部分溶融法における急冷開始温度のBi_2Sr_2CaCu_2O_yの臨界電流密度への影響 The Influence of Starting Temperature of Quench upon the Critical Current Density of Bi_2Sr_2CaCu_2O_y Using Partially Melting Method
We prepared Bi<SUB>2</SUB>Sr<SUB>2</SUB>CaCu<SUB>2</SUB>O<SUB>y</SUB> polycrystalline superconductor by partially melting method in HNO<SUB>3</SUB> or solid state method and investigated the influence of precursor condition and quench temperature upon the critical current density. The best starting temperatures of quench were 650°C in HNO<SUB>3</SUB> method and 500°C in solid state method. In these conditions, critical current densities were 198A/cm<SUP>2</SUP> in the former and 102A/cm<SUP>2</SUP> in the latter. We found that starting temperature of quench influences the break of junctions between grains by thermal contraction and condition of precursor influences the occuring defect and grain growth in melting process.<BR>It is important to select the best conditions of quench and precursor to prepare Bi<SUB>2</SUB>Sr<SUB>2</SUB>CaCu<SUB>2</SUB>O<SUB>y</SUB> polycrystalline superconductor with high critical temperature and density by partially melting and quench method.
粉体および粉末冶金 45(12), 1131-1135, 1998-12-15
Japan Society of Powder and Powder Metallurgy