Improved flux pinning in YxHo1-xBa2Cu3Oy fabricated by powder melting process

Abstract

Flux pinning and the peak effect of YxHo1-xBa2Cu3Oy melt-textured samples fabricated by a powder-melting-process method are investigated by a SQUID magnetometer in a magnetic field parallel to the c-axis of the samples. It has been found that the partial substitution of Ho for Y can lead to a strong enhancement of flux pinning over a wide temperature and field range in melt-textured YBa2Cu3Oy samples. A Jc value as high as 1.3×105 A cm-2 at 77 K and in self-field has been achieved in the Y0.4Ho0.6Ba2Cu3Oy sample. The enhancement of flux pinning may be attributed to the reduction of Y2BaCuO5 particles, the higher density of stacking faults and the paramagnetic moment of Ho3+. Contrary to the pure YBa2Cu3Oy sample, a peak effect can be observed below 77 K in Hc in the Ho-added superconductors.