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Linghang Wang - One of the best experts on this subject based on the ideXlab platform.
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an efficient way to enhance output strain for shear mode pb in1 2nb1 2 o3 pb mg1 3nb2 3 o3 pbtio3 crystals applying uniaxial stress perpendicular to Polar Direction
Applied Physics Letters, 2012Co-Authors: Shujun Zhang, Dabin Lin, Junjie Gao, Linghang WangAbstract:The shear piezoelectric behavior of [001] poled tetragonal and [011] poled rhombohedral Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) crystals, with “1T” and “2R” domain configurations, respectively, were investigated under uniaxial stress perpendicular to Polar Direction. The shear piezoelectric coefficient d15 was found to decrease with increasing compressive stress for both “1T” and “2R” crystals. Based on thermodynamic analysis, the phase structure can be stabilized by applying compressive stress perpendicular to Polar Direction, resulting in a “harder” Polarization rotation process, accounts for the reduced shear piezoelectric coefficient. Of particular importance is that the allowable drive electric field was greatly increased and transverse dielectric loss was drastically reduced under compressive stress, leading to the improved maximum-shear-strain.
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An efficient way to enhance output strain for shear mode Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 crystals: Applying uniaxial stress perpendicular to Polar Direction
Applied Physics Letters, 2012Co-Authors: Shujun Zhang, Dabin Lin, Junjie Gao, Linghang WangAbstract:The shear piezoelectric behavior of [001] poled tetragonal and [011] poled rhombohedral Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) crystals, with “1T” and “2R” domain configurations, respectively, were investigated under uniaxial stress perpendicular to Polar Direction. The shear piezoelectric coefficient d15 was found to decrease with increasing compressive stress for both “1T” and “2R” crystals. Based on thermodynamic analysis, the phase structure can be stabilized by applying compressive stress perpendicular to Polar Direction, resulting in a “harder” Polarization rotation process, accounts for the reduced shear piezoelectric coefficient. Of particular importance is that the allowable drive electric field was greatly increased and transverse dielectric loss was drastically reduced under compressive stress, leading to the improved maximum-shear-strain.
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Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 crystals: Applying uniaxial stress perpendicular to Polar Direction
2012Co-Authors: Shujun Zhang, Dabin Lin, Junjie Gao, Linghang WangAbstract:The shear piezoelectric behavior of [001] poled tetragonal and [011] poled rhombohedral Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) crystals, with “1T” and “2R” domain configurations, respectively, were investigated under uniaxial stress perpendicular to Polar Direction. The shear piezoelectric coefficient d15 was found to decrease with increasing compressive stress for both “1T” and “2R” crystals. Based on thermodynamic analysis, the phase structure can be stabilized by applying compressive stress perpendicular to Polar Direction, resulting in a “harder” Polarization rotation process, accounts for the reduced shear piezoelectric coefficient. Of particular importance is that the allowable drive electric field was greatly increased and transverse dielectric loss was drastically reduced under compressive stress, leading to the improved maximum-shear-strain. V C 2012 American Institute of Physics .[ http://dx.doi.org/10.1063/1.4712129]
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pb in1 2nb1 2 o3 pb mg1 3nb2 3 o3 pbtio3 crystals applying uniaxial stress perpendicular to Polar Direction
2012Co-Authors: Shujun Zhang, Dabin Lin, Junjie Gao, Linghang WangAbstract:The shear piezoelectric behavior of [001] poled tetragonal and [011] poled rhombohedral Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) crystals, with “1T” and “2R” domain configurations, respectively, were investigated under uniaxial stress perpendicular to Polar Direction. The shear piezoelectric coefficient d15 was found to decrease with increasing compressive stress for both “1T” and “2R” crystals. Based on thermodynamic analysis, the phase structure can be stabilized by applying compressive stress perpendicular to Polar Direction, resulting in a “harder” Polarization rotation process, accounts for the reduced shear piezoelectric coefficient. Of particular importance is that the allowable drive electric field was greatly increased and transverse dielectric loss was drastically reduced under compressive stress, leading to the improved maximum-shear-strain. V C 2012 American Institute of Physics .[ http://dx.doi.org/10.1063/1.4712129]
Shujun Zhang - One of the best experts on this subject based on the ideXlab platform.
