The diffusion of Zn in single crystals of α-type material was studied at 848 to 1169K. At temperatures greater than 1068K, the tracer diffusion coefficients

could be described by Arrhenius plots:

2at%Zn:     D (cm2/s) = 3.8 x 101 exp[-256.2(kJ/mol)/RT]

4at%Zn:     D (cm2/s) = 1.9 x 101 exp[-247.5(kJ/mol)/RT]

6at%Zn:     D (cm2/s) = 1.1 x 101 exp[-239.9(kJ/mol)/RT]

8at%Zn:     D (cm2/s) = 6.2 x 100 exp[-232.9(kJ/mol)/RT]

10at%Zn:     D (cm2/s) = 3.9 x 100 exp[-226.4(kJ/mol)/RT]

12at%Zn:     D (cm2/s) = 2.0 x 100 exp[-218.1(kJ/mol)/RT]

At lower temperatures, the diffusion coefficients decreased to below the extrapolated high-temperature Arrhenius lines. The deviation began at a temperature which was about 25K higher than the Curie temperature. At temperatures below 1068K, the experimental results agreed closely with the predictions of the Borg theory. At temperatures close to the Curie point, no decrease in the diffusion coefficients was found as the Zn content decreased towards zero.

I.Richter, M.Feller-Kniepmeier: Physica Status Solidi, 1981, 68[1], 289-300