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.