Structure of HfO₂ modified with Y, Gd, and Zr at ambient conditions and high pressures

Journal Article · 25 November 2019 · Journal of Applied Physics

DOI: https://doi.org/10.1063/1.5121024 · OSTI ID:1607279

Johnson, Brienne ^[1]; Fancher, Chris M.  ^[2]; Hou, Dong  ^[1]; Jones, Jacob L. ^[1]

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1. North Carolina State Univ., Raleigh, NC (United States)
2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

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. Finally, the pressure-induced changes in lattice parameter, relative volume, and spontaneous strain are reported.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA); USDOE Office of Science (SC), Basic Energy Sciences (BES); Army Research Office (USARO)
• Grant/Contract Number: AC05-00OR22725; NA0001974; FG02-99ER45775; AC02-06CH11357; W911NF-15-1-0593
• OSTI ID: 1607279
• Alternate ID(s): OSTI ID: 1575803
• Journal Information: Journal of Applied Physics, Vol. 126, Issue 20; ISSN 0021-8979
• Publisher: American Institute of Physics (AIP)Copyright Statement
• Country of Publication: United States
• Language: English