A resistivity peak close to Tc in Nd2−xCexCuO4−y single crystals

Authors present results of the electrical resistivity of a Nd1.84Ce0.16CuO4-y superconducting (Tc=22.4 K) single crystal in magnetic fields up to 13 T. The measurements were performed by the van der Pauw method in both possible configurations of the electrodes. In one of the configurations a resistivity peak has been observed close to the critical temperature, whereas the peak was not visible for the other configuration. Authors propose a simple model assuming an inhomogeneous distribution of Ce, which may explain this effect. Results of AC-susceptibility measurements on the crystal and its fragments support this model. 15 refs.