On the role of Fe2+ ions and cation vacancies in the disaccommodation of ferrites

A study was made of the disaccommodation spectrum of ferrites Mn_xFe_3–xO_4+y, x>1, in a temperature range above 0°C. A comparison with analogous spectra of ferrites rich in iron (x<1), which contain Fe²⁺ ions in addition to cation vacancies, shows that the disaccommodation maximum around room temperature, observed in iron rich ferrites, is subject to the presence of Fe²⁺ ions. On the other hand, the processes taking place at higher temperatures seem to be substantially common to both types of ferrites and are dependent only on the presence of vacancies.