Resonant photoemission study of electronic structure of rare-earth sesquioxides

Electronic structures of ten kinds of rare-earth sesquioxide single crystals ( R 2 O 3 ; R =La, Pr, Nd, Sm, Eu, Gd, Er, Tm, Yb and Lu) were investigated by 4 d -4 f resonant photoemission measurement. The information of the electronic structure, especially the relative binding energy of 4 f state and O 2 p valence band, was obtained. The 4 d -4 f resonant photoemission spectra of valence band can be explained by multiplet structure of 4 f n -1 final state and the mixing between 4 f and O 2 p . The O 2 p valence band has 4 d -4 f resonance in La 2 O 3 that is in a typical 4 f 0 case. La 5 d character is considered to mix to the O 2 p valence band.