Photoemission Spectroscopy and Electronic Structures of LiMn₂O₄

We study the electronic structures of LiMn₂O₄ by x-ray and ultraviolet photoelectron spectroscopy (XPS, UPS) and resonant photoelectron spectroscopy (RPES). XPS data suggest that the average oxidation state of Mn ions is 3.55, probably due to the small amount of lithium oxides on the surface. UPS and RPES data imply that Mn ions are in a high spin state, and RPES results show strong Mn3d--O2p hybridization in the LiMn₂O₄ valence band.