Disorder-induced broadening of transverse acoustic phonons in SixGe1-x mixed crystals
1.
SYSNO ASEP
0101894
Document Type
J - Journal Article
R&D Document Type
Journal Article
Subsidiary J
Ostatní články
Title
Disorder-induced broadening of transverse acoustic phonons in SixGe1-x mixed crystals
Title
Rozšíření příčných akustických fononů ve smíšených krystalech Si(x)Ge(1-x) vyvolané neuspořádaností
Author(s)
Beraud, A. (FR) Kulda, Jiří (UJF-V) Yonenaga, I. (JP) Foret, M. (FR) Salce, B. (FR) Courtens, E. (FR)
Source Title
Physica B-Condensed Matter. - : Elsevier
- ISSN 0921-4526
Roč. 350, č. 1 (2004), s. 254-257
Number of pages
4 s.
Language
eng - English
Country
NL - Netherlands
Keywords
disordered crystals ; acoustic branches
Subject RIV
BG - Nuclear, Atomic and Molecular Physics, Colliders
R&D Projects
KSK1010104 GA AV ČR - Academy of Sciences of the Czech Republic (AV ČR)
Annotation
Inelastic neutron-scattering measurements of the dispersion and width of transverse acoustic branches are reported for SixGe1-x, particularly for x = 0.51. These alloys form high-quality single crystals. They are strongly disordered dynamically owing to the large Ge/Si mass ratio. This allows to study in function of disorder (x) the relations between the inhomogeneous broadening of acoustic waves, the Boson peak, and low-temperature thermal anomalies common to glasses. For x less than or equal to 0.51 we find no boson peak, apparently no plateau in the thermal conductivity, but at large x a Rayleigh law on the phonon width, Gamma proportional to Q(4), where Q is the scattering vector
