AVS 52nd International Symposium
    Surface Science Tuesday Sessions
       Session SS2-TuM

Paper SS2-TuM5
Surface Reconstruction Variations on Barium Titanate (100)

Tuesday, November 1, 2005, 9:40 am, Room 203

Session: Defects on Oxide Surfaces
Presenter: R. Shao, University of Pennsylvania
Authors: R. Shao, University of Pennsylvania
D. Bonnell, University of Pennsylvania
Correspondent: Click to Email
BaTiO@sub 3@, is a prototype ferroelectric compound and a simple model for interactions in complex oxides. Recently the effect of ferroelectric dipoles on interactions of surfaces has been examined as it relates to domain specific chemical reactivity. Scanning probe microscopy is the obvious probe of local surface reactions; however, it has proven difficult to obtain reproducible atomically smooth surfaces because of its tendency toward non stoichiometry and carbonate formation. In this work, we have determined the sequence of high temperature annealing in oxidizing and reducing atmospheres with which BaTiO@sub 3@ (100) surfaces can be produced with unit cell (0.4 nm) and half unit cell (0.2) step heights. These steps correspond to different lattice plane terminations. Atomic resolution STM is used in conjunction with LEED/AES and Scanning Surface Potentiometry (Kelvin Probe Microscopy) to compare the geometric and electronic structures that occur on these surfaces as a function of thermal history. Differences in electronic structure determined from tunneling spectroscopy are compared to theoretical predictions.