STUDY OF THE INFLUENCE OF SYNTHESIS PARAMETERS ON THE STRUCTURAL AND MAGNETIC PROPERTIES OF COBALT FERRITE

The paper proposes the use of contact low-temperature non-equilibrium plasma for the synthesis of cobalt ferrite. The influence of the pH of the reaction medium, temperature, and duration of treatment on magnetic properties, the intensity of X-ray diffraction peaks, the average size of crystallites, and the value of dislocation density were determined using the central composite rotary design of the experiment. The results of X-ray phase analysis, vibrational magnetometry, and electron microscopy were used to create the models. The results showed that the pH of the reaction medium is the parameter that has the greatest influence on the growth of cobalt ferrite powder crystallites and the magnetic properties of the samples. It was established that the largest size of crystallites (505- 560 & Aring;) was obtained at high temperatures and pH values. The smallest crystallite size (119-165 & Aring;) was obtained at a temperature of 20 degrees C, a minimum processing time of 5 minutes, and a pH of 10. Based on the analysis of hysteresis curves, it is shown that high values of magnetization saturation (120-138 Emu/g) can be achieved at an elevated temperature of 40 degrees C and processing time. This is due to the formation of cobalt ferrite with high crystallinity and large crystallite sizes. Smaller values of saturation magnetization (8-14 Emu/g) are due to the formation of nonmagnetic impurity phases of iron oxides and oxyhydroxides.