire poled area and contributes to a homogeneous in-plane anisotropic biaxial strain, which, in turn, enables the lattice changes and results in the suppression of metal-insulator transition in the mechanically coupled VOx films by 6 K with a resistance change up to 40% over a broad range of temperature. These findings provide a framework for realizing in situ and non-volatile tuning of strain-sensitive order parameters in strongly correlated materials, and demonstrate great potentials in delivering reconfigurable, compactable, and energy-efficient electronic devices. PMID:25088796

  5. Quantification of strain and charge co-mediated magnetoelectric coupling on ultra-thin Permalloy/PMN-PT interface.

    PubMed

    Nan, Tianxiang; Zhou, Ziyao; Liu, Ming; Yang, Xi; Gao, Yuan; Assaf, Badih A; Lin, Hwaider; Velu, Siddharth; Wang, Xinjun; Luo, Haosu; Chen, Jimmy; Akhtar, Saad; Hu, Edward; Rajiv, Rohit; Krishnan, Kavin; Sreedhar, Shalini; Heiman, Don; Howe, Brandon M; Brown, Gail J; Sun, Nian X

    2014-01-01

    Strain and charge co-mediated magnetoelectric coupling are expected in ultra-thin ferromagnetic/ferroelectric multiferroic heterostructures, which could lead to significantly enhanced magnetoelectric coupling. It is however challenging to observe the combined strain charge mediated magnetoelectric coupling, and difficult in quantitatively distinguish these two magnetoelectric coupling mechanisms. We demonstrated in this work, the quantification of the coexistence of strain and surface charge mediated magnetoelectric coupling on ultra-thin Ni0.79Fe0.21/PMN-PT interface by using a Ni0.79Fe0.21/Cu/PMN-PT heterostructure with only strain-mediated magnetoelectric coupling as a control. The NiFe/PMN-PT heterostructure exhibited a high voltage induced effective magnetic field change of 375 Oe enhanced by the surface charge at the PMN-PT interface. Without the enhancement of the charge-mediated magnetoelectric effect by inserting a Cu layer at the PMN-PT interface, the electric field modification of effective magnetic field was 202 Oe. By distinguishing the magnetoelectric coupling mechanisms, a pure surface charge modification of magnetism shows a strong correlation to polarization of PMN-PT. A non-volatile effective magnetic field change of 104 Oe was observed at zero electric field originates from the different remnant polarization state of PMN-PT. The strain and charge co-mediated magnetoelectric coupling in ultra-thin magnetic/ferroelectric heterostructures could lead to power efficient and non-volatile magnetoelectric devices with enhanced magnetoelectric coupling. PMID:24418911

  6. Quantification of strain and charge co-mediated magnetoelectric coupling on ultra-thin Permalloy/PMN-PT interface

    PubMed Central

    Nan, Tianxiang; Zhou, Ziyao; Liu, Ming; Yang, Xi; Gao, Yuan; Assaf, Badih A.; Lin, Hwaider; Velu, Siddharth; Wang, Xinjun; Luo, Haosu; Chen, Jimmy; Akhtar, Saad; Hu, Edward; Rajiv, Rohit; Krishnan, Kavin; Sreedhar, Shalini; Heiman, Don; Howe, Brandon M.; Brown, Gail J.; Sun, Nian X.

    2014-01-01

    Strain and charge co-mediated magnetoelectric coupling are expected in ultra-thin ferromagnetic/ferroelectric multiferroic heterostructures, which could lead to significantly enhanced magnetoelectric coupling. It is however challenging to observe the combined strain charge mediated magnetoelectric coupling, and difficult in quantitatively distinguish these two magnetoelectric coupling mechanisms. We demonstrated in this work, the quantification of the coexistence of strain and surface charge mediated magnetoelectric coupling on ultra-thin Ni0.79Fe0.21/PMN-PT interface by using a Ni0.79Fe0.21/Cu/PMN-PT heterostructure with only strain-mediated magnetoelectric coupling as a control. The NiFe/PMN-PT heterostructure exhibited a high voltage induced effective magnetic field change of 375 Oe enhanced by the surface charge at the PMN-PT interface. Without the enhancement of the charge-mediated magnetoelectric effect by inserting a Cu layer at the PMN-PT interface, the electric field modification of effective magnetic field was 202 Oe. By distinguishing the magnetoelectric coupling mechanisms, a pure surface charge modification of magnetism shows a strong correlation to polarization of PMN-PT. A non-volatile effective magnetic field change of 104 Oe was observed at zero electric field originates from the different remnant polarization state of PMN-PT. The strain and charge co-mediated magnetoelectric coupling in ultra-thin magnetic/ferroelectric heterostructures could lead to power efficient and non-volatile magnetoelectric devices with enhanced magnetoelectric coupling. PMID:24418911

  7. Strain-mediated electric-field control of exchange bias in a Co90Fe10/BiFeO3/SrRuO3/PMN-PT heterostructure.

    PubMed

    Wu, S Z; Miao, J; Xu, X G; Yan, W; Reeve, R; Zhang, X H; Jiang, Y

    2015-01-01

    The electric-field (E-field) controlled exchange bias (EB) in a Co90Fe10/BiFeO3 (BFO)/SrRuO3/PMN-PT heterostructure has been investigated under different tensile strain states. The in-plane tensile strain of the BFO film is changed from +0.52% to +0.43% as a result of external E-field applied to the PMN-PT substrate. An obvious change of EB by the control of non-volatile strain has been observed. A magnetization reversal driven by E-field has been observed in the absence of magnetic field. Our results indicate that a reversible non-volatile E-field control of a ferromagnetic layer through strain modulated multiferroic BFO could be achieved at room temperature. PMID:25752272

  8. Strain-mediated electric-field control of exchange bias in a Co90Fe10/BiFeO3/SrRuO3/PMN-PT heterostructure

    NASA Astrophysics Data System (ADS)

    Wu, S. Z.; Miao, J.; Xu, X. G.; Yan, W.; Reeve, R.; Zhang, X. H.; Jiang, Y.

    2015-03-01

    The electric-field (E-field) controlled exchange bias (EB) in a Co90Fe10/BiFeO3 (BFO)/SrRuO3/PMN-PT heterostructure has been investigated under different tensile strain states. The in-plane tensile strain of the BFO film is changed from +0.52% to +0.43% as a result of external E-field applied to the PMN-PT substrate. An obvious change of EB by the control of non-volatile strain has been observed. A magnetization reversal driven by E-field has been observed in the absence of magnetic field. Our results indicate that a reversible non-volatile E-field control of a ferromagnetic layer through strain modulated multiferroic BFO could be achieved at room temperature.

  9. Strain-mediated electric-field control of exchange bias in a Co90Fe10/BiFeO3/SrRuO3/PMN-PT heterostructure

    PubMed Central

    Wu, S. Z.; Miao, J.; Xu, X. G.; Yan, W.; Reeve, R.; Zhang, X. H.; Jiang, Y.

    2015-01-01

    The electric-field (E-field) controlled exchange bias (EB) in a Co90Fe10/BiFeO3 (BFO)/SrRuO3/PMN-PT heterostructure has been investigated under different tensile strain states. The in-plane tensile strain of the BFO film is changed from +0.52% to +0.43% as a result of external E-field applied to the PMN-PT substrate. An obvious change of EB by the control of non-volatile strain has been observed. A magnetization reversal driven by E-field has been observed in the absence of magnetic field. Our results indicate that a reversible non-volatile E-field control of a ferromagnetic layer through strain modulated multiferroic BFO could be achieved at room temperature. PMID:25752272

  10. Magnetoelectric coupling in multiferroic heterostructure of rf-sputtered Ni-Mn-Ga thin film on PMN-PT

    NASA Astrophysics Data System (ADS)

    Teferi, M. Y.; Amaral, V. S.; Lounrenco, A. C.; Das, S.; Amaral, J. S.; Karpinsky, D. V.; Soares, N.; Sobolev, N. A.; Kholkin, A. L.; Tavares, P. B.

    2012-06-01

    In this paper, we report a preparation of multiferroic heterostructure from thin film of Ni-Mn-Ga (NMG) alloy and lead magnesium niobate-lead titanate (PMN-PT) with effective magnetoelectric (ME) coupling between the film as ferromagnetic material and PMN-PT as piezoelectric material. The heterostructure was prepared by relatively low temperature (400 °C) deposition of the film on single crystal of piezoelectric PMN-PT substrate using rf magnetron co-sputtering of Ni50Mn50 and Ni50Ga50 targets. Magnetic measurements by Superconducting Quantum Interference Design (SQIUD) Magnetometer and Vibrating Sample Magnetometer (VSM) on the film revealed that the film is in ferromagnetically ordered martensitic state at room temperature with saturation magnetization of ˜240 emu/cm3 and Curie temperature of ˜337 K. Piezoresponse force microscopy (PFM) measurement done at room temperature on the substrate showed the presence of expected hysteresis loop confirming the stability of the piezoelectric state of the substrate after deposition. Room temperature ME voltage coefficient (αME) of the heterostructure was measured as a function of applied bias dc magnetic field in Longitudinal-Transverse (L-T) ME coupling mode by lock-in technique. A maximum ME coefficient αME of 3.02 mV/cm Oe was measured for multiferroic NMG/PMN-PT heterostructure which demonstrates that there is ME coupling between the film as ferromagnetic material and PMN-PT as piezoelectric material.

  11. Mechanical confinement for tuning ferroelectric response in PMN-PT single crystal

    NASA Astrophysics Data System (ADS)

    Patel, Satyanarayan; Chauhan, Aditya; Vaish, Rahul

    2015-02-01

    Ferroelectrics form an important class of materials and are employed for a variety of applications. However, specific applications dictate the need of tailored ferroelectric response. This creates a requirement to obtain ferroelectric materials with tunable properties. Generally, chemical modifications or domain engineering are employed to this effect. This study attempts to shed light on the use of compressive pre-stresses for tuning and enhancing the ferroelectric properties. For the purpose, polarization versus electric field hysteresis data for 68Pb(Mn1/3Nb2/3)O3-32PbTiO3 (PMN-PT) single crystals were obtained as a function of uniaxial compressive stresses and operating temperatures. These data were utilized to investigate the effects of mechanical confinement for four individual case studies of electrocaloric effect, electrical energy storage, pyroelectric, and piezoelectric effect. A significant improvement was obtained for all case studies. The adiabatic temperature change was improved by ≈80% (28 MPa, 353 K); energy storage density increased by a factor of five (28 MPa, 353 K); pyroelectric figure of merits improved by an order of magnitude (21 MPa) and the piezoelectric coefficient was tailored (variable stress). The results offer promising insight into the use of directional confinement for improving application specific ferroelectric properties in PMN-PT single crystal.

  12. Magnetoelectric properties of epitaxial Fe3O4 thin films on (011) PMN-PT piezosubstrates

    NASA Astrophysics Data System (ADS)

    Tkach, Alexander; Baghaie Yazdi, Mehrdad; Foerster, Michael; Büttner, Felix; Vafaee, Mehran; Fries, Maximilian; Kläui, Mathias

    2015-01-01

    We determine the magnetic and magnetotransport properties of 33 nm thick Fe3O4 films epitaxially deposited by rf-magnetron sputtering on unpoled (011) [PbMg1/3Nb2/3O3] 0.68-[PbTiO3]0.32 (PMN-PT) substrates. The magnetoresistance (MR), as well as the magnetization reversal, strongly depend on the in-plane crystallographic direction of the epitaxial (011) Fe3O4 film and strain. When the magnetic field is applied along [100], the magnetization loops are slanted and the sign of the longitudinal MR changes from positive to negative around the Verwey transition at 125 K on cooling. Along the [01 1 ¯] direction, the loops are square shaped and the MR is negative above the switching field across the whole temperature range, just increasing in absolute value when cooling from 300 K to 150 K. The value of the MR is found to be strongly affected by poling the PMN-PT substrate, decreasing in the [100] direction and slightly increasing in the [01 1 ¯] direction upon poling, which results in a strained film.

  13. Micromachined High Frequency PMN-PT/Epoxy 1-3 Composite Ultrasonic Annular Array

    PubMed Central

    Liu, Changgeng; Djuth, Frank; Li, Xiang; Chen, Ruimin; Zhou, Qifa; Shung, K. Kirk

    2013-01-01

    This paper reports the design, fabrication, and performance of miniature micromachined high frequency PMN-PT/epoxy 1-3 composite ultrasonic annular arrays. The PMN-PT single crystal 1-3 composites were made with micromachining techniques. The area of a single crystal pillar was 9 μm × 9 μm. The width of the kerf among pillars was ~ 5 μm and the kerfs were filled with a polymer. The composite thickness was 25 μm. A six-element annular transducer of equal element area of 0.2 mm2 with 16 μm kerf widths between annuli was produced. The aperture size the array transducer is about 1.5 mm in diameter. A novel electrical interconnection strategy for high density array elements was implemented. After the transducer was attached to the electric connection board and packaged, the array transducer was tested in a pulse/echo arrangement, whereby the center frequency, bandwidth, two-way insertion loss (IL), and cross talk between adjacent elements were measured for each annulus. The center frequency was 50 MHz and -6 dB bandwidth was 90%. The average insertion loss was 19.5 dB at 50 MHz and the crosstalk between adjacent elements was about -35 dB. The micromachining techniques described in this paper are promising for the fabrication of other types of high frequency transducers e.g. 1D and 2D arrays. PMID:22119324

  14. Thermal-independent properties of PIN-PMN-PT single-crystal linear-array ultrasonic transducers.

    PubMed

    Chen, Ruimin; Wu, Jinchuan; Ho Lam, Kwok; Yao, Liheng; Zhou, Qifa; Tian, Jian; Han, Pengdi; Shung, K Kirk

    2012-12-01

    In this paper, low-frequency 32-element linear-array ultrasonic transducers were designed and fabricated using both ternary Pb(In(1/2)Nb(1/2))-Pb(Mg(1/3)Nb(2/3))-PbTiO(3) (PIN-PMN-PT) and binary Pb(Mg(1/3)Nb(2/3))-PbTiO(3) (PMNPT) single crystals. Performance of the array transducers was characterized as a function of temperature ranging from room temperature to 160°C. It was found that the array transducers fabricated using the PIN-PMN-PT single crystal were capable of satisfactory performance at 160°C, having a -6-dB bandwidth of 66% and an insertion loss of 37 dB. The results suggest that the potential of PIN-PMN-PT linear-array ultrasonic transducers for high-temperature ultrasonic transducer applications is promising. PMID:23221227

  15. Design and Characterization of an Ultrasonic Surgical Tool Using d31 PMN-PT Plate

    NASA Astrophysics Data System (ADS)

    Kuang, Y.; Sadiq, M.; Cochran, S.; Huang, Z.

    An ultrasonic surgical tool for tissue incision and dissection has been designed and characterized. The surgical tool is based on a simple geometry to which PMN-PT d31 plates are bonded directly. The performance of the surgical tool has been defined numerically with the Abaqus finite element analysis (FEA) package and practically with laser vibrometer and impedance spectroscopy. The results show the ability of FEA to accurately predict the behaviors of an ultrasonic device as numerical and practical analysis were found to be in a good agreement. The design of the tool presented has the ability to generate displacement amplitude high enough to carry out soft tissue incision with relatively low driving voltage.

  16. Giant isothermal entropy change In (111)-oriented PMN-PT thin film

    NASA Astrophysics Data System (ADS)

    Hamad, Mahmoud A.

    2014-11-01

    An isothermal entropy change of 240 nm (111)-oriented PMN-PT 65/35 film near the ferroelectric Curie temperature, relative cooling power (RCP) and change of heat capacity have been investigated. The extracted data characterized giant isothermal entropy change of more than 16 J/kg K in electric field shift ΔE of 455 kV cm-1, which is nearly twice than that found for PbZr0.95Ti0.05O3 thin film at 492 kV cm-1 near the Curie point. Furthermore, the RCP ≈ 700 J/kg and change of heat capacity ≈ 233 J/kg K in electric field shift ΔE of 747 kV cm-1.

  17. Field Stability of Piezoelectric Shear Properties in PIN-PMN-PT Crystals Under Large Drive Field

    PubMed Central

    Zhang, Shujun; Li, Fei; Luo, Jun; Xia, Ru; Hackenberger, Wesley; Shrout, Thomas R.

    2013-01-01

    The coercive fields (EC) of Pb(In0.5Nb0.5)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) ternary single crystals were found to be 5 kV/cm, double the value of binary Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMNT) crystals, further increased to 6 to 9 kV/cm using Mn modifications. In addition to an increased EC, the acceptor modification resulted in the developed internal bias (Eint), on the order of ~1 kV/cm. The piezoelectric shear properties of unmodified and Mn-modified PIN-PMN-PT crystals with various domain configurations were investigated. The shear piezoelectric coefficients and electromechanical coupling factors for different domain configurations were found to be >2000 pC/N and >0.85, respectively, with slightly reduced properties observed in Mn-modified tetragonal crystals. Fatigue/cycling tests performed on shear-mode samples as a function of ac drive field level demonstrated that the allowable ac field levels (the maximum applied ac field before the occurrence of depolarization) were only ~2 kV/cm for unmodified crystals, less than half of their coercive field. Allowable ac drive levels were on the order of 4 to 6 kV/cm for Mn-modified crystals with rhombohedral/orthorhombic phase, further increased to 5 to 8 kV/cm in tetragonal crystals, because of their higher coercive fields. It is of particular interest that the allowable ac drive field level for Mn-modified crystals was found to be ≥60% of their coercive fields, because of the developed Eint, induced by the acceptor-oxygen vacancy defect dipoles. PMID:21342812

  18. Thermal-Independent Properties of PIN-PMN-PT Single-Crystal Linear-Array Ultrasonic Transducers

    PubMed Central

    Chen, Ruimin; Wu, Jinchuan; Lam, Kwok Ho; Yao, Liheng; Zhou, Qifa; Tian, Jian; Han, Pengdi; Shung, K. Kirk

    2013-01-01

    In this paper, low-frequency 32-element linear-array ultrasonic transducers were designed and fabricated using both ternary Pb(In1/2Nb1/2)–Pb(Mg1/3Nb2/3)–PbTiO3 (PIN-PMN-PT) and binary Pb(Mg1/3Nb2/3)–PbTiO3 (PMN-PT) single crystals. Performance of the array transducers was characterized as a function of temperature ranging from room temperature to 160°C. It was found that the array transducers fabricated using the PIN-PMN-PT single crystal were capable of satisfactory performance at 160°C, having a −6-dB bandwidth of 66% and an insertion loss of 37 dB. The results suggest that the potential of PIN-PMN-PT linear-array ultrasonic transducers for high-temperature ultrasonic transducer applications is promising. PMID:23221227

  19. Mechanical and thermal transitions in morphotropic PZN-pT and PMN-PT single crystals and their implication for sound projectors.

    PubMed

    Amin, Ahmed; McLaughlin, Elizabeth; Robinson, Harold; Ewart, Lynn

    2007-06-01

    Isothermal compression experiments on multidomain [001] oriented and poled ferroelectric rhombohedral PZN-0.07PT and PMN-0.30PT single crystals revealed elastic instabilities corresponding to zero field ferroelectric-ferroelectric phase transition under mechanical compression. The application of an appropriate dc bias field doubled the stability range of the ferroelectric rhombohedral state under uniaxial compression for both crystals and maintained a linear elastic response. Young's modulus as derived from the quasistatic, zero field stress-strain linear response agreed well with that derived from small signal resonance for the ferroelectric rhombohedral FR state of both PZN-PT and PMN-PT. Elastic compliances s(E)33 as determined from high temperature resonance revealed a monotonically decreasing Young's modulus as a function of temperature in the ferroelectric rhombohedral state with a sudden stiffening near the ferroelectric rhombohedral (FR)-ferroelectric tetragonal (FT) transition. The reversible ferroelectric-ferroelectric transition of morphotropic PZN-PT and PMN-PT single crystals as accessed by mechanical compression is discussed in terms of strain calculations from Devonshire's theory, domain unfolding, and morphotropic phase boundary shift with mechanical stress. The mechanically-induced and thermally-induced ferroelectric-ferroelectric transition trajectories are discussed in terms of the Devonshire theory. Implications of these observations for sound projectors are discussed. A single crystal tonpilz projector fabricated into a 16-element array and a segmented cylinder transducer demonstrated the outstanding capabilities of single crystals to achieve compact, broadband, and high-source level projectors when compared to conventional lead zirconate-titanate PZT8 projectors. PMID:17571807

  20. Characterization and application of piezoelectric microcantilever sensors fabricated from substrate-free PMN-PT layers

    NASA Astrophysics Data System (ADS)

    Zhu, Qing

    Piezoelectric Microcantilever Sensor (PEMS) has attracted tremendous attention and numerous biological and chemical detections have been demonstrated. During detection, adsorption induced surface stress causes the PEMS flexural resonance frequency shift, however, the sensing mechanism due to stress effect is still unclear. The goal of this dissertation is to carry out fundamental study of sensing mechanism and then demonstrate chemical warfare agent detection. When a PEMS is subject to a DC bias field, the flexural resonance frequency shifted as a result of Young's modulus change in the PMN-PT layer which was confirmed by the measurement of width mode frequency and the relative dielectric constant measurement indicated that the Young's modulus change was a result of non-180° domain switching. Similarly, the flexural resonance frequency shift of a PEMS during humidity detection was also due to the Young's modulus change which was two-order-of-magnitude larger than could be accounted for by the mass loading alone. Furthermore, a negative DC field of -6 kV/cm enhanced the relative resonance frequency shift in humidity detection by more than 3 times of the detection without a DC bias. It was shown that during humidity detection, the frequency shift of the flexural mode, Deltaf, was inversely proportional to the square of the PEMS length, L 2; relative resonance frequency shift, Deltaf/f, was inversely proportional to the PEMS thickness, t; and the mass detection sensitivity, Delta f/Deltam, was inversely proportional to wL3 where w is the width. The Young's modulus change and scaling were validated in another independent system-DMMP detection using SAM MUA/Cu2+ coated PEMS. In addition, the flexural frequency shift of the microporous silica powder coated PEMS followed mass loading model while the planar MPS coated PEMS showed two-order-of-magnitude enhancement indicating a continuous coating of adsorbent on PEMS is desired. Array PMN-PT/Cu PEMSs coated with planar MPS

  1. Angled-focused 45 MHz PMN-PT single element transducer for intravascular ultrasound imaging

    PubMed Central

    Yoon, Sangpil; Williams, Jay; Kang, Bong Jin; Yoon, Changhan; Cabrera-Munoz, Nestor; Jeong, Jong Seob; Lee, Sang Goo; Shung, K. Kirk; Kim, Hyung Ham

    2015-01-01

    A transducer with an angled and focused aperture for intravascular ultrasound imaging has been developed. The acoustic stack for the angled-focused transducer was made of PMN-PT single crystal with one matching layer, one protective coating layer, and a highly damped backing layer. It was then press-focused to a desired focal length and inserted into a thin needle housing with an angled tip. A transducer with an angled and unfocused aperture was also made, following the same fabrication procedure, to compare the performance of the two transducers. The focused and unfocused transducers were tested to measure their center frequencies, bandwidths, and spatial resolutions. Lateral resolution of the angled-focused transducer (AFT) improved more than two times compared to that of the angled-unfocused transducer (AUT). A tissue-mimicking phantom in water and a rabbit aorta tissue sample in rabbit blood were scanned using AFT and AUT. Imaging with AFT offered improved contrast, over imaging with AUT, of the tissue-mimicking phantom and the rabbit aorta tissue sample by 23 dB and 8 dB, respectively. The results show that AFT has strong potential to provide morphological and pathological information of coronary arteries with high resolution and high contrast. PMID:25914443

  2. PMN-PT based quaternary piezoceramics with enhanced piezoelectricity and temperature stability

    NASA Astrophysics Data System (ADS)

    Luo, Nengneng; Zhang, Shujun; Li, Qiang; Yan, Qingfeng; He, Wenhui; Zhang, Yiling; Shrout, Thomas R.

    2014-05-01

    The phase structure, piezoelectric, dielectric, and ferroelectric properties of (0.80 - x)PMN-0.10PFN-0.10PZ-xPT were investigated systematically. The morphotropic phase boundary (MPB) was confirmed to be 0.30 < x < 0.34. Both MPB compositions of x = 0.32 and x = 0.33 exhibit high piezoelectric coefficients d33 = 640 pC/N and 580 pC/N, electromechanical couplings kp of 0.53 and 0.52, respectively. Of particular importance is that the composition with x = 0.33 was found to process high field-induced piezoelectric strain coefficient d33* of 680 pm/V, exhibiting a minimal temperature-dependent behavior, being less than 8% in the temperature range of 25-165 °C, which can be further confirmed by d31, with a variation of less than 9%. The temperature-insensitive d33* values can be explained by the counterbalance of the ascending dielectric permittivity and descending polarization with increasing temperature. These features make the PMN-PT based quaternary MPB compositions promising for actuator applications demanding high temperature stability.

  3. Elastic, dielectric and piezoelectric characterization of single domain PIN-PMN-PT: Mn crystals.

    PubMed

    Huo, Xiaoqing; Zhang, Shujun; Liu, Gang; Zhang, Rui; Luo, Jun; Sahul, Raffi; Cao, Wenwu; Shrout, Thomas R

    2012-12-15

    Mn modified 0.26Pb(In(1/2)Nb(1/2))O(3)-0.42Pb(Mg(1/3)Nb(2/3))O(3)-0.32PbTiO(3) (PIN-PMN-PT:Mn) single crystals with orthorhombic perovskite crystal structure were polarized along [011] direction, resulting in the single domain state "1O." The complete set of material constants was determined using the combined resonance and ultrasonic methods. The thickness shear piezoelectric coefficient d(15) and electromechanical coupling factor k(15) were found to be on the order of 3100 pC/N and 94%, respectively, much higher than longitudinal d(33) ∼ 270 pC/N and k(33) ∼ 70%. Using the single domain data, the rotated value of d(33)* along [001] direction was found to be 1230 pC/N, in agreement with the experimentally determined d(33) value of 1370 pC/N, conferring extrinsic contributions being about 10%, which was also confirmed using the Rayleigh analysis. In addition, the mechanical quality factors Q(m) were evaluated for different "1O" vibration modes, where the longitudinal Q(m) was found to be ∼1200, much higher than the value for "4O" crystals, ∼300. PMID:23341689

  4. Electric field mediated non-volatile tuning magnetism in CoPt/PMN-PT heterostructure for magnetoelectric memory devices

    NASA Astrophysics Data System (ADS)

    Yang, Y. T.; Li, J.; Peng, X. L.; Wang, X. Q.; Wang, D. H.; Cao, Q. Q.; Du, Y. W.

    2016-02-01

    We report a power efficient non-volatile magnetoelectric memory in the CoPt/(011)PMN-PT heterostructure. Two reversible and stable electric field induced coercivity states (i.e., high-HC or low-HC) are obtained due to the strain mediated converse magnetoelectric effect. The reading process of the different coercive field information written by electric fields is demonstrated by using a magnetoresistance read head. This result shows good prospects in the application of novel multiferroic devices.

  5. In situ hard x-ray photoemission spectroscopy of barrier-height control at metal/PMN-PT interfaces

    NASA Astrophysics Data System (ADS)

    Kröger, E.; Petraru, A.; Quer, A.; Soni, R.; Kalläne, M.; Pertsev, N. A.; Kohlstedt, H.; Rossnagel, K.

    2016-06-01

    Metal-ferroelectric interfaces form the basis of novel electronic devices. A key effect determining the device functionality is the bias-dependent change of the electronic energy-level alignment at the interface. Here, hard x-ray photoelectron spectroscopy (HAXPES) is used to determine the energy-level alignment at two metal-ferroelectric interfaces—Au versus SrRuO3 on the relaxor ferroelectric Pb (Mg1 /3Nb2 /3 )0.72Ti0.28O3 (PMN-PT)—directly in situ as a function of electrical bias. The bias-dependent average shifts of the PMN-PT core levels are found to have two dominant contributions on the 0.1 -1-eV energy scale: one depending on the metal electrode and the remanent electric polarization and the other correlated with electric-field-induced strain. Element-specific deviations from the average shifts are smaller than 0.1 eV and appear to be related to predicted dynamical charge variations in PMN-PT. In addition, the efficiency of ferroelectric polarization switching is shown to be reduced near the coercive field under x-ray irradiation. The results establish HAXPES as a tool for the in operando investigation of metal-ferroelectric interfaces and suggest electric-field-induced modifications of the polarization distribution as a novel way to control the barrier height at such interfaces.

