Crystal field parameters of the C2 site in Eu2O3

We studied the energy levels of Eu3+ at the C2 lattice site of cubic Eu2O3. We identified 29 Lorentzian lines corresponding to 5D0 → 7F0-6 transitions obtained from photoluminescence spectra at 10 K. The levels were analyzed in terms of the 14 crystal field parameters corresponding to the site symmetry. The energy-level fit yielded a final standard deviation of 12.0 cm−1. The resulting crystal field strength parameter is Nv = 3869 ± 185. This value confirms the linear dependence on the host atomic radius predicted by the extended point charge electrostatic model (PCEM). The present study considered the highest number of transitions to date for Eu3+ in Eu2O3 to the authors’ knowledge.