Spinel lithium nickel aluminium ferrite nanoparticles (Li2–2x
Ni
x
Al2x
Fe2–2x
O4), (x = 0.0, 0.4, and 0.5) were prepared through the low temperature solution combustion method. Urea is employed as a fuel for the burning process. The synthesised samples are subjected to thermal analysis, x-ray diffraction, Fourier transformation infrared, Fourier transformation Raman spectroscopy, scanning electron microscopy, energy dispersive spectroscopy, transmission electron microscopy, selected area electron diffraction, ultraviolet-visible light spectroscopy, and vibrating sample magnetometry techniques. The thermal analysis revealed a combustion reaction occurring at around 300 °C. The structural and morphology results confirmed the nanoparticle nature and required material composition. The structural, optical, and magnetic properties significantly change, all of the particle size, band gap, coercivity, remnant magnetisation, and squareness ratio revealed a decreasing trend, while the dislocation density, micro-strain, saturation magnetisation, and the magnetic moment revealed a reverse trend as increment of Al and Ni content. The obtained optical, and magnetic properties confirm that the prepared materials are optically active, and soft ferrite nanoparticles. The ease of preparation method, observed good optical and magnetic properties together with cheap and environmentally benign precursor’s sources make achieved nanoparticles as promising material for nonlinear optics, microwave devices, and memory recording and storage applications.