EPR of Mn4+ in spinels Li1+xMn2−xO4 with 0≤x≤0.1 Original Research Article

EPR of Mn4+ has been used to study electron–phonon interactions and cation distribution in Li1+xMn2−xO4 spinels with 0≤x≤0.1. The EPR spectra of Mn4+ in 16d spinel sites has been interpreted in terms of the bottleneck-relaxation mechanism. Two additional weak 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 more precisely the Li1+xMn2−xO4 spinels with respect to the cation distribution.