Optical transitions in magnetoelectric Ga0.6Fe1.4O3 from 0.73 to 6.45 eV

The optical properties of polycrystalline Ga0.6Fe1.4O3 bulk are determined by spectroscopic ellipsometry from 0.73 to 6.45 eV. Complex dielectric function ɛ = ɛ1 + iɛ2 spectra are obtained from the multilayer analysis. The ellipsometric data exhibit numerous optical structures, and the transition energies are accurately obtained by analyzing the second-energy derivatives of the data. The origins of the optical structures are explained in terms of Fe3+ ligand field transitions and ligand-to-metal charge transfer transitions.