X-ray photoelectron spectra of La2CuO4 doped with strontium and scandium

• DOI: 10.1063/10.0032728
• Publication Date: 2025-01-31T19:24:07Z
• Authors: M. V. Dobrotvorskaya; M. A. Obolenskii; Yu. B. Poltoratskii; V. L. Sobolev

The changes in the structure of x-ray photoelectron spectra from the surface of La2CuO4 samples are investigated for different degrees of doping with strontium and scandium after mechanical purification and heating in vacuum, as well as under ion and x irradiation. The structure of the spectra of the core shells of the elements constituting the samples is identified. It is shown that the existence of copper in the mixed valence state is essential for the emergence of high-temperature superconductivity in the investigated cuprates, and the ratio of contributions of Cu+ and Cu2+ states to the electron structure of the compounds must be quite definite.