GROWTH OF YBA2CU3OY SINGLE-CRYSTALS FROM A MIXTURE OF YBA2CU3OY AND AG2O

Single crystals of the superconductor YBa2Cu3Oy have been grown from a mixture of solid phase YBa2CU3Oy and liquid phase silver. Crystals with a thickness of up to 1 mm along the c axis can be obtained when the mixture is soaked at 1005-degrees-C for more than 8 h. Silver melt enhances the peritectic partial melting of the YBa2Cu3Oy solid phase, and induces the solution and reprecipitation process during sintering at 1005-degrees-C. Stacked plate-like YBa2Cu3Oy grains grow through a coalescence process. Crystals are heavily twinned after 20 h of 02 annealing at 500-degrees-C. They exhibit a sharp superconducting transition with an onset temperature of 93 K in zero field.