Fig. 3. Temperature evolution of the pseudo-cubic lattice parameters (A and B), the oxygen vacancy parameter δ (C and D) and mole fraction y of Ce3+ (E and F) of different phases formed during cooling of CeO2 (A, C and E) and SDC15 (B, D and F) specimens from 1273 K in H2 atmospheres. The oxygen vacancy parameter and mole fraction y of Ce3+ were calculated from the relationship between the amount of oxygen (i.e. 2–δ) in CeO2–δ and the pseudo-cubic lattice parameters a (termed “model 1”), as well as using eqn (2) (termed “model 2”).
