Growth of Bi-2212 single crystals by the travelling solvent zone melting method

摘要

High quality single crystals of Bi_2Sr_2CaCu_2O_x (Bi-2212) are needed for the development of HTS microelectronics with the intrinsic Josephson junctions and Josephson plasma excitation. In this study, Bi-2212 single crystals were grown by the travelling solvent zone melting (TSZM) technique in a gold crucible. This process involves zone melting with a solvent in a crucible to transfer a molten zone stably during growth. As a result of crystal growth, the typical size of the as-grown boules was 4 mm in diameter and about 10 mm in length. Bi-2212 single crystals of approx 3 X 1 mm~2 were obtained from the boules. The chemical composition of the grown crystals was determined to be Bi:Sr:Ca:Cu = 1.97(4): 1.75(7):0.88(3):2.0, which was close to that of the feeds. The Bi-2212 crystals annealed in oxygen at 1073 K for 72 h showed T_(c,onset) = 91 K and a narrow superconducting transition. These results suggest that the TSZM method is effective in composition control of the Bi-2212 single crystals.