Force-constant changes and localized modes for iron impurities in cubic metals from Mössbauer-fraction measurements

Abstract

Precision M\"ossbauer-fraction measurements have been used in combination with Mannheim's impurity-lattice theory to determine impurity-host force-constant changes and anharmonicity parameters for ${\mathrm{Fe}}^{57}$ in Cu, Pd, Pt, Au, Al, Nb, and Cr. Combining these with available data on host-phonon frequency distributions, the impurity dynamic-response functions have been calculated. The theory predicts the existence of localized modes in Cu, Pt, and Au. The possible existence of localized modes in V, Zn, and Ni is also discussed.