Permeability Spectral Analysis and Determination of Microstructural Parameters for Mn0.7+xZn0.3SixFe2-2xO4 Series

In this communication, the compositional dependence of the real part (μ′) and an imaginary part (μ″) of complex permeability for polycrystalline compositions of ferrite series, Mn0.7+xZn0.3SixFe2-2xO4 (x = 0.1–0.3), over the wide frequency and temperature ranges has been discussed. The μ′ decrease with Mn-Si concentration (x) is mainly due to the reduction in saturation magnetization (Ms) and average grain size (D). The D decreases due to smaller solid solubility in the spinel structure and segregation of SiO2 at grain boundaries. The μ′(f) plots at 300 K show a relaxed type of spectra. The observed maximum in the vicinity of Neel temperature in μ′(T) curves is due to the relative rate of change of anisotropy constant and Ms values, whereas in μ″(T) plots it is because of the domain wall damping. The derived microstructural parameters related to grain structure have been discussed in a systematic manner.