Oxygen vacancy mediated cubic phase stabilization at room temperature in pure nano-crystalline zirconia films: a combined experimental and first-principles based investigation

Abstract

We report the formation of cubic phase, under ambient conditions, in thin films of Zirconia synthesized by electron beam evaporation technique. The stabilization of the cubic phase was achieved without the use of chemical stabilizers and/or concurrent ion beam bombardment. Films of two different thickness (660 nm, 140 nm) were deposited. The 660 nm and 140 nm films were found to be stoichiometric (ZrO2) and off-stoichiometric (ZrO1.7) respectively by Resonant Rutherford back-scattering spectroscopy. While the 660 nm as-deposited films were in the cubic phase, as indicated by X-ray diffraction and Raman spectroscopy measurements, the 140 nm asdeposited films were amorphous and the transformation to cubic phase was obtained after thermal annealing. Extended X-ray absorption fine structure measurements revealed the existence of Oxygen vacancies in the local structure surrounding Zirconium for all films. However, the amount of these Oxygen vacancies was found to be significantly higher for the amorphous films as compared to the films in the cubic phase (both 660 nm as-deposited and 140 nm annealed films).The cubic phase stabilization is explained on the basis of suppression of the soft X2mode of vibration of the Oxygen sub-lattice due to the presence of the Oxygen vacancies. Our firstprinciples modeling under the framework of density functional theory shows that the cubic structure with Oxygen vacancies is indeed more stable at ambient conditions than its pristine (without vacancies) counterpart. The requirement of a critical amount of these vacancies for the stabilization of the cubic phase is also discussed.

General synthesis strategy of ZrO2 nanofilms with few-atom layered thickness for boosting triethylamine detection

“…2b) of ZrO 2 NFs shows that the prepared sample is completely corresponding to the ICDD PDF card (PDF #49-1642), and the (111) plane is the preferential exposure surface. 14 Furthermore, the HRTEM image (Fig. 2c) shows that ZrO 2 NFs have good crystallinity, and (111) crystal faces can be identified based on the lattice stripe spacing of 0.296 nm, which verifies the results of XRD analysis.…”

Adsorption prospects of ultrafine, cubic 8 mol.% Y2O3‐stabilized ZrO2 nanoparticles

“…34,35 Oxygen vacancies for any particular doped-zirconia system generally follow the trend: cubic > tetragonal > monoclinic. 24,34,36 This argument can also be conclusively shown using Kröger-Vink notations for YSZ systems, 34,37,38 where the defect equations may be written as follows:…”

Mechanical and Magnetic Properties of Double Layered Nanostructures of Tin and Zirconium Oxides Grown by Atomic Layer Deposition

“…The latter inevitably accompanies the nanocrystalline nature of the thin solid structures and concurrent stabilization of metastable polymorphs. The role of vacancies as likely the main factor affecting the surface energies and inducing stabilization of metastable polymorphs in nanocrystalline ZrO 2 has earlier been studied and is a widely recognized phenomenon [36][37][38][39][40]. Magnetic properties may, in a somewhat similar manner, appear and become measurable in SnO 2 based oxide films.…”