Computational Studies of the Structure and of the Proton Transport Phenomena in Systems Derived from Barium Cerate Perovskite Structure

The final task of the whole research project is the design of new ceramic materials for protonic conduction in the range of temperature 350-750 °C. To this aim, it was planned to deepen the information on the systems obtained by doping the Ce site in the BaCeO3 perovskite matrices. In these compounds, cerium has been substituted by trivalent elements (Y, In), thus creating – to fulfill charge neutrality – oxygen vacancies that could be filled by hydroxyls groups. In this way protons have been introduced in the structure. These materials are currently investigated by both experimental and computational approaches to integrate framework structure and proton transport phenomena analyses. Due to the characteristics of the studied materials, Hartree-Fock and DFT approaches have mainly been investigated. The computational methods and the choice of the models and protocols have been tuned according to the machines capabilities, balancing the reliability of the results against the computational time. Geometry calculations have been performed on framed (by hydrogen cut-off atoms) large-material-fragments and/or on small-material-fragments by mimicking experimental structures and proton transfer mechanisms.