Thermal Conductivity of Small Nickel Particles

Abstract

The thermal conductivity of nanoscale nickel particles due to phonon heat transfer is extrapolated from thin film results calculated using nonequilibrium molecular dynamics (NEMD). The electronic contribution to the thermal conductivity is deduced from the electrical conductivity using the Wiedemann-Franz law. Based on the relaxation time approximation, the electrical conductivity is calculated with the Kubo linear-response formalism. At the average temperature of T = 300 K, which is lower than the Debye temperature D = 450 K, the results show that in a particle size range of 1.408-10.56 nm, the calculated thermal conductivity decreases almost linearly with decreasing particle size, exhibiting a remarkable reduction compared with the bulk value. The phonon mean free path is estimated, and the size effect on the thermal conductivity is attributed to the reduction of the phonon mean free path according to the kinetic theory.

Heat conduction in coaxial nanocables of Au nanowire core and carbon nanotube shell: A molecular dynamics simulation

“…Generally, the ETC is deduced from the electrical conductivity according to the WiedemanneFranz law [31]. The WiedemanneFranz law is valid for materials in bulk form.…”

“…The elastic scattering and diffuse reflections on the nanowire surface are taken into account. The ETC of gold NWs with a circular cross section was given by the solution of Boltzmann transport equation (see the reference [33] for mathematical details) and WiedemanneFranz law [31].…”

Thermal transport in composites of self-assembled nickel nanoparticles embedded in yttria stabilized zirconia

“…2͒. Given that these minimum thermal conductivity values are much smaller than estimates from molecular dynamics simulations, 20 it seems likely that the actual Ni/YSZ interface conductance is closer to the lower limit of ϳ200 MW m −2 K −1 . In summary, we examined the thermal transport in nanocomposites composed of Ni nanoparticles embedded in a YSZ matrix.…”

“…2 20 predict that the thermal conductivity of nickel nanoparticles will always be above 30 W m −1 K −1 for nanoparticles greater than 7 nm in diameter. These results illustrate the critical importance of the interface if one intends to enhance the thermal conductivity of a composite material by introducing high conductivity particles.…”

Molecular scale analysis of dry sliding copper asperities

“…At the nano scale, the thermal transport decreases due to boundary scattering of electrons and phonons, and size effects (Yuan and Jiang 2006). Since the mean free path for electrons is larger than that of phonons, electrons suffer more scattering than phonons and therefore their contribution to thermal transport decreases (Feng et al 2009).…”