Degradation of fully oxygenated YBa2Cu3Oxbelow 350 degrees C

Abstract
We report here a significant degradation in the superconducting properties of YBa2Cu3Ox when heated to temperatures in the range as low as 200-350 degrees C, even though no oxygen evolution is detected from the sample. The degradation is attributed to the weakening of intergrain coupling in the sintered material. We point out the crucial impact that this observation will have on the deployment of YBa2Cu3Ox in the construction and subsequent operation of practical devices.