Studying the effect of oxygen content on the electron structure of Nd1.85Ce0.15CuO4 by means of photoelectron spectromicroscopy

In English Changes in the electron structure of the surface layer of Nd1.85Ce0.15CuO4 (NCCO) epitaxial films, which were caused by variation of the oxygen content and modification of the crystal structure of samples as a result of Ar+ ion etching and annealing, have been studied by means of photoelectron spectromicroscopy. A method is proposed for the cleaning the surface of oxygen-containing superconductors, which includes sequential stages of deep ion etching, high-temperature annealing in an oxygen-containing atmosphere (for the structural recovery and saturation with oxygen), a short-term ion etching (for the removal of an adsorbed layer of the oxidizer), and the final vacuum annealing of radiation-induced effects. The application of this procedure to NCCO films allowed an electron structure to be obtained, which was identical to that inherent in the surface of single crystals cleaved in situ in the measurement chamber.