Elastic properties of superconductors with A 15-type structure

The renormalization of the phonon spectrum induced by the polaron effect in superconductors with A 15-type structure is considered. The electron–phonon interaction constant is used to obtain a microscopic expression for the Poisson ratio σ without any empirical parameters. The results of calculations of σ(λ) and the temperature dependence σ(T) for transition metals and alloys, as well as for six A 15 compounds with known elastic properties, are in good agreement with the experimental data. Elastic properties have been calculated for 30 A 15 compounds for which no experimental data are available.