CRYSTAL-GROWTH IN BI-SR-CA-CU-O SYSTEM

We report growth of Bi2Sr2CaCu2O8+delta single crystals with dimension s of 6 x 2 x 0.03 mm(3) using a melt and growth technique. The oxygen content is determined to be delta approximate to 0.13 by iodometric ti tration. The crystal is shown to be homogeneous and close to stoichiom etric cation ratio. The superconducting temperature with a sharp trans ition width (10-90% level:) of 6-8 K vias determined to be T-c,= 92 K from resistivity and de susceptibility measurements. The predominant i mpurity phase is a Cu-free crystal, whose composition is identified as Bi10Sr11Ca5Ox,. The crystal structure of Bi10Sr11Ca5Ox, is monoclinic with a = 11.108(1) Angstrom, b = 5.9487(1) Angstrom; c = 19.838 (3) A ngstrom and beta = 101.5 degrees (P2(1/c), space group). (C) 1998 Publ ished by Elsevier Science Ltd. All rights reserved.