Search for Isotope Effect in Superconducting Y-Ba-Cu-O

Abstract
An isotope effect has been searched for in the high-Tc superconductor YBa2Cu3O7δ through substitution of O18 for O16. No shift in the superconducting transition temperature Tc is observed by electrical resistivity or magnetic susceptibility measurements. We discuss the implications of this result for mechanisms of superconductivity in the high-Tc oxides.