Physics – Condensed Matter – Materials Science
Scientific paper
2011-08-18
Phys. Rev. B 84, 195206 (2011)
Physics
Condensed Matter
Materials Science
Scientific paper
10.1103/PhysRevB.84.195206
The relaxation of a spatially sinusoidal temperature perturbation in a dielectric crystal at a temperature comparable to or higher than the Debye temperature is investigated theoretically. We assume that most phonons contributing to the specific heat have mean free path (MFP) much shorter than the thermal transport distance and can be described by the thermal diffusion model. Low-frequency phonons that may have MFP comparable to or longer than the grating period are described by the Boltzmann transport equation. These low-frequency phonons are assumed to interact with the thermal reservoir of high frequency phonons but not with each other. Within the single mode relaxation time approximation, an analytical expression for the thermal grating relaxation rate is obtained. We show that the contribution of "ballistic" phonons with long MFP to the effective thermal conductivity governing the grating decay is suppressed compared to their contribution to thermal transport at long distances. The reduction in the effective thermal conductivity in Si at room temperature is found to be significant at grating periods as large as 10 microns.
Johnson Jeremy A.
Maznev Alexei A.
Nelson Keith A.
No associations
LandOfFree
Onset of non-diffusive phonon transport in transient thermal grating decay does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Onset of non-diffusive phonon transport in transient thermal grating decay, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Onset of non-diffusive phonon transport in transient thermal grating decay will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-181446