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an efficient way to enhance output strain for shear mode pb in1 2nb1 2 o3 pb mg1 3nb2 3 o3 pbtio3 crystals applying uniaxial stress perpendicular to Polar Direction
Applied Physics Letters, 2012Co-Authors: Shujun Zhang, Dabin Lin, Junjie Gao, Linghang WangAbstract:The shear piezoelectric behavior of [001] poled tetragonal and [011] poled rhombohedral Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) crystals, with “1T” and “2R” domain configurations, respectively, were investigated under uniaxial stress perpendicular to Polar Direction. The shear piezoelectric coefficient d15 was found to decrease with increasing compressive stress for both “1T” and “2R” crystals. Based on thermodynamic analysis, the phase structure can be stabilized by applying compressive stress perpendicular to Polar Direction, resulting in a “harder” Polarization rotation process, accounts for the reduced shear piezoelectric coefficient. Of particular importance is that the allowable drive electric field was greatly increased and transverse dielectric loss was drastically reduced under compressive stress, leading to the improved maximum-shear-strain.
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An efficient way to enhance output strain for shear mode Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 crystals: Applying uniaxial stress perpendicular to Polar Direction
Applied Physics Letters, 2012Co-Authors: Shujun Zhang, Dabin Lin, Junjie Gao, Linghang WangAbstract:The shear piezoelectric behavior of [001] poled tetragonal and [011] poled rhombohedral Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) crystals, with “1T” and “2R” domain configurations, respectively, were investigated under uniaxial stress perpendicular to Polar Direction. The shear piezoelectric coefficient d15 was found to decrease with increasing compressive stress for both “1T” and “2R” crystals. Based on thermodynamic analysis, the phase structure can be stabilized by applying compressive stress perpendicular to Polar Direction, resulting in a “harder” Polarization rotation process, accounts for the reduced shear piezoelectric coefficient. Of particular importance is that the allowable drive electric field was greatly increased and transverse dielectric loss was drastically reduced under compressive stress, leading to the improved maximum-shear-strain.
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Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 crystals: Applying uniaxial stress perpendicular to Polar Direction
2012Co-Authors: Shujun Zhang, Dabin Lin, Junjie Gao, Linghang WangAbstract:The shear piezoelectric behavior of [001] poled tetragonal and [011] poled rhombohedral Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) crystals, with “1T” and “2R” domain configurations, respectively, were investigated under uniaxial stress perpendicular to Polar Direction. The shear piezoelectric coefficient d15 was found to decrease with increasing compressive stress for both “1T” and “2R” crystals. Based on thermodynamic analysis, the phase structure can be stabilized by applying compressive stress perpendicular to Polar Direction, resulting in a “harder” Polarization rotation process, accounts for the reduced shear piezoelectric coefficient. Of particular importance is that the allowable drive electric field was greatly increased and transverse dielectric loss was drastically reduced under compressive stress, leading to the improved maximum-shear-strain. V C 2012 American Institute of Physics .[ http://dx.doi.org/10.1063/1.4712129]
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pb in1 2nb1 2 o3 pb mg1 3nb2 3 o3 pbtio3 crystals applying uniaxial stress perpendicular to Polar Direction
2012Co-Authors: Shujun Zhang, Dabin Lin, Junjie Gao, Linghang WangAbstract:The shear piezoelectric behavior of [001] poled tetragonal and [011] poled rhombohedral Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) crystals, with “1T” and “2R” domain configurations, respectively, were investigated under uniaxial stress perpendicular to Polar Direction. The shear piezoelectric coefficient d15 was found to decrease with increasing compressive stress for both “1T” and “2R” crystals. Based on thermodynamic analysis, the phase structure can be stabilized by applying compressive stress perpendicular to Polar Direction, resulting in a “harder” Polarization rotation process, accounts for the reduced shear piezoelectric coefficient. Of particular importance is that the allowable drive electric field was greatly increased and transverse dielectric loss was drastically reduced under compressive stress, leading to the improved maximum-shear-strain. V C 2012 American Institute of Physics .[ http://dx.doi.org/10.1063/1.4712129]
Shunro Fuke - One of the best experts on this subject based on the ideXlab platform.
