Theoretical modeling of defect segregation and space-charge formation in the BaZrO3 (210) 001 tilt grain boundary
Journal article, 2013
Density-functional theory (DFT) has been used to determine the structure and interface energy of different rigid body translations (RBTs) of the (210)10011 grain boundary (GB) in BaZrO3. There exist several different stable structures with almost equally low interfacial energy. Segregation energies of protons and oxygen vacancies have been determined for the most stable (210)10011 grain boundary structure. The results suggest that both defect species favor segregation to the same site at the boundary interface with minimum segregation energies of - 1.45 eV and - 1.32 eV for vacancies and protons respectively. The segregation energies have been used in a thermodynamic space-charge model to obtain equilibrium defect concentrations and space-charge potentials at a 10% dopant concentration. Space-charge,potential barriers around 0.65 V were obtained at intermediate temperatures under hydrated conditions, where protons are the main contributor to the excess core charge. The potential is slightly lower under dry conditions. (C) 2013 Elsevier B.V. All rights reserved.
BASIS-SET
PROTON-CONDUCTING
INITIO MOLECULAR-DYNAMICS
BAZRO3
STABILITY
CHEMISTRY
TOTAL-ENERGY CALCULATIONS
AUGMENTED-WAVE METHOD
Grain boundary
Defect segregation
Space-charge model
OXIDES
METALS
Density-functional theory
BaZrO3
Author
Anders Lindman
Chalmers, Applied Physics, Materials and Surface Theory
Edit Ahlberg Helgee
Chalmers, Applied Physics, Materials and Surface Theory
Göran Wahnström
Chalmers, Applied Physics, Materials and Surface Theory
Solid State Ionics
0167-2738 (ISSN)
Vol. 252 121-125Driving Forces
Sustainable development
Subject Categories
Physical Sciences
Areas of Advance
Energy
Materials Science
Infrastructure
C3SE (Chalmers Centre for Computational Science and Engineering)
DOI
10.1016/j.ssi.2013.04.008