  6. Effect of Elevated Pressure on the Heat Transfer and Power Requirements During Bridgman Growth of PMN-PT Crystals

    NASA Technical Reports Server (NTRS)

    Bune, Andris; Ostrogorsky, Aleksandar; Marin, Carlos; Nicoara, Irina; Rose, M. Franklin (Technical Monitor)

    2000-01-01

    Performance of the furnace during Bridgman growth of the lead magnesium niobate-lead titanate crystal (PMN-PT) is analyzed. PMN-PT is electrostrictive ceramic that has near ideal strain-voltage function. Furthermore piezoelectric (2000 to 2300 pC/N) and coupling (92 to 95%) constants are exceptionally good. Due to these properties PMN-PT has wide range of applications - from sonars to transducers in a high precision optical systems. In this research first attempt to crystallize PMN-PT in a Mellen type vertical Bridgman furnace was not successful, as melting temperature of precursor materials was not achieved. At this point choice was between building a new more powerful facility or finding ways to enhance performance of the existing furnace. Besides adjusting power supply to the individual heating elements, redesigning ampoule holding cartridge and improving furnace insulation one more radical improvement was proposed. The entire furnace was placed into the high pressure chamber. Further experiments confirmed that temperature inside the furnace was increased sufficiently to melt precursor materials to obtain PMN-PT. Numerical modeling is undertaken to find limitations of this technique and to predict temperature distribution inside the ampoule. It is of interest also to account for main factors contributing to a higher temperatures achieved in the furnace under the higher pressure (up to 10 atm.). Numerical model of the furnace is based on general purpose finite - element code FIDAP and on previous efforts to model Bridgman type furnace with multiply heaters. In order to account for all heat transfer mechanism involved - conduction, convection and radiation - different parts of the furnace are modeled in accordance with expected dominant mode of heat transfer - conduction in the solid parts, conduction and radiation in the ampoule, gas convection and conduction in the furnace openings complemented with wall-to-wall radiation. Because of these complicating factors

  7. Bulk Crystal Growth of Piezoelectric PMN-PT Crystals Using Gradient Freeze Technique for Improved SHM Sensors

    NASA Technical Reports Server (NTRS)

    Aggarwal, Mohan D.; Kochary, F.; Penn, Benjamin G.; Miller, Jim

    2007-01-01

    There has been a growing interest in recent years in lead based perovskite ferroelectric and relaxor ferroelectric solid solutions because of their excellent dielectric, piezoelectric and electrostrictive properties that make them very attractive for various sensing, actuating and structural health monitoring (SHM) applications. We are interested in the development of highly sensitive and efficient PMN-PT sensors based on large single crystals for the structural health monitoring of composite materials that may be used in future spacecrafts. Highly sensitive sensors are needed for detection of defects in these materials because they often tend to fail by distributed and interacting damage modes and much of the damage occurs beneath the top surface of the laminate and not detectable by visual inspection. Research is being carried out for various combinations of solid solutions for PMN-PT piezoelectric materials and bigger size crystals are being sought for improved sensor applications. Single crystals of this material are of interest for sensor applications because of their high piezoelectric coefficient (d33 greater than 1700 pC/N) and electromechanical coefficients (k33 greater than 0.90). For comparison, the commonly used piezoelectric ceramic lead zirconate titanate (PZT) has a d33 of about 600 pC/N and electromechanical coefficients k33 of about 0.75. At the present time, these piezoelectric relaxor crystals are grown by high temperature flux growth method and the size of these crystals are rather small (3x4x5 mm(exp 3). In the present paper, we have attempted to grow bulk single crystals of PMN-PT in a 2 inch diameter platinum crucible and successfully grown a large size crystal of 67%PMN-33%PT using the vertical gradient freeze technique with no flux. Piezoelectric properties of the grown crystals are investigated. PMN-PT plates show excellent piezoelectric properties. Samples were poled under an applied electric field of 5 kV/cm. Dielectric properties at a

  8. Tuning the functional properties of PMN-PT single crystals via doping and thermoelectrical treatments

    NASA Astrophysics Data System (ADS)

    Luo, Laihui; Dietze, Matthias; Solterbeck, Claus-Henning; Luo, Haosu; Es-Souni, Mohammed

    2013-12-01

    Single crystals based on solid solutions of lead-magnesium-niobate (PMN) and lead titanate (PT) have emerged as highly promising multifunctional systems combining piezoelectric, pyroelectric, and electro-optic properties that surpass by far those of the best known lead-zirkonium-titanate ceramics. In this paper we present new findings on how the phase transition temperature and the dielectric and ferroelectric properties can be tuned depending on crystal composition, orientation, and thermoelectrical treatment. Mn-doped and pure 0.72PbMg1/3Nb2/3O3-0.28PbTiO3 (0.72PMN-0.28PT) single crystals with ⟨111⟩ and ⟨001⟩ orientations were investigated. A special attention was devoted to field cooling (FC), i.e., cooling under electric field from different temperatures. The results illustrate different findings that were not reported before: the Curie temperature, i.e., ferroelectric-paraelectric transition temperature, is enhanced after field cooling of the Mn-doped, ⟨001⟩-oriented crystal while such a shift is not observed in the ⟨111⟩-oriented and the non-doped crystals. In addition, substantial polarization suppression occurs in the Mn-doped crystals upon FC from high temperature regardless of orientation. Based on piezoforce microscopy of the domain structure that shows suppression of domain growth following field cooling from 200 °C, we propose a mechanism for polarization suppression based on domain pinning by charged defects. The practical importance of our results lies in showing the opportunity offered by a proper choice of crystal composition and poling conditions for tuning the functional properties of PMN-PT single crystals for a specific application. This should contribute to the understanding of their properties towards advanced sensor and transducers devices.

  9. Low Frequency Magnetoelectric Interactions in Single Crystal YIG/PMN-PT Bilayers

    NASA Astrophysics Data System (ADS)

    Devreugd, C. P.; Srinivasan, G.; Mantese, J. V.

    2004-03-01

    This work is concerned with magnetoelectric (ME) coupling in novel layered ferromagnetic-ferroelectric composites. The heterostructures are capable of electric-to-magnetic field conversion that is mediated by mechanical stress [1]. We recently developed a theoretical model for low frequency effects that predicts an order of magnitude enhancement in ME coupling in single crystals compared to polycrystalline samples [2]. Use of single crystals is critical for probing the influence of piezomagnetism, ac magnetostriction, and ferroelasticity of the magnetic component and similar parameters for the ferroelectric component. The studies are also important for the creation of an optimal interface to accomplish strong ME interactions. Bilayers were prepared by bonding epitaxial (100), (110), and (111) films of YIG and (001) single crystals of PMN-PT. Low frequency ME voltage coefficients were measured for transverse (dc magnetic field H and ac field in-plane) and longitudinal (magnetic fields out-of-plane) fields. Important results are as follows. (i) The ME voltage coupling is the largest for H along <111> of YIG and is the weakest for H along <100>. (ii) The voltage coefficient increases with increasing volume of YIG. (iii) The transverse coefficient is an order of magnitude higher than the longitudinal coefficient. (iv) Studies on bilayers with (111) YIG films reveal a significant influence of in-plane anisotropy on ME coupling. 1. G. Srinivasan, E. T. Rasmussen, and R. Hayes, Phys. Rev. B. 67, 014418 (2003). 2. M. I. Bichurin, V. M. Petrov, and G. Srinivasan, Phys. Rev. B 68, 054402 (2003). This work was supported by a grant from the National Science Foundation (DMR-0322254)

  10. Implementation of a PMN-PT piezocrystal-based focused array with geodesic faceted structure.

    PubMed

    Qiu, Zhen; Qiu, Yongqiang; Demore, Christine E M; Cochran, Sandy

    2016-07-01

    The higher performance of relaxor-based piezocrystals compared with piezoceramics is now well established, notably including improved gain-bandwidth product, and these materials have been adopted widely for biomedical ultrasound imaging. However, their use in other applications, for example as a source of focused ultrasound for targeted drug delivery, is hindered in several ways. One of the issues, which we consider here, is in shaping the material into the spherical geometries used widely in focused ultrasound. Unlike isotropic unpoled piezoceramics that can be shaped into a monolithic bowl then poled through the thickness, the anisotropic structure of piezocrystals make it impossible to machine the bulk crystalline material into a bowl without sacrificing performance. Instead, we report a novel faceted array, inspired by the geodesic dome structure in architecture, which utilizes flat piezocrystal material and maximizes fill factor. Aided by 3D printing, a prototype with f#≈ 1.2, containing 96 individually addressable elements was manufactured using 1-3 connectivity PMN-PT piezocrystal-epoxy composite. The fabrication process is presented and the array was connected to a 32-channel controller to shape and steer the beam for preliminary performance demonstration. At an operating frequency of 1MHz, a focusing gain around 30 was achieved and the side lobe intensities were all at levels below -12dB compared to main beam. We conclude that, by taking advantage of contemporary fabrication techniques and driving instrumentation, the geodesic array configuration is suitable for focused ultrasound devices made with piezocrystal. PMID:27104921

  11. Compact magnetic energy storage module

    DOEpatents

    Prueitt, Melvin L.

    1994-01-01

    A superconducting compact magnetic energy storage module in which a plurality of superconducting toroids, each having a toroidally wound superconducting winding inside a poloidally wound superconducting winding, are stacked so that the flow of electricity in each toroidally wound superconducting winding is in a direction opposite from the direction of electrical flow in other contiguous superconducting toroids. This allows for minimal magnetic pollution outside of the module.

  12. Compact magnetic energy storage module

    DOEpatents

    Prueitt, M.L.

    1994-12-20

    A superconducting compact magnetic energy storage module in which a plurality of superconducting toroids, each having a toroidally wound superconducting winding inside a poloidally wound superconducting winding, are stacked so that the flow of electricity in each toroidally wound superconducting winding is in a direction opposite from the direction of electrical flow in other contiguous superconducting toroids. This allows for minimal magnetic pollution outside of the module. 4 figures.

  13. Silver Doped 0.9PMN-PT-0.1PZT Composite Films for very High Frequency Ultrasonic Transducer Applications

    PubMed Central

    Hsu, Hsiu-Sheng; Benjauthrit, Vatcharee; Wei, Qiang; Huang, Yuhong; Zhou, Qifa; Shung, K. Kirk

    2013-01-01

    A series of silver doping concentration into the 0.9PMN-PT-0.1PZT (PMN-PT-PZT) films via the composite sol-gel technique were prepared. The crystallographic properties and microstructures of PMN-PT-PZT films with the silver dopant were investigated. Additionally, the effect of silver doping on dielectric and ferroelectric properties was examined. The results show that in general, the dielectric permittivity and remnant polarization increase as the silver doping concentration is increased. The PMN-PT-PZT+ 2.5 mol% Ag film exhibits a dielectric constant of 3,610 at 1 kHz and a remnant polarization of 57.6 µC/cm2 at room temperature. From this silver doped film, very high frequency ultrasonic needle transducers were fabricated and evaluated. The representative transducer had the center frequency of 225 MHz with a −6 dB bandwidth of 29% (65 MHz) and 62 dB insertion loss. The performance of this transducer is comparable to other composite sol-gel films transducer. The results suggest that this silver-doped PMN-PT-PZT film is a promising candidate as an alternative piezoelectric film for very high frequency transducer applications. PMID:23814408

  14. Silver doped 0.9PMN-PT-0.1PZT composite films for very high frequency ultrasonic transducer applications

    NASA Astrophysics Data System (ADS)

    Hsu, Hsiu-Sheng; Benjauthrit, Vatcharee; Wei, Qiang; Huang, Yuhong; Zhou, Qifa; Shung, K. Kirk

    2013-05-01

    A series of silver doping concentration into the 0.9PMN-PT-0.1PZT (PMN-PT-PZT) films via the composite sol-gel technique were prepared. The crystallographic properties and microstructures of PMN-PT-PZT films with the silver dopant were investigated. Additionally, the effect of silver doping on dielectric and ferroelectric properties was examined. The results show that in general, the dielectric permittivity and remnant polarization increase as the silver doping concentration is increased. The PMN-PT-PZT+2.5 mol% Ag film exhibits a dielectric constant of 3,610 at 1 kHz and a remnant polarization of 57.6 μC/cm2 at room temperature. From this silver doped film, very high frequency ultrasonic needle transducers were fabricated and evaluated. The representative transducer had the center frequency of 225 MHz with a -6 dB bandwidth of 29 % (65 MHz) and 62 dB insertion loss. The performance of this transducer is comparable to other composite sol-gel films transducer. The results suggest that this silver-doped PMN-PT-PZT film is a promising candidate as an alternative piezoelectric film for very high frequency transducer applications.

  15. Silver Doped 0.9PMN-PT-0.1PZT Composite Films for very High Frequency Ultrasonic Transducer Applications.

    PubMed

    Hsu, Hsiu-Sheng; Benjauthrit, Vatcharee; Wei, Qiang; Huang, Yuhong; Zhou, Qifa; Shung, K Kirk

    2013-05-01

    A series of silver doping concentration into the 0.9PMN-PT-0.1PZT (PMN-PT-PZT) films via the composite sol-gel technique were prepared. The crystallographic properties and microstructures of PMN-PT-PZT films with the silver dopant were investigated. Additionally, the effect of silver doping on dielectric and ferroelectric properties was examined. The results show that in general, the dielectric permittivity and remnant polarization increase as the silver doping concentration is increased. The PMN-PT-PZT+ 2.5 mol% Ag film exhibits a dielectric constant of 3,610 at 1 kHz and a remnant polarization of 57.6 µC/cm(2) at room temperature. From this silver doped film, very high frequency ultrasonic needle transducers were fabricated and evaluated. The representative transducer had the center frequency of 225 MHz with a -6 dB bandwidth of 29% (65 MHz) and 62 dB insertion loss. The performance of this transducer is comparable to other composite sol-gel films transducer. The results suggest that this silver-doped PMN-PT-PZT film is a promising candidate as an alternative piezoelectric film for very high frequency transducer applications. PMID:23814408

  16. Performance of PIN-PMN-PT Single Crystal Piezoelectric versus PZT8 Piezoceramic Materials in Ultrasonic Transducers

    NASA Astrophysics Data System (ADS)

    DeAngelis, D. A.; Schulze, G. W.

    The recent advancements in the manufacturing of single crystal PIN-PMN-PT piezoelectric materials now make them a cost-competitive alternative to PZT4 and PZT8 (Navy Types I and III) piezoceramic materials, which have been the workhorse of power ultrasonic applications (e.g., welding, cutting, sonar, etc.) for over 50 years. Although there are great benefits to the use of single crystal materials with respect to high output, as well as added actuating and sensing abilities, many transducer designers are still reluctant to explore these materials due to inadequate design guidelines for substituting the familiar PZT materials; for example, what are the implications of the higher capacitance, sensitivity to chipping/cracks, aging effects, frequency shifts, or how much preload can be used are all common questions. This research is a case study on the performance of identical ultrasonic transducer bodies, used for semiconductor wire bonding, assembled with either PZT8 or PIN-PMN-PT piezo material. The main purpose of the study is to establish rule-of-thumb design guidelines for direct substitution of single crystal materials in existing PZT8 transducer designs, along with a side-by-side performance comparison to highlight benefits. Several metrics are investigated such as impedance, frequency, displacement gain, quality factor and electromechanical coupling factor.

  17. Surface acoustic load sensing using a face-shear PIN-PMN-PT single-crystal resonator.

    PubMed

    Kim, Kyungrim; Zhang, Shujun; Jiang, Xiaoning

    2012-11-01

    Pb(In(0.5)Nb(0.5))O(3)-Pb(Mg(1/3)Nb(2/3))O(3)-PbTiO(3) (PIN-PMN-PT) resonators for surface acoustic load sensing are presented in this paper. Different acoustic loads are applied to thickness mode, thickness-shear mode, and face-shear mode resonators, and the electrical impedances at resonance and anti-resonance frequencies are recorded. More than one order of magnitude higher sensitivity (ratio of electrical impedance change to surface acoustic impedance change) at the resonance is achieved for the face-shear-mode resonator compared with other resonators with the same dimensions. The Krimholtz, Leedom, and Matthaei (KLM) model is used to verify the surface acoustic loading effect on the electrical impedance spectrum of face-shear PIN-PMN-PT single-crystal resonators. The demonstrated high sensitivity of face-shear mode resonators to surface loads is promising for a broad range of applications, including artificial skin, biological and chemical sensors, touch screens, and other touch-based sensors. PMID:23192819

  18. Multipeak self-biased magnetoelectric coupling characteristics in four-phase Metglas/Terfenol-D/Be-bronze/PMN-PT structure

    NASA Astrophysics Data System (ADS)

    Huang, Dongyan; Lu, Caijiang; Bing, Han

    2015-04-01

    This letter develops a self-biased magnetoelectric (ME) structure Metglas/Terfenol-D/Be-bronze/PMN-PT (MTBP) consisting of a magnetization-graded Metglas/Terfenol-D layer, a elastic Be-bronze plate, and a piezoelectric 0.67Pb(Mg1/3Nb2/3)O3-0.33PbTiO3 (PMN-PT) plate. By using the magnetization-graded Metglas/Terfenol-D layer and the elastic Be-bronze plate, multi-peak self-biased ME responses are obtained in MTBP structure. The experimental results show that the MTBP structure with two layers of Metglas foil has maximum zero-biased ME voltage coefficient (MEVC). As frequency increases from 0.5 to 90 kHz, eleven large peaks of MEVC with magnitudes of 0.75-33 V/(cm Oe) are observed at zero-biased magnetic field. The results demonstrate that the proposed multi-peak self-biased ME structure may be useful for multifunctional devices such as multi-frequency energy harvesters or low-frequency ac magnetic field sensors.

  19. Shear piezoelectric coefficients of PZT, LiNbO3 and PMN-PT at cryogenic temperatures

    NASA Astrophysics Data System (ADS)

    Bukhari, Syed; Islam, Md; Haziot, Ariel; Beamish, John

    2014-12-01

    Piezoelectric transducers are used to detect stress and to generate nanometer scale displacements but their piezoelectric coefficients decrease with temperature, limiting their performance in cryogenic applications. We have developed a capacitive technique and directly measured the temperature dependence of the shear coefficient d15 for ceramic lead zirconium titanate (PZT), 41° X-cut lithium niobate (LiNbO3) and single crystal lead magnesium niobium-lead titanate (PMN-PT). In PZT, d15 decreases nearly linearly with temperature, dropping by factor of about 4 by 1.3 K. LiNbO3 has the smallest room temperature d15, but its value decreased by only 6% at the lowest temperatures. PMN-PT had the largest value of d15 at room temperature (2.9 × 10-9 m/V, about 45 times larger than for LiNbO3) but it decreased rapidly below 75 K; at 1.3 K, d15 was only about 8% of its room temperature value.

  20. Giant electric field control of magnetism and narrow ferromagnetic resonance linewidth in FeCoSiB/Si/SiO2/PMN-PT multiferroic heterostructures

    NASA Astrophysics Data System (ADS)

    Gao, Y.; Wang, X.; Xie, L.; Hu, Z.; Lin, H.; Zhou, Z.; Nan, T.; Yang, X.; Howe, B. M.; Jones, J. G.; Brown, G. J.; Sun, N. X.

    2016-06-01

    It has been challenging to achieve combined strong magnetoelectric coupling and narrow ferromagnetic resonance (FMR) linewidth in multiferroic heterostructures. Electric field induced large effective field of 175 Oe and narrow FMR linewidth of 40 Oe were observed in FeCoSiB/Si/SiO2/PMN-PT heterostructures with substrate clamping effect minimized through removing the Si substrate. As a comparison, FeCoSiB/PMN-PT heterostructures with FeCoSiB film directly deposited on PMN-PT showed a comparable voltage induced effective magnetic field but a significantly larger FMR linewidth of 283 Oe. These multiferroic heterostructures exhibiting combined giant magnetoelectric coupling and narrow ferromagnetic resonance linewidth offer great opportunities for integrated voltage tunable RF magnetic devices.

  1. The memory effect of magnetoelectric coupling in FeGaB/NiTi/PMN-PT multiferroic heterostructure

    NASA Astrophysics Data System (ADS)

    Zhou, Ziyao; Zhao, Shishun; Gao, Yuan; Wang, Xinjun; Nan, Tianxiang; Sun, Nian X.; Yang, Xi; Liu, Ming

    2016-02-01

    Magnetoelectric coupling effect has provided a power efficient approach in controlling the magnetic properties of ferromagnetic materials. However, one remaining issue of ferromagnetic/ferroelectric magnetoelectric bilayer composite is that the induced effective anisotropy disappears with the removal of the electric field. The introducing of the shape memory alloys may prevent such problem by taking the advantage of its shape memory effect. Additionally, the shape memory alloy can also “store” the magnetoelectric coupling before heat release, which introduces more functionality to the system. In this paper, we study a FeGaB/NiTi/PMN-PT multiferroic heterostructure, which can be operating in different states with electric field and temperature manipulation. Such phenomenon is promising for tunable multiferroic devices with multi-functionalities.

  2. The memory effect of magnetoelectric coupling in FeGaB/NiTi/PMN-PT multiferroic heterostructure.

    PubMed

    Zhou, Ziyao; Zhao, Shishun; Gao, Yuan; Wang, Xinjun; Nan, Tianxiang; Sun, Nian X; Yang, Xi; Liu, Ming

    2016-01-01

    Magnetoelectric coupling effect has provided a power efficient approach in controlling the magnetic properties of ferromagnetic materials. However, one remaining issue of ferromagnetic/ferroelectric magnetoelectric bilayer composite is that the induced effective anisotropy disappears with the removal of the electric field. The introducing of the shape memory alloys may prevent such problem by taking the advantage of its shape memory effect. Additionally, the shape memory alloy can also "store" the magnetoelectric coupling before heat release, which introduces more functionality to the system. In this paper, we study a FeGaB/NiTi/PMN-PT multiferroic heterostructure, which can be operating in different states with electric field and temperature manipulation. Such phenomenon is promising for tunable multiferroic devices with multi-functionalities. PMID:26847469

  3. The memory effect of magnetoelectric coupling in FeGaB/NiTi/PMN-PT multiferroic heterostructure

    PubMed Central

    Zhou, Ziyao; Zhao, Shishun; Gao, Yuan; Wang, Xinjun; Nan, Tianxiang; Sun, Nian X.; Yang, Xi; Liu, Ming

    2016-01-01

    Magnetoelectric coupling effect has provided a power efficient approach in controlling the magnetic properties of ferromagnetic materials. However, one remaining issue of ferromagnetic/ferroelectric magnetoelectric bilayer composite is that the induced effective anisotropy disappears with the removal of the electric field. The introducing of the shape memory alloys may prevent such problem by taking the advantage of its shape memory effect. Additionally, the shape memory alloy can also “store” the magnetoelectric coupling before heat release, which introduces more functionality to the system. In this paper, we study a FeGaB/NiTi/PMN-PT multiferroic heterostructure, which can be operating in different states with electric field and temperature manipulation. Such phenomenon is promising for tunable multiferroic devices with multi-functionalities. PMID:26847469

  4. Direct crystallization of perovskite phase in PMN-PT thin films prepared by polyvinylpyrrolidone modified sol-gel processing and their properties

    SciTech Connect

    Du, Z.H.; Zhang, T.S.; Zhu, M.M.; Ma, J.

    2009-07-15

    A modified sol-gel processing has been developed by using polyvinylpyrrolidone (PVP) as modifier and lead nitrate as lead source to synthesize (1-x)Pb(Mg{sub 1/3},Nb{sub 2/3})O{sub 3}-xPbTiO{sub 3} (PMN-PT) thin films with x=0.23-0.43. With PVP additions, perovskite phase could directly crystallize from amorphous films at the temperature as low as 430 deg. C via bypassing the metastable phase-pyrochlore and crystallinity was significantly enhanced. The PVP addictives have been optimized with molecular weight <630 K and the ratio of PVP monomer/PMN-PT at 0.25-1.0. XPS analysis indicates that the chemical states of the elements in the well-crystallized PMN-PT films are close to the literature data for the PMN-PT single crystals and the films possess highly desired electrical and optical properties. - Graphical abstract: A polyvinylpyrrolidone modified sol-gel processing was developed to synthesize pure-perovskite Pb(Mg{sub 1/3},Nb{sub 2/3})O{sub 3}-PbTiO{sub 3} films via bypassing pyrochlore phase.

  5. In-plane anisotropic effect of magnetoelectric coupled PMN-PT/FePt multiferroic heterostructure: Static and microwave properties

    NASA Astrophysics Data System (ADS)

    Vargas, Jose M.; Gómez, Javier

    2014-10-01

    The effects of the electric and magnetic field variation on multiferroic heterostructure were studied in this work. Thin films of polycrystalline Fe50Pt50 (FePt) were grown by dc-sputtering on top of the commercial slabs of lead magnesium niobate-lead titanate (PMN-PT). The sample was a (011)-cut single crystal and had one side polished. In this condition, the PMN-PT/FePt operates in the L-T (longitudinal magnetized-transverse polarized) mode. A FePt thin film of 20 nm was used in this study to avoid the characteristic broad microwave absorption line associated with these films above thicknesses of 40 nm. For the in-plane easy magnetization axis (01-1), a microwave magnetoelectric (ME) coupling of 28 Oe cm kV -1 was estimated, whereas a value of 42 Oe cm kV -1 was obtained through the hard magnetization axis (100). Insight into the effects of the in-plane strain anisotropy on the ME coupling is obtained from the dc-magnetization loops. It was observed that the trend was opposite along the easy and hard magnetic directions. In particular, along the easy-magnetic axis (01-1), a square and narrow loop with a factor of Mr/MS of 0.96 was measured at 10 kV/cm. Along the hard-magnetic axis, a factor of 0.16 at 10 kV/cm was obtained. Using electric tuning via microwave absorption at X-band (9.78 GHz), we observe completely different trends along the easy and hard magnetic directions; Multiple absorption lines along the latter axis compared to a single and narrower absorption line along the former. In spite of its intrinsic complexity, we propose a model which gives good agreement both for static and microwave properties. These observations are of fundamental interest for future ME microwave components, such as filters, phase-shifters, and resonators.

  6. Electric field controlled strain induced reversible switching of magnetization in Galfenol nanomagnets delineated on PMN-PT substrate

    NASA Astrophysics Data System (ADS)

    Ahmad, Hasnain; Atulasimha, Jayasimha; Bandyopadhyay, Supriyo

    We report a non-volatile converse magneto-electric effect in elliptical Galfenol (FeGa) nanomagnets of ~300 nm lateral dimensions and ~10nm thickness delineated on a PMN-PT substrate. This effect can be harnessed for energy-efficient non-volatile memory. The nanomagnets are fabricated with e-beam lithography and sputtering. Their major axes are aligned parallel to the direction in which the substrate is poled and they are magnetized in this direction with a magnetic field. An electric field in the opposite direction generates compressive strain in the piezoelectric substrate which is partially transferred to the nanomagnets and rotates their magnetization away from the major axes to metastable orientations. There they remain after the field is removed, resulting in non-volatility. Reversing the electric field generates tensile strain which returns the magnetization to the original state. The two states can encode two binary bits which can be written using the correct voltage polarity, resulting in non-toggle behavior. Scaled memory fashioned on this effect can exhibit write energy dissipation of only ~2 aJ. Work is supported by NSF under ECCS-1124714 and CCF-1216614. Sputtering was carried out at NIST Gaithersburg.

  7. Molecular dynamics computational studies of relaxor ferroelectric behavior in Pb(Mg1/4Ti1/4Nb1/2)O3 (PMN-PT)

    NASA Astrophysics Data System (ADS)

    Takenaka, Hiroyuki; Grinberg, Ilya; Rappe, Andrew

    2009-03-01

    Relaxor ferroelectrics are of fundamental scientific interest and are also used in a variety of applications, such as piezoelectric transducers and capacitors. They exhibit permittivity peaks that are broad with respect to both temperature and frequency. We have developed a bond-valence model for Pb(Mg1/4Ti1/4Nb1/2)O3 (PMN-PT) and performed atomistic bond-valence molecular dynamics (BVMD) simulations of PMN-PT. We have studied relaxor behavior at a range of temperatures, in order to analyze polar nanoregion dynamics and relaxation lifetimes. We find that even for a fairly small simulation size of 6x6x6 supercell (1080 atoms), the system exhibits frequency dispersion. We present the results of 6x6 x6, 8x8x8 and 10x10x10 supercell BVMD simulations, analyze the pair distribution function of the PMN-PT and elucidate the local chemical origin of relaxor behavior.

  8. Room-temperature magneto-dielectric response in multiferroic ZnFe2O4/PMN-PT bilayer thin films

    NASA Astrophysics Data System (ADS)

    Garg, T.; Kulkarni, A. R.; Venkataramani, N.

