EPR of Mn4+ in spinels Li1+xMn2-xO4 with 0 <= x <= 0.1

EPR of Mn4+ has been used to study electron-phonon interactions and cation distribution in Li1+xMn2-xO4 spinels with 0 less than or equal to x less th an or equal to 0.1. The EPR spectra of Mn4+ in 16d spinel sites has been in terpreted in terms of the bottleneck-relaxation mechanism. Two additional w eak signals were registered that were attributed to Mn4+ ions located near oxygen vacancies and to Mn4+ ions in a lithium rich environment. These Mn4 defects are sensitive towards the Li/Mn ratio and the cooling rate. It has been demonstrated that EPR monitoring of Mn4+ allows us to distinguish mor e precisely the Li1+xMn2-xO4 spinels with respect to the cation distributio n. (C) 2000 Elsevier Science Ltd. All rights reserved.