Dynamic disorder in BaTiS<sub>3 </sub>
ORAL
Abstract
BaTiS3 exhibits a hexagonal perovskite structure comprised of columns of sulphur coordinated Ti linked by barium making it a quasi-1D structure. Neutron pair distribution function measurements reveal that the Ti atomic displacement parameters increase with decreasing temperature. This observation suggest proximity to a ferroelectric type phase transition or, alternatively, dynamic disorder persisting in the ground state. A combination of phonon spectroscopy by inelastic x-ray scattering and inelastic neutron scattering supports the dynamic disorder scenario which extends into the quantum regime with Ti occupying a double-well potential. This unique dynamics have a profound consequence on the thermal conductivity and suggest a novel mechanism for thermal transport design.
*Research supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Materials Sciences and Engineering Division. This research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory and at the Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357
–
Presenters
-
Raphael Hermann
- Oak Ridge National Laboratory
- Oak Ridge National Lab