High Temperature Superconductivity at 90 K in Orthorhombic LaBa₂Cu₃O_y

Abstract

A LaBa2Cu3Oy sample with an orthorhombic crystal structure was synthesized. It showed superconductivity with an onset temperature of 95 K and zero resistance at 80 K (midpoint 90 K). From the magnetic susceptibility measurement, about 30% of the whole volume of the sample was found to be the 90 K superconducting phase. The 90 K superconducting phase in LaBa2Cu3Oy is thus considered to have an oxygen defect perovskite structure which is most probably identical to that of the typical 90 K superconductor orthorhombic YBa2Cu3Oy.