Abstract
The investigated compositions of the Li-Ga ferrite system Li0.5Fe2.5-xGaxO4 (where x = 0.0. 0.1, 0.2, 0.3, 0.4 and 0.5) were studied by means of infrared (IR) spectroscopy. The analysis of IR spectra indicates the presence of splitting in the absorption band due to the presence of Fe2+ ions in ferrite. The dielectric constant epsilon', the dielectric loss epsilon '' and the loss tangent tan delta were measured at elevated temperatures ranging from room temperature up to 850 K as a function of frequency(f = 10(2)-10(6) Hz) for the investigated compositions. Maximum peak in tan delta and inverse peaks in epsilon' appeared for some samples due to the resonance phenomenon. The obtained data were discussed based on the valence exchange between (Fe2+ and Fe2+) and (Ga3+ and Ga2+), i.e. hopping mechanism. (C) 2008 Elsevier B.V. All rights reserved.