Study on the influence of magnesium doping on the magnetic properties of spinel Zn-Mg ferrite

Polycrystalline spinel ferrite powders of Zn(1-)(x)Mg(x)Fe(2)O(4), (x = 0.0, 0.4, 0.8, and 1.0) have been synthesized by solid-state reaction. An antiferromagnetic Néel temperature (T(N) = 25 K) point is observed in ZnFe(2)O(4,) while MgFe(2)O(4) shows a strong ferromagnetism. The magnetization value of Zn(1-)(x)Mg(x)Fe(2)O(4) increases first and then decreases with the increase of x. When x = 0.8 (Zn(0.2)Mg(0.8)Fe(2)O(4)), the value of the saturation magnetization (M(s)) reaches a maximum as 85.566 emu/g. The magnetization of Zn(1-)(x)Mg(x)Fe(2)O(4) shows a very sensitive response to the Mg(2+) concentration at the tetrahedral sites (A-sites) or the octahedral sites (B-sites). I suggest that the A–B super-exchange interaction is enhanced after Mg(2+) ions substituting Zn(2+) ions.