Radiotracer and serial sectioning methods were used to study the diffusion of 59Fe isotope in ferrites at between 1130 and 1280C in air. In general, the diffusion profiles exhibited fast and slow regimes. At below 1280C, the diffusion coefficients changed monotonically; depending upon the composition of the ferrite. In the solid solution, cation diffusion occurred much more slowly and with a higher activation energy than in the end-members. The results (table 93) indicated that, in Zn-containing ferrites, the cation diffusion was governed by the preliminary treatment which was given to the samples. In particular, the caking temperature had an effect upon the point defect concentration.

M.V.Slinkina, V.M.Zhukovskii: Izvestiya Akademii Nauk SSSR - Neorganicheskie Materialy, 1988, 24[11], 1883-6. (Inorganic Materials, 1988, 24[11], 1609-12)

Table 93

Diffusion Parameters for Fe in (Ni,Zn)Fe2O4 Ferrites

between 1130 and 1280C

Table 94

Diffusion Parameters for Ni in (Ni,Zn)Fe2O4 Ferrites

between 1130 and 1280C