Nuclear and Electron Density Distributions of LiMn₂O₄ Analyzed by Combination of Rietveld/Maximum Entropy Method

Abstract

We investigated the crystal structure and the neutron/electron density distributions of LiMn₂O₄ in the temperature range from 150 to 573 K by the combination of Rietveld refinement and maximum entropy method (MEM). While we refined the crystal structure of LiMn₂O₄ with the space group Fddd from 150 to 240 K, we refined that with the space group, Fd-3m from 270 to 573 K. The electron density distribution which was estimated by MEM applied to X-ray diffraction, suggested that the electrons diffuse through the Mn–O sites and O–O sites at room temperature. On the other hand, the nuclear density distribution which was estimated by MEM applied to neutron diffraction, indicated that the Li atoms diffuse through 8b and 16d sites in LiMn₂O₄ with space group, Fd-3m. [DOI: 10.1380/ejssnt.2015.247]