Evidence of metallic samarium at the samarium nitride surface
Phys. Rev. B 113, 045301 – Published 2 January, 2026
DOI: https://doi.org/10.1103/p5wd-2g54
Abstract
Among the intrinsic ferromagnetic semiconducting lanthanide nitrides, samarium nitride (SmN) stands out for its combined ferromagnetic and superconducting behaviors at low temperatures. This has triggered an interest in developing a better understanding of the electronic structure of SmN utilizing both experimental and computational methods. In this study, we report an extensive in situ x-ray photoelectron spectroscopy and near-edge x-ray absorption study of the surface of samarium nitride compared with metallic samarium. Atomic multiplet calculations were completed to guide the interpretation of our experimental data. X-ray photoelectron spectroscopy depth-profiling provides evidence of a nonstoichiometric SmN surface, with the topmost atomic layers showing spectral features consistent with metallic Sm, including the presence of . In addition, we show that samarium ions in the bulk layers of SmN remain trivalent, with no evidence of mixed valence.
