The ac magnetic susceptibility,the magnetoresistance R(H)and the dependence of the resistivity on temperature under different applied field were investigated in the Pb-doped Bi-Ca-Sr-Cu-O system.A superconducting phas...The ac magnetic susceptibility,the magnetoresistance R(H)and the dependence of the resistivity on temperature under different applied field were investigated in the Pb-doped Bi-Ca-Sr-Cu-O system.A superconducting phase with Tc-100K exists tn this sintered sample.It forms a well connecting network,and therefore the Josephson coupling between the superconducting grains is sharply improved by doping lead.展开更多
To explore high Tce in Bi-Sr-Ca-Cu-O system,many different nominal compositions have been investigated.Zero resistance temperature Tce as high as 105K and only one sharp 3uperconducting transition in a.c.susceptibilit...To explore high Tce in Bi-Sr-Ca-Cu-O system,many different nominal compositions have been investigated.Zero resistance temperature Tce as high as 105K and only one sharp 3uperconducting transition in a.c.susceptibility measurement has been observed in the nominal composition Bi_(2)Sr_(2)Ca_(3)Cu_(4)O_(y) by using the method of crystallization from glassy Bi-Sr-Ca-Cu-O at 875°C for above 50h.展开更多
Results of resistivity,ac magnetic susceptibility,and Halleffect measurements for Ba_(1.2)Y_(0.9)V_(0.9)Cu_(3)0_(7-δ)are reported.The positive value of Hall constant indicates that the material conducts via holes wit...Results of resistivity,ac magnetic susceptibility,and Halleffect measurements for Ba_(1.2)Y_(0.9)V_(0.9)Cu_(3)0_(7-δ)are reported.The positive value of Hall constant indicates that the material conducts via holes with a carrier concentration of 1.6×10^(21)cm^(-3)at room temperature.A large anomaly in RH near Tc is observed.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
Two kinds of single crystal YbBa_(2)Cu_(3)O_(7-y) and ErBa_(2)Cu_(3)O_(7-y) have been grown by the fluxed method.They are orthorhombic structure with space group Pmmm,cell parameters are a=3.88Å,b=3.82Å,c=11...Two kinds of single crystal YbBa_(2)Cu_(3)O_(7-y) and ErBa_(2)Cu_(3)O_(7-y) have been grown by the fluxed method.They are orthorhombic structure with space group Pmmm,cell parameters are a=3.88Å,b=3.82Å,c=11.68Åand their typical size are 3×2×2mm^(3).The superconducting critical temperature is over 90K.Their superconductivity is discussed.展开更多
文摘The ac magnetic susceptibility,the magnetoresistance R(H)and the dependence of the resistivity on temperature under different applied field were investigated in the Pb-doped Bi-Ca-Sr-Cu-O system.A superconducting phase with Tc-100K exists tn this sintered sample.It forms a well connecting network,and therefore the Josephson coupling between the superconducting grains is sharply improved by doping lead.
文摘To explore high Tce in Bi-Sr-Ca-Cu-O system,many different nominal compositions have been investigated.Zero resistance temperature Tce as high as 105K and only one sharp 3uperconducting transition in a.c.susceptibility measurement has been observed in the nominal composition Bi_(2)Sr_(2)Ca_(3)Cu_(4)O_(y) by using the method of crystallization from glassy Bi-Sr-Ca-Cu-O at 875°C for above 50h.
文摘Results of resistivity,ac magnetic susceptibility,and Halleffect measurements for Ba_(1.2)Y_(0.9)V_(0.9)Cu_(3)0_(7-δ)are reported.The positive value of Hall constant indicates that the material conducts via holes with a carrier concentration of 1.6×10^(21)cm^(-3)at room temperature.A large anomaly in RH near Tc is observed.
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.
文摘Two kinds of single crystal YbBa_(2)Cu_(3)O_(7-y) and ErBa_(2)Cu_(3)O_(7-y) have been grown by the fluxed method.They are orthorhombic structure with space group Pmmm,cell parameters are a=3.88Å,b=3.82Å,c=11.68Åand their typical size are 3×2×2mm^(3).The superconducting critical temperature is over 90K.Their superconductivity is discussed.
