Structural and magnetic properties of Mg-substituted NiZnCo ferrite nanopowders

Abstract Mg-substituted NiZnCo ferrite nanopowders, Ni 0.5− x Zn 0.5 Mg x Co 0.1 Fe 1.9 O 4 (0≤ x ≤0.20), were synthesized by sol–gel auto-combustion method. The effect of Mg substitution on the structural and magnetic properties have been investigated. X-ray diffraction and vibrating scanning magnetometer were used to characterize the structural and magnetic properties. XRD revealed single-phase of cubic spinel. Both average crystallite size and lattice parameter increase with increasing Mg substitution. The saturation magnetization initially increases with the increase of Mg substitution when x ≤0.05, and decreases when x> 0.05, which indicates excessive nonmagnetic cations in tetrahedral site will decrease the superexchange interaction between tetrahedral and octahedral sites. The decrease in the coercivity values with increasing Mg substitution indicates the decrease of magnetocrystalline anisotropy energy.