Annealing induced structural alternations in yttria partially stabilized zirconia

Abstract

Annealing-induced microstructural changes in yttria partially stabilized zirconia (YSZ) have been investigated by scanning transmission electron microscopy combined with computer simulation. It is shown that the high-temperature annealing results in the formation of voids in YSZ and structural ordering in the surrounding area of the voids. Atomic-scale Z-contrast imaging shows one-dimensional distortion of the cation sub-lattice by alternate arrangement of narrow and wide (100) planes of the cation sub-lattice along the [100] direction of the cubic ZrO2 structure. Such distortion of the cation sub-lattice is attributed to the 1/4[001] displacement of the oxygen atoms in the (100) plane, which is confirmed experimentally by annual bright field imaging along with the density-functional theory and computer simulations of the atomic-scale Z-contrast imaging and electron diffraction.