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RESEARCH PRODUCT
Engineering the hypersonic phononic band gap of hybrid Bragg stacks.
George FytasGeorge FytasYoussef El HassouaniWolfgang TremelDirk SchneiderFaroha LiaqatBahram Djafari-rouhaniE. H. El BoudoutiHans-jürgen Buttsubject
Hypersonic speedMaterials scienceLightBand gapSuperlatticeBioengineering02 engineering and technology01 natural sciencesOpticsDispersion relation0103 physical sciencesScattering RadiationGeneral Materials ScienceComputer SimulationParticle Size010306 general physicsNanoscopic scaleBrillouin SpectroscopyCondensed matter physicsbusiness.industryMechanical EngineeringGeneral Chemistry021001 nanoscience & nanotechnologyCondensed Matter PhysicsNanostructuresBrillouin zoneShear (sheet metal)RefractometryModels Chemical0210 nano-technologybusinessdescription
We report on the full control of phononic band diagrams for periodic stacks of alternating layers of poly(methyl methacrylate) and porous silica combining Brillouin light scattering spectroscopy and theoretical calculations. These structures exhibit large and robust on-axis band gaps determined by the longitudinal sound velocities, densities, and spacing ratio. A facile tuning of the gap width is realized at oblique incidence utilizing the vector nature of the elastic wave propagation. Off-axis propagation involves sagittal waves in the individual layers, allowing access to shear moduli at nanoscale. The full theoretical description discerns the most important features of the hypersonic one-dimensional crystals forward to a detailed understanding, a precondition to engineer dispersion relations in such structures.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2012-01-01 | Nano letters |