Lattice vibrations and local order in substitutional solid solutions. I

Expressions are derived for the effective mean square amplitudes of the thermal vibrations of atoms and the Debye characteristic temperatures for the case of binary, substitutional, metallic solid solutions. Both solid solutions with random distribution of atoms and also those with a partially ordered distribution of atoms are investigated. The calculations respect the change in the vibrational state of atoms on solid solution formation. The parameterα, characterizing this change, can be determined from X-ray diffraction experiments or from the concentration dependence of the melting temperature and lattice constant. The results are applied to a solid solution of Ag in Al. A comparison with the experimental values measured by M. Simerská (Czech. J. Phys.B 13 (1963), 737) shows good agreement.