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Title: Experimental evidence of high-frequency complete elastic bandgap in pillar-based phononic slabs

We present strong experimental evidence for the existence of a complete phononic bandgap, for Lamb waves, in the high frequency regime (i.e., 800 MHz) for a pillar-based phononic crystal (PnC) membrane with a triangular lattice of gold pillars on top. The membrane is composed of an aluminum nitride film stacked on thin molybdenum and silicon layers. Experimental characterization shows a large attenuation of at least 20 dB in the three major crystallographic directions of the PnC lattice in the frequency range of 760 MHz–820 MHz, which is in agreement with our finite element simulations of the PnC bandgap. The results of experiments are analyzed and the physics behind the attenuation in different spectral windows is explained methodically by assessing the type of Bloch modes and the in-plane symmetry of the displacement profile.
Authors:
; ; ;  [1] ;  [2]
  1. School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States)
  2. Institut FEMTO-ST, Université de Franche-Comté, CNRS, 32 Avenue de l'Observatoire, 25044 Besançon Cedex (France)
Publication Date:
OSTI Identifier:
22395464
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 105; Journal Issue: 23; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ALUMINIUM NITRIDES; ATTENUATION; COMPUTERIZED SIMULATION; CRYSTALS; ENERGY GAP; FILMS; FINITE ELEMENT METHOD; GOLD; LAYERS; MEMBRANES; MHZ RANGE; MOLYBDENUM; PHONONS; SILICON; SLABS; SYMMETRY