Synthesis and Characterization of Samarium Doped Bi₁.₆Pb₀.₄Sr₂Ca₂Cu₃O₁₀ Superconductor Prepared Via Coprecipitation Method

Abstract

The coprecipitation technique was used in the preparation of samarium doped Bi₁.₆Pb₀.₄Sr₂Ca₂Cu₃O₁₀ polycrystalline ceramic superconductor. In this study, four sites (calcium, bismuth, strontium and copper) were separately subjected to Sm doping with nominal composition ranging from x=0 to x=0.3 at different sintering times. The superconducting properties of the samples have been investigated. The pure sample, which exhibits TC(R=O) around 102 -103 K and TC-onset around 108 K, showed large flaky grains of ~7 µm in size which are randomly distributed_ However at longer sintering time the pure superconductor showed a better orientation as compared to that of the short sintering time sample. The calculated value of Josephson current 10 , obtained from the ac susceptibility data showed a much higher value (I₀=138.7µA) as compared to the conventional prepared to that of the sample prepared by conventional method (I₀=55.9 µA). This indicates better grain connectivity and higher 2223 phase content, which was confirmed by SEM photographs