Formation of ordered tetragonal PtCo from epitaxial Pt(001)/Co(001) multilayers was observed via in situ X-ray diffraction measurements at four different annealing temperatures. The measured activation energy of formation of ordered PtCo is 2.1 ± 0.2 eV. Ordering in the PtCo phase is not complete even after 1100 min annealing at 570°C. Growth proceeds by nucleation of domains less than 10 Å in thickness, which thicken at a rate approximately proportional to the square root of time.
Artymowicz, D. M., Lairson, B. M., & Clemens, B. M. (1996). Formation of ordered tetragonal PtCo from epitaxial Pt/Co multilayers. Journal of Crystal Growth, 169(1), 83–88. https://doi.org/10.1016/0022-0248(96)00265-5