| 摘要 |
PROBLEM TO BE SOLVED: To provide electrolyte whose ion conductivity is remarkably improved more than conventional one and which shows output density in a stable condition for many hours when it is used in a cell material for a fuel cell by setting an effective index to a value of a specific range in a fluorite type ceria system compound expressed by a specific composition formula. SOLUTION: In a fluorite type ceria system compound expressed by a composition formula (Mx Cei-x )O2-y , when an average ion radius of a cation to constitute the fluorite type ceria system compound is denoted by RC and an average ion radius of a dopant M is denoted by RM and an ion radius of cerium is denoted by Rce and an ion radius of oxygen is denoted by Ro , defective fluorite type ceria system solid electrolyte, on which an effective index E.F. defined by a general equation [E.F.=(Rc /Ro )*(RM/Rce )] is (0.875<E.F.<1.05), is formed. |
