Effect of gaseous atmosphere on the chemical reactions and polymorphic inversions in the system zirconia-ceria

Structural Properties and Thermal Stability of Ceria-Zirconia and Related Materials

“…The existence of the former compound, however, has not been confirmed [7,8]. Finally, in the discussion of the features of the Ce0 2 -Zr0 2 phase diagrams, it must be considered that upon reduction of the Ce0 2 -Zr0 2 mixed oxides a still different situation is observed [4] and the presence of different phases was inferred. For example, Otsuka-YaoMatsuo et al suggested that under reducing conditions at high temperatures (> 1273 K), the pyrocholore Ce 2 Zr 2 0 7 may originate [39].…”

“…As for the Ce0 2 -Zr0 2 is concerned, presence of three Ce0 2 -Zr0 2 phases is also observed at RT (Fig.6.2.). Despite the intense work on the definition of this phase diagram [1][2][3][4][5][6][7][8][9][10][11][12][13][14], its exact appearance is often matter of discussion. We adopt the phase classification suggested by Yashima et al [22][23][24], which further distinguishes the tetragonal phases into t, f and t" phases, according to the type of the tetragonal distortion and its nature, i.e.…”

Phases in Ce0.5Zr0.5O2−x system

“…In Leonov's report, the oxide with composition of 50 mol% of Ce 2 O 3 and 50 mol% of ZrO 2 has pyrochlore structure, but they did not mention what will happy while it is oxidized. The formation of -phase [5].…”

“…Leonov et al [4,5] indicated that if the Ce 4+ cations are reduced to the Ce 3+ state, the system ZrO 2 -CeO 2 should transfer into the system ZrO 2 -Ce 2 O 3 . However, these two systems have completely different phase diagrams as shown in Fig.…”

Phase assembly and microstructure of CeO2-doped ZrO2 ceramics prepared by spark plasma sintering

“…The influence of different atmospheres on the phase relation of solid solutions in the Zr-Ce-O system has been investigated by Leonov et al 17,18 They reported that Ce 4+ in solid solution of ZrO 2 was reduced to Ce 3+ at increased temperatures in reducing atmospheres and in vacuum of 10 −1 to 10 −2 Pa. In the present work, the starting powder was prepared by mixing of monoclinic ZrO 2 and pure CeO 2 powder.…”