Among advanced materials for clean energy, non-stoichiometric BaxSr1-xCo1-yFeyO3-d (BSCF) and LaxSr1-xCo1-yFeyO3-d (LSCF) are considered as promising materials for cathodes in solid oxide fuel cells (SOFC) and oxygen permeation membranes [1,2]. Figure 1. <img src='https://acs-archive-assets2.s3.amazonaws.com/239nm/uploads/14440_scheme1.jpg' alt='' />To understand the mechanism(s) of this unwanted process, the first principles quantum mechanical calculations of BSCF and LSCF crystals with different non-stoichiometry were performed and possible decomposition scenarios were studied. It is shown [3] that formation energies of oxygen vacancies in the cubic and hexagonal phases of BSCF differ considerably and also behave in quite different ways depending on non-stoichiometry; in fact, it is the oxygen non-stoichiometry that makes the cubic phase more stable than the hexagonal phase.In comparison, LSCF is shown to be much more stable with respect to both the phase transformation and phase decomposition.This work is supported by the GIF research project # 1-1025-5-10/2009 and NSF.[1] L. Wang et al, J. Mater. Res. 27, 2000 (2012); M.M. Kuklja et al, Phys. Chem. Chem. Phys., 2013, 15, 5443-5471.[2] Yu.A. Mastrikov et al, Phys. Chem. Chem. Phys., 2013, 15 , 911--918[3] M.M. Kuklja et al, J Phys Chem C 116, 18605 (2012), Kotomin et al, Energy Conversion�Solid Oxide Fuel Cells: First-Principles Modeling of Elementary Processes in Computational Approaches to Energy Materials, Editors: C. Richard A. Catlow, Alexey A. Sokol and Aron Walsh, 2013 by John Wiley & Sons, Ltd., pp. 149-186.

First principles modeling of complex perovskites for energy applications

246th National Meeting (2013)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.