Heat flux engineering in planar nanostructures

In the paper is shown that one can obtain the decreasing of thermal flux in heterostructure in comparison with thermal flux in the slab covering the heat conducting nano slab with claddings with smaller elasticity constants. As an example, the Si-based heterostructure was chosen. The dispersion relations for acoustic phonons were obtained in the framework of molecular-dynamic Face-centered cubic cell model. It is shown, that there are three types of phonon modes in three-layered heterostructure: (1) 'common' modes (distributed over whole heterostructure thickness), (2) 'internal' modes and (3) 'external' modes, which are concentrated mainly in the core and cladding layers correspondingly. One can reach the thermal flux decreasing, enhancing the phonon external boundary scattering of 'common' modes. (authors)