The directional dependence of the diffusivity of 113Sn (table 125) 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 125

Diffusivity of 113Sn in Ni61Sn39 Single Crystals