We present the results of roomand low-temperature measurements of second-order Raman scattering for perfect GaN and AlN crystals as well as the Raman-scattering data for strongly disordered samples. A complete group-theory analysis of phonon symmetry throughout the Brillouin zone and symmetry behavior of phonon branches, including the analysis of critical points, has been performed. The combine...

We have performed molecular dynamics simulations of FeS0Nizo alloys using an inter-atomic potential of the EAM-type which allows the simulation of the martensiteaustenite transition. We present results, showing the development of an inhomogeneous shear system on a nanoscale during the thermally induced austenitic transformation. In addition to this we obtained the phonon dispersion relations of...

We have performed molecular dynamics simulations of Fe 80 Ni 20 alloys using an inter-atomic potential of the EAM-type which allows the simulation of the martensite-austenite transition. We present results, showing the development of an inhomogeneous shear system on a nanoscale during the thermally induced austenitic transformation. In addition to this we obtained the phonon dispersion relation...

The phonon structure of GaP quantum dots is studied using an atomistic potential model. The dot eigenmodes are obtained from a direct diagonalization of the dynamical matrix and classified using an efficient dual-space analysis method. Our calculations provide a theoretical explanantion for several experimental observations. ~1! Depending on the spatial localization, the phonon modes of dots ar...

The study of surface phonon dispersion curves is motivated by the quest for a detailed understanding of the forces between the atoms at the surface and in the bulk. In the case of graphene, additional motivation comes from the fact that thermal conductivity is dominated by contributions from acoustic phonons, while optical phonon properties are essential to understand Raman spectra. In this art...

Weak phonon modes at 2032,5; 2040; 2046; and 2 0 5 3 c m 1 in K 3 Cu(CN) 4 have been assigned to originate from 13C = 14N and 12C = 15N vibrations. The assignments have been carried out using measurements at He-temperatures and in aqueous solutions. Furthermore calculations have been used concerning the frequency shifts and relative intensities with respect to the 12C = 14N vibrations. The coup...

Similar to electron waves, the phonon states in semiconductors can undergo changes induced by external boundaries. However, despite strong scientific and practical importance, conclusive experimental evidence of confined acoustic phonon polarization branches in individual free-standing nanostructures is lacking. Here we report results of Brillouin-Mandelstam light scattering spectroscopy, which...