Structure refinement of quaternary spinel oxides experiments and modelling

Comprehensive studies have been undertaken, inclusive of experimental and c omputational techniques, on the structure and cation distribution of spinel solid solutions formed between the normal spinel LiMn2O4 and inverse LiFe5 O8. Series of solid solutions of a composition (l - x)LiMn2O4 . xLi(0.5)Fe( 2.5)O(4) are single phase products with spinel structure in the whole range of x, displaying a cubic structure. With increasing Fe3+ content, the tend ency of ordering by lithium ions in octahedral spinel sites and a strongly marked preference of Li+ cations to occupy the octahedral positions is appa rent. Modelling and refinement of crystal structure of such spinel solid so lution series have been undertaken by the energy minimisation procedure, to gether with the interatomic potentials calculation, explaining some diverge nces of the experimental data. (C) 2000 Elsevier Science Ltd. All rights re served.