In this study, the magnetic compound Cu1-xMgxFe2O4 is synthesized using the sol-gel method at distinct magnesium concentrations (x = 0, 0.2, 0.4, and 0.6) to investigate the influence of RF plasma exposure on its structural and magnetic properties. X-ray diffraction analysis, applied to examine the prepared ferrite, confirms the formation of the face-centered cubic (FCC) structure in the samples. Utilizing X-ray diffraction broadening and Scherrer's equation for particle size determination, sizes are found to range from 37.73 nm to 19.870 nm prior to plasma exposure and 30.35 nm to 19.115 nm subsequent to exposure. The study of the compound's magnetic properties demonstrates that the saturation magnetization spans from 33.5 to 32.1 emu/g, with an initial coercivity decrease from 150 to 50 Oe, further diminishing as magnesium concentration increases. Notably, following plasma exposure, alterations in saturation magnetization values (35.32-27.4 emu/g) and coercivity (150-25 Oe) are observed. The results underscore the impact of rising magnesium concentrations and plasma exposure on the compound's structural properties, potentially attributable to atomic rearrangement within the crystalline structure. In terms of magnetic properties, a reduction in coercive force following plasma exposure is discerned, thereby enhancing the ferrite's properties, which are applicable in transformer cores to minimize eddy currents.