A computer-controlled sputter-sectioning apparatus was described which was particularly
useful for performing self-diffusion studies at low temperatures. The technique was used here to measure the diffusion coefficient of 55Fe in the magnetite lattice as a function of O activity at 500C (table 100). The results were in broad agreement with extrapolations of previous diffusion data for temperatures greater than 900C.
55Fe Diffusion in Magnetite Crystals at 500C and its Relevance to Oxidation of Iron. A.Atkinson, M.L.O’Dwyer, R.I.Taylor: Journal of Materials Science, 1983, 18[8], 2371-9
Table 100
Diffusivity of 55Fe in Magnetite at 500C
O Activity (atm) | D (cm2/s) |
7 x 10-20 | 7.1 x 10-15 |
2 x 10-20 | 2.1 x 10-14 |
2 x 10-21 | 4.0 x 10-15 |
2 x 10-22 | 4.2 x 10-17 |
1 x 10-24 | 4.6 x 10-16 |
2 x 10-25 | 9.7 x 10-17 |
1 x 10-25 | 4.0 x 10-16 |
2 x 10-26 | 2.1 x 10-16 |
5 x 10-27 | 5.7 x 10-16 |
1 x 10-29 | 3.5 x 10-15 |