Point contact spectroscopy on electron doped Pr1-xLaCexCuO4-y

Point contact spectroscopy has been used to address the question of the symmetry of the order parameter in the superconducting Pr1-xLaCexCuO4-y compound. We recorded a huge variety of data that were consistently interpreted by considering a d-wave symmetry of the superconducting order parameter. Despite the different features appearing in the tunneling conductance spectra, all data inferred a superconducting energy gap amplitude. Delta similar or equal to 3.6 +/- 0.2 meV, with a conventional BCS temperature dependence and a ratio 2 Delta/KBTc similar or equal to 3.5 +/- 0.2. Also for the rare contacts showing a smaller gap value Delta similar or equal to 2.0 meV we found the same BCS ratio confirming that we are probing a sample area with reduced superconductivity (T-c similar or equal to 14K).