YBa2Cu3Oy Annealed under High-Pressure Oxidizing Atmosphere

Abstract
Heat treatment under high-pressure oxidizing atmosphere (oxygen partial pressure of 400 atm) is found to lower the T c of the superconductor YBa2Cu3O y . The powder X-ray diffraction pattern and the oxygen content measurement suggest that the excess oxygen occupies the oxygen defect site between the Ba-Ba layers.