Optical absorption and nuclear magnetic resonance in lithium titanium spinel doped by chromium

The optical absorption and nuclear magnetic resonance spectra of Li4 - x Cr-3x Ti5 - 2x O-12 (x = 0, 0.01, 0.02, 0.04) solid solutions have been investigated. It has been found that, in the Li4Ti5O12 spinel, lithium ions migrate from tetrahedral to octahedral positions with increasing temperature. Doping of chromium to the spinel favors an increase in the fraction of tetrahedrally coordinated lithium and hinders diffusion.