Characterization of Diffuse Scattering in Yttria-Stabilized Zirconia by Electron Diffraction and High-Resolution Transmission Electron Microscopy

Abstract

Different phases from the ZrO 2 -Y 2 O 3 system corresponding to 8, 10, 14, 21, 32, and 37 mol % Y 2 O 3 , prepared by quenching from high temperature, have been studied by selected area electron diffraction (SAED) and high-resolution electron microscopy (HRTEM). The results of the 8 and 10 mol% Y 2 O 3 are consistent with a crystal microstructure of three kind of domains of the t or t′ phase with the c axes oriented along three mutually perpendicular directions and small displacements of the cations (Zr and Y) from their ideal crystallographic positions. The materials with higher dopant concentration show a modulated fluorite-type structure due to partial or short-range ordering of the oxygen vacancies related to a pyrochlore-type and/or C-type crystal structures.

Oxygen ion diffusivity in strained yttria stabilized zirconia: where is the fastest strain?

“…36,38 More recent experimental work using selected area diffraction also indicated a random distribution of oxygen vacancies, maximizing the distance between them, in up to 10% yttria doped YSZ. 42 Consistent with the findings of Bogicevic and Wolverton, theoretical results by Predith et al 43 suggest even the existence of the ordering of the dopant cations (Y) in YSZ at high doping concentrations, and this cation ordering could exist locally in YSZ at the lower Y concentration range. Among these three types of defect-defect interactions, the vacancy-vacancy interaction is the strongest followed by the vacancy-cation interaction, and the cation-cation interaction is the weakest of the three.…”

Crystal Structure and Electrical Properties of Magnesia Co-Doped Scandia Stabilized Zirconia

“…Besides, reflections at G F ±(110)*, G F ±(001)*, and G F ±(021)* arise by a double diffraction effect. These extra lattice reflections are well observed in the SAED patterns of YSZ with yttria content of 8 mol% (8YSZ), indicating the formation of domains of t or t' phase in the average cubic crystals21 .Figure 5 also shows a HRTEM image and the corresponding FFT of a crystal with composition (ZrO 2 ) 0.89 (Sc 2 O 3 ) 0.08 (MgO) 0.03 along the -110 zone axis. The contrast differences of the image are characteristic of fluorite structure and the FFT does not show superlattice reflections.…”

Effect of Thermal Aging on the Phase Stability of 1Yb2O3–xSc2O3–(99 – x)ZrO2 (x = 7, 8 mol %)

“…Further, the diffuse scattering around the principal reflections, which is found to be lower in the aged 1Yb8ScSZ sample, arises from the partial or short-range ordering of oxygen-ion vacancies to further lower the anisotropy of the lattice distortion. 36,41 3.3.3. Raman Spectroscopy Analysis.…”