It was found that the data for 204Tl, at 250 to 500C, could be described by:

D (cm2/s) = 1.48 x 10-4 exp[-2.25(kcal/mol)/RT]

K.G.Davis, P.Fryzuk: Transactions of the Metallurgical Society of AIME, 1967, 239, 1105-6