Elastic interface acoustic waves in twinned crystals

TL;DR

This paper introduces a new type of interface acoustic waves in twinned orthotropic crystals, providing analytical solutions and classifying wave types for materials like Gallium Arsenide and Silicon.

Contribution

It presents the first analytical formulation of elastic interface acoustic waves in twinned crystals with specific polarization and wave type classifications.

Findings

IAWs are linearly polarized at the interface

Analytical secular equations are derived

Wave types identified for Gallium Arsenide and Silicon

Abstract

A new type of Interface Acoustic Waves (IAW) is presented, for single-crystal orthotropic twins bonded symmetrically along a plane containing only one common crystallographic axis. The effective boundary conditions show that the waves are linearly polarized at the interface, either transversally or longitudinally. Then the secular equation is obtained in full analytical form using new relationships for the displacement-traction quadrivector at the interface. For Gallium Arsenide and for Silicon, it is found that the IAWs with transverse (resp. longitudinal) polarization at the interface are of the Stoneley (resp. leaky) type.