Grain Growth and Phase Stability of Nanocrystalline Cubic Zirconia under Ion Irradiation

Journal Article · Fri Jan 01 04:00:00 EST 2010 · Physical Review B

DOI:https://doi.org/10.1103/PhysRevB.82.184105· OSTI ID:993456

Zhang, Yanwen ^[1]; Jiang, Weilin ^[2]; Wang, Chongmin ^[2]; Namavar, Fereydoon ^[3]; Edmondson, Philip D. ^[2]; Zhu, Zihua ^[2]; Gao, Fei ^[2]; Lian, Jie ^[4]; Weber, William J ^[1]

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1. ORNL
2. Pacific Northwest National Laboratory (PNNL)
3. University of Nebraska Medical Center
4. Rensselaer Polytechnic Institute (RPI)

Grain growth, oxygen stoichiometry and phase stability of nanostructurally-stabilized cubic zirconia (NSZ) are investigated under 2 MeV Au ion bombardment at 160 and 400 K to doses up to 35 displacements per atom (dpa). The NSZ films are produced by ion-beam-assisted deposition technique at room temperature with an average grain size of 7.7 nm. The grain size increases with dose, and follows a power law (n=6) to a saturation value of ~30 nm that decreases with temperature. Slower grain growth is observed under 400 K irradiations, as compared to 160 K irradiations, indicating that the grain growth is not thermally activated and irradiation-induced grain growth is the dominating mechanism. While the cubic structure is retained and no new phases are identified after the high-dose irradiations, oxygen reduction in the irradiated NSZ films is detected. The ratio of O to Zr decreases from ~2.0 for the as-deposited films to ~1.65 after irradiation to ~35 dpa. The loss of oxygen suggests a significant increase of oxygen vacancies in nanocrystalline zirconia under ion irradiation. The oxygen deficiency may be essential in stabilizing the cubic phase to larger grain sizes.

• Research Organization: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 993456
• Journal Information: Physical Review B, Journal Name: Physical Review B Journal Issue: 18 Vol. 82; ISSN 1098-0121; ISSN 1550-235X
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ATOMS
DEPOSITION
GRAIN GROWTH
GRAIN SIZE
IRRADIATION
OXYGEN
PHASE STABILITY
SATURATION
STOICHIOMETRY
VACANCIES
defect
grain boundary
migration
nanocrystalline materials
vacancy
zirconia