Efficient mechanical modulation of the phonon thermal conductivity of Mo 6 S 6 nanowires.

Mo 6 S 6 nanowires are emerging as key building blocks for flexible devices and are competitive with carbon nanotubes due to easier separation and functionalization. Here, it is reported the phonon thermal conductivity ( κ ) of Mo 6 S 6 nanowires via molecular dynamics simulations. It shows a large tunability of low-frequency phonon thermal conductivity ( κ lf )Amax from 27.2-191 W (m K) -1 , an increase of around 702% via mechanical strain. Below critical tension/torsion strain, their phonon thermal conductivity monotonically reduces/enlarges; whereas above this value, an inverse trend is identified. On the other hand, Mo 6 S 6 nanowires show unusual auxetic behavior. The transitions involved in phonon thermal conductivity are molecularly illustrated by a strain-induced crossover in bond configurations and are explained based on a competition mechanism between phonon scattering and group velocity. This study provides insights into the thermal transport and auxetic properties of low-dimensional structures and the thermal management of Mo 6 S 6 nanowire-based systems.