The diffusion and electrotransport of Fe in the α- and β phases were measured at 970 to 1515C. It was found that the diffusion coefficients were of the order of 10-9 to 10-10m2/s in both phases (table 253). The effective valence was negative at all temperatures (table 254), corresponding to solute migration in the direction of electron flow. The activation energy for the diffusion of Fe in the α-phase was 54kJ/mol and the pre-exponential factor was equal to 1.5 x 10-7m2/s.
S.C.Axtell, I.C.I.Okafor,, R.J.Conzemius, O.N.Carlson: Journal of the Less-Common Metals, 1986, 115[2], 269-79
Table 253
Diffusivity of Fe in Sc
Temperature (C) | Phase | D (m2/s) |
I517 | β | 4.4 x 10-9 |
1482 | β | 3.4 x 10-9 |
1429 | β | 2.6 x 10-9 |
1370 | β | 4.1 x 10-9 |
1255 | α | 1.9 x 10-9 |
1126 | α | 1.5 x 10-9 |
1096 | α | 1.3 x 10-9 |
1062 | α | 1.2 x 10-9 |
968 | α | 7.0 x 10-10 |
Table 254
Electromigration Parameters for Fe in Sc
Temperature (C) | Phase | Mobility (m2/sV) | Valence |
1517 | β | 1.0 x 10-7 | -3.5 |
1482 | β | 6.5 x 10-8 | -2.9 |
1429 | β | 7.2 x 10-8 | -4.1 |
1255 | α | 7.9 x 10-8 | -5.5 |
1126 | α | 5.6 x 10-8 | -4.4 |
1096 | α | 9.4 x 10-8 | -8.4 |
1062 | α | 6.9 x 10-8 | -6.9 |
968 | α | 9.5 x 10-8 | -14.1 |