Improved Properties of Li-Mn-Ti Ferrites by Microwave Sintering

Substituted Li-ferrites are attractive materials for research due to their important properties like high Curie temperature leading to high thermal stability, high and wide range of saturation magnetization, low stress sensitivity of remanence and they are very good dielectric materials. The properties are very sensitive to the type and amount of substituents, method of preparation and sintering conditions. Attempts to minimize loss of lithia and oxygen during sintering by adopting various processing method, which otherwise is very difficult to control technologically by conventional method, has been a continuous efforts for the researchers. The present paper reports the improvements that arise in the properties of Li-Mn-Ti ferrite by using novel microwave (MW) processing technique. Mn4+ and Ti4+ substituted Li-ferrites having the compositional formula Li0.60Mn0.1Ti0.1Fe2.20O4 were prepared by both the conventional and microwave techniques. XRD confirmed the formation of single phase with spinel structures in both the samples. Dielectric properties were studied as a function of temperature. Dielectric properties of MW processed sample were found to be more stable with temperature. Significant improvement in the d. c. resistivity was observed in the MW sintered sample over the conventional sintered sample. The possible mechanisms involved are discussed.