Abstract
Lattice dynamics measurements are often crucial tools for understanding how materials transform between different structures. We report time-resolved x-ray scattering-based measurements of the nonequilibrium lattice dynamics in SnSe, a monochalcogenide reported to host a novel photoinduced lattice instability. By fitting interatomic force models to the fluence dependent excited-state dispersion, we determine the nonthermal origin of the lattice instability to be dominated by changes of interatomic interactions along a bilayer-connecting bond, rather than of an intralayer bonding network that is of primary importance to the lattice instability in thermal equilibrium.
| Original language | English |
|---|---|
| Article number | 156902 |
| Journal | Physical Review Letters |
| Volume | 131 |
| Issue number | 15 |
| DOIs | |
| State | Published - Oct 13 2023 |
Funding
Preliminary x-ray characterization was performed at beamline 7-2 at the Stanford Synchrotron Radiation Lightsource (SSRL). Y. H., S. T., G. d. P, D. A. R., A. M. L., and M. T. were supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences through the Division of Materials Sciences and Engineering under Contract No. DE-AC02-76SF00515. S. Y. acknowledges support from the Fitzpatrick Institute for Photonics through a Chambers Scholarship. O. D. acknowledges support from the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division, under Award No. DE-SC0019978. Use of the LCLS and S. S. R. L. is supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences under Contract No. DE-AC02-76SF00515. Sample synthesis and characterization (A. F. M.) was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences, and Engineering Division. D. A. R. acknowledges discussions with Ivana Savic and Stephen Fahy. Y. H. acknowledges discussions with Xing He.