Interplay of microstructure and magnetic properties in epitaxially grown Co35Pd65 alloy films on Cu/Si(100)

The authors have investigated the correlation between magnetic properties, growth structure, and internal stress of epitaxially grown Co₃₅Pd₆₅ alloy films on Cu-Si(100) in the alloy thickness range from 1 monolayer (ML) to 10 ML. An in situ surface magneto-optical Kerr effects (SMOKE) study revealed that Co₃₅Pd₆₅ alloy films showed room-temperature ferromagnetism at a coverage of 2 ML with a strong in-plane anisotropy and the Kerr intensity and coercivity was increased with the Co₃₅Pd₆₅ thickness. Interestingly, a kink was observed at about 3 ML alloy thickness in the variation of either the Kerr intensity or the coercivity as a function of the film thickness. A careful study for the growth structure of Co₃₅Pd₆₅ alloy films using scanning tunneling microscope and reflection high-energy electron diffraction together with in situ stress measurement reveals that the formation of three-dimensional island and atomic steps around 3 ML Co₃₅Pd₆₅ alloy thickness plays an important role for the observed kinks in the Kerr intensity and the coercivity variation.