The directional dependence of the diffusivity of 113Sn (table 213) was measured in single crystals by using the layer grinding technique. The activation energies for diffusion parallel and perpendicular to the hexagonal c-axis were 2.93 and 3.07eV, respectively, while the corresponding pre-exponential factors were 4.6 and 9.9cm2/s. The ratio of the perpendicular, to the parallel, diffusivities ranged from 0.56 to 0.75; depending upon the temperature. It was concluded that the main mechanism was a normal vacancy mechanism; with superposed minor processes which accounted for the temperature dependence of the diffusivity ratio.

H.Schmidt, G.Frohberg, W.Miekeley, H.Wever: Physica Status Solidi B, 1992, 171[1], 29-37

 

Table 209

Diffusion of Co in Ni-Si Alloys

 

Si

Temperature (K)

D (cm2/s)

0.017

1410

1.05 x 10-10

0.026

1410

1.16 x 10-10

0.045

1410

1.39 x 10-10

0.081

1410

2.18 x 10-10

0.017

1465

2.61 x 10-10

0.025

1465

2.82 x 10-10

0.045

1465

3.38 x 10-10

0.081

1465

5.49 x 10-10