Speaker: Andrew Rappe, University of Pennsylvania
Date & Time: January 24, 2008 - 12:00pm
Location: Chem 260
Ferroelectric Oxide Surfaces: Cutting Edge Chemistry
Laboratory for Surface Modification
Andrew Rappe, University of Pennsylvania
12:00 Noon, Chem 260
The surfaces of ferroelectric ABO oxides are charged due to the bulk material polarization, and this surface charge leads to exotic surface chemistry. In this talk, three illustrations of this effect will be presented. 1) In LiNbO3 the polar stacking of ionic layers combines with ferroelectricity to make the intrinsic surfaces nonstoichiometric. 2) With BaTiO3 flipping the ferroelectric polarization changes the sticking coefficient for incoming molecules. 3) For PbTiO3 supported Pt, the oxide polarization strongly affects chemisorption and reactivity on Pt. These examples underscore the message that surface chemistry can be dramatically influenced by tailoring the bulk ferroelectric properties of the support.