Interdiffusion in Ni80Fe20/Mo magnetic multilayers prepared by magnetron sputtering

The interdiffusion in Ni80Fe20/Mo magnetic multilayers with a repeat length of 3.4 nm has been investigated using x-ray diffraction (XRD) technology. The multilayers have been fabricated by using a magnetron sputtering system . The decay with annealing time in the intensity of the first-order x-ray s atellite peak arising from the composition modulation was used to determine the effective interdiffusion coefficient Dh As the annealing temperature i s below 483 K, the interdiffusion is found to be relatively slow (D-lambda < 8.88 x 10(-25) m(2)/s). This result suggests that the Ni80Fe20/Mo multila yers have a strong resistance to the atomic interdiffusion between sublayer s. The diffusivities over the temperature range 343-683 K have an Arrhenius -type temperature dependence with a pre-exponential factor D-0 = (4.02 +/- 1.21) x 10(-22) m(2)/s and an activation enthalpy of about 0.26 +/- 0.08 eV . The much lower activation enthalpy is attributed to the coherence strains existing in the multilayers.