Acoustoelastic effect in anisotropic layered structures
Acoustoelastic effect in anisotropic layered structures
复制标题
DOI：
10.1103/physrevb.62.13963
复制
发表时间：
2000-12
影响因子：
3.7
通讯作者：
A. Osetrov;H. Fröhlich;R. Koch;E. Chilla
中科院分区：
文献类型：
--
作者：
A. Osetrov;H. Fröhlich;R. Koch;E. Chilla
机械应力改变了声波的速度，这种现象被称为AE（声弹性）效应，这对层状异质结构中的波传播特别重要。为了计算应力作用下层状体系的声发射效应，我们将声波传播的传递矩阵法推广到考虑了密度的变化、残余应力的影响以及残余应变和三阶常数对弹性刚度张量的修正。本文用广义方法计算了Ge（001）晶体切面上横向体模和声表面波声发射效应的角色散。AE效应被发现显着依赖于传播方向，甚至可以改变符号。最大速度变化发生在平行于[110]方向传播的横向极化波。对于Ge/Si（001）层状系统，研究了[100]和[110]方向Love模的声发射效应。声发射效应随着层厚的增加而迅速增加，当波仍然穿透到无应力的基底时，声发射效应几乎达到最大值。对于高阶Love模式，AE效应的增加甚至更陡，并且可以达到更高的值。
Mechanical stress alters the velocity of acoustic waves, a phenomenon known as AE (acoustoelastic) effect, which is of particular importance for the wave propagation in layered heterostructures. In order to calculate the AE effect of layered systems in the presence of stress we extended the transfer-matrix method for acoustic wave propagation by considering the change of the density, the influence of residual stress, and the modification of the elastic stiffness tensor by residual strain and by third-order constants. The generalized method is applied to the calculation of the angular dispersion of the AE effect for transverse bulk modes and surface acoustic waves on the Ge(001) crystal cut. The AE effect is found to depend significantly on the propagation direction and can even change sign. The maximum velocity change occurs for transversally polarized waves propagating parallel to the [110] direction. For the layered Ge/Si(001) system the AE effect is investigated for Love modes propagating in the [100] and [110] directions. The AE effect increases rapidly with increasing layer thickness and reaches almost its maximum value when the wave is still penetrating into the unstressed substrate. For higher-order Love modes the increase of the AE effect is even steeper and, furthermore, can reach higher values.