Study of the temperature dependence of both permeability and selectivity of Mg Zn hexaferrites

Abstract The permeability of a series of polycrystalline BaZn 2− x Mg x Fe 16 O 27 W-type hexagonal ferrite ( x =0.0, 0.4, 0.8, 1.2, 1.6, 2), was investigated using a resonance circuit. The temperature dependence of both permeability and selectivity of the six prepared compositions was plotted in two ranges of temperature (300–750 K and 130–300 K) approximately. The permeability results were interpreted on the basis of its dependence on both magnetization and anisotropy constants. The decrease in selectivity values as Mg content increases was attributed to the decrease in the eddy currents and accordingly in the reflection resistance contained in the numerator of the selectivity. Moreover, the variation of permeability with composition at some selected temperatures was investigated.