The residual activity technique was used to study the self-diffusion of 59Fe in several Fe-Mo alloys. In the paramagnetic region, T > TC, where TC was the Curie point, the temperature dependence of D obeyed Arrhenius equations,
Fe-0.54wt%: D (cm2/s) = 1.55 x 101 exp[-263(kJ/mol)/RT]
Fe-1.06wt%: D (cm2/s) = 2.36 x 101 exp[-257(kJ/mol)/RT]
Fe-1.50wt%: D (cm2/s) = 2.85 x 101 exp[-266(kJ/mol)/RT]
Fe-2.50wt%: D (cm2/s) = 4.77 x 101 exp[-264(kJ/mol)/RT]
and the frequency-factor and activation energy for self-diffusion were independent of the alloy composition. A marked effect of ferromagnetic ordering upon the temperature
dependence of D was observed at T < TC, where log[D] was not proportional to 1/T (table 124).
J.Ruzicková, B.Million: Kovove Materialy, 1977, 15[2], 140-5
Table 123
Diffusion of 59Fe in Fe-Mo Alloys
Temperature C) | Mo (wt%) | D (cm2/s) |
700 | 0.54 | 3.96 x 10-14 |
700 | 1.06 | 3.07 x 10-14 |
700 | 1.50 | 3.81 x 10-14 |
700 | 2.50 | 6.96 x 10-14 |
720 | 0.54 | 1.20 x 10-13 |
720 | 1.06 | 7.41 x 10-14 |
720 | 1.50 | 1.12 x 10-13 |
720 | 2.50 | 7.19 x 10-14 |
740 | 0.54 | 2.81 x 10-13 |
740 | 1.06 | 2.56 x 10-13 |
740 | 1.50 | 2.94 x 10-13 |
740 | 2.50 | 2.71 x 10-13 |
759 | 2.50 | 3.85 x 10-13 |
761 | 1.50 | 3.65 x 10-13 |
761 | 2.50 | 4.54 x 10-13 |
762 | 1.50 | 3.26 x 10-13 |
763 | 1.06 | 3.52 x 10-13 |
763 | 1.50 | 2.49 x 10-13 |
764 | 1.06 | 3.11 x 10-13 |
765 | 0.54 | 7.31 x 10-13 |
765 | 1.06 | 4.01 x 10-13 |
766 | 0.54 | 6.58 x 10-13 |
767 | 0.54 | 6.86 x 10-13 |
771 | 0.54 | 8.05 x 10-13 |
771 | 1.06 | 6.34 x 10-13 |
771 | 1.50 | 6.26 x 10-13 |
771 | 2.50 | 4.68 x 10-13 |
810 | 0.54 | 2.42 x 10-12 |
continued
Table 123 (continued)
Diffusion of 59Fe in Fe-Mo Alloys
Temperature C) | Mo (wt%) | D (cm2/s) |
810 | 1.06 | 2.75 x 10-12 |
810 | 1.50 | 3.28 x 10-12 |
810 | 2.50 | 2.47 x 10-12 |
850 | 0.54 | 7.74 x 10-12 |
850 | 1.06 | 7.19 x 10-12 |
850 | 1.50 | 6.60 x 10-12 |
850 | 2.50 | 6.87 x 10-12 |
860 | 0.54 | 1.45 x 10-11 |
860 | 1.06 | 1.99 x 10-11 |
860 | 1.50 | 2.21 x 10-11 |
860 | 2.50 | 1.12 x 10-11 |
890 | 0.54 | 3.04 x 10-11 |
890 | 1.06 | 2.97 x 10-11 |
890 | 1.50 | 3.16 x 10-11 |
890 | 2.50 | 3.26 x 10-11 |