    2016-08-01

    The magneto-dielectric response in multiferroic ZnFe2O4/PMN-PT bilayer thin films prepared on a glass substrate using RF magnetron sputtering has been investigated in this work. PMN-PT thin films (i.e. PMN-PT/LCMO/Pt/Ti/glass) deposited on glass were used as a substrate for deposition of ZnFe2O4 thin films. ZnFe2O4 thin films were annealed ex situ at different temperatures. Structural, magnetic, ferroelectric, dielectric and magneto-dielectric studies were carried out on these multiferroic bilayer thin films. Structural studies revealed the presence of each layer in its respective single phase. Magnetic and ferroelectric studies revealed the ferromagnetic and ferroelectric behaviors of these bilayers. To quantify the magnetoelectric coupling, the dielectric constant of the bilayer was measured at room temperature as a function of frequency with and without the applied magnetic field. The magneto-dielectric response MD(%) was calculated by finding the relative change in dielectric constant at 1 kHz as a percentage. The observed MD response was correlated with magnetization of the ferrite layer. An MD response of 2.60% was found for a bilayer film annealed at 350 °C. At this particular annealing temperature, the ZnFe2O4 layer also has the highest saturation magnetization of 1900 G.

  9. Equivalent properties of 1-3 piezocomposites made of PMN-PT single crystals for underwater sonar transducers

    NASA Astrophysics Data System (ADS)

    Kim, Jinwook; Roh, Yongrae

    2011-04-01

    The design of a piezocomposite transducer is accomplished by such advanced modeling technique as finite element method (FEM). However, accurate analysis of a 1-3 piezocomposite transducer enforces three dimensional (3D) modeling that requires very finemeshing of the transducer structure, which is frequently over affordable calculation resource capacity. In order to simplify the FEM model for complicated underwater transducers, the 1-3 piezocomposite needs to be simulated with a single phase material of equivalent properties. The 1-3 piezocomposite material in this study is made of the PMN-PT single crystal as the active material and urethane as the matrix material. Theoretical models for the calculation of new material parameters of 1-3 composites having fine lateral periodicity have been derived. For the validation of the equivalent properties, TE (thickness extensional), LE (length extensional), LTE (length thickness extensional), and TS (thickness shear) FEM models have been built to compare the impedance-frequency spectra of the 1-3 composite material and an equivalent material. Through the simulation with the models, all the equivalent elastic, dielectric and piezoelectric constants of the single phase material are determined. Further, 3D and axis-symmetric 2D FEM models of a multi-mode Tonpilz transducer have been constructed with the equivalent material properties. The equivalent material provides a very good correlation between the 2D and 3D transducer models, which is not easily attainable with the full 1-3 piezocomposite model. This result confirms the efficacy of the equivalent material properties of the 1-3 piezocomposites.

  10. Compact nanomechanical plasmonic phase modulators

    SciTech Connect

    Dennis, B. S.; Haftel, M. I.; Czaplewski, D. A.; Lopez, D.; Blumberg, G.; Aksyuk, V. A.

    2015-03-30

    Highly confined optical energy in plasmonic devices is advancing miniaturization in photonics. However, for mode sizes approaching ≈10 nm, the energy increasingly shifts into the metal, raising losses and hindering active phase modulation. Here, we propose a nanoelectromechanical phase-modulation principle exploiting the extraordinarily strong dependence of the phase velocity of metal–insulator–metal gap plasmons on dynamically variable gap size. We experimentally demonstrate a 23-μm-long non-resonant modulator having a 1.5π rad range, with 1.7 dB excess loss at 780 nm. Analysis shows that by simultaneously decreasing the gap, length and width, an ultracompact-footprint π rad phase modulator can be realized. This is achieved without incurring the extra loss expected for plasmons confined in a decreasing gap, because the increasing phase-modulation strength from a narrowing gap offsets rising propagation losses. Such small, high-density electrically controllable components may find applications in optical switch fabrics and reconfigurable plasmonic optics.

  11. Fabrication and Performance of Endoscopic Ultrasound Radial Arrays Based on PMN-PT Single Crystal/Epoxy 1-3 Composite

    PubMed Central

    Zhou, Dan; Cheung, Kwok Fung; Chen, Yan; Lau, Sien Ting; Zhou, Qifa; Shung, K. Kirk; Luo, Hao Su; Dai, Jiyan; Chan, Helen Lai Wa

    2011-01-01

    In this paper, 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 (PMN-PT) single crystal/epoxy 1–3 composite was used as the active material of the endoscopic ultrasonic radial array transducer, because this composite exhibited ultrahigh electromechanical coupling coefficient (kt = 0.81%), very low mechanical quality factor (Qm = 11) and relatively low acoustic impedance (Zt = 12 MRayls). A 6.91 MHz PMN-PT/epoxy 1–3 composite radial array transducer with 64 elements was tested in a pulse-echo response measurement. The −6-dB bandwidth of the composite array transducer was 102%, which was ~30% larger than that of traditional lead zirconate titanate array transducer. The two-way insertion loss was found to be −32.3 dB. The obtained results show that this broadband array transducer is promising for acquiring high-resolution endoscopic ultrasonic images in many clinical applications. PMID:21342833

  12. Influence of piezoelectric strain on the Raman spectra of BiFeO3 films deposited on PMN-PT substrates

    DOE PAGESBeta

    Himcinschi, Cameliu; Guo, Er -Jia; Talkenberger, Andreas; Dorr, Kathrin; Kortus, Jens

    2016-01-27

    In this study, BiFeO3 epitaxial thin films were deposited on piezoelectric 0.72Pb(Mg1/3Nb2/3)O3-0.28PbTiO3 (PMN-PT) substrates with a conductive buffer layer (La0.7Sr0.3MnO3 or SrRuO3) using pulsed laser deposition. The calibration of the strain values induced by the electric field applied on the piezoelectric PMN-PT substrates was realised using X-Ray diffraction measurements. The method of piezoelectrically induced strain allows to obtain a quantitative correlation between strain and the shift of the Raman-active phonons, ruling out the influence of extrinsic factors, such as growth conditions, crystalline quality of substrates, or film thickness. Using the Poisson number for BiFeO3 one can determine the volume changemore » induced by strain, and therefore the Gr neisen parameters for specific phonon modes.« less

  13. Influence of piezoelectric strain on the Raman spectra of BiFeO3 films deposited on PMN-PT substrates

    NASA Astrophysics Data System (ADS)

    Himcinschi, Cameliu; Guo, Er-Jia; Talkenberger, Andreas; Dörr, Kathrin; Kortus, Jens

    2016-01-01

    BiFeO3 epitaxial thin films were deposited on piezoelectric 0.72Pb(Mg1/3Nb2/3)O3-0.28PbTiO3 (PMN-PT) substrates with a conductive buffer layer (La0.7Sr0.3MnO3 or SrRuO3) using pulsed laser deposition. The calibration of the strain values induced by the electric field applied on the piezoelectric PMN-PT substrates was realised using X-Ray diffraction measurements. The method of piezoelectrically induced strain allows one to directly obtain a quantitative correlation between the strain and the shift of the Raman-active phonons. This is a prerequisite for making Raman scattering a strong tool to probe the strain coupling in multiferroic nanostructures. Using the Poisson's number for BiFeO3, one can determine the volume change induced by strain, and therefore the Grüneisen parameters for specific phonon modes.

  14. Double-modulation CPT cesium compact clock

    NASA Astrophysics Data System (ADS)

    Yun, Peter; Mejri, Sinda; Tricot, Francois; Abdel Hafiz, Moustafa; Boudot, Rodolphe; de Clercq, Emeric; Guérandel, Stéphane

    2016-06-01

    Double-modulation coherent population trapping (CPT) is based on a synchronous modulation of Raman phase and laser polarization, which allows the atomic population to accumulate in a common dark state. The high contrast signal obtained on the clock transition with a relative compact and robust laser system is interesting as basis of a high performance microwave clock. Here we study the parameters of a double-modulation CPT Cs clock working in cw mode. The optimal polarization modulation frequency and cell temperature for maximum contrast of clock transition are investigated. The parameters of the detection are also studied. With the optimal parameters, we observe a CPT signal with contrast of 10% and linewidth of 492 Hz, which is well suited for implementing a cw atomic clock.

  15. Compact Solid State Cooling Systems: Compact MEMS Electrocaloric Module

    SciTech Connect

    2010-10-01

    BEETIT Project: UCLA is developing a novel solid-state cooling technology to translate a recent scientific discovery of the so-called giant electrocaloric effect into commercially viable compact cooling systems. Traditional air conditioners use noisy, vapor compression systems that include a polluting liquid refrigerant to circulate within the air conditioner, absorb heat, and pump the heat out into the environment. Electrocaloric materials achieve the same result by heating up when placed within an electric field and cooling down when removed—effectively pumping heat out from a cooler to warmer environment. This electrocaloric-based solid state cooling system is quiet and does not use liquid refrigerants. The innovation includes developing nano-structured materials and reliable interfaces for heat exchange. With these innovations and advances in micro/nano-scale manufacturing technologies pioneered by semiconductor companies, UCLA is aiming to extend the performance/reliability of the cooling module.

  16. On the Binding Stress-Enhanced Sensitivity of (Pb(Mg1/3Nb2/3)O3)0.65-(PbTiO3) 0.35 (PMN-PT) Piezoelectric Plate Sensor (PEPS)

    NASA Astrophysics Data System (ADS)

    Wu, Wei

    (Pb(Mg1/3Nb2/3)O3)0.65-(PbTiO 3)0.35 (PMN-PT) piezoelectric plate sensor (PEPS) showed enhanced sensitivity in chemical and biological sensing applications which has been attributed to binding-induced crystalline orientation switching in the PMN-PT layer. However, so far there has been no direct demonstration of PEPS crystalline orientation switching upon target-analyte binding. Using biotin and streptavidin binding as a model detection system and by direct X-Ray diffraction observations after analyte binding we have unambiguously demonstrated that switching of the crystalline orientations of the PMN-PT layer indeed occurred. In addition, we have shown that PEPS sensitivity enhancement increased with an increasing transverse electromechanical coupling constant, -k31, of the PMN-PT layer--which is known to correlate with the crystalline orientation switching capability--by increasing the grain size of the PMN-PT layer or by applying a DC bias electric field. Finally, unprecedented high sensitivity of PEPS with high -k31, (i.e., -k31 > 0.3) were illustrated by the aM (10-18 M) sensitivity of in situ DNA hybridization detection without amplification and by the 100 fg/ml (10-13 g/ml) sensitivity of rapid, in situ protein detection in biological fluids such as troponin I detection in serum for early sign of myocardial infarction (heart attack), Her2 detection in serum for cancer treatment and monitoring, Tn antigen and anti-Tn antibody detection in serum for early cancer detection, and Toxins detection in stool for Clostridium difficile infection detection.

  17. Apparatus for the compact cooling of modules

    SciTech Connect

    Iyengar, Madhusudan K.; Parida, Pritish R.

    2015-07-07

    An apparatus for the compact cooling of modules. The apparatus includes a clip, a first cover plate coupled to a first side of the clip, a second cover plate coupled to a second side of the clip opposite to the first side of the clip, a first frame thermally coupled to the first cover plate, and a second frame thermally coupled to the second cover plate. Each of the first frame and the second frame may include a plurality of channels for passing coolant through the first frame and the second frame, respectively. Additionally, the apparatus may further include a filler for directing coolant through the plurality of channels, and for blocking coolant from flowing along the first side of the clip and the second side of the clip.

  18. Non-volatile ferroelastic switching of the Verwey transition and resistivity of epitaxial Fe3O4/PMN-PT (011)

    PubMed Central

    Liu, Ming; Hoffman, Jason; Wang, Jing; Zhang, Jinxing; Nelson-Cheeseman, Brittany; Bhattacharya, Anand

    2013-01-01

    A central goal of electronics based on correlated materials or ‘Mottronics’ is the ability to switch between distinct collective states with a control voltage. Small changes in structure and charge density near a transition can tip the balance between competing phases, leading to dramatic changes in electronic and magnetic properties. In this work, we demonstrate that an electric field induced two-step ferroelastic switching pathway in (011) oriented 0.71Pb(Mg1/3Nb2/3)O3-0.29PbTiO3 (PMN-PT) substrates can be used to tune the Verwey metal-insulator transition in epitaxial Fe3O4 films in a stable and reversible manner. We also observe robust non-volatile resistance switching in Fe3O4 up to room temperature, driven by ferroelastic strain. These results provides a framework for realizing non-volatile and reversible tuning of order parameters coupled to lattice-strain in epitaxial oxide heterostructures over a broad range of temperatures, with potential device applications. PMID:23703150

  19. Electric field control of magnetic states in isolated and dipole-coupled FeGa nanomagnets delineated on a PMN-PT substrate.

    PubMed

    Ahmad, Hasnain; Atulasimha, Jayasimha; Bandyopadhyay, Supriyo

    2015-10-01

    We report observation of a 'non-volatile' converse magneto-electric effect in elliptical FeGa nanomagnets delineated on a piezoelectric PMN-PT substrate. The nanomagnets are first magnetized with a magnetic field directed along their nominal major axes. Subsequent application of a strong electric field across the piezoelectric substrate generates strain in the substrate, which is partially transferred to the nanomagnets and rotates the magnetizations of some of them away from their initial orientations. The rotated magnetizations remain in their new orientations after the field is removed, resulting in 'non-volatility'. In isolated nanomagnets, the magnetization rotates by <90° upon application of the electric field, but in a dipole-coupled pair consisting of one 'hard' and one 'soft' nanomagnet, which are both initially magnetized in the same direction by the magnetic field, the soft nanomagnet's magnetization rotates by [Formula: see text] upon application of the electric field because of the dipole influence of the hard nanomagnet. This effect can be utilized for a nanomagnetic NOT logic gate. PMID:26373868

  20. Non-volatile ferroelastic switching of the Verwey transition and resistivity of epitaxial Fe3O4/PMN-PT (011).

    PubMed

    Liu, Ming; Hoffman, Jason; Wang, Jing; Zhang, Jinxing; Nelson-Cheeseman, Brittany; Bhattacharya, Anand

    2013-01-01

    A central goal of electronics based on correlated materials or 'Mottronics' is the ability to switch between distinct collective states with a control voltage. Small changes in structure and charge density near a transition can tip the balance between competing phases, leading to dramatic changes in electronic and magnetic properties. In this work, we demonstrate that an electric field induced two-step ferroelastic switching pathway in (011) oriented 0.71Pb(Mg1/3Nb2/3)O3-0.29PbTiO3 (PMN-PT) substrates can be used to tune the Verwey metal-insulator transition in epitaxial Fe3O4 films in a stable and reversible manner. We also observe robust non-volatile resistance switching in Fe3O4 up to room temperature, driven by ferroelastic strain. These results provides a framework for realizing non-volatile and reversible tuning of order parameters coupled to lattice-strain in epitaxial oxide heterostructures over a broad range of temperatures, with potential device applications. PMID:23703150

  1. Fabrication of a PMN-PT Single Crystal-Based Transcranial Doppler Transducer and the Power Regulation of Its Detection System

    PubMed Central

    Yue, Qingwen; Liu, Dongxu; Wang, Wei; Di, Wenning; Lin, Di; Wang, Xi'an; Luo, Haosu

    2014-01-01

    Doppler sonographic measurement of flow velocity in the basal cerebral arteries through the intact skull was developed using a pulsed Doppler technique and 2 MHz emitting frequency. Relaxor-based ferroelectric single crystals Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) were chosen to be the piezoelectric transducer material due to their ultrahigh piezoelectric coefficients, high electromechanical coupling coefficients and low dielectric loss. The pulse-echo response of the transducer was measured using the conventional pulse-echo method in a water bath at room temperature. The −6 dB bandwidth of the transducer is 68.4% and the sensitivity is −17.4 dB. In order to get a good match between transducer and detection system, different transmission powers have been regulated by changing the impedance of the transmitting electric circuit. In the middle cerebral artery (MCA) measurement photograph results, as the transmission power is increasing, the detection results become clearer and clearer. A comparison at the same transmission power for different transducers shows that the detection photograph obtained by the crystal transducer was clearer than that obtained with a commercial transducer, which should make it easier for doctors to find the cerebral arteries. PMID:25536000

  2. Electric field control of magnetic states in isolated and dipole-coupled FeGa nanomagnets delineated on a PMN-PT substrate

    NASA Astrophysics Data System (ADS)

    Ahmad, Hasnain; Atulasimha, Jayasimha; Bandyopadhyay, Supriyo

    2015-10-01

    We report observation of a ‘non-volatile’ converse magneto-electric effect in elliptical FeGa nanomagnets delineated on a piezoelectric PMN-PT substrate. The nanomagnets are first magnetized with a magnetic field directed along their nominal major axes. Subsequent application of a strong electric field across the piezoelectric substrate generates strain in the substrate, which is partially transferred to the nanomagnets and rotates the magnetizations of some of them away from their initial orientations. The rotated magnetizations remain in their new orientations after the field is removed, resulting in ‘non-volatility’. In isolated nanomagnets, the magnetization rotates by \\lt 90^\\circ upon application of the electric field, but in a dipole-coupled pair consisting of one ‘hard’ and one ‘soft’ nanomagnet, which are both initially magnetized in the same direction by the magnetic field, the soft nanomagnet’s magnetization rotates by \\gt 90^\\circ upon application of the electric field because of the dipole influence of the hard nanomagnet. This effect can be utilized for a nanomagnetic NOT logic gate.

  3. Fabrication of a PMN-PT single crystal-based transcranial Doppler transducer and the power regulation of its detection system.

    PubMed

    Yue, Qingwen; Liu, Dongxu; Wang, Wei; Di, Wenning; Lin, Di; Wang, Xi'an; Luo, Haosu

    2014-01-01

    Doppler sonographic measurement of flow velocity in the basal cerebral arteries through the intact skull was developed using a pulsed Doppler technique and 2 MHz emitting frequency. Relaxor-based ferroelectric single crystals Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) were chosen to be the piezoelectric transducer material due to their ultrahigh piezoelectric coefficients, high electromechanical coupling coefficients and low dielectric loss. The pulse-echo response of the transducer was measured using the conventional pulse-echo method in a water bath at room temperature. The -6 dB bandwidth of the transducer is 68.4% and the sensitivity is -17.4 dB. In order to get a good match between transducer and detection system, different transmission powers have been regulated by changing the impedance of the transmitting electric circuit. In the middle cerebral artery (MCA) measurement photograph results, as the transmission power is increasing, the detection results become clearer and clearer. A comparison at the same transmission power for different transducers shows that the detection photograph obtained by the crystal transducer was clearer than that obtained with a commercial transducer, which should make it easier for doctors to find the cerebral arteries. PMID:25536000

  4. Photomagnetism and photoluminescence (PL) of (Pb-Fe-e -) complex in lead magnesium niobate-lead titanate (PMN-PT) crystals containing β-PbO nanoclusters

    NASA Astrophysics Data System (ADS)

    Bairavarasu, Sundar R.; Edwards, Matthew E.; Sastry, Medury D.; Kochary, Faris; Kommidi, Praveena; Reddy, B. Rami; Lianos, Dimitrios; Aggarwal, Manmohan D.

    2008-12-01

    We present electron paramagnetic resonance (EPR)—evidence of photomagnetism under the conditions of in situ green laser illumination (photo-EPR) in lead magnesium niobate-lead titanate, Pb(Mg,Nb)O 3-PbTiO 3 (PMN-PT), containing nanoparticles/wires of orthorhombic β-PbO as identified by Raman spectroscopy. Photo-EPR studies of the sample containing β-PbO, brownish red in color, have shown intense line at g = 2.00, and its yield increased when produced in the presence of 7.5 kG external magnetic field suggesting the formation of magnetic polaron. This was identified as due to interaction between Fe 3+, photoinduced Pb 3+ and unpaired electron trapped at oxygen vacancies. The photoinduced growth and decay of magnetic polaron has shown a non-exponential behavior. Photoluminescence (PL) studies were conducted with excitation at 308 nm (XeCl laser) and also at 454.5, 488 and 514.5 nm using Ar + laser. The excitation with 308 nm gave broad PL centered at 500 and 710 nm the latter being quite prominent in β-PbO containing crystals, along with cooperative luminescence at 350 nm involving two emitting centers. The excitation with Ar + laser lines, close to the electronic absorption in samples containing β-PbO gave richer and sharp PL emission in red region from the constituents of the magnetic polaron and also intense anti-Stokes emission on excitation with 514.5 nm radiation. This appears to be due to phototransfer optically stimulated luminescence (PT-OSL) involving electron-hole recombination at photoinduced magnetic polaron site.

  5. Design of compact Marx module with square pulse output.

    PubMed

    Liu, Hongwei; Xie, Weiping; Yuan, Jianqiang; Wang, Lingyun; Ma, Xun; Jiang, Ping

    2016-07-01

    Compact pulsed power system based on compact Marx generator is widely used in terms of drive resistance and capacitive loads. This system usually adopts high performance components such as high energy density capacitors, compact switches, and integrated structure. Traditional compact Marx generator can only output double-exponential pulse profile. In this paper a compact, low-impedance Marx module which can output rectangular pulse profile is design and tested. This module has multiple circuits of different discharge frequencies in parallel to generate quasi-rectangular pulse. Discharge characteristic of an ideal module with infinite branches is calculated theoretically. A module with two branches has been designed and tested. Test results show that the impedance of the module is 1.2 Ω. When charging voltage is 100.6 kV and load resistance is 1 Ω, the peak output pulse is 45.2 kV voltage, the peak power is about 2 GW, the pulse width is about 130 ns, and the rise time is about 35 ns. The energy density and power density of the module are 15 kJ/m(3) and 140 GW/m(3), respectively. PMID:27475580

  6. Design of compact Marx module with square pulse output

    NASA Astrophysics Data System (ADS)

    Liu, Hongwei; Xie, Weiping; Yuan, Jianqiang; Wang, Lingyun; Ma, Xun; Jiang, Ping

    2016-07-01

    Compact pulsed power system based on compact Marx generator is widely used in terms of drive resistance and capacitive loads. This system usually adopts high performance components such as high energy density capacitors, compact switches, and integrated structure. Traditional compact Marx generator can only output double-exponential pulse profile. In this paper a compact, low-impedance Marx module which can output rectangular pulse profile is design and tested. This module has multiple circuits of different discharge frequencies in parallel to generate quasi-rectangular pulse. Discharge characteristic of an ideal module with infinite branches is calculated theoretically. A module with two branches has been designed and tested. Test results show that the impedance of the module is 1.2 Ω. When charging voltage is 100.6 kV and load resistance is 1 Ω, the peak output pulse is 45.2 kV voltage, the peak power is about 2 GW, the pulse width is about 130 ns, and the rise time is about 35 ns. The energy density and power density of the module are 15 kJ/m3 and 140 GW/m3, respectively.

  7. Compact narrow linewidth semiconductor laser module

    NASA Astrophysics Data System (ADS)

    Poulin, M.; Ayotte, S.; Latrasse, C.; Painchaud, Y.; Cliche, J. F.; Babin, A.; Aubé, M.; Picard, M.; Costin, F.; Têtu, M.; Lafrance, G.

    2009-05-01

    Frequency noise reduction of semiconductor lasers using electrical feedback from an optical frequency discriminator is an efficient and simple approach to realize narrow linewidth lasers. These lasers are of great interest for applications such as LIDAR, RF photonics and interferometric sensing. In this paper, we review the technological choices made by TeraXion for the realization of its Narrow Linewidth Laser modules. The method enables to decrease the linewidth of DFB lasers from several hundreds of kHz to a few kHz. We present the work in progress to integrate such system into a miniature package and to incorporate advanced functionalities such as multi-laser phase locking.

  8. Mechanical compaction directly modulates the dynamics of bile canaliculi formation.

    PubMed

    Wang, Yan; Toh, Yi-Chin; Li, Qiushi; Nugraha, Bramasta; Zheng, Baixue; Lu, Thong Beng; Gao, Yi; Ng, Mary Mah Lee; Yu, Hanry

    2013-02-01

    Homeostatic pressure-driven compaction is a ubiquitous mechanical force in multicellular organisms and is proposed to be important in the maintenance of multicellular tissue integrity and function. Previous cell-free biochemical models have demonstrated that there are cross-talks between compaction forces and tissue structural functions, such as cell-cell adhesion. However, its involvement in physiological tissue function has yet to be directly demonstrated. Here, we use the bile canaliculus (BC) as a physiological example of a multicellular functional structure in the liver, and employ a novel 3D microfluidic hepatocyte culture system to provide an unprecedented opportunity to experimentally modulate the compaction states of primary hepatocyte aggregates in a 3D physiological-mimicking environment. Mechanical compaction alters the physical attributes of the hepatocyte aggregates, including cell shape, cell packing density and cell-cell contact area, but does not impair the hepatocytes' remodeling and functional capabilities. Characterization of structural and functional polarity shows that BC formation in compact hepatocyte aggregates is accelerated to as early as 12 hours post-seeding; whereas non-compact control requires 48 hours for functional BC formation. Further dynamic immunofluorescence imaging and gene expression profiling reveal that compaction accelerated BC formation is accompanied by changes in actin cytoskeleton remodeling dynamics and transcriptional levels of hepatic nuclear factor 4α and Annexin A2. Our report not only provides a novel strategy of modeling BC formation for in vitro hepatology research, but also shows a first instance that homeostatic pressure-driven compaction force is directly coupled to the higher-order multicellular functions. PMID:23233209

  9. Compact multiwavelength transmitter module for multimode fiber optic ribbon cable

    DOEpatents

    Deri, Robert J.; Pocha, Michael D.; Larson, Michael C.; Garrett, Henry E.

    2002-01-01

    A compact multiwavelength transmitter module for multimode fiber optic ribbon cable, which couples light from an M.times.N array of emitters onto N fibers, where the M wavelength may be distributed across two or more vertical-cavity surface-emitting laser (VCSEL) chips, and combining emitters and multiplexer into a compact package that is compatible with placement on a printed circuit board. A key feature is bringing together two emitter arrays fabricated on different substrates--each array designed for a different wavelength--into close physical proximity. Another key feature is to compactly and efficiently combine the light from two or more clusters of optical emitters, each in a different wavelength band, into a fiber ribbon.

  10. Compaction Behavior of Granular Materials

    NASA Astrophysics Data System (ADS)

    Endicott, Mark R.; Kenkre, V. M.; Glass, S. Jill; Hurd, Alan J.

    1996-03-01

    We report the results of our recent study of compaction of granular materials. A theoretical model is developed for the description of the compaction of granular materials exemplified by granulated ceramic powders. Its predictions are compared to observations of uniaxial compaction tests of ceramic granules of PMN-PT, spray dried alumina and rutile. The theoretical model employs a volume-based statistical mechanics treatment and an activation analogy. Results of a computer simulation of random packing of discs in two dimensions are also reported. The effect of type of particle size distribution and other parameters of that distribution on the calculated quantities are discussed. We examine the implications of the results of the simulation for the theoretical model.

  11. Compact, maintainable 80-KeV neutral beam module

    DOEpatents

    Fink, Joel H.; Molvik, Arthur W.

    1980-01-01

    A compact, maintainable 80-keV arc chamber, extractor module for a neutral beam system immersed in a vacuum of <10.sup.-2 Torr, incorporating a nested 60-keV gradient shield located midway between the high voltage ion source and surrounding grounded frame. The shield reduces breakdown or arcing path length without increasing the voltage gradient, tends to keep electric fields normal to conducting surfaces rather than skewed and reduces the peak electric field around irregularities on the 80-keV electrodes. The arc chamber or ion source is mounted separately from the extractor or ion accelerator to reduce misalignment of the accelerator and to permit separate maintenance to be performed on these systems. The separate mounting of the ion source provides for maintaining same without removing the ion accelerator.

