Impact of oxygen annealing on the heat capacity and magnetic resonance of superconducting Pr0.88LaCe0.12CuO4−...

We use thermodynamic and neutron-scattering measurements to study the effect of oxygen annealing on the superconductivity and magnetism in Pr0.88LaCe0.12CuO4−. Although the transition temperature Tc measured by susceptibility and superconducting coherence length increases smoothly with gradual oxygen removal from the annealing process, bulk superconductivity, marked by a specific-heat anomaly at Tc and the presence of a neutron magnetic resonance, only appears abruptly when Tc is close to the largest value. These results suggest that the effect of oxygen annealing must first be determined in order to establish a Ce doping dependence of antiferromagnetism and superconductivity phase diagram for electron-doped copper oxides.