Processing and Oxygenation of YBaCuO Melted Textured Ceramics at High and Enhanced Pressures and Temperatures

It has been established that the oxygenation of the structure of YBa2Cu3O7–δ (Y123) textured ceramic materials under elevated pressure (up to 10–16 MPa) and high temperatures (700–900°C) for a relatively short time (72 h) makes it possible to attain the record superconducting (at 77 K in the ab plane of Y123 phase jc ≈ 100 kA/cm2 (0 T), 55 kA/cm2 (2 T) and Hirr 9.5 T) and mechanical (microhardness up to HV = 7.6 GPa and fracture toughness up to KIc = 4.4 MPa⋅m0.5 under 4.9 N) properties. The high material characteristics have been explained by the formation of a nanostructure from twins acting as pinning centers (the density of twinning being 20–35 m–1) and a considerably smaller amount of microcracks (< 0.2 m–1) as well as by prevention of macrocracking.