Remarkable influence on the dielectric and magnetic properties of lithium ferrite by Ti and Zn substitution

The effect of Zn and Ti substitution on the magnetic and electrical properties of Li0.5ZnxTixMn0.05Fe2.45−2xO4 ferrites (x=0.0 to 0.30 in steps of 0.05) +0.5wt% Bi2O3 prepared by a standard ceramic technique has been investigated. Electrical conductivity and dielectric measurements at different temperatures from 300 K to 700 K in the frequency range from 100 Hz to 2 MHz have been analysed. The variation of the real part of dielectric constant ( ε ′ ) and loss tangent ( tan δ ) with frequency and temperature has been studied; it follows the Maxwell–Wagner model based on the interfacial polarization in consonance with the Koops phenomenological theory. It is found that the permittivity of zinc and titanium substituted lithium ferrite improves and shows a maximum value (∼ 1.5×105) at 100 Hz for the x=0.25 sample. The dielectric transition temperature ( T d ) depends on the concentration of Ti and Zn in Li0.5ZnxTixMn0.05Fe2.45−2xO4. The saturation magnetization and Curie temperature both decrease with increase in the concentration of Ti and Zn in the ferrite.