Paramagnetic defects in electron-irradiated yttria-stabilized zirconia: Effect of yttria content

Journal Article · Tue Dec 20 04:00:00 EST 2011 · Journal of Applied Physics, 110(12):Article No. 123506

DOI:https://doi.org/10.1063/1.3666062· OSTI ID:1033831

Costantini, Jean-Marc; Beuneu, Francois; Morrison-Smith, Sarah E; Devanathan, Ramaswami; Weber, William J

We have studied the effect of the yttria content on the paramagnetic centres in electron-irradiated yttria-stabilized zirconia (ZrO2: Y3+) or YSZ. Single crystals with 9.5 mol% or 18 mol% Y2O3 were irradiated with electrons of 1.0, 1.5, 2.0 and 2.5 MeV. The paramagnetic centre production was studied by X-band EPR spectroscopy. The same paramagnetic centres were identified for both chemical compositions, namely two electron centres, i.e. i) F+-type centres (involving singly ionized oxygen vacancies), and ii) so-called T centres (Zr3+ in a trigonal symmetry site), and hole-centres. A strong effect is observed on the production of hole-centres which are strongly enhanced when doubling the yttria content. However, no striking effect is found on the electron centres (except the enhancement of an extra line associated to the F+-type centres). It is concluded that hole-centres are produced by inelastic interactions, whereas F+-type centres are produced by elastic collisions with no effect of the yttria content on the defect production rate. In the latter case, the threshold displacement energy (Ed) of oxygen is estimated from the electron-energy dependence of the F+-type centre production rate, with no significant effect of the yttria content on Ed. An Ed value larger than 120 eV is found. Accordingly, classical molecular dynamics (MD) simulations with a Buckingham-type potential show that Ed values for Y and O are likely to be in excess of 200 eV. It is concluded that F+-type centres might be actually oxygen divacancies (F2+-type centres). Due to the difficulty in displacing O or Y atoms, the radiation-induced defects may alternatively be a result of Zr atom displacements for Ed = 80 ± 1 eV with subsequent defect re-arrangement.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1033831
• Report Number(s): PNNL-SA-77664; 30472; KC0201020
• Journal Information: Journal of Applied Physics, 110(12):Article No. 123506, Journal Name: Journal of Applied Physics, 110(12):Article No. 123506
• Country of Publication: United States
• Language: English

Related Subjects

Environmental Molecular Sciences Laboratory
colour centres
electron irradiation
electron paramagnetic resonance
yttria-stabilized zirconia