High-order cumulants of wolfram metal in anharmonic EXAFS theory calculated using the correlated Einstein model

Abstract

The anharmonic extended X-ray absorption fine structure (EXAFS) cumulants of wolfram metal (W) in expansion to the 4^th order have been calculated under the influence of thermal disorder. The temperature-dependent EXAFS cumulants were calculated explicitly and simply from a theoretical model developed based on the anharmonic effective potential and classical statistical theory within the correlated Einstein model. The thermodynamic parameters of W have been considered the influence of the nearest neighbor atoms on the backscattering and absorbing atoms. The obtained numerical results of W at temperatures from 0 to 800 K fit with those obtained from the experimental EXAFS data and the anharmonic correlated Debye (ACD) model at various temperatures. These results indicate that the present theoretical model can helpfully analyze experimental EXAFS signals of W and other similar metals.