Physics Department, Faculty of Science, Zagazig University, Egypt.
The mixed ferrites Mg1-x Znx Fe2O4 (where x = 0.0, 0.2, 0.3, 0.4, 0.5 and 0.6) were prepared by the ceramic method. Infrared absorption (IR) and dielectric properties were used to investigate this ferrite. The IR spectra in the range from 200 to 1000 cm−1 were reported and only, two bands were observed. The band υA around 560 cm−1 and the band υB around 400 cm−1 were assigned to the tetrahedral and octahedral complexes, respectively. The a.c. conductivity of the above compositions was studied in a wide range of temperature from 300 up to 720K. Over this range of temperature, the a.c. conductivity seems to be independent of frequency at high temperatures for all values of x. In the relatively low temperature regions, the frequency dissipation is attributed to the hopping conduction of the localized carriers. The dielectric constant έ, dielectric loss ε″ and loss tangent tan δ increase with increasing temperature. The dielectric behaviour is explained by using the mechanism of polarization process, which is correlated to that of electron exchange interaction.
