The growth of CdZnTe crystals with diameter up to 60 mm using bottom-seeded Bridgman method as well as Bridgman accelerated crucible rotation technique (ACRT-B) was investigated. Both ingots exhibit high yields, where...The growth of CdZnTe crystals with diameter up to 60 mm using bottom-seeded Bridgman method as well as Bridgman accelerated crucible rotation technique (ACRT-B) was investigated. Both ingots exhibit high yields, where single crystal with the volume exceeding 200 cm3 is produced. The crystal properties of two ingots were compared in the aspects of yields, crystalline quality and composition uniformity. For CdZnTe ingot grown by bottom-seeded Bridgman method, the full width at half-maximum (FWHM) of X-ray rocking curve was determined to be 36″, indicating a better crystalline quality than ingot grown by ACRT-B method, which gave FWHM of 56″. The composition distribution of Zn and In in CdZnTe was determined by using electron probe microanalysis (EPMA) and inductively coupled plasma mass spectrometry (ICP-MS), respectively. The effective segregation coefficients of Zn kZn and In kIn in the two ingots were evaluated by fitting the experimental data with the Pfann equation.展开更多
Accelerated crucible rotation technique(ACRT) has been used for the directional solidification of Al-4.5wt% Cu binary alloy.By rotating the crucible at varying rate and direction,forced liquid flows are aroused These ...Accelerated crucible rotation technique(ACRT) has been used for the directional solidification of Al-4.5wt% Cu binary alloy.By rotating the crucible at varying rate and direction,forced liquid flows are aroused These flows include Ekman flow,Couette flow and Spiral Shear flow.Especially,Ekman flow acts directly at the L/S interface,changes diffusion and heat exchange conditions and has strong influences on the morphology of L/S interface.Experimental results show that,compared with normal Bridgman specimens,the solidification region is much narrower and the cell spacing is much smaller in ACRT specimens.These influences become much stronger when the accelerating rate is increased.展开更多
A Bridgman growth furnace was modified by adding adiabatic material between two furnace tubes. The appropriate temperature gradient of 10-30 ℃/cm at the growth interface was obtained by adjusting the distance between...A Bridgman growth furnace was modified by adding adiabatic material between two furnace tubes. The appropriate temperature gradient of 10-30 ℃/cm at the growth interface was obtained by adjusting the distance between the two sections and controlling their temperature. The infrared nonlinear optical （NLO） crystal LiInS2 was successfully grown by the accelerated crucible rotation technique （ACRT）. The crystal was characterized by using XRD and transmission microscopy. It is found that the UV-VIS-NIR and Mid-IR transmittances are about 40%.展开更多
基金Project(50772091) supported by the National Natural Science Foundation of ChinaProject(2008044185) supported by China Postdoctoral Science Foundation
文摘The growth of CdZnTe crystals with diameter up to 60 mm using bottom-seeded Bridgman method as well as Bridgman accelerated crucible rotation technique (ACRT-B) was investigated. Both ingots exhibit high yields, where single crystal with the volume exceeding 200 cm3 is produced. The crystal properties of two ingots were compared in the aspects of yields, crystalline quality and composition uniformity. For CdZnTe ingot grown by bottom-seeded Bridgman method, the full width at half-maximum (FWHM) of X-ray rocking curve was determined to be 36″, indicating a better crystalline quality than ingot grown by ACRT-B method, which gave FWHM of 56″. The composition distribution of Zn and In in CdZnTe was determined by using electron probe microanalysis (EPMA) and inductively coupled plasma mass spectrometry (ICP-MS), respectively. The effective segregation coefficients of Zn kZn and In kIn in the two ingots were evaluated by fitting the experimental data with the Pfann equation.
文摘Accelerated crucible rotation technique(ACRT) has been used for the directional solidification of Al-4.5wt% Cu binary alloy.By rotating the crucible at varying rate and direction,forced liquid flows are aroused These flows include Ekman flow,Couette flow and Spiral Shear flow.Especially,Ekman flow acts directly at the L/S interface,changes diffusion and heat exchange conditions and has strong influences on the morphology of L/S interface.Experimental results show that,compared with normal Bridgman specimens,the solidification region is much narrower and the cell spacing is much smaller in ACRT specimens.These influences become much stronger when the accelerating rate is increased.
基金the NNSFC (No. 50590403, 50325311)the 973 program of China (No. 2004CB619002)
文摘A Bridgman growth furnace was modified by adding adiabatic material between two furnace tubes. The appropriate temperature gradient of 10-30 ℃/cm at the growth interface was obtained by adjusting the distance between the two sections and controlling their temperature. The infrared nonlinear optical （NLO） crystal LiInS2 was successfully grown by the accelerated crucible rotation technique （ACRT）. The crystal was characterized by using XRD and transmission microscopy. It is found that the UV-VIS-NIR and Mid-IR transmittances are about 40%.
