Determination of the interdiffusion coefficient at low temperature in Ni/NiCr nanometer-scale multilayers using X-ray reflectivity
Résumé
The interdiffusion coefficient in the Ni/Cr system was determined at low temperature using Ni/Ni0.78Cr0.22 nanometer-scale multilayers with periods of 3.65 and 4.50 nm. X-ray reflectivity measurements were carried out to monitor the 1st Bragg peak intensity with annealing time, at both 400 and 450 °C temperatures. The obtained kinetics of the composition modulation decay allowed determining the interdiffusion coefficients of the uniform final solid solution, Ni0.89Cr0.11. Values in the order of 10−21 to 10-20 cm2.s−1 at 400 °C and 450 °C, respectively, were found, in line with extrapolations from data of Cr diffusion obtained at higher temperature.