Loffe-Regel' crossover and boson peaks in disordered solid solutions and similar anomalies in heterogeneous crystalline structures

Abstract

Low-frequency features of the phonon spectra of disordered solid solutions and heterogeneous crystalline structures are analyzed at the microscopic level. It is shown that boson-peak type excitations can arise in disordered solid solutions whose sites have only translational degrees of freedom. Thus it is established that such excitations appear mainly because of the additional positional dispersion of sound waves which is due to the disordering. The influence of boson-peak excitations on the low-temperature specific heat is investigated. It is found that in a number of cases the specific heat is more sensitive to excitations of this kind than the low-frequency density of states is. It is shown that anomalies similar to Ioffe-Regel' crossover and boson peaks can also arise in disordered heterogeneous crystalline structures with a complicated lattice.

Publication DOI: https://doi.org/10.1063/1.2967512
Divisions: College of Engineering & Physical Sciences
College of Engineering & Physical Sciences > Aston Institute of Photonics Technology
Additional Information: Copyright © 2008 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Low Temperature Physics 34, 655 (2008) and may be found at https://doi.org/10.1063/1.2967512
Uncontrolled Keywords: Physics and Astronomy (miscellaneous)
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Related URLs: http://www.scop ... tnerID=8YFLogxK (Scopus URL)
https://aip.sci ... .1063/1.2967512 (Publisher URL)
PURE Output Type: Article
Published Date: 2008-10-09
Authors: Gospodarev, I. A.
Grishaev, V. I.
Kotlyar, A. V. (ORCID Profile 0000-0002-2744-0132)
Kravchenko, K. V.
Manzheliǐ, E. V.
Syrkin, E. S.
Feodos'Ev, S. B.

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