Lattice thermal conductivity of (Bi1-xSbx)2Te3 alloys with embedded nanoparticles

The lattice thermal conductivity of (Bi1-x Sb-x)(2)Te-3 alloys, with and without spherical nanoparticle inclusions, has been computed using the Boltzmann transport equation with classical interatomic potentials within the relaxation time approximation. The experimental thermal conductivity of the pure alloys is fairly well reproduced as a function of concentration. We establish upper and lower limits for the thermal conductivities that could be obtained via seamlessly embedded spherical nanoparticles as a function of their size, density, and volume fraction. Large reductions in thermal conductivities (40-50%) can only be achieved with small nanoparticles with diameters below 10 nm.