Microstructure and magnetic studies of Mg–Ni–Zn–Cu ferrites

Soft Mg–Ni–Zn–Cu spinel ferrites having general chemical formula NixMg0.5−xCu0.1Zn0.4Fe2O4 (where x = 0.1, 0.2, 0.3, 0.4 and 0.5) were prepared by standard double sintering ceramic method. The samples were characterized by X-ray diffraction at room temperature. The X-ray diffraction (XRD) study revealed that lattice parameter decreases with increase in Ni content, resulting in a reduction in lattice strain. The electrical and magnetic properties of the synthesized ferrites have been investigated as a function of temperature. The variation of initial permeability and AC susceptibility with temperature exhibits normal ferrimagnetic behavior. The variation of initial permeability with frequency is studied. The Curie temperature (TC) in the present work was determined from initial permeability and AC susceptibility. The Curie temperature increases with Ni content.

► NixMg0.5−xCu0.1Zn0.4Fe2O4 ferrite shows spinel structure.
► Lattice parameter, X-ray density, porosity increase with increase in Ni content.
► The IR spectra show tetrahedral and octahedral complexes.
► Initial permeability remains constant with temperature and drops to zero at certain temperature which is in close agreement with Curie temperature.
► The Curie temperature shows increasing trend with Ni content.