Abstract:
We propose a simple phenomenological model describing composite crystals, constructed from two parallel sets of periodic inter-penetrating chains. In the harmonic approximation and neglecting thermal fluctuations we find the eigenmodes of the system. It is shown that at high frequencies there are two longitudinal sound modes with standard attenuation, while in the low frequency region there is one propagating sound mode and an over-damped phase mode. The crossover between these two regions is analyzed numerically and the dynamical structure factor is calculated. It is shown that the qualitative features of the experimentally observed spectra can be consistently described by our model.
Similar content being viewed by others
Author information
Authors and Affiliations
Additional information
Received 28 November 2001 and Received in final form 23 January 2002
Rights and permissions
About this article
Cite this article
Currat, R., Kats, E. & Luk'yanchuk, I. Sound modes in composite incommensurate crystals. Eur. Phys. J. B 26, 339–347 (2002). https://doi.org/10.1140/epjb/e20020098
Issue Date:
DOI: https://doi.org/10.1140/epjb/e20020098