Structural phase purification of bulk HfO 2 :Y through pressure cycling
- Department of Chemistry, University of Tennessee, Knoxville, TN 37996, Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996
- Department of Mechanical Engineering, University of Rochester, Rochester, NY 14627, Materials Science Program, University of Rochester, Rochester, NY 14627
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY 11973
- Department of Chemistry, University of Tennessee, Knoxville, TN 37996
- Department of Physics and Astronomy, Rutgers University, Piscataway, NJ 08854, Rutgers Center for Emergent Materials, Rutgers University, Piscataway, NJ 08854
- Department of Physics, University of Illinois, Chicago, IL 60607-7059
- Department of Physics and Astronomy, Rutgers University, Piscataway, NJ 08854
We combine synchrotron-based infrared absorption and Raman scattering spectroscopies with diamond anvil cell techniques and first-principles calculations to explore the properties of hafnia under compression. We find that pressure drives HfO :7%Y from the mixed monoclinic ( ) antipolar orthorhombic ( ) phase to pure antipolar orthorhombic ( ) phase at approximately 6.3 GPa. This transformation is irreversible, meaning that upon release, the material is kinetically trapped in the metastable state at 300 K. Compression also drives polar orthorhombic ( ) hafnia into the tetragonal ( ) phase, although the latter is not metastable upon release. These results are unified by an analysis of the energy landscape. The fact that pressure allows us to stabilize targeted metastable structures with less Y stabilizer is important to preserving the flat phonon band physics of pure HfO .
- Sponsoring Organization:
- USDOE
- Grant/Contract Number:
- SC0023144; NA0003975
- OSTI ID:
- 2282781
- Journal Information:
- Proceedings of the National Academy of Sciences of the United States of America, Journal Name: Proceedings of the National Academy of Sciences of the United States of America Journal Issue: 5 Vol. 121; ISSN 0027-8424
- Publisher:
- Proceedings of the National Academy of SciencesCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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