PROCESS AND MECHANISM OF GROWTH OF YBA2CU3O6-CRYSTAL BY THE PULLING METHOD(X SINGLE)

Continuous growth of YBa2Cu3O6+x(Y123) single crystals was achieved by the modified pulling method(1) using BaO+CuO(3:5) solvent and Y2BaCuO 5(Y211) solute. Y211 solid was placed at the bottom of the crucible. T emperature was set ten degrees higher at the bottom than on the surfac e of the solution. The crystal rotation speed was 120 rpm at first; bu t as the crystal radius increased, it was reduced to prevent increasin g the interface temperature. The maximum crystal growth rate was about 0.2 mm/h. The crystal growth direction was controlled by the seed cry stal direction.(2) Two-dimensional numerical simulation was performed using a finite-difference method by a supercomputer to investigate the solution flow and temperature distribution.