Element Addition Effect for Superconducting Properties of YBa₂Cu₃O_7-y Ceramics

Abstract

Element addition effects of YBa₂Cu₃O_7-y ceramics on the superconductivity have been studied. Fifty-two kinds of elements, and 163 compositions have been investigated but no element capable of improving the critical temperature (T_c) was found. Pb, Al and W were chosen additives and have been studied in detail about the changes in the superconducting properties and the crystal structures by the ratios of addition. Pb and W had almost no solubility in YBa₂Cu₃O_7-y. The crystal structure of YBa₂Cu₃O_7-y changed from orthorhombic to tetragonal by the addition of Al or W. T_c was lowered along with the change of the crystal structure.