Effect of Ta2O5 addition on the superconducting properties of REBa2Cu3Oy

Abstract We have investigated the effect of Ta 2 O 5 addition on the superconducting properties of REBa 2 Cu 3 O y (RE = Er, Sm and Eu: REBCO) prepared by a powder-sintering method. T c (zero) values showed no degradation up to 1.0 wt.% Ta 2 O 5 addition for ErBCO samples. EuBCO and SmBCO samples showed the increase in T c (zero) from 89 K to 94 K by the addition of 1 wt.% Ta 2 O 5 , and 80 K to 94 K by the addition of 2 wt.% Ta 2 O 5 , respectively. J c values at B  = 0.5 T increased by two times the pure samples for ErBCO with 1.0 wt.% addition, four times for EuBCO with 1.5 wt.% addition, and 33 times for SmBCO with 1.0 wt.% addition. The formation of REBa 2 TaO 6 was observed for the Ta 2 O 5 -added REBCO samples.