MD investigations of of heat flow throw interfaces in 1D systems

Molecular dynamic calculations (MD) of heterogeneous 1D periodical systems are presented. It is proposed the new technique of direct calculations of thermal conductivity, where there is only one thermostat in one piece of unit cell as well as another piece where artificial friction forces act on atoms. With the help of this scheme, calculations of 1D heterogeneous systems having regions with atoms of different atomic masses are presented. It is shown that the difference in atomic masses in adjacent regions of the systems leads to a significant temperature jump at interfaces between these regions. This temperature jump exists independently of the mass ratio on both sides of the interface.The reasons for these jumps are discussed. It is also shown that, by changing the alternation of regions with different masses of atoms, it is possible to reduce the total thermal conductivity of the system by several times. On the base of these results, we can hope that for three-dimensional structures also, the thermal conductivity can be significantly reduced.