Crystallization and resistivity studies on Bi 4Sr 3Ca 3Cu yO x glasses

Abstract

Studies on Bi 4Sr 3Ca 3Cu y O x (433y) glasses (3 ≤ y ≤ 6) and corresponding glass ceramics are reported. No definite correlation is found between the properties of the glasses and the superconducting glass ceramics. The detailed studies, including Differential Scanning Calorimetric, Resistivity and X-ray diffraction, on 4334 glass and glass ceramics show that the activation energy for crystallization is 388 KJ/mol.; the devitrification reaction rate is maximum in the 500–650°C temperature range; Bi 2Sr 2CuO x (Bi-2201) is the first phase which crystallize from the glass and the crystallization is a bulk phenomenon. Metal-insulator transition is observed for RT resistivity 10 −2Ω cm. The Bi 2Sr 2Ca 1Cu 2O x (Bi-2212) phase formation starts above 650°C by a diffusion reaction between Bi-2201 phase, Ca, Cu and O at the sample surface.