Data from: Anomalous thermal transport in Eshelby twisted van der Waals nanowires

Dislocations in van der Waals (vdW) layered nanomaterials induce strain
and structural changes that substantially impact thermal transport.
Understanding these effects could enable the manipulation of dislocations
for improved thermoelectric and optoelectronic applications, but
experimental insights remain limited. In this study, we use synthetic
Eshelby twisted vdW GeS nanowires (NWs) with single screw dislocations as
a model system to explore the interplay between dislocation-induced
structural modifications and lattice thermal conductivity. Our
measurements reveal a monoclinic structure stabilized by the dislocation,
leading to a substantial drop in thermal conductivity for larger diameter
NWs (70% at room temperature), supported by first-principles calculations.
Interestingly, we also find an anomalous enhancement of thermal
conductivity with decreasing diameter in twisted NWs, contrary to typical
trends in non-twisted GeS NWs. This is attributed to increased
conductivity near the NW cores due to compressive strain around the
central dislocations and aligns with a density functional theory-informed
core-shell model. Our results highlight the critical role of dislocations
in thermal conduction, providing fundamental insights for defect and
strain engineering in advanced thermal applications.