Extended Anharmonic Collapse of Phonon Dispersions in SnS
![Extended Anharmonic Collapse of Phonon Dispersions in SnS Extended Anharmonic Collapse of Phonon Dispersions in SnS](https://webarchive.library.unt.edu/web/20201218081913im_/https://neutrons.ornl.gov/sites/default/files/styles/rhpage640/public/5.jpg?itok=HoMGEg3d)
Scientific Achievement
An extreme softening of an entire manifold of low energy acoustic and optic phonon branches in observed in warming SnS through a structural transition.
Significance and Impact
These strong phonon renormalization effects associated with lattice instabilities provide a new mechanism for ultra-low thermal conductivity, a desirable property for thermoelectrics, photovoltaics, and other technologically important materials.
Research Details
- Inelastic neutron scattering was used to map out the phonon excitation spectra across the structural phase transition.
- Complementary high-resolution Raman spectra were collected to probe zone-center optical modes.
- Anharmonic first-principles calculations based on density functional theory were used and to calculate the dynamical susceptibility.
“Extended anharmonic collapse of phonon dispersions in SnS and SnSe”
Tyson Lanigan-Atkins, S. Yang, Jennifer Niedziela, Dipanshu Bansal, Andrew May, Alexander Puretzky, Jiao Lin, Daniel Pajerowski, Tao Hong, Songxue Chi, Georg Ehlers and Olivier Delaire
Nature Communications, 11, 4430 (2020).
DOI: https://doi.org/10.1038/s41467-020-18121-4