Electron Spectroscopy of Nd_2-xCe_xCuO_4-y(x=0, 0.15, and 0.23) Thin Films

Abstract

Electron spectroscopy of Nd 2- x Ce x CuO 4- y ( x =0, 0.15, and 0.23) thin films prepared by rf magnetron sputtering and successive annealing under a reducing condition was carried out. The films showed semiconducting, superconducting, and metallic behaviors according to x . The X-ray photoelectron and Auger electron spectra revealed that the electrons doped by replacing Nd 3+ with Ce 4+ were present in both the CuO 2 plane and the Nd layer of the Nd 2 CuO 4 crystal. The Cu valence was found to be 1+ for the superconducting x =0.15 film by the photoelectron and Auger electron spectra. U dd =9 eV and U pp =6 eV were obtained from the CuL 3 VV and OKVV Auger electron spectra for the x =0.15 film.