  12. Compact pulse width modulation circuitry for silicon photomultiplier readout.

    PubMed

    Bieniosek, M F; Olcott, P D; Levin, C S

    2013-08-01

    The adoption of solid-state photodetectors for positron emission tomography (PET) system design and the interest in 3D interaction information from PET detectors has lead to an increasing number of readout channels in PET systems. To handle these additional readout channels, PET readout electronics should be simplified to reduce the power consumption, cost, and size of the electronics for a single channel. Pulse-width modulation (PWM), where detector pulses are converted to digital pulses with width proportional to the detected photon energy, promises to simplify PET readout by converting the signals to digital form at the beginning of the processing chain, and allowing a single time-to-digital converter to perform the data acquisition for many channels rather than routing many analogue channels and digitizing in the back end. Integrator based PWM systems, also known as charge-to-time converters (QTCs), are especially compact, reducing the front-end electronics to an op-amp integrator with a resistor discharge, and a comparator. QTCs, however, have a long dead-time during which dark count noise is integrated, reducing the output signal-to-noise ratio. This work presents a QTC based PWM circuit with a gated integrator that shows performance improvements over existing QTC based PWM. By opening and closing an analogue switch on the input of the integrator, the circuit can be controlled to integrate only the portions of the signal with a high signal-to-noise ratio. It also allows for multiplexing different detectors into the same PWM circuit while avoiding uncorrelated noise propagation between photodetector channels. Four gated integrator PWM circuits were built to readout the spatial channels of two position sensitive solid-state photomultiplier (PS-SSPM). Results show a 4 × 4 array 0.9 mm × 0.9 mm × 15 mm of LYSO crystals being identified on the 5 mm × 5 mm PS-SSPM at room temperature with no degradation for twofold multiplexing. In principle, much larger

  13. Compact Pulse Width Modulation Circuitry for Silicon Photomultiplier Readout

    PubMed Central

    Bieniosek, M F; Olcott, P D; Levin, C S

    2013-01-01

    The adoption of solid state photo-detectors for positron emission tomography (PET) system design and the interest in 3D interaction information from PET detectors has lead to an increasing number of readout channels in PET systems. To handle these additional readout channels, PET readout electronics should be simplified to reduce the power consumption, cost, and size of the electronics for a single channel. Pulse width modulation (PWM), where detector pulses are converted to digital pulses with width proportional to the detected photon energy, promises to simplify PET readout by converting the signals to digital form at the beginning of the processing chain, and allowing a single time-to-digital converter to perform the data acquisition for many channels rather than routing many analog channels and digitizing in the back end. Integrator based PWM systems, also known as charge-to-time converters (QTC), are especially compact, reducing the front-end electronics to an op-amp integrator with a resistor discharge, and a comparator. QTCs, however, have a long dead-time during which dark count noise is integrated, reducing the output signal to noise ratio. This work presents a QTC based PWM circuit with a gated integrator that shows performance improvements over existing QTC based PWM. By opening and closing an analog switch on the input of the integrator, the circuit can be controlled to integrate only the portions of the signal with a high signal-to-noise ratio. It also allows for multiplexing different detectors into the same PWM circuit while avoiding uncorrelated noise propagation between photodetector channels. Four gated integrator PWM circuits were built to readout the spatial channels of two position sensitive solid state photomultiplier (PS-SSPM). Results show a 4×4 array 0.9mm×0.9mm×15mm of LYSO crystals being identified on the 5mm×5mm PS-SSPM at room temperature with no degradation for 2-fold multiplexing. In principle, much larger multiplexing ratios are

  14. Compact pulse width modulation circuitry for silicon photomultiplier readout

    NASA Astrophysics Data System (ADS)

    Bieniosek, M. F.; Olcott, P. D.; Levin, C. S.

    2013-08-01

    The adoption of solid-state photodetectors for positron emission tomography (PET) system design and the interest in 3D interaction information from PET detectors has lead to an increasing number of readout channels in PET systems. To handle these additional readout channels, PET readout electronics should be simplified to reduce the power consumption, cost, and size of the electronics for a single channel. Pulse-width modulation (PWM), where detector pulses are converted to digital pulses with width proportional to the detected photon energy, promises to simplify PET readout by converting the signals to digital form at the beginning of the processing chain, and allowing a single time-to-digital converter to perform the data acquisition for many channels rather than routing many analogue channels and digitizing in the back end. Integrator based PWM systems, also known as charge-to-time converters (QTCs), are especially compact, reducing the front-end electronics to an op-amp integrator with a resistor discharge, and a comparator. QTCs, however, have a long dead-time during which dark count noise is integrated, reducing the output signal-to-noise ratio. This work presents a QTC based PWM circuit with a gated integrator that shows performance improvements over existing QTC based PWM. By opening and closing an analogue switch on the input of the integrator, the circuit can be controlled to integrate only the portions of the signal with a high signal-to-noise ratio. It also allows for multiplexing different detectors into the same PWM circuit while avoiding uncorrelated noise propagation between photodetector channels. Four gated integrator PWM circuits were built to readout the spatial channels of two position sensitive solid-state photomultiplier (PS-SSPM). Results show a 4 × 4 array 0.9 mm × 0.9 mm × 15 mm of LYSO crystals being identified on the 5 mm × 5 mm PS-SSPM at room temperature with no degradation for twofold multiplexing. In principle, much larger

  15. Compact Multimedia Systems in Multi-chip Module Technology

    NASA Technical Reports Server (NTRS)

    Fang, Wai-Chi; Alkalaj, Leon

    1995-01-01

    This tutorial paper shows advanced multimedia system designs based on multi-chip module (MCM) technologies that provide essential computing, compression, communication, and storage capabilities for various large scale information highway applications.!.

  16. Compact, Miniature MMIC Receiver Modules for an MMIC Array Spectrograph

    NASA Technical Reports Server (NTRS)

    Kangaslahti, Pekka P.; Gaier, Todd C.; Cooperrider, Joelle T.; Samoska, Lorene A.; Soria, Mary M.; ODwyer, Ian J.; Weinreb, Sander; Custodero, Brian; Owen, Heahter; Grainge, Keith; Church, Sarah; Lai, Richard; Mei, Xiaobing

    2009-01-01

    A single-pixel prototype of a W-band detector module with a digital back-end was developed to serve as a building block for large focal-plane arrays of monolithic millimeter-wave integrated circuit (MMIC) detectors. The module uses low-noise amplifiers, diode-based mixers, and a WR10 waveguide input with a coaxial local oscillator. State-of-the-art InP HEMT (high electron mobility transistor) MMIC amplifiers at the front end provide approximately 40 dB of gain. The measured noise temperature of the module, at an ambient temperature of 300 K, was found to be as low as 450 K at 95 GHz. The modules will be used to develop multiple instruments for astrophysics radio telescopes, both on the ground and in space. The prototype is being used by Stanford University to characterize noise performance at cryogenic temperatures. The goal is to achieve a 30-50 K noise temperature around 90 GHz when cooled to a 20 K ambient temperature. Further developments include characterization of the IF in-phase (I) and quadrature (Q) signals as a function of frequency to check amplitude and phase; replacing the InP low-noise amplifiers with state-of-the-art 35-nm-gate-length NGC low-noise amplifiers; interfacing the front-end module with a digital back-end spectrometer; and developing a scheme for local oscillator and IF distribution in a future array. While this MMIC is being developed for use in radio astronomy, it has the potential for use in other industries. Applications include automotive radar (both transmitters and receivers), communication links, radar systems for collision avoidance, production monitors, ground-penetrating sensors, and wireless personal networks.

  17. Compact 40 Gbit/s EML Module Integrated with Driver IC

    NASA Astrophysics Data System (ADS)

    Yagisawa, Takatoshi; Ikeuchi, Tadashi

    A compact (13.3 × 8.0 × 5.6mm) 40Gbit/s 1.55-µm electroabsorption (EA) modulator monolithically integrated distributed feedback (DFB) laser diode (EML) [1] module integrated with a driver IC has been developed. Its compactness was realized by employing a broadband feed-through and a bias tee which were accurately designed by 3-dimensional (3D) electromagnetic simulation. It was confirmed that the simulation results of the frequency response and the actual measurement results are corresponding well. Clear eye opening of the 40Gbit/s optical output waveform of the fabricated EML module was observed. Degradation was not observed even when the 40Gbit/s electrical signal was launched into the module via the flexible printed circuit (FPC).

  18. Compact frequency-modulation Q-switched single-frequency fiber laser at 1083 nm

    NASA Astrophysics Data System (ADS)

    Zhang, Yuanfei; Feng, Zhouming; Xu, Shanhui; Mo, Shupei; Yang, Changsheng; Li, Can; Gan, Jiulin; Chen, Dongdan; Yang, Zhongmin

    2015-12-01

    A compact frequency-modulation Q-switched single-frequency fiber laser is demonstrated at 1083 nm. The short linear resonant cavity consists of a 12 mm long homemade Yb3+-doped phosphate fiber and a pair of fiber Bragg gratings (FBGs) in which the Q-switching and the frequency excursion is achieved by a tensile-induced period modulation. Over 375 MHz frequency-tuning range is achieved with a modulation frequency varying from tens to hundreds of kilohertz. The highest peak power of the output pulse reaching 6.93 W at the repetition rate of 10 kHz is obtained.

  19. A Compact Dual-Crystal Modulated Birefringence-Measurement System for Microgravity Applications

    NASA Technical Reports Server (NTRS)

    Mackey, Jeffrey R.; Das, Kamal K.; Anna, Shelley L.; McKinley, Gareth H.

    1999-01-01

    A compact modulated birefringence-measurement system has been developed for use in microgravity fluid physics applications with non-Newtonian fluids such as polymer solutions. This instrument uses a dual-crystal transverse electro-optical modulator capable of modulation frequencies in excess of 100 MHz. The two crystals are modulated 180 deg. out of phase from each other, The theoretical framework governing the development of this instrument using the Mueller-Stokes polarization matrices is discussed. Several ground-based experiments are performed to compare this system with the theoretical results. Results from this transverse electro-optical modulator-based birefringence-measurement system agree well with the theory. The instrument is also very stable and robust, making it suitable for the extreme acceleration environment to be encountered in a NASA Black Brandt sounding rocket.

  20. Design of Hybrid Lens for Compact Camera Module Considering Diffraction Effect

    NASA Astrophysics Data System (ADS)

    Choi, Hyun; Yoon, Yong-Joong; Kim, Byungwook; Lee, Sang-Hyuck; Kim, Wan-Chin; Park, No-Cheol; Park, Young-Pil; Kang, Shinill

    2008-08-01

    We introduce the design method of a hybrid lens composed a refractive lens and a diffractive optical element (DOE) considering the diffraction effect for a compact camera module. When imaging optical system is designed using the DOE, diffraction efficiency of the DOE and stray light due to the unintended diffraction light should be considered. Therefore, to analyze the effect of diffraction efficiency of the DOE on image characteristics, we evaluate the performances of two designed compact camera lenses, which have different construction wavelengths, using the modulation transfer function (MTF) considering diffraction efficiency. The stray light that is induced by the diffraction effect of the DOE is analyzed by calculating the focal position according to each diffraction order, and a method for the reduction of the stray light is proposed.

  1. A compact high power pulsed modulator based on spiral Blumlein line.

    PubMed

    Liu, Jinliang; Yin, Yi; Ge, Bin; Cheng, Xinbing; Feng, Jiahuai; Zhang, Jiande; Wang, Xinxin

    2007-10-01

    A compact high power pulsed modulator based on spiral water Blumlein line, which consists of primary storage capacitors, a Tesla transformer, a spiral Blumlein line of water dielectric, and a field-emission diode, is described. The experimental results showed that the diode voltage is more than 500 kV, the electron beam current of diode is about 32 kA, and the pulse duration is about 180 ns. The distributions for electrical field in the spiral water Blumlein line were obtained by the simulations. In addition, the process of the charging a spiral Blumlein line was simulated through the PSPICE software to get the wave form of charging voltage of pulse forming line, the diode voltage, and diode current of modulator. The theoretical and simulated results are in agreement. This accelerator is very compact and works stably and reliably. PMID:17979411

  2. Modulation of a chirp gravitational wave from a compact binary due to gravitational lensing

    SciTech Connect

    Yamamoto, Kazuhiro

    2005-05-15

    A possible wave effect in the gravitational lensing phenomenon is discussed. We consider the interference of two coherent gravitational waves of slightly different frequencies from a compact binary, due to the gravitational lensing by a galaxy halo. This system shows the modulation of the wave amplitude. The lensing probability of such the phenomenon is of order 10{sup -5} for a high-z source, but it may be advantageous to the observation due to the magnification of the amplitude.

  3. A compact frequency domain fluorometer with a directly modulated deuterium light source

    NASA Astrophysics Data System (ADS)

    Morgan, C. G.; Hua, Y.; Mitchell, A. K.; Murray, J. G.; Boardman, A. D.

    1996-01-01

    A phase fluorometer based on a low-cost and versatile high-frequency modulated light source and a fast gain-modulated photomultiplier is described. The apparatus is particularly well-suited to high-sensitivity frequency-domain fluorescence measurements requiring ultraviolet excitation. The system is very compact since it features a directly modulated light source, a miniature photomultiplier tube, and an rf synthesizer on a PC board. Equipped with a suitable fiber optic probe sensor, the device has potential as a portable unit for a wide range of remote sensing applications. The lamp can be modulated at frequencies up to 120 MHz and the phase fluorometer has been tested at up to 70 MHz with a range of fluorescent lifetime standards containing quinine sulfate quenched with sodium chloride.

  4. Compact Dielectric Wall Accelerator Development For Intensity Modulated Proton Therapy And Homeland Security Applications

    SciTech Connect

    Chen, Y -; Caporaso, G J; Guethlein, G; Sampayan, S; Akana, G; Anaya, R; Blackfield, D; Cook, E; Falabella, S; Gower, E; Harris, J; Hawkins, S; Hickman, B; Holmes, C; Horner, A; Nelson, S; Paul, A; Pearson, D; Poole, B; Richardson, R; Sanders, D; Stanley, J; Sullivan, J; Wang, L; Watson, J; Weir, J

    2009-06-17

    Compact dielectric wall (DWA) accelerator technology is being developed at the Lawrence Livermore National Laboratory. The DWA accelerator uses fast switched high voltage transmission lines to generate pulsed electric fields on the inside of a high gradient insulating (HGI) acceleration tube. Its high electric field gradients are achieved by the use of alternating insulators and conductors and short pulse times. The DWA concept can be applied to accelerate charge particle beams with any charge to mass ratio and energy. Based on the DWA system, a novel compact proton therapy accelerator is being developed. This proton therapy system will produce individual pulses that can be varied in intensity, energy and spot width. The system will be capable of being sited in a conventional linac vault and provide intensity modulated rotational therapy. The status of the developmental new technologies that make the compact system possible will be reviewed. These include, high gradient vacuum insulators, solid dielectric materials, SiC photoconductive switches and compact proton sources. Applications of the DWA accelerator to problems in homeland security will also be discussed.

  5. A compact roller-gear pitch-yaw joint module: Design and control issues

    NASA Technical Reports Server (NTRS)

    Dohring, Mark E.; Anderson, William J.; Newman, Wyatt S.; Rohn, Douglas A.

    1993-01-01

    Robotic systems have been proposed as a means of accomplishing assembly and maintenance tasks in space. The desirable characteristics of these systems include compact size, low mass, high load capacity, and programmable compliance to improve assembly performance. In addition, the mechanical system must transmit power in such a way as to allow high performance control of the system. Efficiency, linearity, low backlash, low torque ripple, and low friction are all desirable characteristics. This work presents a pitch-yaw joint module designed and built to address these issues. Its effectiveness as a two degree-of-freedom manipulator using natural admittance control, a method of force control, is demonstrated.

  6. Performance characteristics of a compact position-sensitive LSO detector module.

    PubMed

    Vaquero, J J; Seidel, J; Siegel, S; Gandler, W R; Green, M V

    1998-12-01

    We assembled a compact detector module comprised of an array of small, individual crystals of lutetium oxyorthosilicate:Ce (LSO) coupled directly to a miniature, metal-can, position-sensitive photomultiplier tube (PSPMT). We exposed this module to sources of 511-keV annihilation radiation and beams of 30- and 140-keV photons and measured spatial linearity; spatial variations in module gain, energy resolution, and event positioning; coincidence timing; the accuracy and sensitivity of identifying the crystal-of-first-interaction at 511 keV; and the effects of intercrystal scatter and LSO background radioactivity. The results suggest that this scintillator/phototube combination should be highly effective in the coincidence mode and can be used, with some limitations, to image relatively low-energy single photon emitters. Photons that are completely absorbed on their first interaction at 511 keV are positioned by the module at the center of a crystal. Intercrystal scatter events, even those that lead to total absorption of the incident photon, are placed by the module in a regular "connect-the-dot" pattern that joins crystal centers. As a result, the accuracy of event positioning can be made to exceed 90%, though at significantly reduced sensitivity, by retaining only events that occur within small regions-of-interest around each crystal center and rejecting events that occur outside these regions in the connect-the-dot pattern. PMID:10048853

  7. Ultrafast compact silicon-based ring resonator modulators using metal-insulator switching of vanadium dioxide

    NASA Astrophysics Data System (ADS)

    Nag, Joyeeta; Ryckman, Judson D.; Hertkorn, Michael T.; Choi, Bo K.; Haglund, Richard F., Jr.; Weiss, Sharon M.

    2010-02-01

    We present an optical modulator based on a silicon ring resonator coated with vanadium-dioxide (VO2) motivated by the need for compact silicon-compatible optical switches operating at THz speeds. VO2 is a functional oxide undergoing metal-insulator transition (MIT) near 67°C, with huge changes in electrical resistivity and near-infrared transmission. The MIT can be induced thermally, optically (by ultra-fast laser excitation in less than 100 fs), and possibly with electric field. VO2 is easily deposited on silicon and its ultrafast switching properties in the near-infrared can be used to tune the effective index of ring resonators in the telecommunication frequencies instead of depending on the weak electro-optic properties of silicon. The VO2-silicon hybrid ring resonator is expected to operate at speeds up to 10 THz at low Q-factor and with shorter cavity lifetimes, thus enabling compact, faster, more robust devices. We have made ring resonator structures on SOI substrates with rings varying in diameter from 3-10 μm coupled to 5 mm-long nanotapered waveguides at separations of 200 nm. Rings were coated with 80 nm of VO2 by pulsed laser deposition. As proof-of-concept, by switching the VO2 top layer thermally, we were able to modulate the resonance frequency of the ring to match with the predictions from our FDTD simulations.

  8. Compact electro-absorption modulator integrated with vertical-cavity surface-emitting laser for highly efficient millimeter-wave modulation

    SciTech Connect

    Dalir, Hamed; Ahmed, Moustafa; Bakry, Ahmed; Koyama, Fumio

    2014-08-25

    We demonstrate a compact electro-absorption slow-light modulator laterally-integrated with an 850 nm vertical-cavity surface-emitting laser (VCSEL), which enables highly efficient millimeter-wave modulation. We found a strong leaky travelling wave in the lateral direction between the two cavities via widening the waveguide width with a taper shape. The small signal response of the fabricated device shows a large enhancement of over 55 dB in the modulation amplitude at frequencies beyond 35 GHz; thanks to the photon-photon resonance. A large group index of over 150 in a Bragg reflector waveguide enables the resonance at millimeter wave frequencies for 25 μm long compact modulator. Based on the modeling, we expect a resonant modulation at a higher frequency of 70 GHz. The resonant modulation in a compact slow-light modulator plays a significant key role for high efficient narrow-band modulation in the millimeter wave range far beyond the intrinsic modulation bandwidth of VCSELs.

  9. The Central Portion of Factor H (Modules 10–15) Is Compact and Contains a Structurally Deviant CCP Module

    PubMed Central

    Schmidt, Christoph Q.; Herbert, Andrew P.; Mertens, Haydyn D.T.; Guariento, Mara; Soares, Dinesh C.; Uhrin, Dusan; Rowe, Arthur J.; Svergun, Dmitri I.; Barlow, Paul N.

    2010-01-01

    The first eight and the last two of 20 complement control protein (CCP) modules within complement factor H (fH) encompass binding sites for C3b and polyanionic carbohydrates. These binding sites cooperate self-surface selectively to prevent C3b amplification, thus minimising complement-mediated damage to host. Intervening fH CCPs, apparently devoid of such recognition sites, are proposed to play a structural role. One suggestion is that the generally small CCPs 10–15, connected by longer-than-average linkers, act as a flexible tether between the two functional ends of fH; another is that the long linkers induce a 180° bend in the middle of fH. To test these hypotheses, we determined the NMR-derived structure of fH12–13 consisting of module 12, shown here to have an archetypal CCP structure, and module 13, which is uniquely short and features a laterally protruding helix-like insertion that contributes to a prominent electropositive patch. The unusually long fH12–13 linker is not flexible. It packs between the two CCPs that are not folded back on each other but form a shallow vee shape; analytical ultracentrifugation and X-ray scattering supported this finding. These two techniques additionally indicate that flanking modules (within fH11–14 and fH10–15) are at least as rigid and tilted relative to neighbours as are CCPs 12 and 13 with respect to one another. Tilts between successive modules are not unidirectional; their principal axes trace a zigzag path. In one of two arrangements for CCPs 10–15 that fit well with scattering data, CCP 14 is folded back onto CCP 13. In conclusion, fH10–15 forms neither a flexible tether nor a smooth bend. Rather, it is compact and has embedded within it a CCP module (CCP 13) that appears to be highly specialised given both its deviant structure and its striking surface charge distribution. A passive, purely structural role for this central portion of fH is unlikely. PMID:19835885

  10. A phase-modulated laser system of ultra-low phase noise for compact atom interferometers

    NASA Astrophysics Data System (ADS)

    Lee, Ki-Se; Kim, Jaewan; Lee, Sang-Bum; Park, Sang Eon; Kwon, Taek Yong

    2015-07-01

    A compact and robust laser system is essential for mobile atom interferometers. Phase modulation can provide the two necessary phase-coherent frequencies without sophisticated phase-locking between two different lasers. However, the additional laser frequencies generated can perturb the atom interferometer. In this article, we report on a novel method to produce a single high-power laser beam composed of two phase-coherent sidebands without the perturbing carrier mode. Light from a diode laser is phase-modulated by using a fiber-coupled electro-optic modulator driven at 3.4 GHz and passes through a Fabry-Perot cavity with a 6.8 GHz free spectral range. The cavity filters the carrier mode to leave the two first-order sidebands for the two-photon Raman transition between the two hyperfine ground states of 87Rb. The laser beam is then fed to a single tapered amplifier, and the two sidebands are both amplified without mode competition. The phase noise is lower than that of a state-of-the-art optically phase-locked external-cavity diode laser (-135 dBrad2/Hz at 10 kHz) at frequencies above 10 Hz. This technique can be used in all-fiber-based laser systems for future mobile atom interferometers.

  11. High-detection efficiency and picosecond timing compact detector modules with red-enhanced SPADs

    NASA Astrophysics Data System (ADS)

    Giudice, Andrea; Simmerle, Georg; Veronese, Daniele; Biasi, Roberto; Gulinatti, Angelo; Rech, Ivan; Ghioni, Massimo; Maccagnani, Piera

    2012-06-01

    In the last years many progresses have been made in the field of silicon Single Photon Avalanche Diodes (SPAD) thanks to the improvements both in device design and in fabrication technology. Particularly, the Dipartimento di Elettronica e Informazione of Politecnico di Milano and the CNR-IMM of Bologna have been in the forefront of this research activity by designing and fabricating a new device structure enabling the fabrication of SPADs with red enhanced photon detection efficiency. In this paper we present a compact photon counting and timing module that fills the gap between the high temporal resolution and the high detection efficiency systems. The module exploits Red-Enhanced SPAD technology to attain a Photon Detection Efficiency (PDE) as high as 37% at 800 nm (peak of 58% at 600 nm) while maintaining a temporal resolution of about 100 ps FWHM, even with light diffused across the whole active area. A thermo-electric cooling system guarantees a noise as low as few counts per second for a 50 μm diameter SPAD while a low threshold avalanche pick-up circuit assures a limited shift in the temporal response.

  12. Design and development of detector modules for a highly compact and portable preclinical PET system

    NASA Astrophysics Data System (ADS)

    ur-Rehman, Fazal

    Preclinical PET systems image animal models of chronic human disease that are used to evaluate new therapeutic strategies for the treatment of cancer and other diseases. Once these animals are out of a controlled environment for PET imaging, they typically can not be taken back as they may have been exposed to outside disease. A highly compact PET system is thus required to be developed that can operate within a bio-safety cabinet inside a barrier facility. We investigated using 100-mm-long LYSO scintillator crystals oriented in the axial direction and read out at both ends by position sensitive photomultiplier tubes (PSPMTs) to construct a compact PET. The optimization of light collection for axial encoding of events was carried out using different reflector materials and surface treatments of 3 x 2 x 100 mm3 and 2 x 2 x 100 mm3 polished crystals. The detector response was examined by irradiating the crystals at discrete positions using an electronically collimated 511 keV photon beam. The ratio of two PSPMT signals was used to find the axial-resolution while their sum was used to determine the energy resolution. We then explored the effects of creating systematic band patterns of surface roughing on 1 to 4 long surfaces of the crystals to modulate light-transport with the goal of further improving axial-resolution. These experimental results were used to benchmark DETECT2000 Monte Carlo simulations for our detector geometry. The axial-positioning calibration was carried out by evaluating a uniform flood-irradiation method and comparing with the collimated-irradiation method using 2 x 2 x 100 mm3 crystal detectors. The best axial-positioning resolution of 3.4 mm was achieved in this study for 2 x 2 x 100 mm3 Teflon-wrapped crystals with banding-patterns on only two opposite surfaces, fulfilling the design criteria of our proposed PET. The benchmarked DETECT2000 models can now be used to predict the performance of a complete detector module design. The calibration

  13. Design of a Compact, Portable Test System for Thermoelectric Power Generator Modules

    NASA Astrophysics Data System (ADS)

    Faraji, Amir Yadollah; Akbarzadeh, Aliakbar

    2013-07-01

    Measurement of fundamental parameters of a thermoelectric generator (TEG) module, including efficiency, internal electrical resistance, thermal resistance, power output, Seebeck coefficient, and figure of merit ( Z), is necessary in order to design a thermoelectric-based power generation system. This paper presents a new design for a compact, standalone, portable test system that enables measurement of the main parameters of a TEG over a wide range of temperature differences and compression pressures for a 40 mm × 40 mm specimen. The Seebeck coefficient and figure of merit can also be calculated from the information obtained. In the proposed system, the temperature of each side of the TEG can be set at the desired temperature—the hot side as high as 380°C and the cold side as low as 5°C, with 0.5°C accuracy—utilizing an electrical heating system and a thermoelectric-based compact chilling system. Heating and cooling procedures are under control of two proportional-integral-derivative (PID) temperature controllers. Using a monitored pressure mechanism, the TEG specimen is compressed between a pair of hot and cold aluminum cubes, which maintain the temperature difference across the two sides of the TEG. The compressive load can be varied from 0 kPa to 800 kPa. External electrical loading is applied in the form of a direct-current (DC) electronic load. Data collection and processing are through an Agilent 34972A data logger, a computer, and BenchLink software, with results available as computer output. The input power comes from a 240-V general-purpose power point, and the only sound-generating component is a 4-W cooling fan. Total calculated uncertainty in results is approximately 7%. Comparison between experimental data and the manufacturer's published datasheet for a commercially available specimen shows good agreement. These results obtained from a preliminary experimental setup serve as a good guide for the design of a fully automatic portable test system

  14. Compact high voltage, high peak power, high frequency transformer for converter type modulator applications

    NASA Astrophysics Data System (ADS)

    Reghu, T.; Mandloi, V.; Shrivastava, Purushottam

    2016-04-01

    The design and development of a compact high voltage, high peak power, high frequency transformer for a converter type modulator of klystron amplifiers is presented. The transformer has been designed to operate at a frequency of 20 kHz and at a flux swing of ±0.6 T. Iron (Fe) based nanocrystalline material has been selected as a core for the construction of the transformer. The transformer employs a specially designed solid Teflon bobbin having 120 kV insulation for winding the high voltage secondary windings. The flux swing of the core has been experimentally found by plotting the hysteresis loop at actual operating conditions. Based on the design, a prototype transformer has been built which is per se a unique combination of high voltage, high frequency, and peak power specifications. The transformer was able to provide 58 kV (pk-pk) at the secondary with a peak power handling capability of 700 kVA. The transformation ratio was 1:17. The performance of the transformer is also presented and discussed.

