A serial sectioning technique was used to study the diffusion of 82Br in material which contained about 5ppm of impurities. The data for 305 to 427C could be described by:

D (cm2/s) = 9.0 x 101 exp[-36.6(kcal/mol)/RT]

A.P.Batra, L.Slifkin: Journal of the Physics and Chemistry of Solids, 1969, 30[6], 1315-20