Mechanism of NiZn ferrite formation

The regularities in the change of character of the ferrite formation process as a function of Ni_1?xZn_xFe₂O₄ solid solution and of the degree of zinc oxide saturation of the Ni_1?xZn_xO solid solution (x = 0.14; 0.29; 0.43) are established in the temperature range 1220–1305°C. It is shown that in the reaction zone of interacting NiO, (Ni, ZnO), or ZnO with Fe₂O₃ the ferrite phase crystallizes only on iron oxide. The distribution of the Fe, Ni, and Zn concentrations over the reaction layer thickness using electron probe and X-ray spectrum analysis is obtained. The interdiffusion coefficients over the investigated temperature range calculated in the (Ni, Zn, Fe)O and ferrite phases change from (0.8 – 7.0) × 10^?9 to (1.0 – 12.0) × 10^?10 cm²/sec, respectively. The interaction of (Ni, Zn)O with Fe₂O₃ takes place by the mechanism of interaction of interdiffusion of Fe³⁺, Fe²⁺ and Ni²⁺, Zn²⁺ along with a current of Zn²⁺ ions and electrons or oxygen ions directed to the $\text{ferrite}\text{Fe}{}_2\text{O}{}_3$ interface.