Crystal field splitting and optical bandgap of hexagonal LuFeO3 films

Hexagonal LuFeO3 films have been studied using x-ray absorption and optical spectroscopy. The crystal splitting of Fe3+ is extracted as Ee\u27 - Ee = 0.7 eV and Ea\u271 - Ee\u27 = 0.9 eV, and a 2.0 eV optical bandgap is determined assuming a direct gap. First-principles calculations confirm the experiments that the relative energies of crystal field splitting states do follow Ea\u271 \u3e Ee\u27 \u3e Ee with slightly underestimated values and a bandgap of 1.35 eV