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growth mode and surface morphology of a gan film deposited along the n face Polar Direction on c plane sapphire substrate
Journal of Applied Physics, 2000Co-Authors: Masashi Sumiya, Kohji Ohtsuka, Hideomi Koinuma, Shunro Fuke, Mamoru Yoshimoto, K. Yoshimura, K Mizuno, Akira Ohtomo, Masashi KawasakiAbstract:The dependence of Polar Direction of GaN film on growth conditions has been investigated by changing either the group-V/group-III ratio (V/III ratio) in supplying the source gas or the deposition rate. GaN films were deposited on a nitrided sapphire by two-step metalorganic chemical vapor deposition. The surface morphology changed from flat hexagonal to pyramidal hexagonal facet with the increase of V/III ratio. However, the Polar Direction of GaN on an optimized buffer layer of 20 nm thickness was N-face (−c) Polarity, independent of both the V/III ratio and the deposition rate. The Polarity of the GaN epitaxtial layer can be determined by that of an interface (nitrided sapphire, annealed buffer layer or GaN substrate) at the deposition of GaN epitaxial layer. The higher V/III ratio enhanced the nucleation density, and reduced the size of hexagonal facets. The nuclei, forming the favorable hexagonal facets of wurtzite GaN, should grow laterally along the {1010} Directions to cover a room among the facet...
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Dependence of impurity incorporation on the Polar Direction of GaN film growth
Applied Physics Letters, 2000Co-Authors: Masashi Sumiya, Kohji Ohtsuka, K. Yoshimura, Shunro FukeAbstract:We have investigated the dependence of impurity incorporation on the Polar Direction of GaN growth by using secondary ion mass spectroscopy (SIMS). GaN films were deposited under conditions used for growing device-quality materials on sapphire substrates while controlling their Polar Direction. It was found that the Polarity of the GaN film influences the incorporation of impurities. SIMS analysis has revealed that the impurities related to carbon, oxygen, and aluminum are more readily incorporated into N-face GaN films.
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Nitride Semiconductor Surfaces. Characterization of the Polarity of GaN Semiconductor Films by Coaxial Impact Collision Ion Scattering Spectroscopy. Correlation between GaN Growth Process and the Polar Direction.
Hyomen Kagaku, 2000Co-Authors: Masatomo Sumiya, T Ohnishi, Takahiro Ito, Shunro FukeAbstract:Nondestructive determination of the Polarity of GaN has been achieved by use of coaxial impact collision ion scattering spectroscopy. GaN films were deposited on c-plane sapphire substrates by a two-step atmospheric pressure metalorganic chemical vapor deposition using GaN buffer layers. The correlation between the samples prepared by interrupting the growth sequence at the various stage and their Polarity was systematically investigated. It has been found that the Polar Direction of GaN growth is influenced by the Polarity at the interface prior to the deposition of GaN epitaxial layer. We describe the mechanism of determining the Polar Direction by addressing our recent research related to substrate nitridation, buffer layer, and annealing of buffer layer.
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analysis of the Polar Direction of gan film growth by coaxial impact collision ion scattering spectroscopy
Applied Physics Letters, 1999Co-Authors: Masashi Sumiya, Miyoko Tanaka, Kohji Ohtsuka, T Ohnishi, I Ohkubo, Hideomi Koinuma, Shunro Fuke, Mamoru Yoshimoto, Megumi KawasakiAbstract:Nondestructive determination of the Polarity of GaN has been achieved by the use of coaxial impact-collision ion scattering spectroscopy analysis. The Polarity of a GaN film with a smooth surface on non-nitrided c-plane sapphire was identified (0001) (Ga face; +c). GaN films with a 20 nm buffer layer on nitrided sapphire had (0001) (N face; −c) Polarity and a hexagonal faceted surface. The influence of both the buffer layer and of substrate nitridation on the Polarity of wurtzite {0001} GaN films deposited by two-step metal organic chemical vapor deposition (MOCVD) has been investigated. The Polarity of the buffer layer on a nitrided sapphire substrate was altered by varying its thickness or the annealing time. It was found that the Polarity of the GaN film is determined by the Polarity of the annealed buffer layer; MOCVD-GaN films on buffer layers with +c and −c Polarity have either +c (smooth surface) or −c (hexagonal facet) Polarity, respectively.
