Stabilization Mechanisms of LaFeO3 (010) Surfaces Determined with First Principles Calculations
Abstract:Density functional theory is used to determine the stabilization mechanisms of LaFeO3 (010) surfaces over a range of surface oxygen stoichiometries. For the stoichiometric LaO surface, and for reduced surface terminations, an electron-rich surface is needed for stabilization. By contrast, in the case of the stoichiometric FeO2 surface and oxidized surface terminations with low-coordinated oxygen atoms, a hole-rich surface is needed for stabilization. The calculations further predict that low coordinated oxygen atoms are more stable on LaO-type surface terminations than on FeO2-type surface terminations due to relatively strong electron transfer. In addition to these electronic effects, atomic relaxation is found to be an important contributor to charge compensation, with LaO-type surface terminations exhibiting larger atomic relaxations than FeO2-type surface terminations. As a result, there is a significant contribution from the sublayers to charge compensation in LaO-type surface terminations.
Document Type: Research Article
Affiliations: 1: Department of Materials Science and Engineering, University of Florida, Gainesville, FLorida 32611-6400 2: Oak Ridge National Laboratory, Materials Science & Technology Division, Oak Ridge, Tennessee 37831-6071 3: Pacific Northwest National Laboratory, Chemical and Materials Sciences Division, Richland, Washington 99352
Publication date: June 1, 2011