Superconductivity of Ba₂Y(Cu, Ti)₃O_y Oxide

Abstract

Samples of Ba 2 Y(Cu, Ti) 3 O y oxide were synthesized and the effect of substituting Cu with Ti was studied. In the Ba 2 Y(Cu 3- x Ti x )O y (0≦ x ≦0.9), specimens were obtained which indicated a T c of over 80 K. In the composition Ba α YCu β Ti 0.6 O y (1.9≦α≦2.3, 2.3≦β≦3.5), some (Cu Ti)-rich samples indicated a T c of over 95 K which was as high as that of the existing Ba 2 YCu 3 O y . Diamagnetic signals measured by AC susceptibility at room temperature were detected in some specimens. Zero electric resistance was observed (<10 -4 Ωcm at our experimental resolution) up to 300 K in the composition Ba 2 YCu 2.4 Ti 0.6 O y sintered at 940°C.