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Control of the Polarity and Surface Morphology of GaN Films Deposited on C-Plane Sapphire
MRS Internet Journal of Nitride Semiconductor Research, 1999Co-Authors: Masatomo Sumiya, Miyoko Tanaka, Kohji Ohtsuka, T Ohnishi, Hideomi Koinuma, Mamoru Yoshimoto, Akira Ohtomo, Masashi Kawasaki, Shunro FukeAbstract:Control of the Polarity of GaN films deposited by metalorganic chemical vapor deposition was achieved by substrate nitridation and subsequent annealing of a buffer layer. The surface morphology and optical properties of 1.2μm GaN films were influenced by the different growth mode due to the Polar Direction. Coaxial impact collision ion scattering spectroscopy revealed that the Polarity composition of a buffer layer on nitrided sapphire varied by annealing in a H2 atmosphere. It was considered that the systematic variation of the surface morphology was caused by the Polarity composition of the buffer layer.
Philippe Stee - One of the best experts on this subject based on the ideXlab platform.
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The environment of the fast rotating star Achernar - Thermal infrared interferometry with VLTI/MIDI and SIMECA modeling
Astronomy & Astrophysics, 2008Co-Authors: Pierre Kervella, Samer Kanaan, Anthony Meilland, Alain Spang, Armando Domiciano De Souza, Philippe SteeAbstract:Context: As is the case of several other Be stars, Achernar is surrounded by an envelope, recently detected by near-IR interferometry. Aims: We search for the signature of circumstellar emission at distances of a few stellar radii from Achernar, in the thermal IR domain. Methods: We obtained interferometric observations on three VLTI baselines in the N band (8-13 mic), using the MIDI instrument. Results: From the measured visibilities, we derive the angular extension and flux contribution of the N band circumstellar emission in the Polar Direction of Achernar. The interferometrically resolved Polar envelope contributes 13.4 +/- 2.5 % of the photospheric flux in the N band, with a full width at half maximum of 9.9 +/- 2.3 mas (~ 6 Rstar). This flux contribution is in good agreement with the photometric IR excess of 10-20% measured by fitting the spectral energy distribution. Due to our limited azimuth coverage, we can only establish an upper limit of 5-10% for the equatorial envelope. We compare the observed properties of the envelope with an existing model of this star computed with the SIMECA code. Conclusions: The observed extended emission in the thermal IR along the Polar Direction of Achernar is well reproduced by the existing SIMECA model. Already detected at 2.2mic, this Polar envelope is most probably an observational signature of the fast wind ejected by the hot Polar caps of the star.
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The environment of the fast rotating star Achernar - II. Thermal infrared interferometry with VLTI/MIDI
2008Co-Authors: Pierre Kervella, Armando Domiciano De Souza, Samer Kanaan, Anthony Meilland, Alain Spang, Philippe SteeAbstract:Context: As is the case of several other Be stars, Achernar is surrounded by an envelope, recently detected by near-IR interferometry. Aims: We search for the signature of circumstellar emission at distances of a few stellar radii from Achernar, in the thermal IR domain. Methods: We obtained interferometric observations on three VLTI baselines in the N band (8-13 mic), using the MIDI instrument. Results: From the measured visibilities, we derive the angular extension and flux contribution of the N band circumstellar emission in the Polar Direction of Achernar. The interferometrically resolved Polar envelope contributes 13.4 +/- 2.5 % of the photospheric flux in the N band, with a full width at half maximum of 9.9 +/- 2.3 mas (~ 6 Rstar). This flux contribution is in good agreement with the photometric IR excess of 10-20% measured by fitting the spectral energy distribution. Due to our limited azimuth coverage, we can only establish an upper limit of 5-10% for the equatorial envelope. We compare the observed properties of the envelope with an existing model of this star computed with the SIMECA code. Conclusions: The observed extended emission in the thermal IR along the Polar Direction of Achernar is well reproduced by the existing SIMECA model. Already detected at 2.2mic, this Polar envelope is most probably an observational signature of the fast wind ejected by the hot Polar caps of the star.
