Scattering of elastic waves by elastic spheres in a NaCl-type phononic crystal

TL;DR

This paper introduces a simplified method to analyze elastic wave scattering in NaCl-type phononic crystals, calculating band structures and wave transmission, reflection, and absorption for finite slabs using multiple scattering theory.

Contribution

It presents a straightforward approach to study NaCl-type phononic crystals, extending existing formalism to include complex band structures and wave interaction properties.

Findings

Calculated complex band structures for the infinite crystal.

Determined transmission, reflection, and absorption coefficients for elastic waves.

Validated the method for different incident angles and wave types.

Abstract

Based on the formalism developed by Psarobas et al [Phys. Rev. B 62, 278(2000)], which using the multiple scattering theory to calculate properties of simple phononic crystals, we propose a very simple method to study the NaCl-type phononic crystal. The NaCl-type phononic crystal consists of two kinds of non-overlapping elastic spheres with different mass densities, $L\acute{a}me$ coefficients and radius following the same periodicity of the ions in the real NaCl crystal. We focus on the (001) surface, and view the crystal as a sequence of planes of spheres, each plane of spheres has identical 2D periodicity. We obtained the complex band structure of the infinite crystal associated with this plane, and also calculated the transmission, reflection and absorption coefficients for an elastic wave (longitudinal or transverse) incident, at any angle, on a slab of the crystal of finite thickness.