Mechanochemical effects on synthesis and pulverization of Ba2YCu3O7−y, superconductor and Ba2YCu3O7−y–Ag composite

Abstract

Mechanochemical effects on the synthesis and pulverization process of the Ba2YCu3O7−y superconductor (abbreviated to BYCO) and BYCO–Ag composite were examined. Grinding of the precursor of BYCO promoted the homogeneous distribution of each element and subsequently the crystallinity of the precursors was decreased. The sintered body obtained by using the ground and calcined powder had complicated crystal phases consisting of the BYCO phase with secondary phases and resulted in the impairment of the superconducting transport current property. Grinding of crystallized BYCO powder decreased its grain size and crystallinity; the crystallinity was recovered by annealing. On the other hand, grinding contributed to the synthesis of the BYCO–Ag superconducting composite by minimizing the particle sizes and mixing of components. The BYCO–Ag composite so obtained displayed improvement of superconducting properties.