[15p-317-1~13] 11.1 Fundamental properties

[15p-317-2] Phase formation of Y247 and Ca-doping effect on its superconductivity

〇Yota Saito¹, Akito Sakaguchi¹, Takanori Motoki¹, Jun-ichi Shimoyama¹ (1.Aoyama Univ.)

Keywords:Superconductor, RE247, Ca-dope

Synthesis conditions of Y247 to suppress Y / Ba substitution and effects of Ca-doping on superconducting properties have been systematically studied. T_c of Y247 systematically increased with a shortening of the sintering time. These results suggested that short time sintering was effective to suppress Y / Ba substitution. Ca-doped Y247 samples were synthesized in almost single (Y,Ca)247 phases with Ca-doping level up to 10 mol%. T_c of (Y,Ca)247 was enhanced by Ca-doping and the 5 mol% Ca-doped sample showed the highest T_c ~ 91 K.