  Strain engineering is critical to the performance enhancement of electronic
and thermoelectric devices because of its influence on the material thermal
conductivity. However, current experiments cannot probe the detailed physics of
the phonon-strain interaction due to the complex, inhomogeneous, and
long-distance features of the strain field in real materials. Dislocations
provide us with an excellent model to investigate these inhomogeneous strain
fields. In this study, non-equilibrium molecular dynamics simulations were used
to study the lattice thermal conductivity of PbTe under different strain status
tuned by dislocation densities. The extended 1D McKelvey-Shockley flux method
was used to analyze the frequency dependence of phonon scattering in the
inhomogeneously strained regions of dislocations. A spatially resolved phonon
dislocation scattering process was shown, where the unequal strain in different
regions affected the magnitude and frequency-dependence of the scattering rate.
Our study not only advances the knowledge of strain scattering of phonon
propagation but offers fundamental guidance on optimizing thermal management by
structure design.
