Structure and magnetism in Co/Pt multilayers

The structure of [Co(t(Co))/Pt(10 Angstrom)](30) multilayers has been studied by x-ray absorption spectroscopy and x-ray diffraction using in-plane and out- of-plane polarized synchrotron radiation. The x-ray absorption near-edge spectroscopy shows that the Co layer is like a fcc pseudomorphic structure for t(Co) less than 4 Angstrom. For t(Co)=10 Angstrom, the spectra in both directions are separated and look closer to the bulk hcp Co. The extended x-ray absorption fine structure studies reveal that the Co-Pt interface of the multilayers fitted with a sharp boundary better than an interdiffusion model. The in-plane x-ray diffraction shows that the Pt layer in the multilayer possesses a 2%-3.5% compressible strain. Although the saturation magnetization M-s does not depend on t(Co) or interfacial roughness in any simple form, the M-s values scale quite linearly with the in-plane Pt strain. We conclude that the interfacial strain is important for the perpendicular magnetization in the Co/Pt multilayers. (C) 2001 American Institute of Physics.