Consequences of anisotropic sound velocities in hcp solid He4

Abstract

The elastic constants for hcp solid He4 recently published by Crepeau, Heybey, Lee, and Strauss are used for calculating the wave surfaces associated with elastic waves, according to the recent method of Wanner. The deviation of the energy path or ray from the wave normal is calculated and is correlated with experimental sound-velocity data previously obtained by the authors. © 1972 The American Physical Society.