Influence of zn impurities on the superconducting y-ba-cu-o compound

Abstract

The influence of the Zn impurity has been studied in the superconducting compound $\mathrm{Y}{\mathrm{Ba}}_{2}{\mathrm{Cu}}_{3}{\mathrm{O}}_{7\ensuremath{-}\ensuremath{\delta}}$ by using two different methods of preparation: substitution of Cu by Zn or addition of Zn at the starting materials. In both cases scanning electron microscopy and electron probe microanalysis studies of the superconducting phase show a substitution of copper by zinc in a partial amount only. The effect of Zn on the superconducting properties of $\mathrm{Y}{\mathrm{Ba}}_{2}{\mathrm{Cu}}_{3}{\mathrm{O}}_{7\ensuremath{-}\ensuremath{\delta}}$ is found to be quite different from the influence of magnetic impurities.