Effect of hydrogen intercalation on the critical parameters of YBa2Cu3Oy

Resumo

The effect of hydrogenation at T = 150 and 200°C on the electrophysical properties of highly textured YBa₂Cu₃O_y ceramics with different oxygen content has been investigated. Like hydration, hydrogenation results in the deterioration of these properties. However, in samples with high oxygen contents (y = 6.96) hydrogenated at T = 150°C after oxidation (400°C) or recovery annealing with subsequent oxidation, the critical current density and first critical field increase compared to the initial state. The improvement of the properties occurs mainly in a magnetic field applied perpendicularly to the c axis. As after hydration, this is connected with the formation of planar defects in the course of low-temperature annealing. In addition, in the process of the hydrogenation, the partial reduction of copper occurs with the formation of microinclusions of Cu₂O and other products of chemical decomposition, which are extra pinning centers of magnetic vortices.