Superconducting properties and microstructure of Bi2Sr2Ca2Cu3O10 prepared by oxidation of a liquid quenched alloy precursor

We have produced the Bi2Sr2Ca2Cu3O10 phase by oxidation of a rapidly quenched alloy precursor. Metallic fragments of Bi2Sr2Ca2Cu3 are prepared by planar flow casting. After oxidation and annealing in air, the 2223 phase is the major constituent obtained (>80%). The structure is pseudo-tetragonal with a = 0.3814 nm, c = 3.702 nm, and we also observe a modulation along the [110] direction. The superconducting onset temperature is at 115 K and zero resistance is reached at ∼ 25 K after treatment in air and ∼ 70 K after treatment under oxygen at 400 °C. Microstructural studies suggests that various defects as well as the stoichiometry of the 2223 phase may explain the aspect of the transitions in the resistivity data.