HIGH-TC SUPERCONDUCTING YBA2CU3O7-X FILAMENTS - AN IMPROVED THERMAL-TREATMENT

An Y-Ba-Cu-O suspension was spun into a filament using a phase inversi on technique. The flexible ''green product' wire needs a high temperat ure heat treatment and oxygen anneal to form the superconducting YBa2C u3O7-x phase. The quality of the wire and its superconductive properti es are highly dependent on the sinter conditions. Thermal treatment is optimized to improve the superconductive properties of the wire. To i mprove sintering, YBa2Cu3O7-x is decomposed peritecticly into Y2BaCuO5 and a liquid phase at relative low temperature by reducing the pressu re in the furnace. Subsequently the pressure is increased and the reac tion is reversed; restoring the superconductive phase. A precise activ ation and deactivation of partial melting can be accomplished in this way.