| abstract |
(57) [Summary] (with correction) [PROBLEMS] To provide a high oxide ion conductive ceria-based solid electrolyte exhibiting stable conductive properties even for various gases. A composition formula: (La 1-x M x ) y Ce 1-y O 2-z (where M is one or two elements of Sr or Ba. X and y are 0.1 ≦ x ≦ 0.5, 0.1 <y < 0.2 and 0.05 <z <0.15. ), The average ionic radius of all cations is Rc, the average ionic radius of cations other than Ce is Rd, the ionic radius of Ce is R ce , and the ionic radius of oxygen is R If o is set, Effective Index = (R d / R ce ) * (Rc / Ro) is 0.925 <Effectiv A high oxide ion conductive ceria-based solid electrolyte having an e Index <1.20. |