Correlation between magnetic properties and cationic distribution of Zn0.85−x Ni x Mg0.05Cu0.1Fe2O4 nano spinel ferrite: effect of Ni doping

Abstract

The correlation among magnetic properties and cationic distribution of Ni-doped Zn0.85−xNixMg0.05Cu0.1Fe2O4 (x = 0.00, 0.17, 0.34, 0.51, 0.85) ferrite, synthesized using sol–gel auto-combustion process is studied by X-ray diffraction (XRD), scanning electron microscope (SEM), energy-dispersive X-ray analysis (EDAX), and magnetic measurements. XRD patterns revealed a pure phase spinel ferrite structure for all samples with Scherrer’s grain diameter (D) ranging from 33.55 to 42.07 nm. Experimental, theoretical lattice constant (aexp., ath.), specific surface area (S), and the distances between cations (Me–Me) (b, c, d, e, f) of the annealed Zn–Ni–Mg–Cu ferrite decrease with the increase in Ni doping. Elemental analysis, particle diameter, and surface morphology were examined by EDAX and SEM. Coercivity (Hc) and saturation magnetization (Ms) of Zn–Ni–Mg–Cu ferrite ranges between 0.97–167.5 Oe and 47.63–136.93 Am2 kg−1, respectively, signifying the soft character of annealed samples. Magnetic parameters such as Hc, magnetocrystalline anisotropy (K1), remanence (Mr), and reduced remanent magnetization (Mr/Ms) increase up to x = 0.51 and then reduce thereafter with Ni doping. Particle size dependence of Hc reveals superparamagnetic, single domain, and multi-domain nature of the studied ferrite. Observed similar trend of Ms, Neel/experimental magnetic moment (nBN, nBe) with Ni content (x) follows the Neel’s two-sublattice model of ferrimagnetism and is accredited to the cationic distribution and B–B exchange interaction. All these results establish a strong connection between magnetic properties and cationic distribution of Zn0.85−xNixMg0.05Cu0.1Fe2O4 ferrite.