Screening effect of Ti4+ ions on the electrical conductivity and thermoelectric power of Mg ferrite Original Research Article

The samples Mg1+xTixFe2−2xO4 were prepared in a single phase spinel structure as indicated from X-ray analysis. The preference of Mg2+ ions to the octahedral site decreases the ratio of the normal spinel in the investigated ferrite where the Mg2+ increases on the expense of the Fe3+ ions on the same site. The increase in the conductivity was found to be due to thermally activated mobility of charge carriers. The mobility data enhances the use of Verway model of conductivity which depends on the electron exchange between iron ions of different valences located on the same crystallographic sites. The existence of Ti4+ ions on the octahedral site screens the polarization and decreases the conductivity of the samples. Peculiar behavior was obtained for Ti content of 0.7 and 0.8 due to the presence of secondary phases.