Metastability and Glass State in Superconducting La₂CuO_4-y: Ba

Susceptibility measurements for 1.9 to 35K in magnetic field from 0.015 to 1.5 Tesla in superconducting La2CuO4-y: Ba are reported. The diamagnetism created by the zero-field cooling and switching on a field shows non-exponential time-decays indicating an existence of superconducting glass state. Measuring with different fields, a quasi de Almeida-Thouless line separating ergodic from nonergodic areas in H–T plane has also been obtained. © 1987 The Japan Society of Applied Physics.