Introduction: Nano-structured semiconductor devices play a vital role in areas ranging from CMOS [1] to thermo-electricity [2]. The finite extent and increased surface to volume ratio in the nano-structured devices result in very different phonon dispersions compared to the bulk materials. This work investigates the effect of geometrical confinement on the phonon dispersion, sound velocity(Vsnd...

für Naturforschung in cooperation with the Max Planck Society for the Advancement of Science under a Creative Commons Attribution 4.0 International License. Dieses Werk wurde im Jahr 2013 vom Verlag Zeitschrift für Naturforschung in Zusammenarbeit mit der Max-Planck-Gesellschaft zur Förderung der Wissenschaften e.V. digitalisiert und unter folgender Lizenz veröffentlicht: Creative Commons Namen...

A study of the normal modes of vibration and their dispersion in polyinosinic acid [poly (I)] along the helix axis based on Urey-Bradley force field is reported. It leads to a better interpretation of Raman and FTIR spectra. A comparison of dispersion curves of poly (I) with poly (G) has been made. Characteristic features of dispersion curves, such as regions of high density-of-states, repulsio...

I present the detailed behavior of phonon dispersion curves near momenta which span the electronic Fermi sea in a superconductor. I demonstrate that an anomaly, similar to the metallic Kohn anomaly, exists in a superconductor’s dispersion curves when the frequency of the phonon spanning the Fermi sea exceeds twice the superconducting energy gap. This anomaly occurs at approximately the same mom...

Micro-Raman spectra of single-walled carbon nanotubes in the range of two-phonon 2D bands are investigated in detail. The fine structure of two-phonon 2D bands in the low-temperature Raman spectra of the mixture and individual single-walled carbon nanotubes is considered as the reflection of structure of their π-electron zones. The dispersion behavior of 2D band fine structure components in the...

The self-consistent phonon (SCP) theory is used to study the dynamics of monolayers of xenon, krypton, and methane adsorbed on graphite. Only the ~3Xv 3 sohd phase is considered. It is shown that the phonon energies of the Xe monolayers are very similar to those of their Soating counterparts, while the interaction of the Kr and CH4 monolayers vnth the graphite signNcantly a8ects the phonon disp...

in this work we use density functional theory based on the ultra-soft pseudo-potential to calculate thestructural, mechanical and thermal properties of narrow single walled bn, aln and gan nanotubes.the electron-electron interactions were expressed within the local density approximation (lda). wehave also obtained the phonon dispersion and elastic constants of these nanotubes using the densityf...

We measured the phonon dispersion of silicene (monolayer Si with a honeycomb lattice) on ZrB2(0 0 0 1) using high-resolution electron energy loss spectroscopy. The measured phonon dispersion was compared with ab initio density functional theory calculations for a silicene model with [Formula: see text] periodicity of the substrate. The most stable [Formula: see text] silicene structure, which i...

This paper reports dependency of specific heat and ballistic thermal conductance on cross-sectional geometry (tube versus rod) and size (i.e., diameter and wall thickness), in free-standing isotropic non-metallic crystalline nanostructures. The analysis is performed using dispersion relations found by numerically solving the Pochhammer-Chree frequency equation for a tube. Estimates for the allo...