Attenuation of longitudinal-acoustic phonons in amorphous SiO2 at frequencies up to 440 GHz.
Attenuation of longitudinal-acoustic phonons in amorphous SiO2 at frequencies up to 440 GHz.
复制标题
非晶 SiO2 中纵向声声子在频率高达 440 GHz 时的衰减。
DOI：
10.1103/physrevb.44.4281
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发表时间：
1991
期刊：
影响因子：
--
通讯作者：
J. Tauc
中科院分区：
文献类型：
--
作者：
Timothy C. Zhu;H. Maris;J. Tauc
本文报道了在76-440 GHz频率范围内，在80-300K温度范围内，测量了非晶态SiO_2中纵向声学声子的衰减。样品是生长在钨衬底上的化学气相沉积薄膜，声子是用皮秒光学技术产生和探测的。发现声子衰减对温度的影响很小。在频率范围的上部，有一些证据表明频率依赖比二次相关快，这表明衰减不能用经典的松弛理论来解释。讨论了这些结果与导热系数测量分析之间的关系。
We report measurements of the attenuation of longitudinal-acoustic phonons in amorphous SiO{sub 2} for frequencies between 76 and 440 GHz, and in the temperature range 80--300 K. The samples are chemical-vapor-deposited films grown on tungsten substrates, and the phonons are generated and detected using picosecond optical techniques. The phonon attenuation is found to depend only weakly on temperature. In the upper part of the frequency range, there is some evidence that the frequency dependence is faster than quadratic, thus indicating that the attenuation cannot be explained by classical relaxation theory. A discussion of the relation between these results and the analysis of thermal-conductivity measurements is given.