Effect of compositional variation on the properties of Y-Ba-Cu-O compounds

Single phase YBa₂Cu₃O_7– as well as multi-phase compositions of the Y-Ba-Cu-O system have been prepared by ceramic techniques. The effects of the additional phases on the superconducting transition and normal state properties have been investigated. Measurements show that while the transition temperature is not effected, grain growth, resistivity and unit cell volume of the 123 phase are dependent on the presence of multi phases. The observed changes in cell volume and resistivity can both be explained by a change in the oxygen concentration in the range 0 to 0.15.