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M K Balyan - One of the best experts on this subject based on the ideXlab platform.
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Dependence of X-ray asymmetrical Bragg case Plane-wave rocking curves on the deviation from exact Bragg orientation in and perpendicular to the Diffraction Plane.
Acta Crystallographica Section A Foundations and Advances, 2019Co-Authors: M K BalyanAbstract:For the asymmetrical Bragg case the X-ray Plane-wave reflection coefficients and rocking-curve dependences on the deviation angles from the exact Bragg orientation in the Diffraction Plane and in the direction perpendicular to the Diffraction Plane are analysed. The region of total reflection and its size dependence on two deviation angles are analysed as well. New peculiarities of the rocking curves are obtained.
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Dependence of X-ray Plane-wave rocking curves on the deviation from exact Bragg orientation in and perpendicular to the Diffraction Plane for the asymmetrical Laue case.
Acta Crystallographica Section A Foundations and Advances, 2018Co-Authors: M K BalyanAbstract:For the asymmetrical Laue case the X-ray Plane-wave transmission and reflection coefficients and rocking curves are analysed as a function of the deviation angles from the exact Bragg orientation in the Diffraction Plane and in the direction perpendicular to the Diffraction Plane. New peculiarities of the rocking curves are obtained. The peculiarities of both the effective absorption coefficient and rocking curves in thick crystals are also investigated.
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Rocking Curves of X-ray Asymmetrical Laue Diffraction with Two-Dimensional Curvature of Wave Front
Journal of Contemporary Physics (Armenian Academy of Sciences), 2018Co-Authors: M K BalyanAbstract:X-ray asymmetrical Laue Diffraction in a perfect crystal with Plane front surface was considered taking into account the two-dimensional curvature of a wave incident on the crystal. Using an appropriate Green function the dependences of rocking curves on deviation angles from selected exact Bragg direction were examined in the Diffraction Plane and in the direction perpendicular to the Diffraction Plane in locally Plane wave approximation. The dependence of rocking curves on the degree of asymmetry of Diffraction geometry was investigated. Analytical expressions for half widths of rocking curves in the Diffraction Plane and in the direction perpendicular to the Diffraction Plane are obtained. Some requirements to spatial and temporal coherence are estimated.
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rocking curves in the laue geometry depending on the departure of incident Plane x ray wave from the bragg condition in the Diffraction Plane and in the direction perpendicular to the Diffraction Plane
Journal of Contemporary Physics-armenian Academy of Sciences, 2017Co-Authors: M K BalyanAbstract:Using the method of Green functions in the symmetric Laue geometry the rocking curves of Plane X-ray wave were theoretically investigated depending on the departure of a beam from exact Bragg condition in the Diffraction Plane and in the direction perpendicular to the Diffraction Plane. The Si(220) reflection of MoKα radiation was considered by way of illustration.
J A O Huguenin - One of the best experts on this subject based on the ideXlab platform.
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effect of metallic surface roughness on the speckle pattern formation at Diffraction Plane
Optics and Lasers in Engineering, 2012Co-Authors: J B Meireles, L Da Silva, D P Caetano, J A O HugueninAbstract:Abstract We report on the experimental investigation of speckle pattern formation from rough metallic surfaces at Diffraction Plane. It is found that the ratio between bright and dark regions of the binarized speckle patterns exponentially increases when the surface roughness increases. We also propose an alternative technique for measuring surface roughness.
J B Meireles - One of the best experts on this subject based on the ideXlab platform.
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effect of metallic surface roughness on the speckle pattern formation at Diffraction Plane
Optics and Lasers in Engineering, 2012Co-Authors: J B Meireles, L Da Silva, D P Caetano, J A O HugueninAbstract:Abstract We report on the experimental investigation of speckle pattern formation from rough metallic surfaces at Diffraction Plane. It is found that the ratio between bright and dark regions of the binarized speckle patterns exponentially increases when the surface roughness increases. We also propose an alternative technique for measuring surface roughness.
Rajdeep Singh Rawat - One of the best experts on this subject based on the ideXlab platform.
