Theory of the Crossover in the Low-Frequency Dynamics of an Incommensurate System, Hg3-δAsF6
Abstract
The dynamic structure factor of a three-dimensional crystal, with an interpenetrating set of atomic chains which form one-dimensional fluids, is studied. At high frequencies there are two longitudinal acoustic modes arising from the separate motion of the lattice and fluid. At low frequencies there is one combined propagating longitudinal acoustic mode and a diffusive excitation due to particle motion. The crossover between these regions is predicted to occur at a frequency ~ MHz in Hg3-δAsF6.
- Publication:
-
Physical Review Letters
- Pub Date:
- August 1982
- DOI:
- 10.1103/PhysRevLett.49.468
- Bibcode:
- 1982PhRvL..49..468F
- Keywords:
-
- 63.10.+a;
- 62.65.+k;
- 62.80.+f;
- General theory;
- Acoustical properties of solids;
- Ultrasonic relaxation