Formation of ordered tetragonal PtCo from epitaxial multilayers

Abstract

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.