Identification of a single-phase Y-Ba-Cu-O system superconducting at 91 K

Abstract
The authors have studied a series of compounds of the type Y1-xBaxCuOy (y undetermined) with the aim of identifying the superconducting phase in the multiphase system Y1.2Ba0.8CuO4 reported recently. The compounds with x=0.65 and 0.7 exhibit zero electrical resistance at 91 K and the onset of diamagnetic susceptibility at 92 K. These compounds are identified to crystallise in the La3Ba3Cu6O14 type tetragonal (or distorted form) structure.