Influence of the doping of Ti⁴⁺ ions on electrical and magnetic properties of Mn_1+xFe_2-2xTi_xO₄ ferrite

ac conductivity and magnetic behaviour have been studied for a series of polycrystalline ferrite with general formula Mn_1-xFe_2-2xTi_xO₄, (0 ≤ x ≤ 0.5), prepared using a conventional solid-state reaction technique. The results of ac conductivity show that σ_ac increases as the frequency and the temperature increase; whereas it decreases as Ti content increases except for a sample x = 0.1. The values of activation energies E_f for conduction process are determined from Arrhenius plots, and the variations of these activation energies as a function of composition have been discussed. The conduction mechanism used in present study have been discussed in the light of electron exchange between Fe² and Fe³ ions and hole hopping between Mn⁺³ and Mn⁺² ions at the octahedral B-sites. It observed that the saturation magnetization decreases with increase Ti⁴⁺ substitution, which is explained by the weakening of the exchange in the system according to Neel's molecular field model.