High-Temperature Protonic Conduction in LaP[sub 3]O[sub 9]

A novel proton-conducting material based on was developed and its electrical conduction properties were investigated by measuring conductivities under 0.4-5 kPa of and 0.01-100 kPa of at 573-973 K. conducted protons dominantly by partial substitution of Sr for La. Conductivities of the 1 mol % Sr-doped were to S cm−1 at 573-973 K, and were relatively higher than those of other proton-conducting rare earth phosphates such as and Conductivities of the Sr-doped were almost independent of suggesting dominant protonic conduction even under low conditions.