The phase stability region of the ferrite spinel, Fe2.11Mn0.54Zn0.35O4, was deduced from the isothermal variation in total conductivity as a function of O partial pressure at high temperatures. Its mean cationic transference number was found by using a modified Tubandt-like electrotransport method over the entire stability range. It was found that, at a given temperature, the ionic transference number increased with increasing O partial pressure in oxidizing atmospheres, and with decreasing O partial pressure in reducing atmospheres; with a minimum between the 2 behaviors. By combining the total conductivity with the transference number, the partial ionic conductivity was estimated and was analyzed in terms of the defect structure, and the mobility in the ferrite spinel structure. It was observed that electrotransport-induced de-mixing occurred; especially under reducing atmospheres.

Y.I.Jang, H.I.Yoo: Solid State Ionics, 1996, 84[1-2], 77-88