Many physical properties on the sintered multicrystal materials have been measured,but they did not provide enough data for theorists to understand the superconducting mechanism,because some special properties can onl...Many physical properties on the sintered multicrystal materials have been measured,but they did not provide enough data for theorists to understand the superconducting mechanism,because some special properties can only be measured on tbe single crystals of large size and perfect quality.Several papers have reported the growth of superco ducting single crystals in Bi-Sr-CarCu-O system^(1-3),but the crystal size is small and the crystai quality is imperfect.Up to now,no published papers have reported the systematic investigation of the effects of growth conditions on the crystal size and quality.In tbis paper we report a systematic investigation of the effects of the grwoth conditions on the crystai size in Bi-Sr-Ca-Cu-O system.展开更多
An anomalous resistance drop was observed near 190K in the R-T measurement on a sample in Bi-Sr-Ca-Cu-O system and the transition completed at 80K.After keeping the sample at room temperature for 10h,the temperature d...An anomalous resistance drop was observed near 190K in the R-T measurement on a sample in Bi-Sr-Ca-Cu-O system and the transition completed at 80K.After keeping the sample at room temperature for 10h,the temperature dependence of the resistance changed from semiconducting to metallic behavior,while the ending of the transition remained at 80K.This might be an evidence of the existence of a metastable superconducting phase in Bi-Sr-Ca-Cu-O system with Tc as high as 190K.展开更多
Superconducting transition has been observed by electrical resistance and a.c.magnetic susceptibility measurements in Tm_(x)Ba_(1-x)CuO_(3-y) with x=0.6 and 0.7 and y>0.The highest T_(c) of the samples measured is ...Superconducting transition has been observed by electrical resistance and a.c.magnetic susceptibility measurements in Tm_(x)Ba_(1-x)CuO_(3-y) with x=0.6 and 0.7 and y>0.The highest T_(c) of the samples measured is observed in Tm_(0.6)-Ba_(0.4)CuO_(3-y) which has the T_(c)(mid)=91K with ΔT_(c)=0.5K,and T_(c)(ρ=0)=90.1K.The a.c.magnetic susceptibility measurements show a very strong diamagnetism at the temperature of resistive midpoint.展开更多
The highest superconducting transition temperature of 8.42 and 5.16K has been observed in the alloy system PdH and PdCuH,where the atomic ratio n=H/Pd(Cu)are 1 and 0.6,respectively.The effect of lattice disorder induc...The highest superconducting transition temperature of 8.42 and 5.16K has been observed in the alloy system PdH and PdCuH,where the atomic ratio n=H/Pd(Cu)are 1 and 0.6,respectively.The effect of lattice disorder induced by 220keV Ar ion beam bombardment at liquid helium-temperature is detrimental to the superconductivity.展开更多
Ion beam mixing is conducted at liquid helium temperature to study the superconductivlty of AlSi alloy(Al-21.8at%Si).Along with the process of transforming from multilayer structure to Q uniform Al and St alloy3 the s...Ion beam mixing is conducted at liquid helium temperature to study the superconductivlty of AlSi alloy(Al-21.8at%Si).Along with the process of transforming from multilayer structure to Q uniform Al and St alloy3 the superconducting properties are continuously improved.The highest To obtained is 6.84K.展开更多
文摘Many physical properties on the sintered multicrystal materials have been measured,but they did not provide enough data for theorists to understand the superconducting mechanism,because some special properties can only be measured on tbe single crystals of large size and perfect quality.Several papers have reported the growth of superco ducting single crystals in Bi-Sr-CarCu-O system^(1-3),but the crystal size is small and the crystai quality is imperfect.Up to now,no published papers have reported the systematic investigation of the effects of growth conditions on the crystal size and quality.In tbis paper we report a systematic investigation of the effects of the grwoth conditions on the crystai size in Bi-Sr-Ca-Cu-O system.
基金Project suppprted by the Naticma J.Science Foundstion of China(No.1860860)and the Chinese Superconducting Research Center.
文摘An anomalous resistance drop was observed near 190K in the R-T measurement on a sample in Bi-Sr-Ca-Cu-O system and the transition completed at 80K.After keeping the sample at room temperature for 10h,the temperature dependence of the resistance changed from semiconducting to metallic behavior,while the ending of the transition remained at 80K.This might be an evidence of the existence of a metastable superconducting phase in Bi-Sr-Ca-Cu-O system with Tc as high as 190K.
文摘Superconducting transition has been observed by electrical resistance and a.c.magnetic susceptibility measurements in Tm_(x)Ba_(1-x)CuO_(3-y) with x=0.6 and 0.7 and y>0.The highest T_(c) of the samples measured is observed in Tm_(0.6)-Ba_(0.4)CuO_(3-y) which has the T_(c)(mid)=91K with ΔT_(c)=0.5K,and T_(c)(ρ=0)=90.1K.The a.c.magnetic susceptibility measurements show a very strong diamagnetism at the temperature of resistive midpoint.
基金supported in part by National M.S.Research Grant of China.
文摘The highest superconducting transition temperature of 8.42 and 5.16K has been observed in the alloy system PdH and PdCuH,where the atomic ratio n=H/Pd(Cu)are 1 and 0.6,respectively.The effect of lattice disorder induced by 220keV Ar ion beam bombardment at liquid helium-temperature is detrimental to the superconductivity.
文摘Ion beam mixing is conducted at liquid helium temperature to study the superconductivlty of AlSi alloy(Al-21.8at%Si).Along with the process of transforming from multilayer structure to Q uniform Al and St alloy3 the superconducting properties are continuously improved.The highest To obtained is 6.84K.
