Study of the local atomic structure of a silver aluminum alloy by the method of extended electron energy loss fine structure (EELFS)

Abstract

Extended energy loss fine structure spectra are obtained for electrons at the Al K and Ag M4,5 edges for an Al-20 wt %Ag solid solution after high-temperature aging, as well as for the pure alloy components. The analysis layer depth was ∼20 A. Radial distribution functions for the atoms are determined by Fourier transforming these spectra with a correction for the phase shift and the method of regularization. For pure aluminum and silver it is found that the position of the first coordinate spheres does not differ from bulk interatomic distances. For the binary alloy it was shown that the state of the sample corresponds to a decomposed solid solution with inclusions of a phase enriched with silver against an aluminum host background. The interatomic Al-Al distances in the binary alloy correspond to the length of a pure aluminum bond. The partial distances to the first two coordination spheres for the pairs Ag-Ag, Ag-Al are the same and equal the interatomic distances of the γ-phase Ag2Al.