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Structural, optical and magnetic properties of (ZnO)1−x(MnO2)x thin films deposited at room temperature
Applied Surface Science, 2008Co-Authors: S. Karamat, S. Mahmood, Jinjun Lin, Zhenying Pan, Paul Lee, T.l. Tan, Stuart Victor Springham, Raju V. Ramanujan, Rajdeep Singh RawatAbstract:Abstract The structural, magnetic and optical properties of (ZnO)1−x(MnO2)x (with x = 0.03 and 0.05) thin films deposited by pulsed laser deposition (PLD) were studied. The pellets used as target, sintered at different temperatures ranging from 500 °C to 900 °C, were prepared by conventional solid state method using ZnO and MnO2 powders. The observation of non-monotonic shift in peak position of most preferred (1 0 1) ZnO Diffraction Plane in XRD spectra of pellets confirmed the substitution of Mn ions in ZnO lattice of the sintered targets. The as-deposited thin film samples are found to be polycrystalline with the preferred orientation mostly along (1 1 0) Diffraction Plane. The UV–vis spectroscopy of the thin films revealed that the energy band gap exhibit blue shift with increasing Mn content which could be attributed to Burstein–Moss shift caused by Mn doping of the ZnO. The deposited thin films exhibit room temperature ferromagnetism having effective magnetic moment per Mn atom in the range of 0.9–1.4μB for both compositions.
Shuxiang Dong - One of the best experts on this subject based on the ideXlab platform.
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quantitative domain engineering for realizing d36 piezoelectric coefficient in tetragonal ceramics
Acta Materialia, 2020Co-Authors: Jingen Wu, Zhongqiang Hu, Renci Peng, Guohua Dong, Zhiguang Wang, Ziyao Zhou, Bin Peng, Shuxiang DongAbstract:Abstract Piezoelectric devices based on d36 mode are remarkably stable that depolarization rarely occurs in d36 face shear mode, because d36 mode is completely different from d15 thickness shear mode, where the applied electric field is perpendicular to poling direction and depolarization is ineluctable due to 90° dipole rotation. However, piezoelectric ceramics conventionally possess three piezoelectric coefficients (i.e., d33, d31, and d15), while d36 only exists in single crystals of specific point groups and cut directions. In this work, we propose a method to realize d36 piezoelectric coefficient in tetragonal piezoelectric ceramics by mechanical and electric domain engineering. This method is successfully applied in bismuth scandium-lead titanate (abbreviated as BS-PT) high-temperature piezoelectric ceramics with a resultant d36 up to 160 pC/N, which broadens the application of BS-PT ceramics, such as face shear actuator, energy harvester, transducer, etc. We find that domain engineering by transversal electric poling is preferred compared with the transversal mechanical poling, due to the simpler process, higher reliability, and higher resultant d36 piezoelectric coefficient. By combining the Diffraction-Plane-Transformation (DPT) model with the domain engineering via transversal electric poling, we demonstrate a quantitative domain engineering method for the first time, which could be used for optimizing the piezoelectric properties by precise design of the domain structures in piezoelectric materials.
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A Diffraction-Plane-transformation model for quantitatively evaluating 90° domain evolution in tetragonal BS-PT piezoelectric ceramic
Journal of Alloys and Compounds, 2018Co-Authors: Xiangyu Gao, Jikun Yang, Shuxiang DongAbstract:Abstract The domain structure of 0.367 BiScO 3 - 0.633 PbTiO 3 piezoelectric ceramic is investigated from the view of different electrical poling. The X-ray-Diffraction (XRD) approach is used to acquire relative intensity ratio of domain reflections, thus the domain switching fraction or domain texture that results from electrical poling is directly observed. Based on the XRD profiles, a Diffraction-Plane-transformation (DPT) model that can provide a visualized insight into domain switching in tetragonal perovskite phase is proposed. The intensity variation of Diffraction reflections in XRD pattern is comprehensively explained by DPT model, meanwhile an alternative method is also proposed to estimate the domain switching fraction in comparison with previously reported method. The experimental results show that the proposed DPT model is a simple, rational and effective method, which is also of edificatory significance to other tetragonal perovskite piezoelectric ceramic.