Evidence of induced structural and conduction anisotropy in scandia‐stabilized zirconia ceramics

Abstract

Evidence of current induced structural and conduction anisotropy was experimentally established in scandia‐stabilized zirconia ceramics. It was found that these effects are observed only when the material is in the rhombohedral phase. It was shown using conductivity measurements and X‐ray phase analysis that anisotropic behavior of polycrystalline ZrO2‐Sc2O3 ceramics is induced by a low‐amplitude alternating current in the temperature range corresponding to a rhombohedral‐to‐cubic phase transition.

Understanding the High Ionic Conductivity in Nanostructured Ytterbium Stabilized Zirconia Thin Films

“…The cubic phase is the most stable one and it is usually assumed to be present in the XRD pattern. But other phases have been reported in nanometric zirconia thin films or for low dopant concentrations [15,[19][20][21][22]. The solid solution is substitutional where the Yb 3+ ions occupy the Zr 4+ ion sites, creating oxygen vacancies (inset of Figure 1).…”

Conduction anisotropy in the Laplace pressure‐induced rhombohedral phase of ScSZ ceramics

“…Previously [10] we had established experimentally that both magnitudes of ionic conductivity values and appearance of curves in Arrhenius coordinates remain the same within measurement error after storage of specimens during 10 days at room temperature. However induced anisotropy completely disappeared after storage during one year or more.…”

“…Specific feature of observed hysteresis in the finegrained material is its diffusivity within the temperature range, value of hysteresis achieves about 144 K. It can be concluded from comparing our results of present and previous study [9] for ceramics 89 mol.% ZrO 2 + 10 mol.% Sc 2 O 3 + 0.01 mol.% CeO 2 that the indicated hysteresis loop in the fine-grained material spans both the hightemperature interval of conversion of the material from rhombohedral phase to cubic (750÷900 K) and the lowtemperature interval of mutual ordering of grains occurring in rhombohedral phase (600÷630 K). We assume that such It was earlier mentioned [10] that the rhombohedral phase in scandia-stabilized zirconia at Sc 2 O 3 concentrations above 9.3 mol. % inherits anisotropic properties of Sc-OSc clusters during formation.…”