PROTON SITES AND DEFECT-INTERACTIONS IN SRZRO3 SINGLE-CRYSTALS STUDIED BY INFRARED-ABSORPTION SPECTROSCOPY

Infrared (IR) absorption spectra of OH-stretching mode have been studi ed in single samples of the protonic conductor, SrZrO3:M(3+) (M(3+) = SC3+, Y3+, Yb3+, Er3+). Four absorption bands, which correspond to fou r different sites of protons, are observed in IR spectra. Proton dynam ics in these sites are studied by the annealing time dependence of IR spectra, which are quenched from high temperature. We have found that the relative population of protons among different sites changes as th e proton concentration changes the crystal. This result indicates that the trapping energy for protons is different among these sites.