(PECASE) UNRAVELING PHONONS AT THE ATOMIC SCALE: A NEW TOOL TO EXPLORE THE SCIENCE OF THERMAL TRANSPORT
Abstract
The goal of research program is to develop the science to quantify thermal transport at the atomic scale. Thermal displacements of atoms mediate a wide range of physical and quantum properties encompassing magnetism, ferroelectricity, conventional superconductivity, and thermoelectricity. Precise tuning and control of material behavior requires a complete understanding of the impact of defects, microstructure, and alloying on these thermal vibrations. The primary objective of this proposal is thus to develop the fundamental science and methods to enable robust quantification of atomic displacements associated with thermal transport. The outcome will be to assist in explaining the key thermodynamic material properties and to establish comprehensive protocols for future quantum materials and characterization research. To date, work to quantify the thermal and static displacements from scanning transmission electron microscopy (STEM) image intensities has been limited. As the intensity of atom columns in a STEM image depends intimately on thermal vibrations, new STEM techniques have the potential to connect phonon related atomic displacements at a spatial resolution that is inaccessible to x-ray and neutron diffraction. Building upon this critical observation, we aim to develop STEM into a tool capable of probing phonon behavior at single defects, interfaces, and nanoparticles. With a unique combination of expertise and instrumentation, we are poised to revolutionize quantification of phonon propagation at the atomic scale. At the completion of this study, significant contributions to the science of connecting thermal motion to STEM imaging will be made. By morphing these competencies into quantitative methods that can be widely applied, the results of this proposal will develop new insights into material thermal properties that are currently out of reach. This progress will transform quantification of thermal transport controlled by local structure, composition, and nanostructuring, which will enable new understanding of structure-property relationships controlled at the atomic scale.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 12, 2021
- Source ID
- FA95502010066
Entities
People
- James M. LeBeau
Organizations
- Air Force Office of Scientific Research
- Massachusetts Institute of Technology
- United States Air Force