Physical Properties of LiMn2O4 Spinel Prepared at Moderate Temperature

A moderate-temperature method of preparation of the spinel LiMn2O4 was developed around 500 degrees C. Physical features of the products were identified by X-ray photoelectron spectroscopy, X-ray diffractometry, Raman scattering and FTIR spectroscopy. The electronic conductivity of LiMn2O4 has been studied as a function of annealing temperature. The product LiMn2O4 is identified as a micron-sized powder and analysis of the local environment is in good accordance with the classical structural model of Fd3m space group. LiMn2O4 exhibits an electrical conductivity of 1.9x10(-5) S/cm at room temperature with an activation energy of 0.16 eV which corresponds to an electron hopping mechanism between the two charge states of Mn3+ and Mn4+ ions. A first-order phase transition is observed at 292 K.