Fabrication, microstructure, mechanical and transporting properties of BaZrO3-particles-dispersed YBa2Cu3O7−δ mixed conduction composites

A mixed conducting YBa2Cu3O7−δ (YBC)-based composite was developed via addition of excess BaO and iso-molar ZrO2 to form BaZrO3 (BZ) dispersed particles in situ. XRD shows that as-synthesized composites are composed of binary phases of YBC and BZ. It is found that the dispersed BZ particles can effectively suppress the grain growth of basic phase YBC especially in the longitudinal c-axis direction, leading to change in grains from bar-like to cubic-like. Compared with the pure phase YBC, the composite with 10 mol% of BZ exhibits higher relative density and oxygen permeability and much improved mechanical strength. The electrical conductivity measurement shows that the electrical transporting properties of the composites are also affected due to the change in microstructure and densification.