Defects clustering and ordering in di- and trivalently doped ceria

Sr2(Mg1−Ga )Ge2O7+0.5: Melilite-type oxygen ionic conductor associated with fivefold coordinated germanium and gallium

“…S3(a)). Furthermore, the oxygen ordering and clustering with Ga 3þ ions at high concentrations cannot be excluded as one of the reasons for the decrease of ionic conductivity [17,18]. The temperature dependence of the conductivity computed from the bulk resistance in Sr 2 Mg 0.8 Ga 0.2 Ge 2 O 7.1 is shown in Fig.…”

Thermal stability of nano Ce1−xTixO2 material system for X < 0.2

“…In addition, surface Ti 4+ concentration was found to be higher than in the bulk concentration, pointing to solute segregation. 46,47,[58][59][60][61] Even so, while TiO 2 addition to CeO 2 inhibits coarsening, relative to pure CeO 2 , the effect is not injective. Segregation was followed by precipitation of anatase, generally occurring above 700°C.…”

“…Generally, in ceramic materials, and specifically in oxides, the addition of dopant elements results in coarsening inhibition due to salute drag, as is the case here. 46,47,[58][59][60][61] Even so, while TiO 2 addition to CeO 2 inhibits coarsening, relative to pure CeO 2 , the effect is not injective. In other words, an increase in TiO 2 concentration does not further slow the coarsening rate.…”

Study of Oxygen Vacancy Diffusion in Yttria-doped Ceria and Yttria-stabilized Zirconia by Statistical Moment Method

“…The associations between the oxygen vacancies and Y 3+ ions form the charged defect clusters or electrically neutral clusters [19]. In these clusters, the oxygen vacancies tend to occupy either the first nearest neighbor sites (1NN) or the second nearest neighbor sites (2NN) to Y 3+ ions.…”

“…The vacancy-dopant association energy in doped ceria and zirconia was calculated by atomistic simulation and/or MD methods [19,20]. The association energy between an oxygen vacancy V…”