Phonons in cesium

Abstract

Inelastic neutron time-of-flight spectra from polycrystalline cesium were measured at 50, 100, and 290 K for a large variety of momentum transfers $Q$ and energy transfers $\omega$. Born-von Kármán models were fitted to the resulting ($Q, \omega$) topography. These models were used to calculate the phonon dispersion curves and the phonon densities of states. The results confirm theoretical predictions. The elastic constants $c_{44}$ and $c^{\prime }$ determined from the measured data agree with ultrasonic results.