Eur. Phys. J. B (2014) 87: 150
https://doi.org/10.1140/epjb/e2014-50239-5

Regular Article

Effect of structural features on the thermal conductivity of SiGe-based materials

Department of Physics, University of Cagliari, Cittadella Universitaria, 09042 Monserrato ( CA), Italy

^a e-mail: konstanze.hahn@dsf.unica.it

Received: 9 April 2014
Received in final form: 14 May 2014
Published online: 7 July 2014

Abstract

Approach-to-equilibrium molecular dynamics have been utilized to investigate the thermal transport in SiGe-based materials focusing on the effect of structural changes while the chemical composition has been kept constant. At a Si:Ge ratio of 1:1, the thermal conductivity has been evaluated for crystalline SiGe with a periodic (ZnS-like) and random (alloy) distribution of Si and Ge atoms, for SiGe nanocomposite and for amorphous SiGe. Thermal conductivity has been found to be lowest in amorphous SiGe (0.9 W/mK). In the regime studied here, a non-linear behavior of 1/κ to 1/L_z has been observed for amorphous SiGe, while a linear trend is found for all crystalline materials (ZnS-like, alloy and nanocomposite). This has been attributed to a wide spread in the mean free path of phonons dominating the thermal transport in the amorphous system.