- Interdiffusion studies were performed in the Fe-Al system using diffusion couples between Fe50Al50 and Fe70Al30. Concentration depth profiles were measured by electron microprobe analysis. Interdiffusion coefficients were deduced thereof. They show linear Arrhenius behaviour over the investigated temperature range of 950 to 1450 K. From the interdiffusion coefficients Al diffusion coefficients were deduced via Darken-Manning's equation using published Fe tracer diffusion coefficients and theoretical results for the thermodynainic factor. Al diffusion is in the same range as Fe diffusion, depending on the model used for the calculation of the thermodynamic factor.