Sorption and Desorption Characteristics of Water Vapour on YBa2Cu3O7-x Powders

Abstract
The sorption isotherms of water vapour of YBa2Cu3O7-x were determined volumetrically at 26°C. The reaction of the powders with water is observed at relative pressures above 0.2, where a small amount of oxygen desorption is detected. Temperature-programmed desorption spectra of the powders exposed to water vapour at 26, 120 and 200°C have two desorption peaks of water. One is due to the chemisorbed water and the other originates from the reacted hydroxide which is considered to be in the amorphous phase.