It was found that the data for 1150 to 1400C could be described by:

Cu-0.025%Ni:     D (cm2/s) = 5.9 x 10-3 exp[-12.96(kcal/mol)/RT]

Cu-0.25%Ni:     D (cm2/s) = 2.31 x 10-3 exp[-7.69(kcal/mol)/RT]

Cu-2.50%Ni:     D (cm2/s) = 1.79 x 10-2 exp[-9.90(kcal/mol)/RT]

Cu-3.25%Ni:     D (cm2/s) = 5.81 x 10-2 exp[-12.56(kcal/mol)/RT]

J.Gerlach, B.Leidel: Zeitschrift für Naturforschung, 1967, 22a[1], 58-61