Superconductivity above 70 K in Ba-La-Cu oxide

Last December Ba-La-Cu oxide was prepared and the temperature dependence of resistance was measured by the four-point method. Zero resistance temperatures are 53 K and 67 K for sample A and sample B, respectively. The results of resistance transition under 10 kbar show T/sub c/ (onset) to be 94 K for sample B. About two months later the mutual-inductance method was adopted to measure the ac magnetic susceptibility by using a new measuring system. The onsets of diamagnetism were 83 K and 79 K for sample A and B, respectively.