Structure of HfO2 modified with Y, Gd, and Zr at ambient conditions and high pressures
Abstract
High-resolution and high-pressure X-ray diffraction measurements were performed to determine the effects of 5% Y, 3% Gd, and 50% Zr substitution on the crystal structure and polymorphism of HfO2. High-resolution experiments at ambient pressure show a mixture of monoclinic and cubic fluorite phases in 5% Y:HfO2 and 3% Gd:HfO2, while 50% Zr:HfO2 formed a monoclinic, single-phase solid solution. Crystallographic refinement using the Rietveld method indicates that Y and Gd substitute for Hf in both the monoclinic and cubic phases. High-pressure X-ray diffraction was performed in situ up to 31 GPa and shows that the pressure-induced phase transitions were reduced with the addition of either Y, Gd, or Zr relative to the transition pressures in undoped HfO2. The pressure-induced changes in lattice parameter, relative volume, and spontaneous strain are reported.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Nov 25, 2019
- Source ID
- 10.1063/1.5121024
Entities
People
- Brienne Johnson
- Chris M Fancher
- Dong Hou
- Jacob L. Jones
Organizations
- Army Research Office
- North Carolina State University
- Oak Ridge National Laboratory
- United States Department of Energy