Comparison of atomic structure anisotropy between Co-Pd alloys and Co/Pd multilayer films

Abstract

We have employed Co K-edge extended x-ray absorption fine structure measurements with linear polarization dependence to investigate the chemical short-range order (SRO) and interatomic distance anisotropy in CoxPd1-x alloy (X = 0.16, 0.31) and [Co(2 Angstrom)/Pd(Y Angstrom)](13) multilayer films (Y = 15, 32). The SRO parameters of in-plane first nearest neighbors, 0.063-0.068 in the alloys and 0.012-0.036 in the multilayers, are observed. Surprisingly, these counterintuitive results show clear evidence that the Co atoms at the Co/Pd interfaces in multilayers have more alloylike characteristic than those in alloys with respect to local chemical environment.