Densification and high critical current densities in bulk YBa2Cu3O7−y superconductor by the solid state reaction technique

Bulk samples of YBa2Cu3O7−y prepared by the solid state reaction method exhibited high density (96%) and high Jc (2586 A cm−2) values at 77 K and zero magnetic field. The effect of extended heat treatments on the density and oxygen content of the samples is discussed in connection with microstructure and changes observed in Jc, Tc and transition width ΔTc.