Role of oxygen in the electron-doped superconducting cuprates

Abstract

We report on resistivity and Hall measurements in thin films of the electron-doped superconducting cuprate ${\mathrm{Pr}}_{2\ensuremath{-}x}{\mathrm{Ce}}_{x}\mathrm{Cu}{\mathrm{O}}_{4\ifmmode\pm\else\textpm\fi{}\ensuremath{\delta}}$. Comparisons between $x=0.17$ samples subjected to either ion irradiation or oxygenation demonstrate that changing the oxygen content has two separable effects: (1) a doping effect similar to that of cerium and (2) a disorder effect. These results are consistent with prior speculations that apical oxygen removal is necessary to achieve superconductivity in this compound.