High-temperature superconductivity in the oxide system (Y1-xBax)2CuO4(0.2⩽x⩽0.5)

Abstract
In the Y-Ba-Cu-O system, oxides with nominal cation composition (Y1-xBax)2CuO4 and x ranging from 0.2 to 0.5 have been prepared and examined for the occurrence of superconductivity. Four-probe DC resistivity and AC susceptibility measurements reveal that all these compositions exhibit superconductivity with superconducting onset temperatures in the range 90-95 K. However, the transition width and the temperature at which zero resistance is observed depend on x or the Ba/Y ratio.