The diffusivity of protons in Sr2+-doped LaScO3 single crystals was determined by means of in situ infra-red absorption spectroscopy (Figure 4). It was found that the high-temperature absorption spectrum exhibited a broad peak, due to O–H stretching bands, which differed from that observed at room temperature. The diffusion coefficient was evaluated using 2 different methods. That is, by suddenly changing the water-vapor partial pressure and by exchanging H2O and D2O-saturated atmospheres. The diffusivity and activation energy were limited mainly by the diffusivity of O-ion vacancies, based upon the first method, at high temperatures. The proton self-diffusion coefficients were obtained by using the second method, and the activation energy was 0.51eV.

Proton Diffusion in LaSrScO3 Single Crystals Studied by In situ Infrared Absorption Spectroscopy. J.Liu, H.Yugami: Solid State Ionics, 2007, 178[27-28], 1507-11