| abstract |
This proton conductor includes a metal oxide that has a perovskite structure and is represented by formula (1): A x B 1-y M y O 3-δ , where: chemical element A is at least one selected from the group consisting of Ba, Ca, and Sr; the chemical element B is at least one selected from the group consisting of Ce and Zr; the chemical element M is at least one selected from the group consisting of Y, Yb, Er, Ho, Tm, Gd, In, and Sc; δ is an oxygen loss quantity; and the relationships 0.95 ≤ x ≤ 1 and 0 < y ≤ 0.5 are satisfied. |