Elastic constants in Nb-Zr alloys from zero temperature to the melting point: Experiment and theory

The elastic constants of bcc Nb-Zr alloys are measured over a composition range between 100 and 30 at.% of Nb and temperatures between zero and the melting point, using a new technique for the high-temperature measurements. Anomalous behavior is found for C₄₄. The anomaly is a band-structure effect which is corroborated by theoretical calculations using electron-lattice coupling constants derived from a tight-binding parametrization scheme. The calculation is of a type similar to phonon dispersion ones, having the further complication of temperature effects which have convergence difficulties and need a special interpolation method.