The A1 substitution in the T1-Ba-Ca-Cu-O superconducting system was studied.Up to 70%of Tl can be substituted by Al,without significant reduction of Tc.X-ray diffraction indicates partial A1 substitution does not alte...The A1 substitution in the T1-Ba-Ca-Cu-O superconducting system was studied.Up to 70%of Tl can be substituted by Al,without significant reduction of Tc.X-ray diffraction indicates partial A1 substitution does not alter the crystal structure of the 2223 phase.Excessive A1 formed Al-Cu alloy and unidentified phases,which gradually destroyed the superconductivity.展开更多
Photor&fleatanae of GaAs doping superlattices has been measured at 300K.The spectra exhibi,te features cowesponding to spatially direct transitions due to quantized electron or hole states.We demonstrate the utili...Photor&fleatanae of GaAs doping superlattices has been measured at 300K.The spectra exhibi,te features cowesponding to spatially direct transitions due to quantized electron or hole states.We demonstrate the utility of the photoreflectance technique for studying quantum size effects tn doping superlattices.展开更多
文摘The A1 substitution in the T1-Ba-Ca-Cu-O superconducting system was studied.Up to 70%of Tl can be substituted by Al,without significant reduction of Tc.X-ray diffraction indicates partial A1 substitution does not alter the crystal structure of the 2223 phase.Excessive A1 formed Al-Cu alloy and unidentified phases,which gradually destroyed the superconductivity.
文摘Photor&fleatanae of GaAs doping superlattices has been measured at 300K.The spectra exhibi,te features cowesponding to spatially direct transitions due to quantized electron or hole states.We demonstrate the utility of the photoreflectance technique for studying quantum size effects tn doping superlattices.
