The reactivity of Cu 2+ ion concentration in Ni–Zn spinel matrix fabricated using solution combustion route has been investigated. The specimens of nanocrystalline Ni 0.8− x Cu x Zn 0.2 Fe 2 O 4 (x=0.0⩽0.6 with steps of 0.2) exhibits single phase cubic structure. The detailed studies regarding the physico-chemical stability, crystal structural stability, surface morphology and magnetic properties as a function of Cu 2+ ion concentration were performed. The annealing treatment does not alter the crystal structure but increases the crystallinity of the samples. The cation occupancies of the prepared materials were estimated by using X-ray diffraction (XRD) data analysis. The morphological investigations of the samples were studied by using field emission scanning electron microscopy (FE-SEM) technique. The crystallographic analyses of all the compositions were systematically investigated by Fourier transform infrared spectroscopy (FTIR). The saturation magnetization (M–H plots) at room temperature with field 10kOe exhibits strong influence of Cu 2+ ion content and annealing temperature.