Abstract: A solid composition provides high oxygen ion conductivity, and includes a metal oxide combined with multiple dopants. The oxide may, for example, include zirconia, bismuth trioxide, thoria or hafnia. The dopants are chosen such that they are of similar ionic radius to the oxide, but such that they generally have different valences. For example, zirconium has a +4 valence, while dopants are usually chosen which have +2 or +3 valences. Possible dopants include materials such as magnesia, yttria, and oxides of calcium, barium, strontium, lanthanum, ytterbium, and scandium. It has been found that choosing the dopants such that they exist in the composition at specified ratios results in surprising ability to transport oxygen ions. In the case of a composition which includes magnesia and yttria dopants placed within a zirconia matrix, it has been found desirable to maintain the ratio of the mole percentages of the magnesia to the yttria in the range of from about 5.75:10 to about 11:10.

Abstract: A solid composition provides high oxygen ion conductivity, and includes a metal oxide combined with multiple dopants. The oxide may, for example, include zirconia, bismuth trioxide, thoria or halfnia. The dopants are chosen such that they are of similar ionic radius to the oxide, but such that they generally have different valences. For example, zirconium has a +4 valence, while dopants are usually chosen which have +2 or +3 valences. Possible dopants include materials such as magnesia, yttria, and oxides of calcium, barium, strontium, lanthanum, and scandium. It has been found that choosing the dopants such that they exist in the composition at specified ratios results in surprising ability to transport oxygen ions. In the case of a composition which includes magnesia and yttria dopants placed within a zirconia matrix, it has been found desirable to maintain the ratio of the mole percentages of the magnesia to the yttria in the range of from about 6.5:10 to about 9.5:10.