Phonon thermal transport through tilt grain boundaries in strontium titanate
- Univ. of Florida, Gainesville, FL (United States)
Here, we perform nonequilibrium molecular dynamics simulations to study phonon scattering at two tilt grain boundaries (GBs) in SrTiO3. Mode-wise energy transmission coefficients are obtained based on phonon wave-packet dynamics simulations. The Kapitza conductance is then quantified using a lattice dynamics approach. The obtained results of the Kapitza conductance of both GBs compare well with those obtained by the direct method, except for the temperature dependence. Contrary to common belief, the results of this work show that the optical modes in SrTiO3 contribute significantly to phonon thermal transport, accounting for over 50% of the Kapitza conductance. To understand the effect of the GB structural disorder on phonon transport, we compare the local phonon density of states of the atoms in the GB region with that in the single crystalline grain region. Our findings reflect that the excess vibrational modes introduced by the structural disorder do not have a significant effect on phonon scattering at the GBs, but the absence of certain modes in the GB region appears to be responsible for phonon reflections at GBs. This work has also demonstrated phonon mode conversion and simultaneous generation of new modes. Some of the new modes have the same frequency as the initial wave packet, while some have the same wave vector but lower frequencies.
- Research Organization:
- Energy Frontier Research Centers (EFRC) (United States). Center for Materials Science of Nuclear Fuel (CMSNF)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES); National Science Foundation (NSF)
- Grant/Contract Number:
- AC07-05ID14517; SC0006539
- OSTI ID:
- 1369987
- Journal Information:
- Journal of Applied Physics, Vol. 116, Issue 7; Related Information: CMSNF partners with Idaho National Laboratory (lead); Colorado School of Mines; University of Florida; Oak Ridge National Laboratory; Purdue University; University of Wisconsin at Madison; ISSN 0021-8979
- Publisher:
- American Institute of Physics (AIP)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
The impact of tilt grain boundaries on the thermal transport in perovskite SrTiO 3 layered nanostructures. A computational study
|
journal | January 2018 |
Thermal Conductivity of Diamond/SiC Nano-Polycrystalline Composites and Phonon Scattering at Interfaces
|
journal | May 2017 |
Similar Records
Thermal transport at (001) twist grain boundaries in UO{sub 2}
Thermal conductivity and its relation to atomic structure for symmetrical tilt grain boundaries in silicon