Comment on the Elastic Properties ofβBrass

Abstract

The Pippard equation relating $C_p$ (the constant-pressure heat capacity) to $\alpha$ (the volume coefficient of thermal expansion) near a $\lambda$ point is shown to be valid for $\beta$ brass. As a result of this, one can predict that the static adiabatic compressibility should have a very small peak at $T_{\lambda }$ (and the low-frequency elastic constant $c_{11}$, a small dip). It is suggested that the failure to observe such a dip in $c_{11}$ for 10-Mc/sec ultrasonic waves is due to the long relaxation time associated with ordering in $\beta$ brass.