Rate of heating and sintering temperature effect on the electrical properties of Nd ferrite

The real part of the dielectric constant (e′) and the dielectric loss angle (tan δ) as well as the ac conductivity of ferrite Mg1+xTixNdyFe2−2x−yO4 0.1 ≤ x ≤ 0.9 at fixed Nd concentration of 0.025 were measured at different temperatures as a function of frequencies. The variation of activation energy as a function of the applied frequency was reported. The obtained data were discussed on the basis of the valence exchange between (Fe3+, Fe2+), (Fe2+, Nd3+) and (Fe2+, Ti4+). Also the effect of sintering temperature and heating rate of preparation were discussed.