process and mechanism of growth of YBa2Cu3O6+x single crystal by the pulling method
Continuous growth of YBa2Cu3O6+x(Y123) single crystals was achieved by the modified pulling method1 using BaO+CuO(3:5) solvent and Y2BaCuO5(Y211) solute. Y211 solid was placed at the bottom of the crucible. Temperature was set ten degrees higher at the bottom than on the surface of the solution. The crystal rotation speed was 120 rpm at first; but as the crystal radius increased, it was reduced to prevent increasing the interface temperature. The maximum crystal growth rate was about 0.2 mm/h. The crystal growth direction was controlled by the seed crystal direction.2 Two-dimensional numerical simulation was performed using a finite-difference method by a supercomputer to investigate the solution flow and temperature distribution.