Flux pinning at grain boundaries in liquid phase sintered YBCO

Flux pinning behavior in liquid phase sintered YBa₂Cu₃O_7-δ (YBCO) has been investigated in terms of preparation processing and pinning behavior. Liquid phase sintering method, which composed of two processes, mixing of YBCO precursor and liquid phase component and sintering at temperatures above the melting point of the liquid phase component, showed obvious Jc increase at high magnetic fields. Structure of the samples showing the increase of Jc by the liquid phase sintering is quite different from that showing no Jc increase. Structural dependence suggests that this pinning effect possibly originates from grain boundaries and oxygen deficiencies in the samples.