Clear evidence for strain changes according to Co layer thickness in metastable Co/Pd(111) multilayers: An extended x-ray absorption fine structure study

Abstract

We have measured fluorescence-yield extended x-ray absorption fine structure (EXAFS) on a series of (Co x \AA{}+Pd 11 \AA{}${)}_{13}$ metallic multilayers. To examine the local atomic structure around Co and its anisotropy, Co K-edge EXAFS measurements were performed at near-grazing incidence of synchrotron radiation incorporating linear polarization dependence. We generally observed, with decreasing Co layer thickness, increasing, in-plane interatomic distance and decreasing, out-of-plane interatomic distance in Co atoms. For a (Co 10 \AA{} +Pd 11 \AA{}${)}_{13}$ multilayer, strain values of in-plane and out-of-plane Co atoms are estimated to be 3.6\ifmmode\pm\else\textpm\fi{}0.5% in tensile and 3.0\ifmmode\pm\else\textpm\fi{}0.4% in compressive strain. \textcopyright{} 1996 The American Physical Society.