Transport and magnetic anomalies below 70 K in a hydrogen-cycled Pd foil with a thermally grown oxide

Electron transport and magnetic properties have been studied in a deformed 12.5-mu m-thick Pd foil with a thermally-grown oxide and a low residual concentration of hydrogen. This foil was deformed by cycling across the Pd hydride miscibility gap and the residual hydrogen was trapped at dislocation cores. Anomalies of both resistance and magnetic susceptibility have been observed below 70 K, indicating the appearance of excess conductivity and a diamagnetic response that we interpret in terms of filamentary superconductivity. These anomalies are attributed to a condensed hydrogen-rich phase at dislocation cores near the Pd-Pd oxide interface.