Dynamics of the Perovskite-Based High-Temperature Proton-Conducting Oxides: Theory and Experiment

Abstract

ABSTRACTThe dynamics of the doped perovskite-based high-temperature protonie conductors (HTPC) were studied by means of neutron vibrational spectroscopy (NVS) and first-principles pseudopotential supercell calculations. Vibrational spectra from hydrogen-charged samples with different rare-earth dopants revealed three well-defined vibrational bands in the energy ranges 20–60, 60–90, and 100–140 meV. The two lowest-energy bands were insensitive to the dopants. First-principles phonon calculations indicate that they are mainly associated with oxygen modes. In contrast, the high-energy band was very sensitive to the dopant, and in this case, calculations indicate that it is associated with OH bending modes.