Abstract
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≤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, Γ∝Q4, where Q is the scattering vector.
Original language | English |
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Pages (from-to) | 254-257 |
Number of pages | 4 |
Journal | Physica B: Condensed Matter |
Volume | 350 |
Issue number | 1-3 |
DOIs | |
Publication status | Published - 2004 Jul 30 |
Keywords
- Acoustic branches
- Disordered crystals
- Thermal conductivity
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering