Theoretical and experimental research of thermal conductivity of silver(Ag) nanowires in mesoporous substrate

Abstract

Thermal conductivities of Ag nanowires with different sizes and temperatures were studied theoretically. The lattice and electronic thermal conductivities of Ag nanowires include contributions from interface scattering and grain boundary scattering. While the molecular dynamic simulation was used to get the contribution of interface scattering to the lattice thermal conductivity of Ag nanowires along the axial direction, a model derived from Boltzmann transport equation and the Wiedemann-Franz relation were applied to calculate electronic thermal conductivities of Ag nanowires along the axial direction. And then coupling with the lattice and electronic thermal conductivities, the effective thermal conductivity of Ag nanowire along the axial direction was obtained. Furthermore, Kubo linear-response formalism was used to approximately predict the thermal conductivity in the plane perpendicular to the axis of the Ag nanowire. It turns out that effective thermal conductivities of Ag nanowire in the r-θ plane and along the Z direction show a great anisotropy. Finally, by measuring the thermal conductivities of Ag/SBA-15, the thermal conductivity of a single Ag nanowire can be obtained by using PWDM model, and the theoretical thermal conductivities of Ag nanowire were compared with the experimental results.