Interdiffusion coefficients in the  phase were measured at temperatures ranging from 1116 to 1583K. No appreciable concentration dependence of the coefficient was observed in the present single-phase couples. The temperature dependence of the interdiffusivity could be described by:

D(m2/s) = 0.00028 exp[-295(kJ/mol)/RT]

W.Sprengel, N.Oikawa, H.Nakajima: Intermetallics, 1996, 4[3], 185-9