DOPING OF CO3O4 WITH LITHIUM BY A SOLID-STATE REACTION IN AIR .2. DISTRIBUTION OF LITHIUM IN THE SOLID-SOLUTION

The distribution of the lithium ions in the crystallites of Co3O4 powder samples doped with Li by a solid state reaction in air at 500-750°C was studied by chemical analysis, magnetic susceptibility measurements, EPR, IR and DTA. The core of Co3O4 spinel crystallites accomodate relatively small lithium amounts (up to 2 mol%) in sites and interstices of the spinel lattice. With up to 7-9 mol% lithium, the Li concentration in the core of the crystallites does not change significantly and the rest of the lithium ions accumulate in domains comprising 10-15% of the total crystallite volume. In these lithium-rich domains, mainly Li+ and Co3+ ions are present. © 1990.