Silver substitution for Copper in Y1Ba2Cu307-y

Abstract

Abstract A variety of samples with different amounts of silver substituted for copper in Y1Ba2(Cu1-xAgx)3O7-y were prepared and sintered at temperatures between 940°C and 1030°C. Samples with values of x up to 0.4 were superconducting above 77 K and the the room temperature resistivity was generally lower in samples sintered at or in excess of 980 C. The samples were analysed using x-ray diffraction and scanning electron microscopy. The results presented here show that silver remains largely isolated in intergranular cavities, resulting in improved connectivity and transport properties, despite the formation of impurity phases which emerge due to disturbances in the stoichiometry of the superconducting phase. Additionally, samples sintered at temperatures in excess of the melting point of silver exhibit enhanced grain growth, a denser morphology and more metallic behaviour in the normal state.