Theoretical modeling of defect segregation and space-charge formation in the BaZrO3 (210) 001 tilt grain boundary
Artikel i vetenskaplig tidskrift, 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

Författare

Anders Lindman

Chalmers, Teknisk fysik, Material- och ytteori

Edit Ahlberg Helgee

Chalmers, Teknisk fysik, Material- och ytteori

Göran Wahnström

Chalmers, Teknisk fysik, Material- och ytteori

Solid State Ionics

0167-2738 (ISSN)

Vol. 252 121-125

Drivkrafter

Hållbar utveckling

Ämneskategorier

Fysik

Styrkeområden

Energi

Materialvetenskap

Infrastruktur

C3SE (Chalmers Centre for Computational Science and Engineering)

DOI

10.1016/j.ssi.2013.04.008