Interdiffusion in epitaxial Co/Pt multilayers

Interdiffusion kinetics were measured using x-ray diffraction methods in epitaxial (001) and (111) Co/Pt multilayers in which the chemical modulation wavelength was in the range 2.5–4.0 nm. Multilayers were prepared by e-beam evaporation and were subsequently annealed in vacuum at temperatures between 275 and 375 °C. The activation enthalpy of the interdiffusion process in this temperature range was estimated using a novel approach for scaling nonlinear diffusion data. Activation enthalpies for interdiffusion in (001) and (111) multilayers were determined to be 1.1±0.2 and 0.8±0.2 eV, respectively. The low values obtained for the activation enthalpies may result from coherency strains or “short-circuit’’ diffusion in the faulted, epitaxial multilayers.