Method for measurement of diffusivity: Calorimetric studies of Fe/Ni multilayer thin films

A calorimetric method for the measurement of diffusivity in thin film multilayers is introduced and applied to the Fe–Ni system. Using this method, the diffusivity in [Fe (25 nm)/Ni (25 nm)]20 multilayer thin films is measured as 4 × 10−3 exp (−1.6 ± 0.1 eV/kBT) cm2/s, respectively. The diffusion mechanism in the multilayers and its relevance to laboratory synthesis of L10 ordered FeNi are discussed.