  15. Compact high voltage, high peak power, high frequency transformer for converter type modulator applications.

    PubMed

    Reghu, T; Mandloi, V; Shrivastava, Purushottam

    2016-04-01

    The design and development of a compact high voltage, high peak power, high frequency transformer for a converter type modulator of klystron amplifiers is presented. The transformer has been designed to operate at a frequency of 20 kHz and at a flux swing of ±0.6 T. Iron (Fe) based nanocrystalline material has been selected as a core for the construction of the transformer. The transformer employs a specially designed solid Teflon bobbin having 120 kV insulation for winding the high voltage secondary windings. The flux swing of the core has been experimentally found by plotting the hysteresis loop at actual operating conditions. Based on the design, a prototype transformer has been built which is per se a unique combination of high voltage, high frequency, and peak power specifications. The transformer was able to provide 58 kV (pk-pk) at the secondary with a peak power handling capability of 700 kVA. The transformation ratio was 1:17. The performance of the transformer is also presented and discussed. PMID:27131709

  16. Nanodomain structures with hierarchical inhomogeneities in PMN-PT.

    PubMed

    Kurushima, Kosuke; Kobayashi, Keisuke; Mori, Shigeo

    2012-09-01

    The nanometric domain configuration of (1 - x) Pb(Mg(1/3)Nb(2/3))O(3-x)PbTiO(3) [(1 - x)PMN-xPT] single crystals in the monoclinic phase around a morphotropic phase boundary (MPB) has been examined thoroughly by means of transmission electron microscopy (TEM). Domain structures with hierarchically inhomogeneous configuration were found in the monoclinic phase near the MPB region around x ~ 0.32, which are characterized as nanoscaled lamella-type domain structures with ~10 nm width inside macroscopic-sized banded domains with 100 to 200 nm width. To elucidate formation processes of the domain structures with hierarchically inhomogeneous configuration, an in situ TEM observation of changes of the domain structures in the temperature window between 298K and 500K was carried out. It is revealed that these nanoscaled lamella-type domain structures with ~10 nm width appear inside the banded domains as a result of the tetragonal structure and are inherent to the monoclinic phase. PMID:23007758

  17. Compact electro-optic modulator on silicon-on-insulator substrates using cavities with ultra-small modal volumes

    NASA Astrophysics Data System (ADS)

    Schmidt, Bradley; Xu, Qianfan; Shakya, Jagat; Manipatruni, Sasikanth; Lipson, Michal

    2007-03-01

    We experimentally demonstrate a micron-size electro-optic modulator using a high-index-contrast silicon Fabry-Pérot resonator cavity. This compact device consists of a 1-D cavity formed within a single mode silicon channel waveguide and an embedded p-i-n junction on a silicon-oninsulator platform. The entire device is 6.0 microns in length. We demonstrate modulation depths as large as 5.87 dB at speeds of 250 Mbps limited only by fabrication imperfections, with optimized theoretical speeds of several Gbps.

  18. Compact fiber-pigtailed InGaAs photoconductive antenna module for terahertz-wave generation and detection.

    PubMed

    Han, Sang-Pil; Kim, Namje; Ko, Hyunsung; Ryu, Han-Cheol; Park, Jeong-Woo; Yoon, Young-Jong; Shin, Jun-Hwan; Lee, Dong Hun; Park, Sang-Ho; Moon, Seok-Hwan; Choi, Sung-Wook; Chun, Hyang Sook; Park, Kyung Hyun

    2012-07-30

    We propose a compact fiber-pigtailed InGaAs photoconductive antenna (FPP) module having an effective heat-dissipation solution as well as a module volume of less than 0.7 cc. The heat-dissipation of the FPP modules when using a heat-conductive printed circuit board (PCB) and an aluminium nitride (AlN) submount, without any cooling systems, improve by 40% and 85%, respectively, when compared with a photoconductive antenna chip on a conventional PCB. The AlN submount is superior to those previously reported as a heat-dissipation solution. Terahertz time-domain spectroscopy (THz-TDS) using the FPP module perfectly detects the absorption lines of water vapor in free space and an α-lactose sample. PMID:23038394

  19. Frequency and amplitude modulation of ultra-compact terahertz quantum cascade lasers using an integrated avalanche diode oscillator

    PubMed Central

    Castellano, Fabrizio; Li, Lianhe; Linfield, Edmund H.; Davies, A. Giles; Vitiello, Miriam S.

    2016-01-01

    Mode-locked comb sources operating at optical frequencies underpin applications ranging from spectroscopy and ultrafast physics, through to absolute frequency measurements and atomic clocks. Extending their operation into the terahertz frequency range would greatly benefit from the availability of compact semiconductor-based sources. However, the development of any compact mode-locked THz laser, which itself is inherently a frequency comb, has yet to be achieved without the use of an external stimulus. High-power, electrically pumped quantum cascade lasers (QCLs) have recently emerged as a promising solution, owing to their octave spanning bandwidths, the ability to achieve group-velocity dispersion compensation and the possibility of obtaining active mode-locking. Here, we propose an unprecedented compact architecture to induce both frequency and amplitude self-modulation in a THz QCL. By engineering a microwave avalanche oscillator into the laser cavity, which provides a 10 GHz self-modulation of the bias current and output power, we demonstrate multimode laser emission centered around 3 THz, with distinct multiple sidebands. The resulting microwave amplitude and frequency self-modulation of THz QCLs opens up intriguing perspectives, for engineering integrated self-mode-locked THz lasers, with impact in fields such as nano- and ultrafast photonics and optical metrology. PMID:26976199

  20. FERRITE-FREE, OIL-SWITCHED, FOUR-STAGE, HIGH-GRADIENT MODULE FOR COMPACT PULSED POWER APPLICATIONS

    SciTech Connect

    Rhodes, M A; Watson, J; Sanders, D; Sampayan, S; Caporaso, G

    2007-06-15

    We describe the design and present initial experimental results of a novel, high-gradient, compact pulsed power module. Our application focus is linear accelerators but our technology is easily applicable to a wide range of pulse-power applications. Our design incorporates and combines for the first time a number of our recently developed, enabling technologies including: a novel, bipolar pulse-forming line allowing module stacking without ferrites, very compact and fast oil filled switches, novel high-dielectric constant insulator/energy storage material, and a novel method for reducing edge enhancements in the pulse forming structure. The combination of these technologies enables us to design a very compact stackable module that will deliver high-gradient (5-10 MV/m) voltage at 5-10kA to arbitrary loads. Our prototype is comprised of four stages. Each stage is designed to operate at 300kV producing 1.2-MV into 120 Ohms. The pulse length is 25-ns and the pulse-shape is rectangular. We present initial experimental results up to 75 kV per stage with the switches operating in self-break mode.

  1. Frequency and amplitude modulation of ultra-compact terahertz quantum cascade lasers using an integrated avalanche diode oscillator

    NASA Astrophysics Data System (ADS)

    Castellano, Fabrizio; Li, Lianhe; Linfield, Edmund H.; Davies, A. Giles; Vitiello, Miriam S.

    2016-03-01

    Mode-locked comb sources operating at optical frequencies underpin applications ranging from spectroscopy and ultrafast physics, through to absolute frequency measurements and atomic clocks. Extending their operation into the terahertz frequency range would greatly benefit from the availability of compact semiconductor-based sources. However, the development of any compact mode-locked THz laser, which itself is inherently a frequency comb, has yet to be achieved without the use of an external stimulus. High-power, electrically pumped quantum cascade lasers (QCLs) have recently emerged as a promising solution, owing to their octave spanning bandwidths, the ability to achieve group-velocity dispersion compensation and the possibility of obtaining active mode-locking. Here, we propose an unprecedented compact architecture to induce both frequency and amplitude self-modulation in a THz QCL. By engineering a microwave avalanche oscillator into the laser cavity, which provides a 10 GHz self-modulation of the bias current and output power, we demonstrate multimode laser emission centered around 3 THz, with distinct multiple sidebands. The resulting microwave amplitude and frequency self-modulation of THz QCLs opens up intriguing perspectives, for engineering integrated self-mode-locked THz lasers, with impact in fields such as nano- and ultrafast photonics and optical metrology.

  2. Frequency and amplitude modulation of ultra-compact terahertz quantum cascade lasers using an integrated avalanche diode oscillator.

    PubMed

    Castellano, Fabrizio; Li, Lianhe; Linfield, Edmund H; Davies, A Giles; Vitiello, Miriam S

    2016-01-01

    Mode-locked comb sources operating at optical frequencies underpin applications ranging from spectroscopy and ultrafast physics, through to absolute frequency measurements and atomic clocks. Extending their operation into the terahertz frequency range would greatly benefit from the availability of compact semiconductor-based sources. However, the development of any compact mode-locked THz laser, which itself is inherently a frequency comb, has yet to be achieved without the use of an external stimulus. High-power, electrically pumped quantum cascade lasers (QCLs) have recently emerged as a promising solution, owing to their octave spanning bandwidths, the ability to achieve group-velocity dispersion compensation and the possibility of obtaining active mode-locking. Here, we propose an unprecedented compact architecture to induce both frequency and amplitude self-modulation in a THz QCL. By engineering a microwave avalanche oscillator into the laser cavity, which provides a 10 GHz self-modulation of the bias current and output power, we demonstrate multimode laser emission centered around 3 THz, with distinct multiple sidebands. The resulting microwave amplitude and frequency self-modulation of THz QCLs opens up intriguing perspectives, for engineering integrated self-mode-locked THz lasers, with impact in fields such as nano- and ultrafast photonics and optical metrology. PMID:26976199

  3. A comparison of pressure compaction and diametral compression tests for determining granule strengths

    SciTech Connect

    Glass, S.J.; Newton, C.

    1994-12-31

    Lightning strikes can cause structural damage, ignite flammable materials, and produce circuit malfunctions in missiles, aircraft, and ground systems. Lightning arrestor connectors (LACs) are used to divert harmful lightning energy away from these systems by providing less destructive breakdown paths. Ceramic granules in the size range of 150--200 {micro}m are used in LACs to provide physical and electrical separation of contacts (pins) from the surrounding metal web, and to control the voltage breakdown level. Pressure compaction (P-C) tests were used to characterize the strength of ceramic granules. When compaction data are plotted as relative density of the compact versus the compaction pressure two linear regions are generally observed. The intersection of these regions, which is known as the ``breakpoint,`` has been used as a semi-quantitative measure of granule strength. Comparisons were made between the P-C breakpoint and strengths of 150--200 {micro}m diameter ZnO, TiO{sub 2} (rutile), and lead magnesium niobate-lead titanate (PMN-PT) granules, where the strengths were determined by diametral compression (D-C) tests. At high compaction pressures the compliance of the die itself is significant and was accounted for in the analyses. Tests were conducted at different compaction rates, and with different aspect ratio compacts. High aspect ratios and loading rates decrease the slope of the second linear portion of the compaction curve and produce higher apparent P-C breakpoints. Comparison of the P-C breakpoint to the average D-C strength indicates that the D-C strength is approximately fifty percent higher for PMN-PT granules. To eliminate the uncertainty in results due to irregular granules sizes and shapes, comparisons were made for uniform size (210 {micro}m) glass spheres. In this case the average D-C strength coincided with a second breakpoint in the P-C data, which occurred after compaction by a mechanism of bridge formation and collapse had ceased.

  4. Application of single-crystalline PMN-PT and PIN-PMN-PT in high-performance pyroelectric detectors.

    PubMed

    Yu, Ping; Ji, Yadong; Neumann, Norbert; Lee, Sang-Goo; Luo, Hasou; Es-Souni, Mohammed

    2012-09-01

    The suitability for use in pyroelectric detectors of single-crystalline doped and undoped lead indium niobate-lead magnesium niobate-lead titanate was tested and compared with high-quality Mn-doped lead magnesium niobate-lead titanate and standard lithium tantalate. Pyroelectric and dielectric measurements confirmed an increased processing and operating temperature range because of the higher phase transitions of lead indium niobate-lead magnesium niobate-lead titanate. Pyroelectric coefficients of 705 to 770 μC/m(2)K were obtained with doped and undoped lead indium niobate-lead magnesium niobate-lead titanate, which are about 70% to 80% of the pyroelectric coefficient of lead magnesium niobate-lead titanate but 4 times higher than standard lithium tantalate. Manganese doping has been proved as a solution to decrease the dielectric loss of lead magnesium niobate-lead titanate and it also works well for lead indium niobate-lead magnesium niobate-lead titanate. An outstanding specific detectivity D* of about 1.1 · 10(9) cm·Hz(1/2)/W was achieved at a frequency of 2 Hz for Mn-doped lead magnesium niobate-based detectors. PMID:23007771

  5. Haemoglobin content modulated deformation dynamics of red blood cells on a compact disc.

    PubMed

    Kar, Shantimoy; Ghosh, Uddipta; Maiti, Tapas Kumar; Chakraborty, Suman

    2015-12-21

    We investigate the deformation characteristics of red blood cells (RBCs) on a rotating compact disc platform. Our study brings out the interplay between haemoglobin content and RBC deformability in a centrifugally actuated microfluidic environment. We reveal that RBC deformations follow the similar trend of principal stress distributed throughout the radial direction, rendering an insight into the mechano-physical processes involved. This study can be used as a diagnostic marker to determine haematological disorders in diseased blood samples tested on compact disc based microfluidic platforms. PMID:26502076

  6. Compact acousto-optic modulator operatingin the purely Raman - Nath diffraction regime as a phase modulator in FM spectroscopy

    SciTech Connect

    Baryshev, Vyacheslav N; Epikhin, V M

    2010-08-03

    We report fabrication of a new acousto-optic modulator (AOM-RN) operating purely in the Raman - Nath diffraction regime. This device can be used as an external phase modulator in frequency-modulation (FM) optical heterodyne spectroscopy for fast and broadband frequency control of diode lasers. The AOM-RN design is significantly simplified, and its dimensions are minimised due to a decrease (by almost an order of magnitude in comparison with the existing AOMs) in the acousto-optic interaction length and the absence of impedance matching circuit. The FM spectroscopy based on AOM-RN makes it possible to analyse both absorption and dispersion properties of optical resonances under study; this possibility is shown by the example of saturated-absorption resonances in cesium vapour. The possibility of detecting coherent population trapping resonances using FM spectroscopy with AOM-RN as an external phase modulator is experimentally demonstrated.

  7. Test Results of a Compact Conventional Modulator for Two-Klystron Operation

    SciTech Connect

    Gold, S

    2004-05-04

    Modulator technology has not advanced greatly over the last 30 years. Today, with the advent of the High Voltage, High Power IGBT there are several approaches for a solid state ON/OFF switched modulator. Klystron and accelerator technology is forcing voltages and peak powers higher such as the demand for 500 kV and 500 amperes peak to power two X-Band klystrons. Conventional technology (line-type modulators) were never overly concerned about rise time and efficiency. A few years ago, the klystron department at Stanford Linear Accelerator Center (SLAC) undertook an investigation into what could be done in a conventional modulator at 500 kV. We have reported on test bed measurements and shown both conceptual and hardware pictures during design and construction. We have now completed the modulator tank.

  8. A compact 7-cell Si-drift detector module for high-count rate X-ray spectroscopy

    PubMed Central

    Hansen, K.; Reckleben, C.; Diehl, I.; Klär, H.

    2015-01-01

    A new Si-drift detector module for fast X-ray spectroscopy experiments was developed and realized. The Peltier-cooled module comprises a sensor with 7 × 7-mm2 active area, an integrated circuit for amplification, shaping and detection, storage, and derandomized readout of signal pulses in parallel, and amplifiers for line driving. The compactness and hexagonal shape of the module with a wrench size of 16mm allow very short distances to the specimen and multi-module arrangements. The power dissipation is 186mW. At a shaper peaking time of 190 ns and an integration time of 450 ns an electronic rms noise of ~11 electrons was achieved. When operated at 7 °C, FWHM line widths around 260 and 460 eV (Cu-Kα) were obtained at low rates and at sum-count rates of 1.7 MHz, respectively. The peak shift is below 1% for a broad range of count rates. At 1.7-MHz sum-count rate the throughput loss amounts to 30%. PMID:26366028

  9. A compact, high-density gamma-detection module for Time-of-Flight measurements in PET applications

    NASA Astrophysics Data System (ADS)

    Sacco, I.; Dohle, R.; Fischer, P.; Piemonte, C.; Ritzert, M.

    2016-07-01

    We present a very compact γ-detection module primarily designed for PET applications. On a total area of about 30 × 30mm2, 144 SiPM photodetectors coupled to scintillator crystals are read out individually with fast timing ASICs. The core of the module is a LTCC ceramic substrate with internal water channels for efficient and stable liquid cooling. The top side of the LTCC is covered by 12×12 SiPMs in a regular pitch of 2.5 mm. The SiPMs are designed in the RGB-HD technology from FBK with a single cell size of 25 × 25 μm2, very low dark-count rate and stable performance over a wide temperature range from 0 to 20 °C. The readout of the SiPMs is done with 4 specialized PETA5 ASICs flip-chip mounted to the bottom side of the substrate. Each chip has 36 readout channels (available in single or differential ended configuration) with self-triggered hit detection, a very low noise discriminator, signal amplitude integration and digitization, a TDC with 50 ps binwidth, neighbor logic and fast veto mechanisms. The full height of the assembly, including the connector to the main readout board, is less than 1 cm. In a 1:1 coupling configuration with 10 mm high LYSO scintillator arrays for detection of 511 keV gammas, the module has already reached 205 ps CRT time resolution (FWHM in coincidence between channels on two different modules), sufficient for ToF operation in PET. The module design, details on chip operation and latest results with LYSO arrays are described.

  10. Design and integration of a compact common miniature environment-insensitive navigation module for unmanned vehicles

    NASA Astrophysics Data System (ADS)

    Dai, Gang; Su, Wei; Li, Mei

    2010-10-01

    A common miniature environment-insensitive navigation module which not only can provide the accurate position through different environment but also can easily be configured to adapt to the different type of unmanned vehicles is proposed in this paper. The module prototype is composed of a integrated MEMS inertial navigation unit using MEMS accelerometers and gyroscopes, a hard aluminum module structure with rubber isolator, a series of sensor interface of magnetometer, embedded GPS receiver, infrared sensor, vision camera, radio frequency communication etc and a FPGA based central control and navigation calculation circuit. The fabricated MEMS accelerometers and gyroscopes can resist high-g shock and have temperature drift compensation. The structure of the module uses hard aluminum with finite element analysis to find the appropriate position for sensors. All sensors without antenna are packaged in the structure with moisture, heat isolation and rubber isolator. The navigation computation scheme use the status of connected sensors to choose appropriate algorithm function to compute the navigation output. FPGA is used to be the main control and process unit of this module. Algorithms are embedded in the FPGA using the DSP core. The multiply interfaces to other sensor are implemented using the flexible configuration of the FPGA and peripheral. The conclusions are reached at last.

  11. A Compact Disk Type Plasma Propulsion System with Modulated Magnetic Field for Nanoscale Space Vehicles

    NASA Astrophysics Data System (ADS)

    Fukuda, Takeshi; Ueda, Satoshi; Ohnishi, Yukihiro; Inomoto, Michiaki

    2008-12-01

    A compact 5 mm disk type plasma thruster simply composed of only a set of antenna windings and bias field coil which produces significant thrust of 0.74 mN with rotating magnetic field has been proposed and successfully developed for future applications to low altitude nanosatellites. The key technology issue is that the rotating speed is set above the ion plasma frequency but far below the electron plasma frequency, in order to produce the electron drag current and axial electric field as a consequence of the interaction with the bias field. The formation of axial electric field was confirmed and the produced plasma density was >6×1018 m-3, whereas the power consumption is 500 W in the inductively coupled mode of operation. The anticipated thrust density and specific thrust could potentially be extended to 7.64 Nm-2 and 850 s, respectively, which is comparable to conventional Hall effect thrusters.

  12. Versatile compact X-ray radiography module for materials science under microgravity conditions

    NASA Astrophysics Data System (ADS)

    Kargl, F.; Balter, M.; Stenzel, Ch; Gruhl, Th; Daneke, N.; Meyer, A.

    2011-12-01

    A versatile compact microfocus X-ray radiography facility is presented. The facility serves as a technology demonstrator showing the applicability of X-ray radiography to experiments in space. It has been designed as an insert fully compatible with requirements of the Materials Science Laboratory aboard the International Space Station. The facility consists of a microfocus X-ray source delivering up to 20 W X-ray power at 100kV acceleration voltage and a 49.2×49.3mm RadEye2 sensor with a Scint-X scintillator at 48μm per pixel resolution with a 14bit dynamic range. The total device weight including sample chamber is 43 kg. The facility is classified as a fully protected radiography equipment according to German radiation safety laws. The capabilities of the facility for research in materials sciences are demonstrated in ground-based experiments.

  13. A Compact Disk Type Plasma Propulsion System with Modulated Magnetic Field for Nanoscale Space Vehicles

    SciTech Connect

    Fukuda, Takeshi; Ueda, Satoshi; Ohnishi, Yukihiro; Inomoto, Michiaki

    2008-12-31

    A compact 5 mm disk type plasma thruster simply composed of only a set of antenna windings and bias field coil which produces significant thrust of 0.74 mN with rotating magnetic field has been proposed and successfully developed for future applications to low altitude nanosatellites. The key technology issue is that the rotating speed is set above the ion plasma frequency but far below the electron plasma frequency, in order to produce the electron drag current and axial electric field as a consequence of the interaction with the bias field. The formation of axial electric field was confirmed and the produced plasma density was >6x10{sup 18} m{sup -3}, whereas the power consumption is 500 W in the inductively coupled mode of operation. The anticipated thrust density and specific thrust could potentially be extended to 7.64 Nm{sup -2} and 850 s, respectively, which is comparable to conventional Hall effect thrusters.

  14. Generation of second harmonic light with a wavelength of 560 nm in a compact module

    NASA Astrophysics Data System (ADS)

    Hofmann, Julian; Sahm, Alexander; John, Wilfred; Bugge, Frank; Paschke, Katrin

    2016-09-01

    We demonstrate a continuous wave 133 mW laser module at 560.5 nm on a 50 mm·10 mm optical bench. The setup consists of a 1121 nm distributed Bragg reflector ridge waveguide laser and a MgO:LiNbO3 quasi-phase matched ridge waveguide crystal, which are coupled by a grin lens, as well as two cylindrical lenses for beam collimation behind the crystal. A novel approach to ensure phase matching is used. The laser and the crystal are stabilized by the same heat sink and only the wavelength of the laser is tuned by heating the distributed Bragg reflector section of the laser. This reduces the influence of temperature variations on the module's performance enabling operation with output power variations < 10 % over a temperature range of 20 K. The size and robustness against temperature variations of this setup make it an interesting candidate for future biomedical applications.

  15. Ligand Binding Modulates the Structural Dynamics and Compactness of the Major Birch Pollen Allergen

    PubMed Central

    Grutsch, Sarina; Fuchs, Julian E.; Freier, Regina; Kofler, Stefan; Bibi, Marium; Asam, Claudia; Wallner, Michael; Ferreira, Fátima; Brandstetter, Hans; Liedl, Klaus R.; Tollinger, Martin

    2014-01-01

    Pathogenesis-related plant proteins of class-10 (PR-10) are essential for storage and transport of small molecules. A prominent member of the PR-10 family, the major birch pollen allergen Bet v 1, is the main cause of spring pollinosis in the temperate climate zone of the northern hemisphere. Bet v 1 binds various ligand molecules to its internal cavity, and immunologic effects of the presence of ligand have been discussed. However, the mechanism of binding has remained elusive. In this study, we show that in solution Bet v 1.0101 is conformationally heterogeneous and cannot be represented by a single structure. NMR relaxation data suggest that structural dynamics are fundamental for ligand access to the protein interior. Complex formation then leads to significant rigidification of the protein along with a compaction of its 3D structure. The data presented herein provide a structural basis for understanding the immunogenic and allergenic potential of ligand binding to Bet v 1 allergens. PMID:25517162

  16. Compact second-harmonic generation laser module with 1 W optical output power at 490 nm.

    PubMed

    Fiebig, Christian; Sahm, Alexander; Uebernickel, Mirko; Blume, Gunnar; Eppich, Bernd; Paschke, Katrin; Erbert, Götz

    2009-12-01

    We demonstrate continues-wave 1 W at 490 nm on a 2.5 cm(3) micro-optical bench using single-path second-harmonic generation with a periodically poled MgO:LiNbO(3) bulk crystal. The pump laser is a distributed Bragg reflector tapered diode laser having a single-frequency spectrum and a pump power of 9.5 W. Based on that 1 W blue light could be achieved resulting in an optical conversion efficiency of 11%. Furthermore, the module has an output power stability of better than 2% and the blue laser beam shows an nearly diffraction limited beam quality of M(2)(sigma) = 1.2 in vertical and M(2)(sigma) = 2 in lateral direction. PMID:20052204

  17. Nitric oxide isotopic analyzer based on a compact dual-modulation Faraday rotation spectrometer.

    PubMed

    Zhang, Eric; Huang, Stacey; Ji, Qixing; Silvernagel, Michael; Wang, Yin; Ward, Bess; Sigman, Daniel; Wysocki, Gerard

    2015-01-01

    We have developed a transportable spectroscopic nitrogen isotopic analyzer. The spectrometer is based on dual-modulation Faraday rotation spectroscopy of nitric oxide isotopologues with near shot-noise limited performance and baseline-free operation. Noise analysis indicates minor isotope ((15)NO) detection sensitivity of 0.36 ppbv·Hz(-1/2), corresponding to noise-equivalent Faraday rotation angle (NEA) of 1.31 × 10(-8) rad·Hz(-1/2) and noise-equivalent absorbance (αL)min of 6.27 × 10(-8) Hz(-1/2). White-noise limited performance at 2.8× the shot-noise limit is observed up to ~1000 s, allowing reliable calibration and sample measurement within the drift-free interval of the spectrometer. Integration with wet-chemistry based on acidic vanadium(III) enables conversion of aqueous nitrate/nitrite samples to gaseous NO for total nitrogen isotope analysis. Isotopic ratiometry is accomplished via time-multiplexed measurements of two NO isotope transitions. For 5 μmol potassium nitrate samples, the instrument consistently yields ratiometric precision below 0.3‰, thus demonstrating potential as an in situ diagnostic tool for environmental nitrogen cycle studies. PMID:26473876

  18. Compact multileaf collimator for conformal and intensity modulated fast neutron therapy: electromechanical design and validation.

    PubMed

    Farr, J B; Maughan, R L; Yudelev, M; Blosser, E; Brandon, J; Horste, T; Forman, J D

    2006-09-01

    The electromechanical properties of a 120-leaf, high-resolution, computer-controlled, fast neutron multileaf collimator (MLC) are presented. The MLC replaces an aging, manually operated multirod collimator. The MLC leaves project 5 mm in the isocentric plane perpendicular to the beam axis. A taper is included on the leaves matching beam divergence along one axis. The 5-mm leaf projection width is chosen to give high-resolution conformality across the entire field. The maximum field size provided is 30 x 30 cm2. To reduce the interleaf transmission a 0.254-mm blocking step is included. End-leaf steps totaling 0.762 mm are also provided allowing opposing leaves to close off within the primary radiation beam. The neutron MLC also includes individual 45 degrees and 60 degrees automated universal tungsten wedges. The automated high-resolution neutron collimation provides an increase in patient throughput capacity, enables a new modality, intensity modulated neutron therapy, and limits occupational radiation exposure by providing remote operation from a shielded console area. PMID:17022226

  19. Nitric Oxide Isotopic Analyzer Based on a Compact Dual-Modulation Faraday Rotation Spectrometer

    PubMed Central

    Zhang, Eric; Huang, Stacey; Ji, Qixing; Silvernagel, Michael; Wang, Yin; Ward, Bess; Sigman, Daniel; Wysocki, Gerard

    2015-01-01

    We have developed a transportable spectroscopic nitrogen isotopic analyzer. The spectrometer is based on dual-modulation Faraday rotation spectroscopy of nitric oxide isotopologues with near shot-noise limited performance and baseline-free operation. Noise analysis indicates minor isotope (15NO) detection sensitivity of 0.36 ppbv·Hz−1/2, corresponding to noise-equivalent Faraday rotation angle (NEA) of 1.31 × 10−8 rad·Hz−1/2 and noise-equivalent absorbance (αL)min of 6.27 × 10−8 Hz−1/2. White-noise limited performance at 2.8× the shot-noise limit is observed up to ~1000 s, allowing reliable calibration and sample measurement within the drift-free interval of the spectrometer. Integration with wet-chemistry based on acidic vanadium(III) enables conversion of aqueous nitrate/nitrite samples to gaseous NO for total nitrogen isotope analysis. Isotopic ratiometry is accomplished via time-multiplexed measurements of two NO isotope transitions. For 5 μmol potassium nitrate samples, the instrument consistently yields ratiometric precision below 0.3‰, thus demonstrating potential as an in situ diagnostic tool for environmental nitrogen cycle studies. PMID:26473876

  20. Compact, Intelligent, Digitally Controlled IGBT Gate Drivers for a PEBB-Based ILC Marx Modulator

    SciTech Connect

    Nguyen, M.N.; Burkhart, C.; Olsen, J.J.; Macken, K.; /SLAC

    2010-06-07

    SLAC National Accelerator Laboratory has built and is currently operating a first generation prototype Marx klystron modulator to meet ILC specifications. Under development is a second generation prototype, aimed at improving overall performance, serviceability, and manufacturability as compared to its predecessor. It is designed around 32 cells, each operating at 3.75 kV and correcting for its own capacitor droop. Due to the uniqueness of this application, high voltage gate drivers needed to be developed for the main 6.5 kV and droop correction 1.7 kV IGBTs. The gate driver provides vital functions such as protection of the IGBT from over-voltage and over-current, detection of gate-emitter open and short circuit conditions, and monitoring of IGBT degradation (based on collector-emitter saturation voltage). Gate drive control, diagnostic processing capabilities, and communication are digitally implemented using an FPGA. This paper details the design of the gate driver circuitry, component selection, and construction layout. In addition, experimental results are included to illustrate the effectiveness of the protection circuit.

