Thermal conductivity of nanocrystalline SiGe alloys using molecular dynamics simulations

Autor(es)

da Cruz, Carolina Abs ^[1] ; Katcho, Nebil A. ^[1] ; Mingo, Natalio ^[1] ; Veiga, Roberto G. A. ^[2]

Afiliação do(s) autor(es)

^[1] CEA Grenoble, LITEN, F-38054 Grenoble - France

^[2] Univ Sao Paulo, Dept Met & Mat Engn, Escola Politecn, Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Applied Physics; v. 114, n. 16 OCT 28 2013.
• Citações Web of Science: 8

Resumo

We have studied the effect of nanocrystalline microstructure on the thermal conductivity of SiGe alloys using molecular dynamics simulations. Nanograins are modeled using both the coincidence site lattice and the Voronoi tessellation methods, and the thermal conductivity is computed using the Green-Kubo formalism. We analyze the dependence of the thermal conductivity with temperature, grain size L, and misorientation angle. We find a power dependence of L-1/4 of the thermal conductivity with the grain size, instead of the linear dependence shown by non-alloyed nanograined systems. This dependence can be derived analytically underlines the important role that disorder scattering plays even when the grains are of the order of a few nm. This is in contrast to non-alloyed systems, where phonon transport is governed mainly by the boundary scattering. The temperature dependence is weak, in agreement with experimental measurements. The effect of angle misorientation is also small, which stresses the main role played by the disorder scattering. (C) 2013 AIP Publishing LLC. (AU)

• Processo FAPESP: 11/19564-6 - Modelagem computacional da evolução microestrutural de ligas Fe-Ni-C
• Beneficiário: Roberto Gomes de Aguiar Veiga
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado