Relation between structure, stress, and magnetism in Co/W(001) - art. no. 144422

We present a study of the structure of Co/W(001) determined by low-energy e lectron diffraction, the film stress measured by a bending thin substrate, and the film morphology measured by scanning tunneling microscopy in combin ation with in situ magnetic characterization by the magneto-optic Kerr effe ct. Different regimes in the stress behavior during growth are correlated t o surface effects and structural and morphological changes in the Co film. Initially a compressive stress is observed as the result of the lower surfa ce free energy of Co compared to W, followed by a tensile stress due to the large misfit between film and substrate. The structural transition from bc c to hcp Co as well as dislocation formation is clearly observed in the str ess measurements and by low-energy electron diffraction and scanning tunnel ing microscopy. Additionally, the morphology of the films is correlated wit h the magnetic properties and a new surface alloy at submonolayer coverages is reported.