EPR monitoring of Mn4+ distribution in Li4Mn5O12 spinels

EPR of Mn4+ is used to study the cation-distribution in octahedral sites of Li4Mn5O12 spinel lattice. Analysis of the EPR line width in terms of magne tic dipole-dipole and exchange interactions points to two kinds of Mn4+ in octahedral spinel sites: one of them has as first neighbours five paramagne tic Mn4+ and one diamagnetic Li+, whereas the second type of Mn4+ is in a L i-rich surrounding. On the basis of this, the existing model on the tempera ture dependence of the magnetic susceptibility of Li4Mn5O12 was refined. (C ) 2000 Elsevier Science Ltd. All rights reserved.