Ultrasonic Attenuation in Dirty Dielectric Crystals
Ultrasonic Attenuation in Dirty Dielectric Crystals
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脏电介质晶体中的超声波衰减
DOI：
10.1103/physrev.175.1077
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发表时间：
1968
期刊：
影响因子：
--
通讯作者：
H. Maris
中科院分区：
文献类型：
--
作者：
H. Maris
利用Woodruff和Ehrenreich的玻尔兹曼方程方法计算了声波与介电晶体中热声子的非谐波相互作用的衰减。分别考虑了晶体缺陷对声子的弹性散射（弛豫时间τ e）和固有非弹性非调和过程（弛豫时间τ i）对热声子碰撞率的贡献。纵波的衰减在τ e→0时保持有限，而横波在高对称方向传播时，衰减在此极限下趋于零。对于Ω τ i≪1，对脏晶体（Ω τ e→∞）中的纵波衰减与干净晶体（Ω τ e→0）中的纵波衰减之比进行了估计。这个比值是晶体的颗粒<s:1>尼森常数和温度的敏感函数。
The attenuation of a sound wave by anharmonic interaction with the thermal phonons in a dielectric crystal has been calculated using the Boltzmann-equation approach of Woodruff and Ehrenreich. Contributions to the thermal-phonon collision rate due to elastic scattering of phonons by crystal defects (relaxation time τ e) and due to intrinsic inelastic anharmonic processes (relaxation time τ i) are considered separately. In the case of longitudinal waves the attenuation remains finite as τ e→ 0, whereas for transverse waves propagating in high-symmetry directions the attenuation tends to zero in this limit. For Ω τ i≪ 1, an estimate is made of the ratio of the longitudinal-wave attenuation in a dirty crystal (Ω τ e→∞) to that in a clean crystal (Ω τ e→ 0). This ratio is found to be a sensitive function of the Grüneisen constants of the crystal and of the temperature.