  1. Compact multileaf collimator for conformal and intensity modulated fast neutron therapy: Electromechanical design and validation

    SciTech Connect

    Farr, J. B.; Maughan, R. L.; Yudelev, M.; Blosser, E.; Brandon, J.; Horste, T.; Forman, J. D.

    2006-09-15

    The electromechanical properties of a 120-leaf, high-resolution, computer-controlled, fast neutron multileaf collimator (MLC) are presented. The MLC replaces an aging, manually operated multirod collimator. The MLC leaves project 5 mm in the isocentric plane perpendicular to the beam axis. A taper is included on the leaves matching beam divergence along one axis. The 5-mm leaf projection width is chosen to give high-resolution conformality across the entire field. The maximum field size provided is 30x30 cm{sup 2}. To reduce the interleaf transmission a 0.254-mm blocking step is included. End-leaf steps totaling 0.762 mm are also provided allowing opposing leaves to close off within the primary radiation beam. The neutron MLC also includes individual 45 deg. and 60 deg. automated universal tungsten wedges. The automated high-resolution neutron collimation provides an increase in patient throughput capacity, enables a new modality, intensity modulated neutron therapy, and limits occupational radiation exposure by providing remote operation from a shielded console area.

  2. Compact narrow linewidth diode laser modules for precision quantum optics experiments on board of sounding rockets

    NASA Astrophysics Data System (ADS)

    Kohfeldt, Anja; Kürbis, Christian; Luvsandamdin, Erdenetsetseg; Schiemangk, Max; Wicht, Andreas; Peters, Achim; Erbert, Götz; Tränkle, Günther

    2016-04-01

    We have realized a laser platform based on GaAs diode lasers that allows for an operation in mobile exper-imental setups in harsh environments, such as on sounding rockets. The platform comes in two versions: a master-oscillator-power-amplifier and an extended cavity diode laser. Our very robust micro-optical bench has a footprint of 80 x 25 mm2. It strictly omits any movable parts. Master-oscillator-power-amplifier systems based on distributed feedback master oscillators for 767 nm and 780 nm narrow linewidth emission have been implemented by now. A continuous wave optical output power of > 1 W with a power conversion efficiency of > 25% could be achieved. The continuous tuning range of these lasers is on the order of 100 GHz, the linewidth at 10 μs is about 1 MHz. For applications demanding a narrower linewidth we have developed an extended cavity diode laser that achieves a linewidth of 100 kHz at 10 μs. These lasers achieve a continuous spectral tuning range of about 50 GHz and an continuous wave optical power up to 30 mW. The modules have been successfully vibration tested up to 29 gRMS along all three axes and passed 1500 g shocks, again along all 3 axes. Both, master-oscillator-power-amplifiers and extended cavity diode lasers, have been employed in sounding rocket experiments.

  3. A miniaturized compact open-loop RFOG with demodulation signal compensation technique to suppress intensity modulation noise

    NASA Astrophysics Data System (ADS)

    Ying, Diqing; Mao, Jianmin; Li, Qiang; Jin, Zhonghe

    2016-01-01

    A miniaturized compact open-loop resonator fiber optic gyro (RFOG) prototype with main body size of about 10.4 cm×10.4 cm×5.2 cm is reported, and a demodulation signal compensation technique is proposed, aiming to suppress the drift arising from accompanying intensity modulation induced by semiconductor laser diode (LD). The scheme of how to establish this miniaturized RFOG prototype is specifically stated. The linear relationship between the first-harmonic and second-harmonic demodulated signals respectively for the two counter propagating beams in the resonator is verified by theory and experiment, and based on this relationship, the demodulation signal compensation technique by monitoring the second-harmonic demodulated signal is described in detail. With this compensation technique, the gyro output stability under 1°/s rotation rate is effectively improved from 0.12°/s to 0.03°/s, and especially, an about 0.36°/s peak-to-peak fluctuation due to tuning current reset is significantly suppressed. A long term bias stability of about 4.5°/h in 1 h for such a small-sized RFOG prototype is demonstrated, which is of the same magnitude as that of currently reported large-sized RFOG systems utilizing LD as the laser source as well.

  4. Compact accelerator

    DOEpatents

    Caporaso, George J.; Sampayan, Stephen E.; Kirbie, Hugh C.

    2007-02-06

    A compact linear accelerator having at least one strip-shaped Blumlein module which guides a propagating wavefront between first and second ends and controls the output pulse at the second end. Each Blumlein module has first, second, and third planar conductor strips, with a first dielectric strip between the first and second conductor strips, and a second dielectric strip between the second and third conductor strips. Additionally, the compact linear accelerator includes a high voltage power supply connected to charge the second conductor strip to a high potential, and a switch for switching the high potential in the second conductor strip to at least one of the first and third conductor strips so as to initiate a propagating reverse polarity wavefront(s) in the corresponding dielectric strip(s).

  5. Compact magnetograph

    NASA Technical Reports Server (NTRS)

    Title, A. M.; Gillespie, B. A.; Mosher, J. W.

    1982-01-01

    A compact magnetograph system based on solid Fabry-Perot interferometers as the spectral isolation elements was studied. The theory of operation of several Fabry-Perot systems, the suitability of various magnetic lines, signal levels expected for different modes of operation, and the optimal detector systems were investigated. The requirements that the lack of a polarization modulator placed upon the electronic signal chain was emphasized. The PLZT modulator was chosen as a satisfactory component with both high reliability and elatively low voltage requirements. Thermal control, line centering and velocity offset problems were solved by a Fabry-Perot configuration.

  6. A Compact, Multifunctional Fusion Module Directs Cholesterol-Dependent Homomultimerization and Syncytiogenic Efficiency of Reovirus p10 FAST Proteins

    PubMed Central

    Key, Tim; Duncan, Roy

    2014-01-01

    The homologous p10 fusion-associated small transmembrane (FAST) proteins of the avian (ARV) and Nelson Bay (NBV) reoviruses are the smallest known viral membrane fusion proteins, and are virulence determinants of the fusogenic reoviruses. The small size of FAST proteins is incompatible with the paradigmatic membrane fusion pathway proposed for enveloped viral fusion proteins. Understanding how these diminutive viral fusogens mediate the complex process of membrane fusion is therefore of considerable interest, from both the pathogenesis and mechanism-of-action perspectives. Using chimeric ARV/NBV p10 constructs, the 36–40-residue ectodomain was identified as the major determinant of the differing fusion efficiencies of these homologous p10 proteins. Extensive mutagenic analysis determined the ectodomain comprises two distinct, essential functional motifs. Syncytiogenesis assays, thiol-specific surface biotinylation, and liposome lipid mixing assays identified an ∼25-residue, N-terminal motif that dictates formation of a cystine loop fusion peptide in both ARV and NBV p10. Surface immunofluorescence staining, FRET analysis and cholesterol depletion/repletion studies determined the cystine loop motif is connected through a two-residue linker to a 13-residue membrane-proximal ectodomain region (MPER). The MPER constitutes a second, independent motif governing reversible, cholesterol-dependent assembly of p10 multimers in the plasma membrane. Results further indicate that: (1) ARV and NBV homomultimers segregate to distinct, cholesterol-dependent microdomains in the plasma membrane; (2) p10 homomultimerization and cholesterol-dependent microdomain localization are co-dependent; and (3) the four juxtamembrane MPER residues present in the multimerization motif dictate species-specific microdomain association and homomultimerization. The p10 ectodomain therefore constitutes a remarkably compact, multifunctional fusion module that directs syncytiogenic efficiency and

  7. Compact lightweight payload for covert datalink using a multiple quantum well modulating retroreflector on a small rotary-wing unmanned airborne vehicle

    NASA Astrophysics Data System (ADS)

    Gilbreath, G. Charmaine; Rabinovich, William S.; Meehan, Timothy J.; Vilcheck, Michael J.; Mahon, Rita; Burris, Ray; Ferraro, Mina; Sokolsky, Ilene; Vasquez, John A.; Bovais, Chris S.; Cochrell, Kerry; Goins, Kim C.; Barbehenn, Robin; Katzer, D. Scott; Ikossi-Anastasiou, Kiki; Montes, Marcos J.

    2000-11-01

    In this paper, we describe progress in the development of the NRL Multiple Quantum Well modulating retro-reflector including a description of recent demonstrations of an infrared data link between a small rotary-wing unmanned airborne vehicle and a ground based laser interrogator using the NRL multiple quantum well modulating retro-reflector. Modulating retro-reflector systems couple an optical retro- reflector, such as a corner-cube, and an electro-optic shutter to allow two-way optical communications using a laser, telescope and pointer-tracker on only one platform. The NRL modulating retro-reflector uses a semiconductor based multiple quantum well shutter capable of modulation rates up to 10 Mbps, depending on link characteristics. The technology enable the use of near-infrared frequencies, which is well known to provide covert communications immune to frequency allocation problems. The multiple quantum well modulating retro-reflector has the added advantage of being compact, lightweight, covert, and requires very low power. Up to an order of magnitude in onboard power can be saved using a small array of these devices instead of the Radio Frequency equivalent. In the described demonstration, a Mbps optical link to an unmanned aerial vehicle in flight at a range of 100-200 feet is shown. Near real-time compressed video is also demonstrated at the Mbps level.

  8. Fully passive-alignment pluggable compact parallel optical interconnection modules based on a direct-butt-coupling structure for fiber-optic applications

    NASA Astrophysics Data System (ADS)

    Lim, Kwon-Seob; Park, Hyoung-Jun; Kang, Hyun Seo; Kim, Young Sun; Jang, Jae-Hyung

    2016-02-01

    A low-cost packaging method utilizing a fully passive optical alignment and surface-mounting method is demonstrated for pluggable compact and slim multichannel optical interconnection modules using a VCSEL/PIN-PD chip array. The modules are based on a nonplanar bent right-angle electrical signal path on a silicon platform and direct-butt-optical coupling without a bulky and expensive microlens array. The measured optical direct-butt-coupling efficiencies of each channel without any bulky optics are as high as 33% and 95% for the transmitter and receiver, respectively. Excellent lateral optical alignment tolerance of larger than 60 μm for both the transmitter and receiver module significantly reduces the manufacturing and material costs as well as the packaging time. The clear eye diagrams, extinction ratios higher than 8 dB at 10.3 Gbps for the transmitter module, and receiver sensitivity of better than -13.1 dBm at 10.3 Gbps and a bit error rate of 10-12 for all channels are demonstrated. Considering that the optical output power of the transmitter is greater than 0 dBm, the module has a sufficient power margin of about 13 dB for 10.3 Gbps operations for all channels.

  9. Strain-induced modulation of perpendicular magnetic anisotropy in Ta/CoFeB/MgO structures investigated by ferromagnetic resonance

    NASA Astrophysics Data System (ADS)

    Yu, Guoqiang; Wang, Zhenxing; Abolfath-Beygi, Maryam; He, Congli; Li, Xiang; Wong, Kin L.; Nordeen, Paul; Wu, Hao; Carman, Gregory P.; Han, Xiufeng; Alhomoudi, Ibrahim A.; Amiri, Pedram Khalili; Wang, Kang L.

    2015-02-01

    We demonstrate strain-induced modulation of perpendicular magnetic anisotropy (PMA) in (001)-oriented [Pb(Mg1/3Nb2/3)O3](1-x)-[PbTiO3]x (PMN-PT) substrate/Ta/CoFeB/MgO/Ta structures using ferromagnetic resonance (FMR). An in-plane biaxial strain is produced by applying voltage between the two surfaces of the PMN-PT substrate, and is transferred to the ferromagnetic CoFeB layer, which results in tuning of the PMA of the CoFeB layer. The strain-induced change in PMA is quantitatively extracted from the experimental FMR spectra. It is shown that both first and second-order anisotropy terms are affected by the electric field, and that they have opposite voltage dependencies. A very large value of the voltage-induced perpendicular magnetic anisotropy modulation of ˜7000 fJ/V.m is obtained through this strain-mediated coupling. Using this FMR technique, the magnetostriction coefficient λ is extracted for the ultrathin 1.1 nm Co20Fe60B20 layer, and is found to be 3.7 × 10-5, which is approximately 4 times larger than the previously reported values for CoFeB films thicker than 5 nm. In addition, the effect of strain on the effective damping constant (αeff) is also studied and no obvious modulation of the αeff is observed. The results are relevant to the development of CoFeB-MgO magnetic tunnel junctions for memory applications.

  10. 75 FR 62568 - Meeting of the Compact Council for the National Crime Prevention and Privacy Compact

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-12

    ... of the Council should notify the Federal Bureau of Investigation (FBI) Compact Officer, Mr. Gary S..., FBI Compact Officer, Compact Council Office, Module D3, 1000 Custer Hollow Road, Clarksburg,...

  11. Compact Ku-Band T/R Module for High-Resolution Radar Imaging of Cold Land Processes

    NASA Technical Reports Server (NTRS)

    Andricos, Constantine; Yueh, Simon H.; Krimskiy, Vladimir A.; Rahmat-Samii, Yahya

    2010-01-01

    Global measurement of terrestrial snow cover is critical to two of the NASA Earth Science focus areas: (1) climate variability and change and (2) water and energy cycle. For radar backscatter measurements, Ku-band frequencies, scattered mainly within the volume of the snowpack, are most suitable for the SWE (snow-water equivalent) measurements. To isolate the complex effects of different snowpack (density and snowgrain size), and underlying soil properties and to distinctly determine SWE, the space-based synthetic aperture radar (SAR) system will require a dual-frequency (13.4 and 17.2 GHz) and dual polarization approach. A transmit/receive (T/R) module was developed operating at Ku-band frequencies to enable the use of active electronic scanning phased-array antenna for wide-swath, high-resolution SAR imaging of terrestrial snow cover. The T/R module has an integrated calibrator, which compensates for all environmental- and time-related changes, and results in very stable power and amplitude characteristics. The module was designed to operate over the full frequency range of 13 to 18 GHz, although only the two frequencies, 13.4 GHz and 17.2 GHz, will be used in this SAR radar application. Each channel of the transmit module produces > 4 W (35 dbm) over the operating bandwidth of 20 MHz. The stability requirements of <0.1 dB receive gain accuracy and <0.1 dB transmit power accuracy over a wide temperature range are achieved using a self-correction scheme, which does real-time amplitude calibration so that the module characteristics are continually corrected. All the calibration circuits are within the T/R module. The timing and calibration sequence is stored in a control FPGA (field-programmable gate array) while an internal 128K 8bit high-speed RAM (random access memory) stores all the calibration values. The module was designed using advanced components and packaging techniques to achieve integration of the electronics in a 2 x6.5x1-in. (5x17x2.5-cm) package. The

  12. Coupling of a high-power tapered diode laser beam into a single-mode-fiber within a compact module

    NASA Astrophysics Data System (ADS)

    Jedrzejczyk, D.; Sahm, A.; Carstens, C.; Urban, G.; Pulka, M.; Eppich, B.; Scholz, F.; Paschke, K.

    2015-03-01

    In this work, coupling of radiation generated by a distributed Bragg reflector (DBR) tapered diode laser around 1064 nm into a single-mode-fiber (SMF) within a butterfly module with a footprint < 10 cm2 is demonstrated. The module comprises temperature stabilizing components, a brightness maintaining micro optical assembly mounted with submicrometer precision and a standard FC/APC output connector. The aim of the introduced concept is to improve the beam quality and to eliminate the current dependent beam astigmatism, characteristic for tapered diode lasers and amplifiers, and, thus, provide an efficient, multi-Watt laser light source characterized by a narrow-band spectrum and a stigmatic, nearly Gaussian laser beam independent of the operating point. A maximum power ex SMF of 2.5 W at a coupling efficiency of 57 % is reached in the presented butterfly module.

  13. Fiber Bragg grating sensing system using a TO-can-based compact optical module for wavelength demodulation

    NASA Astrophysics Data System (ADS)

    Song, Hong Joo; Lee, Jun Ho; Roh, Cheong Hyun; Hahn, Cheol-Koo; Choi, Young Bok; Kim, Jeong Soo; Park, Jung Ho

    2015-12-01

    A combined scheme using the light source of a reflective semiconductor optical amplifier (RSOA) and an optical signal processing unit (OSPU) based on the compact TO-can package is fabricated and characterized for a fiber Bragg grating (FBG) sensing system. Due to the optical feedback behavior from the FBG sensor, the RSOA is self-injection locked and lasing occurs at the Bragg wavelength. Using the wavelength-dependent filter method, all of the components in the OSPU are compactly integrated on the TO-can package with a height of 17.6 mm and diameter of 6.0 mm. The wavelength demodulating output signals are based on the optical power difference, depending only on the wavelengths without the effect of input optical power variations. The sensitivity of the output signal to temperature shows 0.026 dB/°C. The entire FBG sensing system has an excellent linear response to temperatures controlled with an accuracy of ±0.3°C.

  14. New light-trapping concept by means of several optical components applied to compact holographic 3D concentration solar module

    NASA Astrophysics Data System (ADS)

    Villamarín Villegas, Ayalid M.; Pérez López, Francisco J.; Calo López, Antonio; Rodríguez San Segundo, Hugo-José

    2014-05-01

    A new light-trapping concept is presented, which joins broad bandwidth volume phase reflection holograms (VPRH) working together with three other optical components: specifically designed three-dimensional (3D) cavities, Total Internal Reflection (TIR) within an optical medium, and specular reflection by means of a highly reflective surface. This concept is applied to the design and development of both low concentration photovoltaic (LCPV) and solar thermal modules reaching a concentration factor of up to 3X. Higher concentrations are feasible for use in concentrated solar power (CSP) devices. The whole system is entirely made of polymeric materials (except for the solar cells or fluid carrying pipes), thus reducing cost by up to 40%. The module concentrates solar light onto solar cells - or fluid carrying pipes - with no need for active tracking of the sun, covering the whole seasonal and daily incident angle spectrum while it also minimizes optical losses. In this work we analyze the first experimentally measured optical characteristics and performance of VPRH in dichromated gelatin film (DCG) in our concept. The VPRH can reach high diffraction efficiencies (˜98%, ignoring Fresnel reflection losses). Thanks to specifically designed raw material, coating and developing process specifications, also very broad selective spectral (higher than 300 nm) and angular bandwidths (˜+20º) per grating are achieved. The VPRH was optimized to use silicon solar cells, but designs for other semiconductor devices or for fluid heating are feasible. The 3D shape, the hologram's and reflective surface's optical quality, the TIR effect and the correct coupling of all the components are key to high performance of the concentration solar module.

  15. Compact high-power low-jitter semiconductor mode-locked laser module for photonic A/D converter applications

    NASA Astrophysics Data System (ADS)

    Braun, Alan M.; Price, Bradford B.; Bechtle, Daniel W.; Kwakernaak, Martin H.; Abeles, Joseph H.; Yilmaz, Tolga; Delfyett, Peter J., Jr.

    2003-07-01

    Low-capacitance, two-section, curved-waveguide gain elements were packaged with lensed polarization-maintaining fiber within standard-sized butterfly-style packages and shown to produce low-jitter pulses when used within a harmonically modelocked sigma cavity laser (jitter = 25 fs; 10 Hz - 10 MHz). Incorporation of a high finesse etalon filter into the sigma-cavity loop resulted in greater than 25 dB suppression of the supermode spurs while maintaining low integrated phase noise (jitter = 30 fs; 10 Hz - 10 MHz). A module containing the in-line sigma-cavity modelocked laser source and packaged semiconductor optical amplifiers was developed to create a configurable low jitter pulse source.

  16. Adult Compacts.

    ERIC Educational Resources Information Center

    Further Education Unit, London (England).

    This bulletin focuses on adult compacts, three-way agreements among employers, potential employees, and trainers to provide the right kind of quality training to meet the employers' requirements. Part 1 is an executive summary of a report of the Adult Compacts Project, which studied three adult compacts in Birmingham and Loughborough, England, and…

  17. Ion-beam induced domain structure in piezoelectric PMN-PT single crystal

    SciTech Connect

    Kim, Kyou-Hyun; Payne, David A.; Zuo Jianmin

    2010-12-27

    We report an investigation of the domain structure in Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}-30%PbTiO{sub 3} single crystals after ion milling. We show that ion milling induces microdomains, typically 0.1-1 {mu}m in size. The induced microdomains disappear after temperature annealing or electric poling, leaving behind nanodomains of a few nanometers in size. We attribute the microdomains to surface stress induced by ion milling. The results demonstrate the general importance of separating sample preparation artifacts from the true domain structure in the study of ferroic materials.

  18. Anisotropic Piezocomposite Actuator Incorporating Machined PMN-PT Single Crystal Fibers

    NASA Technical Reports Server (NTRS)

    Wilkie, W. Keats; Inman, Daniel J.; Lloyd, Justin M.; High, James W.

    2004-01-01

    The design, fabrication, and testing of a flexible, planar, anisotropic piezoelectric composite actuator utilizing machined PMN-32%PT single crystal fibers is presented. The device consists of a layer of rectangular single crystal piezoelectric fibers in an epoxy matrix, packaged between interdigitated electrode polyimide films. Quasistatic free-strain measurements of the single crystal device are compared with measurements from geometrically identical specimens incorporating polycrystalline PZT-5A and PZT-5H piezoceramic fibers. Free-strain actuation of the single crystal actuator at low bipolar electric fields (+/- 250 V/mm) is approximately 400% greater than that of the baseline PZT-5A piezoceramic device, and 200% greater than that of the PZT-5H device. Free-strain actuation under high unipolar electric fields (0-4kV/mm) is approximately 200% of the PZT-5A baseline device, and 150% of the PZT-5H alternate piezoceramic device. Performance increases at low field are qualitatively consistent with predicted increases based on scaling the low-field d(sub 33) piezoelectric constants of the respective piezoelectric materials. High-field increases are much less than scaled d(sub 33) estimates, but appear consistent with high-field freestrain measurements reported for similar bulk single-crystal and piezoceramic compositions. Measurements of single crystal actuator capacitance and coupling coefficient are also provided. These properties were poorly predicted using scaled bulk material dielectric and coupling coefficient data. Rules-of-mixtures calculations of the effective elastic properties of the single crystal device and estimated actuation work energy densities are also presented. Results indicate longitudinal stiffnesses significantly lower (50% less) than either piezoceramic device. This suggests that single-crystal piezocomposite actuators will be best suited to low induced-stress, high strain and deflection applications.

  19. Anisotropic Laminar Piezocomposite Actuator Incorporating Machined PMN-PT Single Crystal Fibers

    NASA Technical Reports Server (NTRS)

    Wilkie, W. Keats; Inman, Daniel J.; Lloyd, Justin M.; High, James W.

    2006-01-01

    The design, fabrication, and testing of a flexible, laminar, anisotropic piezoelectric composite actuator utilizing machined PMN-32%PT single crystal fibers is presented. The device consists of a layer of rectangular single crystal piezoelectric fibers in an epoxy matrix, packaged between interdigitated electrode polyimide films. Quasistatic free-strain measurements of the single crystal device are compared with measurements from geometrically identical specimens incorporating polycrystalline PZT-5A and PZT-5H piezoceramic fibers. Free-strain actuation of the single crystal actuator at low bipolar electric fields (+/- 250 V/mm) is approximately 400% greater than that of the baseline PZT-5A piezoceramic device, and 200% greater than that of the PZT-5H device. Free-strain actuation under high unipolar electric fields (0-4kV/mm) is approximately 200% of the PZT-5A baseline device, and 150% of the PZT-5H alternate piezoceramic device. Performance increases at low field are qualitatively consistent with predicted increases based on scaling the low-field d33 piezoelectric constants of the respective piezoelectric materials. High-field increases are much less than scaled d33 estimates, but appear consistent with high-field freestrain measurements reported for similar bulk single-crystal and piezoceramic compositions. Measurements of single crystal actuator capacitance and coupling coefficient are also provided. These properties were poorly predicted using scaled bulk material dielectric and coupling coefficient data. Rules-of-mixtures calculations of the effective elastic properties of the single crystal device and estimated actuation work energy densities are also presented. Results indicate longitudinal stiffnesses significantly lower (50% less) than either piezoceramic device. This suggests that single-crystal piezocomposite actuators will be best suited to low induced-stress, high strain and deflection applications.

  20. The pyroelectric energy harvesting capabilities of PMN-PT near the morphotropic phase boundary

    NASA Astrophysics Data System (ADS)

    Kandilian, Razmig; Navid, Ashcon; Pilon, Laurent

    2011-05-01

    This paper reports on direct thermal to electrical energy conversion by performing the Olsen cycle on pyroelectric materials. The energy harvesting capability of commercially available [001] oriented 68PbMg1/3Nb2/3O3-32PbTiO3 (PMN-32PT) single crystal capacitors was measured experimentally. An energy density of 100 mJ cm-3/cycle, corresponding to 4.92 mW cm-3, was obtained by successively dipping the material in oil baths at temperatures 80 and 170 °C and cycling the electric field between 2 and 9 kV cm-1. Similarly, an energy density of 55 mJ cm-3/cycle was obtained between 80 and 140 °C. An estimated 40% of this energy resulted from the strain polarization due to the rhombohedral to tetragonal phase transition. The strain from this transition disappeared when the maximum operating temperature exceeded the Curie temperature of about 150 °C. The optimal low electric field used in the Olsen cycle maximizing the energy harvested was found to be around 2 kV cm-1. In addition, the material suffered from (i) dielectric breakdown for electric fields larger than 9 kV cm-1 and (ii) cracking from thermal stress for operating temperature differences in excess of 90 °C. A physical model predicting the total amount of energy harvested was also derived, accounting for thermal expansion as well as temperature dependent dielectric constant and spontaneous polarization. The model predictions fell within 20% of the experimental results in the temperature range between 80 and 170 °C and electric fields ranging from 2 to 9 kV cm-1.

  1. Photoluminescence, FTIR, and laser-Raman spectroscopic studies of PMN-PT containing iron

    NASA Astrophysics Data System (ADS)

    Bairavarasu, Sundar R.; Edwards, Matthew E.; Kukhtareva, Titania; Sastry, Medury D.; Lianos, Dimitrios; Kommidi, Praveena; Reddy, B. Rami; Janeisch, Holger M.; Aggarwal, Monmohan D.

    2007-09-01

    Lead magnesium niobate-lead titanate, Pb(Mg, Nb)O 3-PbTiO 3 is a piezoelectric, ferroelectric crystal at room temperature with large electromechanical coefficient. The crystals were grown by PbO-B IIO 3 flux method. Typically the crystals were colorless and transparent, but a small fraction of them were Brown/reddish colored and show interesting photoluminescence (PL) properties. The PL studies were conducted under XeCl (308nm) excitation and under Argon Ion (Ar +) laser excitation. The excitation with 308nm gave broad PL centered at 500nm and intense emission at 710nm. The emission at 710nm in colorless crystals is very weak. The excitation with Ar + laser coinciding with electronic absorption in brown samples gave rich and sharp PL particularly with 514.5 nm excitation. The PL with 514.5nm-Ar + laserexcitation, consisted of intense anti stokes emission in addition to intense red and near infrared emission, is a result of photo-transfer optically stimulated luminescence (PT-OSL). This involved electron-hole recombination at photoinduced magnetic polaron site. The PL emissions and the centers identified are the followings: 718nm emission due to magnetic polaron and 360nm emission due to cooperative emission from two polarons, Fe-R line at 660nm due to Fe 3+ coupled to a cation; 380nm and 399nm due to Pb 2+ clusters and Nb 5+ center; 630 and 860 nm due to 6p-->6s transition of Pb 3+ and 760nm due to isolated Fe 3+ ions. Raman spectrum of brown samples revealed the presence of nano particles/wires of orthorhombic β PbO. The FTIR spectrum gives evidence of significant amount of hydroxyl impurity.

  2. Epitaxial Ni-Mn-Ga-Co thin films on PMN-PT substrates for multicaloric applications

    SciTech Connect

    Schleicher, B. Niemann, R.; Schultz, L.; Fähler, S.; Diestel, A.; Hühne, R.

    2015-08-07

    Multicaloric stacks consisting of a magnetocaloric film on a piezoelectric substrate promise improved caloric properties as the transition temperature can be controlled by both magnetic and electric fields. We present epitaxially grown magnetocaloric Ni-Mn-Ga-Co thin films on ferroelectric Pb(Mg{sub 1/3}Nb{sub 2/3}){sub 0.72}Ti{sub 0.28}O{sub 3} substrates. Structure and microstructure of two samples, being in the austenitic and martensitic state at room temperature, are investigated by X-ray diffraction in two- and four-circle geometry and by atomic force microscopy. In addition, high temperature magnetometry was performed on the latter sample. The combination of these methods allows separating the influence of epitaxial growth and martensitic transformation. A preferential alignment of twin boundaries is observed already in the as-deposited state, which indicates the presence of prestress, without applying an electric field to the substrate. A temperature-magnetic field phase diagram is presented, which demonstrates the inverse magnetocaloric effect of the epitaxial Ni-Mn-Ga-Co film.

