Marked anomalies in the pressure dependence of the superconducting transition temperature in Tl 2Ba 2CuO 6+y as a function of oxygen content

Abstract

We report the results of experiments of the effect of hydrostatic pressure to 6 kbar on the superconducting transition temperature T c of a Tl 2Ba 2CuO 6+ y sinter for oxygen content y in the range 0.10≤ y≤0.21. superconductivity is detected by an AC inductance technique and pure hydrostatic pressure is generated with a helium gas system. For experiments in which the pressure is changed at room temperature, T c falls rapidly under pressure; when the pressure is changed at low temperature, T c remains almost constant. A subsequent experiment on a YBa 2Cu 3O 7 single crystal revealed no such irreversible behavior.