Abstract
High-temperature oxide superconductor YBa2Cu3Oy reacts with water in moisture producing nonsuperconducting materials, such as BaCO3, Y2BaCuO5, CuO. As a result, the superconductivity of the YBa2Cu3Oy is degraded. In this article, the studies of the degradation of Y, Bi, Tl-based superconductors by the methods of resistive transition, X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscope are summarized. In addition, several attempts to prevent the degradation in moisture, such as coating, are summarized.
