Changes of Ni-Zn Properties by Substitution of Zn With Cu and Co Ions

The effect of partial substitutions of Zn²⁺ ions with Cu²⁺ and Co²⁺ ions in Ni_0.33Zn_0.67Fe₂O₄ ferrite were investigated on magnetic properties. Fine particles of Ni_0.33Zn_0.67-xMe_x, ferrites with Me = Cu²⁺/Co²⁺ were prepared by the self-propagated combustion method. Variation of temperature dependences of the magnetic susceptibility χ(T) with composition is discussed and possible magnetic mechanism is investigated. Grain size is one of the factors determining the magnetic properties of ferrite materials. The chemical and structural changes of ferrite during substitution treatment are analyzed also using Mossbauer spectrum and SEM. Initial permeability varies with ion content x in ferrite materials, which is attributed to the variation of grain size.