It is important to acquire the composition of Si1-xGex layer, especially that with high Ge content, epitaxied on Si substrate. Two nondestructive examination methods, double crystals X-ray diffraction （DCXRD） and mi...It is important to acquire the composition of Si1-xGex layer, especially that with high Ge content, epitaxied on Si substrate. Two nondestructive examination methods, double crystals X-ray diffraction （DCXRD） and micro-Raman measurement, were introduced comparatively to determine x value in Si1-xGex layer, which show that while the two methods are consistent with each other when x is low, the results obtained from double crystals X-ray diffraction are not credible due to the large strain relaxation occurring in Si1-xGex layers when Ge content is higher than about 20%. Micro-Raman measurement is more appropriate for determining high Ge content than DCXRD.展开更多
X-ray powder diffraction data and crystal structure of NiSbY compound were studied by X-ray powderdiffraction. The compound belongs to the space group F43 m with MgAgAs structure type, and the parameters Z=4, a=0.6307...X-ray powder diffraction data and crystal structure of NiSbY compound were studied by X-ray powderdiffraction. The compound belongs to the space group F43 m with MgAgAs structure type, and the parameters Z=4, a=0.63075(2) nm.展开更多
The compound PrNiSn was studied by X ray powder diffraction technique. The crystal structure and the X ray diffraction data for this compound at room temperature were reported. The compound PrNiSn is orthorhombic wi...The compound PrNiSn was studied by X ray powder diffraction technique. The crystal structure and the X ray diffraction data for this compound at room temperature were reported. The compound PrNiSn is orthorhombic with lattice parameters a =0.74569(3) nm, b =0.76851(5) nm, c =0.45676(8) nm, V =0.26176 nm 3, Z =4 and D x=8.076 g·cm -3 , space group Pna2 1(33). The figure of merit F N for the compound is F 30 =54 (0.0093, 60).展开更多
Spectral and structural characteristics of distributed Bragg reflector (DBR) in vertical-cavity surface-emitting lasers were studied with photoluminescence and double-crystal X-ray diffraction measurement.The expected...Spectral and structural characteristics of distributed Bragg reflector (DBR) in vertical-cavity surface-emitting lasers were studied with photoluminescence and double-crystal X-ray diffraction measurement.The expected high quality epitaxial DBR structure was verified.In the X-ray double-crystal rocking curves of DBR the zeroth-order peak,the first and second order satellite peaks were measured.Splitting of diffraction peak appeared in the rocking curves was analyzed.The effects of introduced deep energy levels on the structural perfection and optical properties were discussed.展开更多
The crystal structure of new compound Ba 3BPO 7 has been solved by X ray powder diffraction technique. As a new structure type, the positions of barium, boron and phosphate atoms have been determined by single crystal...The crystal structure of new compound Ba 3BPO 7 has been solved by X ray powder diffraction technique. As a new structure type, the positions of barium, boron and phosphate atoms have been determined by single crystal direct method after profile decomposition from Ba 3BPO 7 X ray powder diffraction patterns. The positions of oxygen atoms have been determined by the interpretation of their vibration spectra which indicate that in this crystal the boron and phosphorus atoms form BO 3 and PO 4 polyhedra. The structure has been refined by Rietveld technique based on the above model.展开更多
采用 X射线三轴晶衍射法 ,根据 As间隙原子对作为过量 As在 Ga As单晶材料中存在的主要形式的模型 ,可以无损、高精度测量半绝缘 Ga As单晶的化学配比 .并探讨了引起晶格变化的原因及其与熔体组分的关系 ,对于制备高质量 Ga As单晶及其...采用 X射线三轴晶衍射法 ,根据 As间隙原子对作为过量 As在 Ga As单晶材料中存在的主要形式的模型 ,可以无损、高精度测量半绝缘 Ga As单晶的化学配比 .并探讨了引起晶格变化的原因及其与熔体组分的关系 ,对于制备高质量 Ga As单晶及其光电器件具有重要的意义 .展开更多
基金This work is supported by the National Natural Science Foundation of China （Grant Nos. 60336010 ＆ 90401001）973 Program （Grant No. TG 2000036603）the Student Innovation Program of CAS （No. 1731000500010）.
文摘It is important to acquire the composition of Si1-xGex layer, especially that with high Ge content, epitaxied on Si substrate. Two nondestructive examination methods, double crystals X-ray diffraction （DCXRD） and micro-Raman measurement, were introduced comparatively to determine x value in Si1-xGex layer, which show that while the two methods are consistent with each other when x is low, the results obtained from double crystals X-ray diffraction are not credible due to the large strain relaxation occurring in Si1-xGex layers when Ge content is higher than about 20%. Micro-Raman measurement is more appropriate for determining high Ge content than DCXRD.
文摘X-ray powder diffraction data and crystal structure of NiSbY compound were studied by X-ray powderdiffraction. The compound belongs to the space group F43 m with MgAgAs structure type, and the parameters Z=4, a=0.63075(2) nm.
文摘The compound PrNiSn was studied by X ray powder diffraction technique. The crystal structure and the X ray diffraction data for this compound at room temperature were reported. The compound PrNiSn is orthorhombic with lattice parameters a =0.74569(3) nm, b =0.76851(5) nm, c =0.45676(8) nm, V =0.26176 nm 3, Z =4 and D x=8.076 g·cm -3 , space group Pna2 1(33). The figure of merit F N for the compound is F 30 =54 (0.0093, 60).
文摘Spectral and structural characteristics of distributed Bragg reflector (DBR) in vertical-cavity surface-emitting lasers were studied with photoluminescence and double-crystal X-ray diffraction measurement.The expected high quality epitaxial DBR structure was verified.In the X-ray double-crystal rocking curves of DBR the zeroth-order peak,the first and second order satellite peaks were measured.Splitting of diffraction peak appeared in the rocking curves was analyzed.The effects of introduced deep energy levels on the structural perfection and optical properties were discussed.
文摘The crystal structure of new compound Ba 3BPO 7 has been solved by X ray powder diffraction technique. As a new structure type, the positions of barium, boron and phosphate atoms have been determined by single crystal direct method after profile decomposition from Ba 3BPO 7 X ray powder diffraction patterns. The positions of oxygen atoms have been determined by the interpretation of their vibration spectra which indicate that in this crystal the boron and phosphorus atoms form BO 3 and PO 4 polyhedra. The structure has been refined by Rietveld technique based on the above model.
