Finding the proton classical spectra for KTaO3 and SrZrO3

PHYS 431

Nana Dufie A. Addo, ndaaddo@mtholyoke.edu, Saryu Jindal, sjindal@mtholyoke.edu, and Debbie Valentin, dvalenti@mtholyoke.edu. Department of Chemistry, Mount Holyoke College, 3159 Blanchard Student Ctr, South Hadley, MA 01075
The rate-determining step of proton conduction has been the subject of many debates. The two possible modes of proton conduction being rotation and transfer, IR spectra have suggested rotation to be the rate-determining step while recent molecular dynamics calculations, Muon diffusion and quasielastic thermal neutron scattering experiments suggest transfer. Additionally, the IR spectral interpretation is unclear. Our research objective is to investigate whether the level of theory that supports transfer as the rate-determining step can yield the experimentally observed IR spectra. Density Functional Theory calculations reveal slight octahedral tilting in SrZrO3 compared to KTaO3. This tilting leads to a greater variety in proton binding sites. Molecular dynamics simulations are started from these proton binding minima. Position auto-correlation functions and their Fourier transforms are calculated from OH displacements and used to assign spectral features to specific OH vibrations. Theoretical and experimental spectra of the O-H stretch are compared.
 

Physical Chemistry Posters
7:30 PM-10:00 PM, Wednesday, 16 March 2005 Convention Center -- Hall D, Poster

Division of Physical Chemistry

The 229th ACS National Meeting, in San Diego, CA, March 13-17, 2005