Elastic Constants ofα-Brasses: Variation with Solute Concentration from 4.2-300°K

Abstract

Elastic constant measurements have been made on a representative series of $\alpha$-brasses in the temperature range 4.2-300°K. No appreciable change with temperature occurs in the dependence of $C$ and $C^{\prime }$ on solute concentration. Possible explanations for this result are considered. The $\Theta$ values for the alloys, as computed for the elastic-constant data at 4.2°K, differ significantly from the calorimetric values. It is believed that this discrepancy results from the difference between the phonon wavelengths used in the ultrasonic measurements and those contributing to the lattice heat capacity of the alloys at low temperatures.