Core-level in rare-earth metals and their trifluorides from exchange splitting photoemission and ground-state calculations

Abstract

Photoemission from Eu, Gd, Tb, and their trifluorides has been investigated with respect to exchange splitting of core-levels. For ${\mathrm{EuF}}_{3}$, a splitting of the $4s$ and $5s$ lines has been observed despite the nonmagnetic Eu ion ground state. The major part of the observed splittings is reproduced by the density-functional theory based calculations. This indicates that the exchange splitting of the core-levels is present in the photoemission initial state of rare-earth ions with partially filled $4f$ shell.