[7a-S42-1~11] 11.1 Fundamental properties

[7a-S42-9] Phase formation of Ca-doped Y247 sintered bulks and their superconducting properties

〇Yota Saito¹, Yukihiro Okamura¹, Takanori Motoki¹, Jun-ichi Shimoyama¹, Shigeru Horii² (1.Aoyama Gakuin Univ., 2.Kyoto Univ.)

Keywords:superconductivity, Y123, Y247

Synthesis conditions of Y247 to suppress Y / Ba substitution and effects of Ca-doping on superconducting properties have been systematically studied. 5 mol% Ca-doped (Y, Ca) 247 showed the highest T_c ~ 89 K sintered for 16 h. (Y, Ca)247 with sintering time for 1 h was synthesized in almost single (Y,Ca)247 phases. T_c of (Y,Ca)247 remained lower than the un-doped Y247. It was suggested that optimum sintering conditions were changed by Ca doping.