Monitoring of water dissolution into high temperature protonic conductors

Water dissolution into a doped strontium cerate ceramics was monitored with Raman spectroscopy. Since a Raman band at 630 cm− 1 is observed when the ceramics possess oxygen vacancies, and a relative intensity of the band to that of the main band at 345 cm− 1 (I630/I345) is proportional to its oxygen vacancy concentration, the parameter I630/I345 was examined for the understanding of water dissolution behavior into the lattice. The parameter for quenched samples after annealing decreased gradually with an increase in water vapor partial pressure, P(H2O) during annealing due to water dissolution, resulting in disappearance of some oxygen vacancies. An in situ monitoring of water dissolution into this ceramics was also performed employing an atmosphere-controlled system.