The crystal growth of Y-Ba-Cu-O by laser floating zone melting

Abstract

The crystal growth of Y-Ba-Cu-O is explored by means of laser-heated pedestal growth (LHPG), which is a new crucible-free floating zone technology for growing oxide crystals from the melt. The result shows that the superconducting phase of YBa2Cu3O7-x melts incongruently, and is separated into two phases of (Y2BaCuO5 and BaCuO2) because of a peritectic reaction at 1010 degrees C during solidification. However, an oriented crystal in which the two phases coexist can be obtained by controlling the growth rate, and then may be transformed into superconductor with Tc above 90 K; such a crystal presents certain textural features following suitable heat treatment. The crystal structure and orientation after solidification and heat treatment are studied with the help of X-rays on electron microprobe and on optical microscope.