Structure and spectroscopic properties of oxygen divacancy in yttrium-stabilized zirconia

Abstract

Abstract. We have studied the structure and spectroscopic properties of the oxygen divacancy defect in Yttrium-stabilized ZrO2 using periodic and embedded cluster methods and GGA and B3LYP density functionals. The results demonstrate that the defect spectroscopic properties depend on the particular arrangement of Y dopants near vacancies. The optical transition energies calculated for the negatively charged state of the divacancy at 2.8 eV and 3.3 eV are in agreement with experimental data. The second set of transitions between 1.9 eV and 2.7 eV corresponds to the electron transfer between vacancies. The calculated EPR g-tensor values are in agreement with other works. The results support the proposed attribution of the optical absorption peaking at 3.3 eV and related EPR spectra to Zr 3+ ions in the YSZ matrix, however, they are not fully conclusive due to dependence on Y concentration.

Point defects induced in yttria-stabilized zirconia by electron and swift heavy ion irradiations

“…Such a low value was assigned to forbidden 4d inner-shell transitions of the Zr 3+ ions. The calculated optical transition at 3.28 eV from a mid-gap state to a resonant localized state (mainly composed of Zr 4d-orbitals) created by the oxygen vacancy inside the conduction band of YSZ [25] is consistent with the experimental values of 3.1 eV (this work) to 3.3 eV [4,24] for the absorption band of T centres. Optical absorption spectra obtained upon low-energy ion (340 keV Xe) [26] and fastneutron irradiations [27] show broad bands peaked at about 2.3 eV and 2.6 eV, respectively.…”

Oxygen Vacancies as Traps Responsible for La-Doped Hf0.5Zr0.5O2 Charge Transport

“…The luminescence peak 2.85 eV is most likely due to the presence of oxygen vacancies, judging by the fact that, for the undoped oxides HfO 2 , ZrO 2 , and Hf 0.5 Zr 0.5 O 2 , it is oxygen vacancies that are responsible for the blue PL. ,,− The interpretation of yellow luminescence is difficult, but it was observed earlier for undoped HfO 2 . , Therefore, it can be assumed that its origin for the studied films is not related to the presence of lanthanum. It can be assumed that the 2.19 eV PL peak is caused by oxygen divacancies (absence of two oxygen atoms near one Hf atom) and corresponds to the electron transfer between the vacancies …”

“…It can be assumed that the 2.19 eV PL peak is caused by oxygen divacancies (absence of two oxygen atoms near one Hf atom) and corresponds to the electron transfer between the vacancies. 36 The PLE spectrum deconvolution shows two maxima with energies 4.57 and 5.45 eV (Figure 3b). Both features are close to the previously observed ones at 4.3−4.5 eV and 5.2 eV for undoped HfO 2 , ZrO 2 , and Hf 0.5 Zr 0.5 O 2 .…”

Investigation of the vibrational properties of cubic yttria-stabilized zirconia: A combined experimental and theoretical study

“…Theoretically, the atomic structure of YSZ has attracted considerable attention, with progress being made on the basis of firstprinciples density-functional theory (DFT) calculations [28][29][30][31][32]. The results of these theoretical investigations largely support the interpretation of experimental results and show that the structure formed is dependent on the percentage of yttria included [28,29,[31][32][33].…”