Influence of Carbon on Critical Temperatures of Superconducting Y-Ba-Cu-O

Abstract

High T c copper oxide superconductors, such as Y-Ba-Cu-O, commonly have a high chemical activity during sintering. Y-Ba-Cu-O superconductors are influenced by impurities in air, which cause degradation of the superconducting properties, critical current density ( J c ) and temperature of zero resistance ( T c zero ). XPS analysis of low J c and T c zero materials shows a presence of carbon in a higher amount compared to high J c and T c zero materials. This paper shows that J c and T c zero are very susceptible to impure gases in air.