GROWTH AND CHARACTERIZATION OF UNDOPED AND DOPED BI2SR2CA1CU2OX SINGLE-CRYSTALS

Growth of Bi2Sr2Ca1Cu2O(x) (2212) crystals by two different ways, usin g alkali halide as a flux and from self flux compositions, has been re ported. X-ray diffraction, electrical transport and quasiparticle tunn elling measurements of undoped, iodine intercalated and lead doped cry stals have been performed. The integrowth of Bi2Sr2Cu1O(y) (2201) phas e in some of the grown crystals is observed. The presence of this impu rity phase is reflected in the R verus T plot of the crystal. The stab ility of 2212 phase in molten alkali halide has been investigated in o rder to determine conditions for the growth of phase pure crystals. Th e results of quasiparticle tunnelling and resistivity measurements sho w that the presence of iodine in the 2212 lattice influences its super conducting properties.