Phase stability and conductivity in the pseudo ternary system of xYb2O3-(12-x)Sc2O3-88ZrO2 (0 ≤ x ≤ 5)

Long-Term Conductivity Stability of Metastable Tetragonal Phases in 1Yb2O3–xSc2O3–(99 – x)ZrO2 (x = 7, 8 mol %)

“…On forming tripoles, a relatively less number of mobile oxygen vacancies is available for diffusion, resulting in the deterioration of conductivity. The addition of the Yb 3+ codopant disturbs this short-range ordering process and lowers the conductivity degradation . The combined effect of the increased extent of tetragonality caused by the oxygen-ion shuffling inside the unit cell and the formation of neutral and stable defect associates impeding the flow of oxygen ions could be the possible reasons for the rise in grain resistivity on thermal aging.…”

“…The addition of the Yb 3+ codopant disturbs this short-range ordering process and lowers the conductivity degradation. 39 The combined effect of the increased extent of tetragonality caused by the oxygen-ion shuffling inside the unit cell and the formation of neutral and stable defect associates impeding the flow of oxygen ions could be the possible reasons for the rise in grain resistivity on thermal aging. On comparing the σ gb of 8ScSZ and 1Yb7ScSZ samples before and after aging, substantial conductivity losses of ∼32 and ∼14% are estimated at 475 °C, respectively.…”

“…Finally, the correlations between the microstructure and conductivity will be established in both the unaged and aged samples. It is important to note that our earlier reported work though focused on Yb 2 O 3 codoping in Sc 2 O 3 –ZrO 2 , the total doping concentration was fixed at 12 mol %. , In this high doping region, only cubic and rhombohedral phases are reported to exist in ScSZ. The present work studies the effect of Yb 2 O 3 codoping on the metastable tetragonal phases ( t ′ and t ″), which were found to exist in 8–9 mol % Sc 2 O 3 –ZrO 2 .…”

Skull Melting Growth and Characterization of (ZrO2)0.89(Sc2O3)0.1(CeO2)0.01 Crystals

“…Earlier data [1][2][3] showed that the formation of the rhombohedral phase in the ZrO 2 -Sc 2 O 3 system solid solutions occurs by ordering of the oxygen vacancies. However, there are indications of cubic phase stabilization in ZrO 2 ceramics containing 12 mol.% of Sc 2 O 3 [4,5]. The formation of the rhombohedral phase in these specimens was attributed to a homogeneous distribution of the Sc 3+ cations in the ZrO 2 matrix, which is achieved due to a low heating rate (~2 • C/min) during solid state synthesis and the presence of a small quantity of impurities [5].…”

“…However, there are indications of cubic phase stabilization in ZrO 2 ceramics containing 12 mol.% of Sc 2 O 3 [4,5]. The formation of the rhombohedral phase in these specimens was attributed to a homogeneous distribution of the Sc 3+ cations in the ZrO 2 matrix, which is achieved due to a low heating rate (~2 • C/min) during solid state synthesis and the presence of a small quantity of impurities [5]. This may destroy the long-range order of the oxygen vacancies and favor the stabilization of the cubic c-phase.…”