  3. High frequency PMN-PT single crystal focusing transducer fabricated by a mechanical dimpling technique.

    PubMed

    Chen, Y; Lam, K H; Zhou, D; Cheng, W F; Dai, J Y; Luo, H S; Chan, H L W

    2013-02-01

    High frequency (∼30MHz and ∼80MHz) focusing ultrasound transducers were fabricated using a PMN-0.28PT single crystal by a mechanical dimpling technique. The dimpled single crystal was used as an active element for the focusing transducer. Compared with a plane transducer, the focusing transducer fabricated with a dimpled active element exhibits much broader bandwidth and higher sensitivity. Besides, a high quality image can be obtained by the 30MHz focusing transducer, in which the -6dB axial and lateral resolution is 27μm and 139μm, respectively. These results prove that the dimpling technique is capable to fabricate the high frequency focusing transducers with excellent performance for imaging applications. PMID:22944074

  4. Epitaxial Ni-Mn-Ga-Co thin films on PMN-PT substrates for multicaloric applications

    NASA Astrophysics Data System (ADS)

    Schleicher, B.; Niemann, R.; Diestel, A.; Hühne, R.; Schultz, L.; Fähler, S.

    2015-08-01

    Multicaloric stacks consisting of a magnetocaloric film on a piezoelectric substrate promise improved caloric properties as the transition temperature can be controlled by both magnetic and electric fields. We present epitaxially grown magnetocaloric Ni-Mn-Ga-Co thin films on ferroelectric Pb(Mg1/3Nb2/3)0.72Ti0.28O3 substrates. Structure and microstructure of two samples, being in the austenitic and martensitic state at room temperature, are investigated by X-ray diffraction in two- and four-circle geometry and by atomic force microscopy. In addition, high temperature magnetometry was performed on the latter sample. The combination of these methods allows separating the influence of epitaxial growth and martensitic transformation. A preferential alignment of twin boundaries is observed already in the as-deposited state, which indicates the presence of prestress, without applying an electric field to the substrate. A temperature-magnetic field phase diagram is presented, which demonstrates the inverse magnetocaloric effect of the epitaxial Ni-Mn-Ga-Co film.

  5. Compact optical transconductance varistor

    SciTech Connect

    Sampayan, Stephen

    2015-09-22

    A compact radiation-modulated transconductance varistor device having both a radiation source and a photoconductive wide bandgap semiconductor material (PWBSM) integrally formed on a substrate so that a single interface is formed between the radiation source and PWBSM for transmitting PWBSM activation radiation directly from the radiation source to the PWBSM.

  6. VIBRATION COMPACTION

    DOEpatents

    Hauth, J.J.

    1962-07-01

    A method of compacting a powder in a metal container is described including the steps of vibrating the container at above and below the resonant frequency and also sweeping the frequency of vibration across the resonant frequency several times thereby following the change in resonant frequency caused by compaction of the powder. (AEC)

  7. Ureilite compaction

    NASA Astrophysics Data System (ADS)

    Walker, D.; Agee, C. B.

    1988-03-01

    Ureilite meteorites show the simple mineralogy and compact recrystallized textures of adcumulate rock or melting residues. A certain amount of controversy exists about whether they are in fact adcumulate rocks or melting residues and about the nature of the precursor liquid or solid assemblage. The authors undertook a limited experimental study which made possible the evaluation of the potential of the thermal migration mechanism (diffusion on a saturation gradient) for forming ureilite-like aggregates from carbonaceous chondrite precursors. They find that the process can produce compact recrystallized aggregates of silicate crystals which do resemble the ureilities and other interstitial-liquid-free adcumulate rocks in texture.

  8. Bidirectional optical subassembly-shaped 20-Gbit/s compact single-mode four-channel wavelength-division multiplexing optical modules for optical multimedia interfaces

    NASA Astrophysics Data System (ADS)

    Lim, Kwon-Seob; Yu, Hong-Yeon; Park, Hyoung-Jun; Kang, Hyun Seo; Jang, Jae-Hyung

    2016-06-01

    Low-cost single-mode four-channel optical transmitter and receiver modules using the wavelength-division multiplexing (WDM) method have been developed for long-reach fiber optic applications. The single-mode four-channel WDM optical transmitter and receiver modules consist of two dual-wavelength optical transmitter and receiver submodules, respectively. The integration of two channels in a glass-sealed transistor outline-can package is an effective way to reduce cost and size and to extend the number of channels. The clear eye diagrams with more than about 6 dB of the extinction ratio and the minimum receiver sensitivity of lower than -16 dBm at a bit error rate of 10-12 have been obtained for the transmitter and receiver modules, respectively, at 5 Gbps/channel. The 4K ultrahigh definition contents have been transmitted over a 1-km-long single-mode fiber using a pair of proposed four-channel transmitter optical subassembly and receiver optical subassembly.

  9. Compaction behavior of roller compacted ibuprofen.

    PubMed

    Patel, Sarsvatkumar; Kaushal, Aditya Mohan; Bansal, Arvind Kumar

    2008-06-01

    The effect of roller compaction pressure on the bulk compaction of roller compacted ibuprofen was investigated using instrumented rotary tablet press. Three different roller pressures were utilized to prepare granules and Heckel analysis, Walker analysis, compressibility, and tabletability were performed to derive densification, deformation, course of volume reduction and bonding phenomenon of different pressure roller compacted granules. Nominal single granule fracture strength was obtained by micro tensile testing. Heckel analysis indicated that granules prepared using lower pressure during roller compaction showed lower yield strength. The reduction in tabletability was observed for higher pressure roller compacted granules. The reduction in tabletability supports the results of granule size enlargement theory. Apart from the granule size enlargement theory, the available fines and relative fragmentation during compaction is responsible for higher bonding strength and provide larger areas for true particle contact at constant porosity for lower pressure roller compacted granules. Overall bulk compaction parameters indicated that granules prepared by lower roller compaction pressure were advantageous in terms of tabletability and densification. Overall results suggested that densification during roller compaction affects the particle level properties of specific surface area, nominal fracture strength, and compaction behavior. PMID:18280716

  10. PMN-PT single crystal thick films on silicon substrate for high-frequency micromachined ultrasonic transducers

    NASA Astrophysics Data System (ADS)

    Peng, J.; Lau, S. T.; Chao, C.; Dai, J. Y.; Chan, H. L. W.; Luo, H. S.; Zhu, B. P.; Zhou, Q. F.; Shung, K. K.

    2010-01-01

    In this work, a novel high-frequency ultrasonic transducer structure is realized by using PMNPT-on-silicon technology and silicon micromachining. To prepare the single crystalline PMNPT-on-silicon wafers, a hybrid processing method involving wafer bonding, mechanical lapping and wet chemical thinning is successfully developed. In the transducer structure, the active element is fixed within the stainless steel needle housing. The measured center frequency and -6 dB bandwidth of the transducer are 35 MHz and 34%, respectively. Owing to the superior electromechanical coupling coefficient ( k t ) and high piezoelectric constant ( d 33) of PMNPT film, the transducer shows a good energy conversion performance with a very low insertion loss down to 8.3 dB at the center frequency.

  11. Compact Reactor

    SciTech Connect

    Williams, Pharis E.

    2007-01-30

    Weyl's Gauge Principle of 1929 has been used to establish Weyl's Quantum Principle (WQP) that requires that the Weyl scale factor should be unity. It has been shown that the WQP requires the following: quantum mechanics must be used to determine system states; the electrostatic potential must be non-singular and quantified; interactions between particles with different electric charges (i.e. electron and proton) do not obey Newton's Third Law at sub-nuclear separations, and nuclear particles may be much different than expected using the standard model. The above WQP requirements lead to a potential fusion reactor wherein deuterium nuclei are preferentially fused into helium nuclei. Because the deuterium nuclei are preferentially fused into helium nuclei at temperatures and energies lower than specified by the standard model there is no harmful radiation as a byproduct of this fusion process. Therefore, a reactor using this reaction does not need any shielding to contain such radiation. The energy released from each reaction and the absence of shielding makes the deuterium-plus-deuterium-to-helium (DDH) reactor very compact when compared to other reactors, both fission and fusion types. Moreover, the potential energy output per reactor weight and the absence of harmful radiation makes the DDH reactor an ideal candidate for space power. The logic is summarized by which the WQP requires the above conditions that make the prediction of DDH possible. The details of the DDH reaction will be presented along with the specifics of why the DDH reactor may be made to cause two deuterium nuclei to preferentially fuse to a helium nucleus. The presentation will also indicate the calculations needed to predict the reactor temperature as a function of fuel loading, reactor size, and desired output and will include the progress achieved to date.

  12. Ceramic powder compaction

    SciTech Connect

    Glass, S.J.; Ewsuk, K.G.; Mahoney, F.M.

    1995-12-31

    With the objective of developing a predictive model for ceramic powder compaction we have investigated methods for characterizing density gradients in ceramic powder compacts, reviewed and compared existing compaction models, conducted compaction experiments on a spray dried alumina powder, and conducted mechanical tests and compaction experiments on model granular materials. Die filling and particle packing, and the behavior of individual granules play an important role in determining compaction behavior and should be incorporated into realistic compaction models. These results support the use of discrete element modeling techniques and statistical mechanics principals to develop a comprehensive model for compaction, something that should be achievable with computers with parallel processing capabilities.

  13. Control of magnetic relaxation by electric-field-induced ferroelectric phase transition and inhomogeneous domain switching

    NASA Astrophysics Data System (ADS)

    Nan, Tianxiang; Emori, Satoru; Peng, Bin; Wang, Xinjun; Hu, Zhongqiang; Xie, Li; Gao, Yuan; Lin, Hwaider; Jiao, Jie; Luo, Haosu; Budil, David; Jones, John G.; Howe, Brandon M.; Brown, Gail J.; Liu, Ming; Sun, Nian

    2016-01-01

    Electric-field modulation of magnetism in strain-mediated multiferroic heterostructures is considered a promising scheme for enabling memory and magnetic microwave devices with ultralow power consumption. However, it is not well understood how electric-field-induced strain influences magnetic relaxation, an important physical process for device applications. Here, we investigate resonant magnetization dynamics in ferromagnet/ferroelectric multiferroic heterostructures, FeGaB/PMN-PT and NiFe/PMN-PT, in two distinct strain states provided by electric-field-induced ferroelectric phase transition. The strain not only modifies magnetic anisotropy but also magnetic relaxation. In FeGaB/PMN-PT, we observe a nearly two-fold change in intrinsic Gilbert damping by electric field, which is attributed to strain-induced tuning of spin-orbit coupling. By contrast, a small but measurable change in extrinsic linewidth broadening is attributed to inhomogeneous ferroelastic domain switching during the phase transition of the PMN-PT substrate.

  14. Piezoelectric single crystal and magnetostrictive Metglas composites: Linear and nonlinear magnetoelectric coupling

    NASA Astrophysics Data System (ADS)

    Wang, Yaojin; Finkel, P.; Li, Jiefang; Viehland, D.

    2014-04-01

    Both the linear (αV) and nonlinear (αV,n) magnetoelectric coefficients were systemically studied in laminated composites of Metglas and [001]-orientated piezoelectric single crystals of Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) and Mn-doped PMN-PT. The coefficients were close in value in both cases at quasistatic mode (i.e., 3.8 V/Oe relative to 3.5 V/Oe) and were enhanced by factors of ×18 (Metglas/PMN-PT) and ×32 (Metglas/Mn-doped PMN-PT) at the electromechanical resonance (EMR). The use of Mn-doped PMN-PT crystals results in a higher gain factor due to a larger mechanical quality factor (i.e., 20.9 relative to 40.6). Accordingly, both types of laminates had similar values of αV,n when modulated at 1 kHz, but Mn-doped PMN-PT ones had a higher value when modulated at the EMR.

  15. Mouse Embryo Compaction.

    PubMed

    White, M D; Bissiere, S; Alvarez, Y D; Plachta, N

    2016-01-01

    Compaction is a critical first morphological event in the preimplantation development of the mammalian embryo. Characterized by the transformation of the embryo from a loose cluster of spherical cells into a tightly packed mass, compaction is a key step in the establishment of the first tissue-like structures of the embryo. Although early investigation of the mechanisms driving compaction implicated changes in cell-cell adhesion, recent work has identified essential roles for cortical tension and a compaction-specific class of filopodia. During the transition from 8 to 16 cells, as the embryo is compacting, it must also make fundamental decisions regarding cell position, polarity, and fate. Understanding how these and other processes are integrated with compaction requires further investigation. Emerging imaging-based techniques that enable quantitative analysis from the level of cell-cell interactions down to the level of individual regulatory molecules will provide a greater understanding of how compaction shapes the early mammalian embryo. PMID:27475854

  16. Reversible DNA compaction.

    PubMed

    González-Pérez, Alfredo

    2014-01-01

    In this review we summarize and discuss the different methods we can use to achieve reversible DNA compaction in vitro. Reversible DNA compaction is a natural process that occurs in living cells and viruses. As a result these process long sequences of DNA can be concentrated in a small volume (compacted) to be decompacted only when the information carried by the DNA is needed. In the current work we review the main artificial compacting agents looking at their suitability for decompaction. The different approaches used for decompaction are strongly influenced by the nature of the compacting agent that determines the mechanism of compaction. We focus our discussion on two main artificial compacting agents: multivalent cations and cationic surfactants that are the best known compacting agents. The reversibility of the process can be achieved by adding chemicals like divalent cations, alcohols, anionic surfactants, cyclodextrins or by changing the chemical nature of the compacting agents via pH modifications, light induced conformation changes or by redox-reactions. We stress the relevance of electrostatic interactions and self-assembly as a main approach in order to tune up the DNA conformation in order to create an on-off switch allowing a transition between coil and compact states. The recent advances to control DNA conformation in vitro, by means of molecular self-assembly, result in a better understanding of the fundamental aspects involved in the DNA behavior in vivo and serve of invaluable inspiration for the development of potential biomedical applications. PMID:24444152

  17. Compaction Behavior of Isomalt after Roll Compaction

    PubMed Central

    Quodbach, Julian; Mosig, Johanna; Kleinebudde, Peter

    2012-01-01

    The suitability of the new isomalt grade galenIQ™ 801 for dry granulation and following tableting is evaluated in this study. Isomalt alone, as well as a blend of equal parts with dibasic calcium phosphate, is roll compacted and tableted. Particle size distribution and flowability of the granules and friability and disintegration time of the tablets are determined. Tensile strength of tablets is related to the specific compaction force during roll compaction and the tableting force. In all cases, the tensile strength increases with raising tableting forces. The specific compaction force has a different influence. For isomalt alone the tensile strength is highest for tablets made from granules prepared at 2 kN/cm and 6 kN/cm and decreases at higher values, i.e., >10 kN/cm. Tensile strength of the blend tablets is almost one third lower compared to the strongest tablets of pure isomalt. Friability of pure isomalt tablets is above the limit. Disintegration time is longest when the tensile strength is at its maximum and decreases with higher porosity and lower tensile strengths. Isomalt proves to be suitable for tableting after roll compaction. Even though the capacity as a binder might not be as high as of other excipients, it is a further alternative for the formulation scientist. PMID:24300366

  18. Compaction behavior of isomalt after roll compaction.

    PubMed

    Quodbach, Julian; Mosig, Johanna; Kleinebudde, Peter

    2012-01-01

    The suitability of the new isomalt grade galenIQ™ 801 for dry granulation and following tableting is evaluated in this study. Isomalt alone, as well as a blend of equal parts with dibasic calcium phosphate, is roll compacted and tableted. Particle size distribution and flowability of the granules and friability and disintegration time of the tablets are determined. Tensile strength of tablets is related to the specific compaction force during roll compaction and the tableting force. In all cases, the tensile strength increases with raising tableting forces. The specific compaction force has a different influence. For isomalt alone the tensile strength is highest for tablets made from granules prepared at 2 kN/cm and 6 kN/cm and decreases at higher values, i.e., >10 kN/cm. Tensile strength of the blend tablets is almost one third lower compared to the strongest tablets of pure isomalt. Friability of pure isomalt tablets is above the limit. Disintegration time is longest when the tensile strength is at its maximum and decreases with higher porosity and lower tensile strengths. Isomalt proves to be suitable for tableting after roll compaction. Even though the capacity as a binder might not be as high as of other excipients, it is a further alternative for the formulation scientist. PMID:24300366

  19. Firefighting Module

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Aviation Power Supply's mobile firefighting module called Firefly II is mounted on a trailer pulled by a pickup truck. Trailer unit has two three- inch water cannons, and the pickup carries a six inch cannon. Completely self contained, module pumps 3,000 gallons of water a minute from hydrants or open bodies of water. Stream can go as far as 400 feet or can be employed in a high-loft mode to reach the tops of tall refinery towers. Compact Firefly II weighs only 2,500 pounds when fully fueled. Key component is a specially designed two stage pump. Power for the pump is generated by a gas turbine engine. Module also includes an electronic/pump controller, multiple hose connections, up to 1,500 feet of hose and fuel for four hours operation. Firefly trailer can be backed onto specially-built large fireboat.

  20. Firefighting Module

    NASA Astrophysics Data System (ADS)

    1980-01-01

    Aviation Power Supply's mobile firefighting module called Firefly II is mounted on a trailer pulled by a pickup truck. Trailer unit has two three- inch water cannons, and the pickup carries a six inch cannon. Completely self contained, module pumps 3,000 gallons of water a minute from hydrants or open bodies of water. Stream can go as far as 400 feet or can be employed in a high-loft mode to reach the tops of tall refinery towers. Compact Firefly II weighs only 2,500 pounds when fully fueled. Key component is a specially designed two stage pump. Power for the pump is generated by a gas turbine engine. Module also includes an electronic/pump controller, multiple hose connections, up to 1,500 feet of hose and fuel for four hours operation. Firefly trailer can be backed onto specially-built large fireboat.

  1. Compact Holographic Data Storage

    NASA Technical Reports Server (NTRS)

    Chao, T. H.; Reyes, G. F.; Zhou, H.

    2001-01-01

    NASA's future missions would require massive high-speed onboard data storage capability to Space Science missions. For Space Science, such as the Europa Lander mission, the onboard data storage requirements would be focused on maximizing the spacecraft's ability to survive fault conditions (i.e., no loss in stored science data when spacecraft enters the 'safe mode') and autonomously recover from them during NASA's long-life and deep space missions. This would require the development of non-volatile memory. In order to survive in the stringent environment during space exploration missions, onboard memory requirements would also include: (1) survive a high radiation environment (1 Mrad), (2) operate effectively and efficiently for a very long time (10 years), and (3) sustain at least a billion write cycles. Therefore, memory technologies requirements of NASA's Earth Science and Space Science missions are large capacity, non-volatility, high-transfer rate, high radiation resistance, high storage density, and high power efficiency. JPL, under current sponsorship from NASA Space Science and Earth Science Programs, is developing a high-density, nonvolatile and rad-hard Compact Holographic Data Storage (CHDS) system to enable large-capacity, high-speed, low power consumption, and read/write of data in a space environment. The entire read/write operation will be controlled with electrooptic mechanism without any moving parts. This CHDS will consist of laser diodes, photorefractive crystal, spatial light modulator, photodetector array, and I/O electronic interface. In operation, pages of information would be recorded and retrieved with random access and high-speed. The nonvolatile, rad-hard characteristics of the holographic memory will provide a revolutionary memory technology meeting the high radiation challenge facing the Europa Lander mission. Additional information is contained in the original extended abstract.

  2. ACOUSTIC COMPACTION LAYER DETECTION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The depth and strength of compacted layers in fields have been determined traditionally using the ASAE standardized cone penetrometer method. However, an on-the-go method would be much faster and much less labor intensive. The soil measurement system described here attempts to locate the compacted...

  3. Dynamical compactness and sensitivity

    NASA Astrophysics Data System (ADS)

    Huang, Wen; Khilko, Danylo; Kolyada, Sergiĭ; Zhang, Guohua

    2016-05-01

    To link the Auslander point dynamics property with topological transitivity, in this paper we introduce dynamically compact systems as a new concept of a chaotic dynamical system (X , T) given by a compact metric space X and a continuous surjective self-map T : X → X. Observe that each weakly mixing system is transitive compact, and we show that any transitive compact M-system is weakly mixing. Then we discuss the relationships between it and other several stronger forms of sensitivity. We prove that any transitive compact system is Li-Yorke sensitive and furthermore multi-sensitive if it is not proximal, and that any multi-sensitive system has positive topological sequence entropy. Moreover, we show that multi-sensitivity is equivalent to both thick sensitivity and thickly syndetic sensitivity for M-systems. We also give a quantitative analysis for multi-sensitivity of a dynamical system.

  4. Stabilization of compactible waste

    SciTech Connect

    Franz, E.M.; Heiser, J.H. III; Colombo, P.

    1990-09-01

    This report summarizes the results of series of experiments performed to determine the feasibility of stabilizing compacted or compactible waste with polymers. The need for this work arose from problems encountered at disposal sites attributed to the instability of this waste in disposal. These studies are part of an experimental program conducted at Brookhaven National Laboratory (BNL) investigating methods for the improved solidification/stabilization of DOE low-level wastes. The approach taken in this study was to perform a series of survey type experiments using various polymerization systems to find the most economical and practical method for further in-depth studies. Compactible dry bulk waste was stabilized with two different monomer systems: styrene-trimethylolpropane trimethacrylate (TMPTMA) and polyester-styrene, in laboratory-scale experiments. Stabilization was accomplished by wetting or soaking compactible waste (before or after compaction) with monomers, which were subsequently polymerized. Three stabilization methods are described. One involves the in-situ treatment of compacted waste with monomers in which a vacuum technique is used to introduce the binder into the waste. The second method involves the alternate placement and compaction of waste and binder into a disposal container. In the third method, the waste is treated before compaction by wetting the waste with the binder using a spraying technique. A series of samples stabilized at various binder-to-waste ratios were evaluated through water immersion and compression testing. Full-scale studies were conducted by stabilizing two 55-gallon drums of real compacted waste. The results of this preliminary study indicate that the integrity of compacted waste forms can be readily improved to ensure their long-term durability in disposal environments. 9 refs., 10 figs., 2 tabs.

  5. Compaction properties of isomalt.

    PubMed

    Bolhuis, Gerad K; Engelhart, Jeffrey J P; Eissens, Anko C

    2009-08-01

    Although other polyols have been described extensively as filler-binders in direct compaction of tablets, the polyol isomalt is rather unknown as pharmaceutical excipient, in spite of its description in all the main pharmacopoeias. In this paper the compaction properties of different types of ispomalt were studied. The types used were the standard product sieved isomalt, milled isomalt and two types of agglomerated isomalt with a different ratio between 6-O-alpha-d-glucopyranosyl-d-sorbitol (GPS) and 1-O-alpha-d-glucopyranosyl-d-mannitol dihydrate (GPM). Powder flow properties, specific surface area and densities of the different types were investigated. Compactibility was investigated by compression of the tablets on a compaction simulator, simulating the compression on high-speed tabletting machines. Lubricant sensitivity was measured by compressing unlubricated tablets and tablets lubricated with 1% magnesium stearate on an instrumented hydraulic press. Sieved isomalt had excellent flow properties but the compactibility was found to be poor whereas the lubricant sensitivity was high. Milling resulted in both a strong increase in compactibility as an effect of the higher surface area for bonding and a decrease in lubricant sensitivity as an effect of the higher surface area to be coated with magnesium stearate. However, the flow properties of milled isomalt were too bad for use as filler-binder in direct compaction. Just as could be expected, agglomeration of milled isomalt by fluid bed agglomeration improved flowability. The good compaction properties and the low lubricant sensitivity were maintained. This effect is caused by an early fragmentation of the agglomerated material during the compaction process, producing clean, lubricant-free particles and a high surface for bonding. The different GPS/GPM ratios of the agglomerated isomalt types studied had no significant effect on the compaction properties. PMID:19327398

  6. Compact microchannel system

    DOEpatents

    Griffiths, Stewart

    2003-09-30

    The present invention provides compact geometries for the layout of microchannel columns through the use of turns and straight channel segments. These compact geometries permit the use of long separation or reaction columns on a small microchannel substrate or, equivalently, permit columns of a fixed length to occupy a smaller substrate area. The new geometries are based in part on mathematical analyses that provide the minimum turn radius for which column performance in not degraded. In particular, we find that straight channel segments of sufficient length reduce the required minimum turn radius, enabling compact channel layout when turns and straight segments are combined. The compact geometries are obtained by using turns and straight segments in overlapped or nested arrangements to form pleated or coiled columns.

  7. Dark compact planets

    NASA Astrophysics Data System (ADS)

    Tolos, Laura; Schaffner-Bielich, Jürgen

    2015-12-01

    We investigate compact objects formed by dark matter admixed with ordinary matter made of neutron-star matter and white-dwarf material. We consider non-self annihilating dark matter with an equation of state given by an interacting Fermi gas. We find new stable solutions, dark compact planets, with Earth-like masses and radii from a few Km to few hundred Km for weakly interacting dark matter which are stabilized by the mutual presence of dark matter and compact star matter. For the strongly interacting dark matter case, we obtain dark compact planets with Jupiter-like masses and radii of few hundred Km. These objects could be detected by observing exoplanets with unusually small radii. Moreover, we find that the recently observed 2 M⊙ pulsars set limits on the amount of dark matter inside neutron stars which is, at most, 1 0-6 M⊙ .

  8. Compact baby Skyrmions

    SciTech Connect

    Adam, C.; Klimas, P.; Sanchez-Guillen, J.; Wereszczynski, A.

    2009-11-15

    For the baby Skyrme model with a specific potential, compacton solutions, i.e., configurations with a compact support and parabolic approach to the vacuum, are derived. Specifically, in the nontopological sector, we find spinning Q-balls and Q-shells, as well as peakons. Moreover, we obtain compact baby skyrmions with nontrivial topological charge. All these solutions may form stable multisoliton configurations provided they are sufficiently separated.

  9. Firefighting module development

    NASA Technical Reports Server (NTRS)

    Burns, R. A.

    1981-01-01

    The firefighting module is a lightweight, compact, self contained, helicopter-transportable unit for fighting harbor and other specialty fires as well as for use in emergency water pumping applications. Units were fabricated and tested. A production type unit is undergoing an inservice evaluation and demonstration program at the port of St Louis. The primary purpose is to promote enhanced harbor fire protection at inland and coastal ports. The module and its development are described.

  10. COMPACT SCHOOL AND $$ SAVINGS.

    ERIC Educational Resources Information Center

    BAIR, W.G.

    A REVIEW OF THE CRITERIA FOR CONSIDERING THE USE OF A TOTAL ENERGY SYSTEM WITHIN A SCHOOL BUILDING STATES THE WINDOWLESS, COMPACT SCHOOL OFFERS MORE EFFICIENT SPACE UTILIZATION WITH LESS AREA REQUIRED FOR GIVEN STUDENT POPULATION AND LOWER OPERATION COSTS. THE AUTHOR RECOMMENDS THAT THESE BUILDINGS BE WINDOWLESS TO REDUCE HEAT COSTS, HOWEVER, AT…

  11. Limestone compaction: an enigma

    USGS Publications Warehouse

    Shinn, Eugene A.; Halley, Robert B.; Hudson, J. Harold; Lidz, Barbara H.

    1977-01-01

    Compression of an undisturbed carbonate sediment core under a pressure of 556 kg/cm2 produced a “rock” with sedimentary structures similar to typical ancient fine-grained limestones. Surprisingly, shells, foraminifera, and other fossils were not noticeably crushed, which indicates that absence of crushed fossils in ancient limestones can no longer be considered evidence that limestones do not compact.

  12. Coast Guard Firefighting Module

    NASA Technical Reports Server (NTRS)

    1977-01-01

    NASA and the U.S. Coast Guard are jointly developing a lightweight, helicopter-transportable, completely self-contained firefighting module for combating shipboard and dockside fires. The project draws upon NASA technology in high-capacity rocket engine pumps, lightweight materials and compact packaging.

