Strong Correlations Between Positron Annihilation Spectroscopy and ESR for Mn0.1Mg x Zn0.9−x Fe2O4 Ceramics

Abstract

A series of single-phase spinel cubic structure Mn-Zn ferrites with the general formula Mn0.1Mg x Zn0.9−x Fe2O4 were prepared by a ceramic method. Mg content improves the crystallinity of Mn-Zn ferrites. The formula of the cation distribution for Mn-Zn ferrites was suggested at different Mg contents showing a good agreement between the theoretical and experimental structural data. The bulk density of the samples decreases by increasing the Mg content. The porosity of ferrite samples is increased from 16.7 to 19% by increasing the Mg content. Scanning electron microscopy (SEM) reveals that the grain diameter of Mn-Zn system decreases with Mg content. ESR measurements show that the resonance field, line width, and dielectric loss increase with Mg content. On the contrary, splitting factor and experimental magnetic moment decrease with Mg content. Thermo-electric power measurements indicate that the preponderance carriers are holes and localized to the lattice. The change of structure and properties of the ferrite samples are accurately observed with high sensitivity using positron annihilation spectroscopy (PAS) techniques. The results reveal that there are strong correlations between the PAS parameters and some parameters of ESR. It is suggested that PAS can be exploited as a powerful technique for characterizing magnetic material such as ferrite systems.