Sentences with phrase «phonon scattering»

Systematic analysis is performed based on the study of the contribution from phonon branches, comparison among the mode level phonon group velocity and lifetime, the detailed process and channels of phonon — phonon scattering, and phonon anharmonicity with potential energy well.

We found that, different from graphene and ML BN, the phonon — phonon scattering selection rule in 2D GaN is slightly broken by the lowered symmetry due to the large difference in the atomic radius and mass between Ga and N atoms.

«The lower the number of non-hexagonal rings in the junction (for example three octagons versus six heptagons), the lower the number of undesirable rings and thus lower phonon scattering and improved thermal transport.»

Not exact matches

Until now, heat transport in nanostructured materials has largely been controlled by introduction of atomic - scale impurities, interfaces, surfaces and nanoparticles that reduce heat flow by scattering the phonons diffusely.

In their experiments, an optical pump pulse centered at 800 nm excites via impulsive Raman scattering a coherent optical phonon with Ag symmetry [movie].

But for much larger heat sources acting on the same material, phonons tend to collide with other phonons and scatter more often.

For example, if an engineer desires a material with certain thermal properties, the mean free path distribution could serve as a blueprint to design specific «scattering centers» within the material — locations that prompt phonon collisions, in turn scattering heat propagation, leading to reduced heat carrying ability.

A multi-partner study published today in Nature Communications has addressed phonon lifetime measurement challenges using inelastic neutron scattering (INS) and neutron resonant spin - echo (NRSE) experiments conducted at the Institut Laue Langevin (ILL) in Grenoble, and Laboratoire Léon Brillouin (LLB) Saclay, France.

In this work, a harmonic lattice dynamics and scattering boundary method based atomistic modeling tool was created to calculate phonon spectra and modal phonon transmission coefficients in nano - phononic structures and diameter - modulated nanowires.

Simulations show that although high frequency phonons are scattering by roughness, remaining long wavelength phonons maintain their phase and traverse the superlattices ballistically.