  13. Optical radiation emissions from compact fluorescent lamps.

    PubMed

    Khazova, M; O'Hagan, J B

    2008-01-01

    There is a drive to energy efficiency to mitigate climate change. To meet this challenge, the UK Government has proposed phasing out incandescent lamps by the end of 2011 and replacing them with energy efficient fluorescent lighting, including compact fluorescent lamps (CFLs) with integrated ballasts. This paper presents a summary of an assessment conducted by the Health Protection Agency in March 2008 to evaluate the optical radiation emissions of CFLs currently available in the UK consumer market. The study concluded that the UV emissions from a significant percentage of the tested CFLs with single envelopes may result in foreseeable overexposure of the skin when these lamps are used in desk or task lighting applications. The optical output of all tested CFLs, in addition to high-frequency modulation, had a 100-Hz envelope with modulation in excess of 15%. This degree of modulation may be linked to a number of adverse effects. PMID:18757896

  14. Analysis of Technology for Compact Coherent Lidar

    NASA Technical Reports Server (NTRS)

    Amzajerdian, Farzin

    1997-01-01

    In view of the recent advances in the area of solid state and semiconductor lasers has created new possibilities for the development of compact and reliable coherent lidars for a wide range of applications. These applications include: Automated Rendezvous and Capture, wind shear and clear air turbulence detection, aircraft wake vortex detection, and automobile collision avoidance. The work performed by the UAH personnel under this Delivery Order, concentrated on design and analyses of a compact coherent lidar system capable of measuring range and velocity of hard targets, and providing air mass velocity data. The following is the scope of this work. a. Investigate various laser sources and optical signal detection configurations in support of a compact and lightweight coherent laser radar to be developed for precision range and velocity measurements of hard and fuzzy targets. Through interaction with MSFC engineers, the most suitable laser source and signal detection technique that can provide a reliable compact and lightweight laser radar design will be selected. b. Analyze and specify the coherent laser radar system configuration and assist with its optical and electronic design efforts. Develop a system design including its optical layout design. Specify all optical components and provide the general requirements of the electronic subsystems including laser beam modulator and demodulator drivers, detector electronic interface, and the signal processor. c. Perform a thorough performance analysis to predict the system measurement range and accuracy. This analysis will utilize various coherent laser radar sensitivity formulations and different target models.

  15. Compact continuum brain model for human electroencephalogram

    NASA Astrophysics Data System (ADS)

    Kim, J. W.; Shin, H.-B.; Robinson, P. A.

    2007-12-01

    A low-dimensional, compact brain model has recently been developed based on physiologically based mean-field continuum formulation of electric activity of the brain. The essential feature of the new compact model is a second order time-delayed differential equation that has physiologically plausible terms, such as rapid corticocortical feedback and delayed feedback via extracortical pathways. Due to its compact form, the model facilitates insight into complex brain dynamics via standard linear and nonlinear techniques. The model successfully reproduces many features of previous models and experiments. For example, experimentally observed typical rhythms of electroencephalogram (EEG) signals are reproduced in a physiologically plausible parameter region. In the nonlinear regime, onsets of seizures, which often develop into limit cycles, are illustrated by modulating model parameters. It is also shown that a hysteresis can occur when the system has multiple attractors. As a further illustration of this approach, power spectra of the model are fitted to those of sleep EEGs of two subjects (one with apnea, the other with narcolepsy). The model parameters obtained from the fittings show good matches with previous literature. Our results suggest that the compact model can provide a theoretical basis for analyzing complex EEG signals.

  16. Progress in Compact Toroid Experiments

    SciTech Connect

    Dolan, Thomas James

    2002-09-01

    The term "compact toroids" as used here means spherical tokamaks, spheromaks, and field reversed configurations, but not reversed field pinches. There are about 17 compact toroid experiments under construction or operating, with approximate parameters listed in Table 1.

  17. Compact stereo endoscopic camera using microprism arrays.

    PubMed

    Yang, Sung-Pyo; Kim, Jae-Jun; Jang, Kyung-Won; Song, Weon-Kook; Jeong, Ki-Hun

    2016-03-15

    This work reports a microprism array (MPA) based compact stereo endoscopic camera with a single image sensor. The MPAs were monolithically fabricated by using two-step photolithography and geometry-guided resist reflow to form an appropriate prism angle for stereo image pair formation. The fabricated MPAs were transferred onto a glass substrate with a UV curable resin replica by using polydimethylsiloxane (PDMS) replica molding and then successfully integrated in front of a single camera module. The stereo endoscopic camera with MPA splits an image into two stereo images and successfully demonstrates the binocular disparities between the stereo image pairs for objects with different distances. This stereo endoscopic camera can serve as a compact and 3D imaging platform for medical, industrial, or military uses. PMID:26977690

  18. Compact Spreader Schemes

    SciTech Connect

    Placidi, M.; Jung, J. -Y.; Ratti, A.; Sun, C.

    2014-07-25

    This paper describes beam distribution schemes adopting a novel implementation based on low amplitude vertical deflections combined with horizontal ones generated by Lambertson-type septum magnets. This scheme offers substantial compactness in the longitudinal layouts of the beam lines and increased flexibility for beam delivery of multiple beam lines on a shot-to-shot basis. Fast kickers (FK) or transverse electric field RF Deflectors (RFD) provide the low amplitude deflections. Initially proposed at the Stanford Linear Accelerator Center (SLAC) as tools for beam diagnostics and more recently adopted for multiline beam pattern schemes, RFDs offer repetition capabilities and a likely better amplitude reproducibility when compared to FKs, which, in turn, offer more modest financial involvements both in construction and operation. Both solutions represent an ideal approach for the design of compact beam distribution systems resulting in space and cost savings while preserving flexibility and beam quality.

  19. Compact waveguide splitter networks.

    PubMed

    Qian, Yusheng; Song, Jiguo; Kim, Seunghyun; Hu, Weisheng; Nordin, Gregory P

    2008-03-31

    We demonstrate compact waveguide splitter networks in siliconon- insulator (SOI) rib waveguides using trench-based splitters (TBSs) and bends (TBBs). Rather than a 90 degrees geometry, we use 105 degrees TBSs to facilitate reliable fabrication of high aspect ratio trenches suitable for 50/50 splitting when filled with SU8. Three dimensional (3D) finite difference time domain (FDTD) simulation is used for splitter and bend design. Measured TBB and TBS optical efficiencies are 84% and 68%, respectively. Compact 105 degrees 1 x 4, 1 x 8, and 1 x 32 trench-based splitter networks (TBSNs) are demonstrated. The measured total optical loss of the 1 x 32 TBSN is 9.15 dB. Its size is only 700 microm x 1600 microm for an output waveguide spacing of 50 microm. PMID:18542598

  20. Compact infrared detector

    NASA Technical Reports Server (NTRS)

    Gupta, A.; Hong, S.; Moacanin, J.

    1981-01-01

    Broadband IR detector integrated into compact package for pollution monitoring and weather prediction is small, highly responsive, and immune to high noise. Sensing material is transparent sheet metalized with reflecting coating and overcoated with black material on same side. Pulse produced by chopping of infrared source beam creates transient "thermal lens" that temporarily defocuses laser beam probe. Detector monitoring beam measures defocusing which parallels infrared intensity.

  1. Compact power reactor

    DOEpatents

    Wetch, Joseph R.; Dieckamp, Herman M.; Wilson, Lewis A.

    1978-01-01

    There is disclosed a small compact nuclear reactor operating in the epithermal neutron energy range for supplying power at remote locations, as for a satellite. The core contains fuel moderator elements of Zr hydride with 7 w/o of 93% enriched uranium alloy. The core has a radial beryllium reflector and is cooled by liquid metal coolant such as NaK. The reactor is controlled and shut down by moving portions of the reflector.

  2. Compact heat exchangers

    SciTech Connect

    Kays, W.M.; London, A.L.

    1984-01-01

    This third edition is an update of the second edition published in 1964. New data and more modern theoretical solutions for flow in the simple geometries are included, although this edition does not differ radically from the second edition. It contains basic test data for eleven new surface configurations, including some of the very compact ceramic matrices. Al dimensions are given in both the English and the Systeme International (SI) system of units.

  3. Granule consolidation during compaction.

    PubMed

    Rubinstein, M H

    1976-03-01

    The deformation of small cylindrical aggregates of dibasic calcium phosphate was measured during compaction. An analogy between these aggregates and cylindrical granules was proposed. No change in the original shape of the aggregates occurred; the cylindrical shape was maintained even at high compaction pressures. Relaxation of the aggregates occurred at pressures higher than 420 MNm-2 (60.9 x 10(3) lb in.-2) when removed from the compacts, but no relaxation took place at pressures below this value. In addition, the aggregates relaxed by an increase in thickness only; there was no corresponding change in diameter. Up to a pressure of 200 MNm-2 (29.0 x 10(3) lb in.-2), an increase in aggregate diameter occurred, which was accompanied by a reduction in thickness. This change produced only a small reduction in volume, which was attributable to interparticulate slippage resulting in a closer packed arrangement. At a pressure of 200 MNm-2, the aggregate diameter no longer increased because solid bridges were formed between the particles and the die wall, preventing further spreading. From 200 to 420 MNm-2, failure of the material occurred by plastic deformation, which produced only a decrease in aggregate thickness. From 420 to 800 MNm-2 (116.0 x 10(3) lb in.-2), a structure was formed that could support the applied load without further reduction of thickness, and this structure was shown to behave elastically. PMID:1263085

  4. Magnetic field-induced ferroelectric domain structure evolution and magnetoelectric coupling for [110]-oriented PMN-PT/Terfenol-D multiferroic composites

    NASA Astrophysics Data System (ADS)

    Fang, F.; Jing, W. Q.

    2016-01-01

    Magnetic field-induced polarization rotation and magnetoelectric coupling effects are studied for [110]-oriented (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3/Tb0.3Dy0.7Fe2(PMN-xPT/Terfenol-D) multiferroic composites. Two compositions of the [110]-oriented relaxor ferroelectric single crystals, PMN-28PT and PMN-33PT, are used. In [110]-oriented PMN-28PT, domains of rhombohedral (R) and monoclinic (MB) phases coexist prior to the magnetic loadings. Upon the applied magnetic loadings, phase transition from monoclinic MB to R phase occurs. In [110]-oriented PMN-33PT, domains are initially of mixed orthorhombic (O) and MB phases, and the phase transition from O to MB phase takes place upon the external magnetic loading. Compared to PMN-28PT, the PMN-33PT single crystal exhibits much finer domain boundary structure prior to the magnetic loadings. Upon the magnetic loadings, more domain variants are induced via the phase transition in PMN-33PT than that in PMN-28PT single crystal. The finer domain band structure and more domain variants contribute to stronger piezoelectric activity. As a result, the composite of PMN-33PT/Terfenol-D manifests a stronger ME coupling than PMN-28PT/Terfenol-D composite.

  5. Advanced Construction of Compact Containment BWR

    SciTech Connect

    Takahashi, M.; Maruyama, T.; Mori, H.; Hoshino, K.; Hijioka, Y.; Heki, H.; Nakamaru, M.; Hoshi, T.

    2006-07-01

    fabricate and perform pressure-test at the factory and transport to the construction-site as a module. Basing on CCR design concept of simplification and compact, reactor building layout design has been carried out. Layout design has been performed taking into account module construction, reduced system and components and compact PCV. As a result, CCR's reactor building, specific volume to power output value is almost equal to ABWR one. Module fabrication and construction method is promising technology from the points of construction duration shortening and construction cost reduction. Electrical equipment are piled up to multi-layer and connected and tested at the factory and transported to the construction-site in one module. Other equipment rooms and areas are also built into the various pre-fabricated module types in CCR construction. The construction of the CCR by the large module is planned to achieve only 24-month construction period from bedrock inspection to commercial operation. The CCR has possibilities of attaining both economical and safe small reactor by simplified system and compact PCV technologies with advanced construction. (authors)

  6. Compact slot-in-type optical correlator

    NASA Astrophysics Data System (ADS)

    Yamamoto, Shota; Kuboyama, Hirotoshi; Arai, Shinichi; Yamaguchi, Kenzo; Fukuda, Mitsuo; Kato, Makoto; Kawaguchi, Tadahiko; Inoue, Mitsuteru

    2010-05-01

    We present a new slot-in type of optical correlator that is more compact than the previous types. The correlator can fit inside the cabinet of commercial personal computers and is fully controllable with windows-based software. The correlator is a Joint Transform type (JTC) and its optical system fits inside a metal box measuring 140 mm (W) x 220 mm (L) x 40 mm (H). The optical source is a 650-nm-band laser diode of the kind used in DVD systems. A spatial light modulator and a CMOS camera are installed in the metal box with the passive optical components required for the JTC. The collimated light from the laser diode is illuminated on the spatial light modulator displaying reference and data to be examined. The light reflected from the modulator is Fourier-transformed by a lens on the plane of the CMOS camera. The computer reads the power spectrum recorded by the camera and modulates the spatial light modulator. This process is repeated. We found that these JTC processes could be performed with the prototype developed in this study.

  7. Criteria of cyclic compactness of the sets from Lp - spaces, associated with vector measure

    NASA Astrophysics Data System (ADS)

    Chilin, V.; Rakhimov, B.; Rakhimov, A.

    2013-09-01

    We study the conditional expectations in the Lp-modules associated with a partition of unity of a Boolean algebra. Cyclic compactness criteria of the subsets of Lp found in terms of convergent nets of conditional expectations.

  8. Electric field mediated non-volatile tuning magnetism at the single-crystalline Fe/Pb(Mg1/3Nb2/3)0.7Ti0.3O3 interface

    NASA Astrophysics Data System (ADS)

    Zhang, Chao; Wang, Fenglong; Dong, Chunhui; Gao, Cunxu; Jia, Chenglong; Jiang, Changjun; Xue, Desheng

    2015-02-01

    We report non-volatile electric-field control of magnetism modulation in Fe/Pb(Mg1/3Nb2/3)0.7Ti0.3O3 (PMN-PT) heterostructure by fabricating an epitaxial Fe layer on a PMN-PT substrate using a molecular beam epitaxy technique. The remnant magnetization with a different electric field shows a non-symmetric loop-like shape, which demonstrates a change of interfacial chemistry and a large magnetoelectric coupling in Fe/PMN-PT at room temperature to realize low loss multistate memory under an electric field. Fitting with the angular-dependence of the in-plane magnetization reveals that the magnetoelectric effect is dominated by the direct electric-field effect rather than the strain effect at the interface. The magnetoelectric effect and the induced surface anisotropy are found to be dependent on the Fe film thickness and are linear with respect to the applied electric field.

  9. Compact laser amplifier system

    DOEpatents

    Carr, R.B.

    1974-02-26

    A compact laser amplifier system is described in which a plurality of face-pumped annular disks, aligned along a common axis, independently radially amplify a stimulating light pulse. Partially reflective or lasing means, coaxially positioned at the center of each annualar disk, radially deflects a stimulating light directed down the common axis uniformly into each disk for amplification, such that the light is amplified by the disks in a parallel manner. Circumferential reflecting means coaxially disposed around each disk directs amplified light emission, either toward a common point or in a common direction. (Official Gazette)

  10. Photometry of compact galaxies.

    NASA Technical Reports Server (NTRS)

    Shen, B. S. P.; Usher, P. D.; Barrett, J. W.

    1972-01-01

    Photometric histories of the N galaxies 3C 390.3 and PKS 0521-36. Four other compact galaxies, Markarian 9, I Zw 92, 2 Zw 136, and III Zw 77 showed no evidence of variability. The photometric histories were obtained from an exhaustive study of those plates of the Harvard collection taken with large aperture cameras. The images of all galaxies reported were indistinguishable from stars due to the camera f-ratios and low surface brightness of the outlying nebulosities of the galaxies. Standard techniques for the study of variable stars are therefore applicable.

  11. Compact Q-balls

    NASA Astrophysics Data System (ADS)

    Bazeia, D.; Losano, L.; Marques, M. A.; Menezes, R.; da Rocha, R.

    2016-07-01

    In this work we deal with non-topological solutions of the Q-ball type in two space-time dimensions, in models described by a single complex scalar field that engenders global symmetry. The main novelty is the presence of stable Q-balls solutions that live in a compact interval of the real line and appear from a family of models controlled by two distinct parameters. We find analytical solutions and study their charge and energy, and show how to control the parameters to make the Q-balls classically and quantum mechanically stable.

  12. Compact LINAC for deuterons

    SciTech Connect

    Kurennoy, S S; O' Hara, J F; Rybarcyk, L J

    2008-01-01

    We are developing a compact deuteron-beam accelerator up to the deuteron energy of a few MeV based on room-temperature inter-digital H-mode (IH) accelerating structures with the transverse beam focusing using permanent-magnet quadrupoles (PMQ). Combining electromagnetic 3-D modeling with beam dynamics simulations and thermal-stress analysis, we show that IHPMQ structures provide very efficient and practical accelerators for light-ion beams of considerable currents at the beam velocities around a few percent of the speed of light. IH-structures with PMQ focusing following a short RFQ can also be beneficial in the front end of ion linacs.

  13. Compact multiframe blind deconvolution.

    PubMed

    Hope, Douglas A; Jefferies, Stuart M

    2011-03-15

    We describe a multiframe blind deconvolution (MFBD) algorithm that uses spectral ratios (the ratio of the Fourier spectra of two data frames) to model the inherent temporal signatures encoded by the observed images. In addition, by focusing on the separation of the object spectrum and system transfer functions only at spatial frequencies where the measured signal is above the noise level, we significantly reduce the number of unknowns to be determined. This "compact" MFBD yields high-quality restorations in a much shorter time than is achieved with MFBD algorithms that do not model the temporal signatures; it may also provide higher-fidelity solutions. PMID:21403711

  14. Compact Plasma Accelerator

    NASA Technical Reports Server (NTRS)

    Foster, John E.

    2004-01-01

    A plasma accelerator has been conceived for both material-processing and spacecraft-propulsion applications. This accelerator generates and accelerates ions within a very small volume. Because of its compactness, this accelerator could be nearly ideal for primary or station-keeping propulsion for spacecraft having masses between 1 and 20 kg. Because this accelerator is designed to generate beams of ions having energies between 50 and 200 eV, it could also be used for surface modification or activation of thin films.

  15. Compact gate valve

    DOEpatents

    Bobo, Gerald E.

    1977-01-01

    This invention relates to a double-disc gate valve which is compact, comparatively simple to construct, and capable of maintaining high closing pressures on the valve discs with low frictional forces. The valve casing includes axially aligned ports. Mounted in the casing is a sealed chamber which is pivotable transversely of the axis of the ports. The chamber contains the levers for moving the valve discs axially, and an actuator for the levers. When an external drive means pivots the chamber to a position where the discs are between the ports and axially aligned therewith, the actuator for the levers is energized to move the discs into sealing engagement with the ports.

  16. Experimental demonstration of microring quadrature phase-shift keying modulators.

    PubMed

    Dong, Po; Xie, Chongjin; Chen, Long; Fontaine, Nicolas K; Chen, Young-kai

    2012-04-01

    Advanced optical modulation formats are a key technology to increase the capacity of optical communication networks. Mach-Zehnder modulators are typically used to generate various modulation formats. Here, we report the first experimental demonstration of quadrature phase-shift keying (QPSK) modulation using compact microring modulators. Generation of 20 Gb/s QPSK signals is demonstrated with 30 μm radius silicon ring modulators with drive voltages of ~6 V. These compact QPSK modulators may be used in miniature optical transponders for high-capacity optical data links. PMID:22466187

  17. Two compact preamps cover 38-GHz bandwidth

    NASA Astrophysics Data System (ADS)

    Osbrink, N. K.; Fake, S. R.; Rosenberg, J. C.

    1985-09-01

    The design and performance characteristics of two compact preamplifiers that provide complete coverage of the 2-18 and 18-40 GHz frequency bands are examined. The 2-18-GHz prototype amplifier consists of four stages of thin-film hybrid microwave integrated circuit (MIC) amplification modules each of which incorporates a single GaAs distributed microwave integrated circuit (MMIC). The amplifier weights about 2 ounces and measures 1.75 x 1.15 x 0.67 inches. The 18-40-GHz amplifier consists of five thin-film MIC balanced gain stages and a MIC voltage regulator module with a throughline. The amplifier displays worst-case noise figures of 11.6 dB at the low frequency end of the band and less than 8 dB over much of the band.

  18. Low cost and compact quantum key distribution

    NASA Astrophysics Data System (ADS)

    Duligall, J. L.; Godfrey, M. S.; Harrison, K. A.; Munro, W. J.; Rarity, J. G.

    2006-10-01

    We present the design of a novel free-space quantum cryptography system, complete with purpose-built software, that can operate in daylight conditions. The transmitter and receiver modules are built using inexpensive off-the-shelf components. Both modules are compact allowing the generation of renewed shared secrets on demand over a short range of a few metres. An analysis of the software is shown as well as results of error rates and therefore shared secret yields at varying background light levels. As the system is designed to eventually work in short-range consumer applications, we also present a use scenario where the consumer can regularly 'top up' a store of secrets for use in a variety of one-time-pad (OTP) and authentication protocols.

  19. Compaction of Titanium Powders

    SciTech Connect

    Stephen J. Gerdemann; Paul D. Jablonski

    2010-11-01

    Accurate modeling of powder densification has been an area of active research for more than 60 years. The earliest efforts were focused on linearization of the data because computers were not readily available to assist with curve-fitting methods. In this work, eight different titanium powders (three different sizes of sponge fines <150 μm, <75 μm, and < 45 μm; two different sizes of a hydride-dehydride [HDH] <75 μm and < 45 μm; an atomized powder; a commercially pure [CP] Ti powder from International Titanium Powder [ITP]; and a Ti 6 4 alloy powder) were cold pressed in a single-acting die instrumented to collect stress and deformation data during compaction. From these data, the density of each compact was calculated and then plotted as a function of pressure. The results show that densification of all the powders, regardless of particle size, shape, or chemistry, can be modeled accurately as the sum of an initial density plus the sum of a rearrangement term and a work-hardening term. These last two terms are found to be a function of applied pressure and take the form of an exponential rise.

  20. Compact electrostatic comb actuator

    DOEpatents

    Rodgers, M. Steven; Burg, Michael S.; Jensen, Brian D.; Miller, Samuel L.; Barnes, Stephen M.

    2000-01-01

    A compact electrostatic comb actuator is disclosed for microelectromechanical (MEM) applications. The actuator is based upon a plurality of meshed electrostatic combs, some of which are stationary and others of which are moveable. One or more restoring springs are fabricated within an outline of the electrostatic combs (i.e. superposed with the moveable electrostatic combs) to considerably reduce the space required for the actuator. Additionally, a truss structure is provided to support the moveable electrostatic combs and prevent bending or distortion of these combs due to unbalanced electrostatic forces or external loading. The truss structure formed about the moveable electrostatic combs allows the spacing between the interdigitated fingers of the combs to be reduced to about one micron or less, thereby substantially increasing the number of active fingers which can be provided in a given area. Finally, electrostatic shields can be used in the actuator to substantially reduce unwanted electrostatic fields to further improve performance of the device. As a result, the compact electrostatic comb actuator of the present invention occupies only a fraction of the space required for conventional electrostatic comb actuators, while providing a substantial increase in the available drive force (up to one-hundred times).

  1. METHOD OF FORMING ELONGATED COMPACTS

    DOEpatents

    Larson, H.F.

    1959-05-01

    A powder compacting procedure and apparatus which produces elongated compacts of Be is described. The powdered metal is placed in a thin metal tube which is chemically compatible to lubricant, powder, atmosphere, and die material and will undergo a high degree of plastic deformation and have intermediate hardness. The tube is capped and placed in the die, and punches are applied to the ends. During the compacting stroke the powder seizes the tube and a thickening and shortening of the tube occurs. The tube is easily removed from the die, split, and peeled from the compact. (T.R.H.)

  2. Multipurpose Compact Spectrometric Unit

    SciTech Connect

    Bocarov, Viktor; Cermak, Pavel; Mamedov, Fadahat; Stekl, Ivan

    2009-11-09

    A new standalone compact spectrometer was developed. The device consists of analog (peamplifier, amplifier) and digital parts. The digital part is based on the 160 MIPS Digital Signal Processor. It contains 20 Msps Flash-ADC, 1 MB RAM for spectra storage, 128 KB Flash/ROM for firmware storage, Real Time Clock and several voltage regulators providing the power for user peripherals (e.g. amplifier, temperature sensors, etc.). Spectrometer is connected with a notebook via high-speed USB 2.0 bus. The spectrometer is multipurpose device, which is planned to be used for measurements of Rn activities, energy of detected particles by CdTe pixel detector or for coincidence measurements.

  3. Compact vacuum insulation embodiments

    DOEpatents

    Benson, D.K.; Potter, T.F.

    1992-04-28

    An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially point' or line' contacts with the metal wall sheets. In the case of monolithic spacers that form line' contacts, two such spacers with the line contacts running perpendicular to each other form effectively point' contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included. 26 figs.

  4. Compact vacuum insulation

    DOEpatents

    Benson, D.K.; Potter, T.F.

    1993-01-05

    An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially point'' or line'' contacts with the metal wall sheets. In the case of monolithic spacers that form line'' contacts, two such spacers with the line contacts running perpendicular to each other form effectively point'' contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included.

  5. Compact vacuum insulation

    DOEpatents

    Benson, David K.; Potter, Thomas F.

    1993-01-01

    An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially "point" or "line" contacts with the metal wall sheets. In the case of monolithic spacers that form "line" contacts, two such spacers with the line contacts running perpendicular to each other form effectively "point" contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included.

  6. Compact vacuum insulation embodiments

    DOEpatents

    Benson, David K.; Potter, Thomas F.

    1992-01-01

    An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially "point" or "line" contacts with the metal wall sheets. In the case of monolithic spacers that form "line" contacts, two such spacers with the line contacts running perpendicular to each other form effectively "point" contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included.

  7. Compact acoustic refrigerator

    DOEpatents

    Bennett, Gloria A.

    1992-01-01

    A compact acoustic refrigeration system actively cools components, e.g., electrical circuits (22), in a borehole environment. An acoustic engine (12, 14) includes first thermodynamic elements (12) for generating a standing acoustic wave in a selected medium. An acoustic refrigerator (16, 26, 28) includes second thermodynamic elements (16) located in the standing wave for generating a relatively cold temperature at a first end of the second thermodynamic elements (16) and a relatively hot temperature at a second end of the second thermodynamic elements (16). A resonator volume (18) cooperates with the first and second thermodynamic elements (12, 16) to support the standing wave. To accommodate the high heat fluxes required for heat transfer to/from the first and second thermodynamic elements (12, 16), first heat pipes (24, 26) transfer heat from the heat load (22) to the second thermodynamic elements (16) and second heat pipes (28, 32) transfer heat from first and second thermodynamic elements (12, 16) to the borehole environment.

  8. Compact SPS - Power delivery

    NASA Astrophysics Data System (ADS)

    Pospisil, M.; Pospisilova, L.

    1982-09-01

    The power deliverable by a compact solar Space Power Station (SPS) is a function of its outer surface shape. Methods of fitting the power delivery curve of such a system to different patterns of daily power demand are considered that involve the appropriate choice of the number of satellites, their maximal power, height to width ratio and the shift of longitude with respect to the receiving station. Changes in the daily delivery curve can be made by altering the longitudes and orientations of the satellites. Certain limitations to the choice of parameters exist, such as: the height to width ratio should be near 1.2, and the sum of longitude and orientation changes will probably not be greater than 50 deg. The optimization of the peak to average power ratio is also discussed.

  9. Compact acoustic refrigerator

    DOEpatents

    Bennett, G.A.

    1992-11-24

    A compact acoustic refrigeration system actively cools components, e.g., electrical circuits, in a borehole environment. An acoustic engine includes first thermodynamic elements for generating a standing acoustic wave in a selected medium. An acoustic refrigerator includes second thermodynamic elements located in the standing wave for generating a relatively cold temperature at a first end of the second thermodynamic elements and a relatively hot temperature at a second end of the second thermodynamic elements. A resonator volume cooperates with the first and second thermodynamic elements to support the standing wave. To accommodate the high heat fluxes required for heat transfer to/from the first and second thermodynamic elements, first heat pipes transfer heat from the heat load to the second thermodynamic elements and second heat pipes transfer heat from first and second thermodynamic elements to the borehole environment. 18 figs.

  10. Compact artificial hand

    NASA Technical Reports Server (NTRS)

    Wiker, G. A.; Mann, W. A. (Inventor)

    1979-01-01

    A relatively simple, compact artificial hand, is described which includes hooks pivotally mounted on first frame to move together and apart. The first frame is rotatably mounted on a second frame to enable "turning at the wrist" movement without limitation. The second frame is pivotally mounted on a third frame to permit 'flexing at the wrist' movement. A hook-driving motor is fixed to the second frame but has a shaft that drives a speed reducer on the first frame which, in turn, drives the hooks. A second motor mounted on the second frame, turns a gear on the first frame to rotate the first frame and the hooks thereon. A third motor mounted on the third frame, turns a gear on a second frame to pivot it.