Synthesis and Processing of Materials: In Situ Scattering and Spectroscopy during Flash Sintering
Abstract
Flash sintering is a revolutionary method of densifying ceramics rapidly at low temperatures, but its mechanisms remain mysterious and insufficiently controlled. The ability to direct the densified volume, power density, and microstructure requires a fundamental understanding that does not exist to date. We propose a comprehensive program using in situ ultraviolet Raman spectroscopy to directly probe defect evolution during the flash process. These will be the first real-time probes of the hypothesized anion vacancies and cation Frenkel interstitials that are believed to accumulate and initiate a flash. We propose in-house transmission X-ray diffraction, electron paramagnetic resonance, and in situ synchrotron diffraction as complementary methods of identifying defects and quantifying their concentrations in the bulk. Our choice of materials systems is unconventional: our spectroscopic approach drives us to focus on materials where the signatures of defects are detectable, and we prefer to begin by investigating compounds where low-field electrical transport is known to be purely electronic or ionic. With this advantage, we seek to provide the first tractable, systematic view of flash sintering that can be extended to covalent materials of structural, optical, and electronic interest.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Sep 11, 2018
- Source ID
- W911NF1710142
Entities
People
- Daniel P. Shoemaker
Organizations
- Army Contracting Command
- United States Army
- University of Illinois Urbana–Champaign