Effect of Nonmagnetic Zn ²⁺ Cations on Initial Permeability of Microwave‐Treated NiMg Ferrites

Magnesium is replaced systematically by zinc in Ni _0.2 Mg _{0.8‐ x} Zn _x Fe ₂ O ₄ ( x = 0.2–0.8) prepared by microwave‐assisted solid‐state reaction route. The structure is confirmed by X‐ray diffractograms. An improvement in initial permeability is observed with substituent in Ni _0.2 Mg _{0.8‐ x} Zn _x Fe ₂ O ₄ due to increase in average grain size. The obtained permeability values are varying between 106 and 687 at 1 MH z. The permeability plots revealed that Curie‐transition temperature ( T _c ) is decreasing with increase in zinc. Both x = 0.2 and 0.4 compositions show low relative loss factor of order 10 ⁻⁵ to 10 ⁻⁴ , which are exhibiting required magnetic properties for transformer and inductor core applications.