Abstract <p>This study examines various spinel oxide powders, including manganese–zinc–iron (Mn–Zn–Fe), nickel–zinc–iron (Ni–Zn–Fe), and copper–zinc–iron (Cu–Zn–Fe). The powder synthesis is performed using the sol-gel auto combustion method, while diethanolamine (DEA) serves as the fuel. The resulting calcined samples are then characterized, using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-visible diffuse reflectance spectroscopy (UV‑DRS), and vibrating sample magnetometry (VSM) to determine the phase formation, morphology, particle size, optical properties, and magnetic behaviors respectively. XRD analysis revealed that the various spinel oxide powders which contained different levels of manganese, nickel, and copper, had a major spinel phase along with trace amounts of bixbyite, tenorite, wurtzite, rock salt, and hematite. Those samples based on nickel and copper demonstrated superior absorption levels when compared to samples with manganese according to the visible and infrared spectra in the UV-DRS analysis. In each of the powders, the bandgap energy (<i>E</i>_<i>g</i>) measured from 1.80 to 2.38 eV, while VSM data indicated the presence of an <i>S</i>-shaped curve which represented ferrimagnetism. The samples of Cu–Zn–Fe and Ni–Cu–Zn exhibit greater improvement in terms of saturation magnetization than the sample of Mn–Zn–Fe. It is possible to account for the variation in the magneton number through the application of the collinear spin ordering model, at the same time taking into consideration the translocation of divalent and trivalent ions between sublattices.</p>