VACANCY CONTENTS AND PHASE-EQUILIBRIA OF TI-SUBSTITUTED MNZN FERRITE

Measurement of the divalent iron content in acid dissolved MnZn ferrites, fired in controlled atmospheres at various temperatures and quenched, allows calculation of cation vacancy contents. Addition of Ti4+ to these ferrites resulted in the introduction of vacancies at the rate of about 0 to 0.3 per Ti4+ depending on heat treatment conditions. Data are presented whereby the vacancy content with Ti4+ can be calculated based on the oxygen content of the undoped ferrite as available in the literature. Ti4+ stabilizes the hexagonal hematite-like structure and the phase boundary is presented as a function of Ti4+ and temperature. The vacancy contents at the phase boundary in Ti4+-doped ferrite as a function of temperature are in agreement with those calculated from the literature for undoped MnZn ferrites. Finally, the total oxygen content of coexisting spinel and hexagonal phases is presented. © 1979.