Abstract
Oxygen self-diffusion coefficients in a manganese zinc ferrous ferrite single crystals were determined at various oxygen partial pressures by means of a secondary ion mass spectrometer. Temperature dependence of diffusivity of oxide ions consisted of three parts. The characteristics at middle temperature range above 5 hPa oxygen partial pressure exhibited a behavior as an extrinsic one and was described as;
D=4.8×10-6⋅P0.35O2 exp(-137kJ/mol/RT)cm2⋅s-1
This activation energy corresponded to the barrier for the migration of oxide ions in spinel structure. The dependence of oxygen self-diffusion on oxygen partial pressure exhibited a positive sign (slope value: 0.35). This phenomenon suggests that the oxygen ions diffuse in Mn-Zn ferrite through interstitial sites above 5 hPa of the oxygen partial pressure.
