Synthesis and soft magnetic properties of Zn_0.8−xNi_xMg_0.1Cu_0.1Fe₂O₄ (x = 0.0−0.8) ferrites prepared by sol–gel auto-combustion method

Highlights: • Ni2+ occupies A and B site, when Zn2+ is fully replaced by Ni2+, it goes to A site. • Change in distribution of cations has significant effect on magnetic properties. • Highest Ms value of 25.04 emu/g, was obtained for x = 0.60. - Abstract: Single phase nanocrystalline Zn_0.8−xNi_xMg_0.1Cu_0.1Fe₂O₄ (x = 0.0−0.8), were synthesized by sol–gel auto-combustion method without post-preparation treatment and, effect of Ni content on structural and magnetic properties is studied by X-ray diffraction (XRD), magnetic measurements and cation distribution. Scherrer's grain diameter range between 23.5 and 35.1 nm. Experimental and theoretical lattice parameter values suggest that the estimated cation distribution is close to the real distribution. Change in Ni-content leads to variation in cation distribution at site A and B. Ni²⁺ ions occupy both A and B site, but when Zn²⁺ is fully replaced by Ni²⁺, it totally goes to A site. Both coercivity measured at 50 Hz and quasi static coercivity value is found to increase with nickel content. Same trend is observed for anisotropy constant values. Best magnetization value of 25.04 emu/g was obtained for the specimen with x = 0.60. Variation of magnetic properties and other parameters (obtained via cation distribution) can be understood in terms of observed changes in distribution of cation(s) on A and B site