title: The effect of dopant at the Zr site on the proton conduction pathways of SrZrO3: an orthorhombic perovskite.
abstract: Doping orthorhombic SrZrO(3) at 12.5% of the Zr sites with Al(3+) leads to a local squaring of the lattice, while doping with larger Y(3+) increases local octahedral distortions. Proton activation energy barriers and transition state theory prefactors are calculated. The wide range of intra-, inter-, and rotational barriers suggest that a comprehensive pathway analysis is needed to find the limiting conduction barriers. Simple seven to ten step periodic pathways leading to system wide conduction are enumerated using vertex coding. At 900-1300 K, the average limiting barriers to long range conduction are 0.6 and 0.4 eV in Al/SrZrO(3) and Y/SrZrO(3), respectively, in reasonable agreement with the experiment. Path analysis gives the added insight that conduction pathways in Al/SrZrO(3) avoid doped regions, while conduction pathways in Y/SrZrO(3) traverse them.
authors: Department of Chemistry, Mount Holyoke College, 50 College Street, South Hadley, Massachusetts 01075, USA. magomez@mtholyoke.edu
authors: Maria A
authors: MA
authors: Gomez
authors: Mythili
authors: M
authors: Chunduru
authors: Lorencia
authors: L
authors: Chigweshe
authors: Katharyn M
authors: KM
authors: Fletcher