Effect of grain size on electric transport and magnetic behavior of strontium hexaferrite (SrFe12O19)

Abstract

Polycrystalline M-type hexagonal strontium hexaferrite (SrFe12O19) was prepared by conventional ceramic route (LG SrM) and auto combustion (SG SrM) method. The single-phase pattern and well grain growth was confirmed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The average crystalline size is found to be 41.35�nm in LG SrM, while that of SG SrM is 36.87�nm. In this report, the electric transport behavior of LG SrM and SG SrM (SrFe12O19) was successfully investigated and the analysis is done in the frequency range 100�Hz to 1�MHz at temperature 30�200��C. The relaxation behavior was examined by considering the impedance and modulus formalism in order to investigate the grain and grain boundary and surface polarization conduction process. The magnetic properties such as saturation magnetization, remanence, coercivity and anisotropy field are calculated from the hysteresis loop measurement. It was found that the saturation magnetization gets increased in LG SrM as compared to SG SrM system while the coercivity of SG SrM is greater than that of LG SrM. � 2016, Springer-Verlag Berlin Heidelberg.