The diffusive behavior of 204Tl in 5N-purity material was studied at 137 to 216C, giving:

D (cm2/s) = 1.2 x 10-3 exp[-14.7(kcal/mol)/RT]

L.Bartha, T.Szalay: International Journal of Applied Radiation and Isotopes, 1969, 20[12], 825-8