ELECTRICAL-CONDUCTION AND DIELECTRIC BEHAVIOR OF THE OXIDIC SPINEL LI0.5+0.5XCR0.3TIXFE2.2-1.5XO4

The electrical conductivity of polycrystalline lithium-chromium ferrites substituted successively with Ti4+ was studied as a function of composition and temperature. The resistivity increased with composition and all the samples exhibited a change in slope in the resistivity-temperature curve. Two different regions with a large variation in activation energies were found. The dielectric constant and loss factor for different compositions were measured in the frequency range of 10kHz to 10 MHz. The dielectric permittivity showed a dispersion with frequency for all the samples. Peaks were observed for the samples with 0.4 ≤ x ≤ 0.8. The possible mechanisms involved are discussed. © 1990 Chapman and Hall Ltd.