A spectrophotometric method was used to investigate the diffusion of Bi in single crystals at temperatures ranging from 275 to 674C. The Arrhenius plot consisted of 2 straight lines which intersected at 400C. The data for temperatures ranging from 275 to 400C could be described by:

D (cm2/s) = 1.7 x 10-3 exp[-0.63(eV)/kT]

The data for temperatures ranging from 400 to 674C could be described by:

D (cm2/s) = 5.6 x 10-3 exp[-0.97(eV)/kT]

In the high-temperature region, the Bi diffused in its divalent state. In the low-temperature range, Bi diffusion occurred in the trivalent state via an interstitial mechanism.

Diffusion of Bismuth Ions in Potassium Chloride Crystals. R.Reisfeld, A.Honigbaum: Journal of Chemical Physics, 1968, 48[12], 5565-9

Figure 12

Self-Diffusion of Cl in KCl Crystals