Abstract <p>Methods of X-ray diffraction, laser diffraction, BET analysis, pulsed magnetometry, and thermomagnetometric measurements have been used for comprehensive investigation of the influence of high-energy ball milling on structural and magnetic characteristics of ferrite powders. Studies were conducted on samples of spinel ferrite with the composition Co_0.7Zn_0.3Fe₂O₄. Correlation dependences have been established between the energy intensity of milling, microstructural parameters (size of coherently scattering domains and level of microstresses), and magnetic properties (saturation magnetization and temperature of magnetic phase transition). Thermomagnetometric analysis has shown that the onset temperature of the ferrimagnetic-to-paramagnetic phase transition is related to the degree of crystal lattice defects in the powder materials, making this method suitable for assessing the microstructural parameters of magnetic powdered materials. The obtained patterns can be applied to obtain various types of ferrites with predetermined structural and magnetic properties through high-energy milling in planetary ball mills.</p>