Preparation of Bi2Sr2CaCu2Ox Superconductors from Amorphous Films by Rapid Quenching after Rapid Melting

Abstract

Complete amorphous films with the composition of Bi₂Sr₂CaCu₂O _x were successfully prepared by the rapid quenching after rapid melting technique without any containers. The evaporation loss was measured to be 0.237 wt%/sec or less at 1673–1773 K in the initial stage of melting. The amorphous materials were crystallized in the Bi₂Sr₂CaCu₂O _x phase above 1073 K through the Bi₂Sr₂CuO _x phase crystallized above 733 K. The crystallized Bi₂Sr₂CaCu₂O _x film showed a superconducting transition at T _co=86.8 K and T _ce=66.7 K.