Electron microprobe analysis was used to study the diffusion of Tl in single crystals. In the extrinsic regime, the diffusivity at temperatures ranging from 48 to 232C could be described by:

D (cm2/s) = 9 x 10-11 exp[-0.25(eV)/kT]

In the intrinsic regime, the diffusivity at temperatures ranging from 480 to 727C could be described by:

D (cm2/s) = 6 x 10-3 exp[-1.42(eV)/kT]

Diffusion of Tl in Single Crystal and Bicrystal KCl. R.J.Tiernan, B.J.Wuensch: Bulletin of the American Ceramic Society, 1970, 49[4], 388