Dabin Lin - One of the best experts on this subject based on the ideXlab platform.
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an efficient way to enhance output strain for shear mode pb in1 2nb1 2 o3 pb mg1 3nb2 3 o3 pbtio3 crystals applying uniaxial stress perpendicular to Polar Direction
Applied Physics Letters, 2012Co-Authors: Shujun Zhang, Dabin Lin, Junjie Gao, Linghang WangAbstract:The shear piezoelectric behavior of [001] poled tetragonal and [011] poled rhombohedral Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) crystals, with “1T” and “2R” domain configurations, respectively, were investigated under uniaxial stress perpendicular to Polar Direction. The shear piezoelectric coefficient d15 was found to decrease with increasing compressive stress for both “1T” and “2R” crystals. Based on thermodynamic analysis, the phase structure can be stabilized by applying compressive stress perpendicular to Polar Direction, resulting in a “harder” Polarization rotation process, accounts for the reduced shear piezoelectric coefficient. Of particular importance is that the allowable drive electric field was greatly increased and transverse dielectric loss was drastically reduced under compressive stress, leading to the improved maximum-shear-strain.
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An efficient way to enhance output strain for shear mode Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 crystals: Applying uniaxial stress perpendicular to Polar Direction
Applied Physics Letters, 2012Co-Authors: Shujun Zhang, Dabin Lin, Junjie Gao, Linghang WangAbstract:The shear piezoelectric behavior of [001] poled tetragonal and [011] poled rhombohedral Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) crystals, with “1T” and “2R” domain configurations, respectively, were investigated under uniaxial stress perpendicular to Polar Direction. The shear piezoelectric coefficient d15 was found to decrease with increasing compressive stress for both “1T” and “2R” crystals. Based on thermodynamic analysis, the phase structure can be stabilized by applying compressive stress perpendicular to Polar Direction, resulting in a “harder” Polarization rotation process, accounts for the reduced shear piezoelectric coefficient. Of particular importance is that the allowable drive electric field was greatly increased and transverse dielectric loss was drastically reduced under compressive stress, leading to the improved maximum-shear-strain.
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Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 crystals: Applying uniaxial stress perpendicular to Polar Direction
2012Co-Authors: Shujun Zhang, Dabin Lin, Junjie Gao, Linghang WangAbstract:The shear piezoelectric behavior of [001] poled tetragonal and [011] poled rhombohedral Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) crystals, with “1T” and “2R” domain configurations, respectively, were investigated under uniaxial stress perpendicular to Polar Direction. The shear piezoelectric coefficient d15 was found to decrease with increasing compressive stress for both “1T” and “2R” crystals. Based on thermodynamic analysis, the phase structure can be stabilized by applying compressive stress perpendicular to Polar Direction, resulting in a “harder” Polarization rotation process, accounts for the reduced shear piezoelectric coefficient. Of particular importance is that the allowable drive electric field was greatly increased and transverse dielectric loss was drastically reduced under compressive stress, leading to the improved maximum-shear-strain. V C 2012 American Institute of Physics .[ http://dx.doi.org/10.1063/1.4712129]
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pb in1 2nb1 2 o3 pb mg1 3nb2 3 o3 pbtio3 crystals applying uniaxial stress perpendicular to Polar Direction
2012Co-Authors: Shujun Zhang, Dabin Lin, Junjie Gao, Linghang WangAbstract:The shear piezoelectric behavior of [001] poled tetragonal and [011] poled rhombohedral Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) crystals, with “1T” and “2R” domain configurations, respectively, were investigated under uniaxial stress perpendicular to Polar Direction. The shear piezoelectric coefficient d15 was found to decrease with increasing compressive stress for both “1T” and “2R” crystals. Based on thermodynamic analysis, the phase structure can be stabilized by applying compressive stress perpendicular to Polar Direction, resulting in a “harder” Polarization rotation process, accounts for the reduced shear piezoelectric coefficient. Of particular importance is that the allowable drive electric field was greatly increased and transverse dielectric loss was drastically reduced under compressive stress, leading to the improved maximum-shear-strain. V C 2012 American Institute of Physics .[ http://dx.doi.org/10.1063/1.4712129]