Chemical diffusion coefficients were deduced from studies of point defect relaxation in magnetite. The vacancy and interstitial tracer diffusion coefficients (table 101) could be described by:

vacancy: D (cm2/s) = 4.33 x 10-11 exp[16770K/T]

interstitial: D (cm2/s) = 7.71 x 107 exp[73880K/T]

R.Dieckmann, H.Schmalzried: Berichte der Bunsengesellschaft für Physikalische Chemie, 1986, 90[7], 564-75

Figure 17

Permeation of O in Sr10-x/2BixFe20Oy

(Squares: x = 10, diamonds: x = 6)

Table 101

Fe Diffusion in Magnetite

 

Temperature (C)

Component

D (cm2/s)

900

vacancy

7.24 x 10-5

900

interstitial

3.61 x 10-20

1000

vacancy

2.61 x 10-5

1000

interstitial

4.10 x 10-18

1100

vacancy

8.00 x 10-6

1100

interstitial

3.48 x 10-16

1200

vacancy

3.44 x 10-6

1200

interstitial

1.36 x 10-14

1300

vacancy

1.82 x 10-6

1300

interstitial

3.60 x 10-13

1400

vacancy

1.14 x 10-6

1400

interstitial

4.40 x 10-12