XPS and Raman spectroscopic characterization of LiMn2O4 spinels.
Résumé
Surface analysis of lithium manganese oxides synthesized by the melt-impregnation method has been made by x-ray photoelectron spectroscopy. These results revealed the change in the average oxidation state of Mn cations upon lithium substitution in Li1+Mn2-O4 spinels. Studies of the local structure characterized by Raman scattering show the MnO bonding evolution as a function of the replacement of manganese cations. Modification in the trigonal distortion of MnO6 octahedra is evidenced by insertion of lithium ions into the octahedral holes of the [B2]O4 spinel framework.