Quasidiffusive propagation of phonons in vitreous silica

✍ Scribed by Hiroshi Ikari

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 185 KB
• Volume: 219-220
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/0921-4526(95)00874-8

✦ Synopsis

The exponential decay of phonon intensity observed in both experiments and simulations for the quasidiffusive propagation regime reflects the elastic and inelastic scattering process of high frequency phonons. In search of the predicted quasidiffusive behaviour, we have removed the contact with liquid helium in the heat pulse measurement of vitreous silica, and greatly reduced the excitation density. The observed exponential decay qualitatively agrees with the Monte Carlo simulation with the simple model proposed by Maris (1990). The resulting strength of the Rayleigh scattering is approximately equal to that needed to fit the thermal conductivity data in amorphous SiO2.