This study presents the synthesis of Cd_0.5Zn_0.5Fe_2−xCr_xO₄ nanoparticles via the sol–gel method, along with a comprehensive characterization of their morphological, structural, infrared, and magnetic properties. The X-ray diffraction pattern confirms the formation of the spinel structure, and the cation distribution is estimated using X-ray analysis and confirmed by magnetization measurements. The crystalline size, ranging from 152 to 189 nm, and lattice parameter, varying from 8.51134 Å to 8.42067 Å, decrease with increasing Cr content. The saturation magnetization decreases from 55 emu/g to 10.8 emu/g, while the remanent magnetization increases (3.5 emu/g ≤ M_r ≤ 6.27 emu/g), and the coercivity increases (82 Oe ≤ H_C ≤ 422.15 Oe) with the addition of Cr ions. Fourier transform infrared (FTIR) spectroscopy reveals two absorption bands at ν₁ and ν₂, located near 600 and 400 cm⁻¹, respectively, which correspond to the vibrations of the metal–oxygen bonds in the spinel structure.