Yang, Jin-Hoon Kim, Byung-Kook Kim, Yeong-Cheol 2024-01-20T06:01:18Z 2024-01-20T06:01:18Z 2022-01-10 2015-10-15 0167-2738 https://pubs.kist.re.kr/handle/201004/124883 We theoretically investigate proton conductivity at the Sigma 3 (111)/[1 (1) over bar0] tilt grain boundary of barium zirconate using density functional theory. In order to evaluate the space charge layer model and the structural disorder model, segregation energies of a +1-charged proton and a +2-charged oxygen vacancy, as well as energy barriers for proton migration, are calculated. The effect of the proton concentration on its segregation is verified and it is found that the segregation energy decreases with increases in the concentration. With consideration of this effect, the segregation energies of the proton and oxygen vacancy are in the range of -0.35 to -0.60 and -0.57 to -0.65 eV, respectively. Based on the segregation energies, an electrostatic potential of 0.51 Vat 600 K is obtained through numerically solving Poisson's equation. An energy barrier range of 0.71-0.95 eV is required for the proton to migrate across the grain boundary core. The proton concentration and mobility that are obtained from the electrostatic potential and energy barrier are used to calculate the proton conductivities in the bulk and at the grain boundary. The calculated proton conductivities are consistent with the experimentally measured proton conductivities in the bulk and at the grain boundaries of barium zirconate. (C) 2015 Elsevier B.V. All rights reserved. English ELSEVIER SCIENCE BV TOTAL-ENERGY CALCULATIONS AUGMENTED-WAVE METHOD SPACE-CHARGE BASIS-SET BAZRO3 CONDUCTORS DISTRIBUTIONS DIFFUSION DEFECT Calculation of proton conductivity at the Sigma 3(111)/[1(1)over-bar0] tilt grain boundary of barium zirconate using density functional theory Article 10.1016/j.ssi.2015.07.018 1 SOLID STATE IONICS, v.279, pp.60 - 65 SOLID STATE IONICS 279 60 65 scie scopus 000378101000010 2-s2.0-84939181898 Chemistry, Physical Physics, Condensed Matter Chemistry Physics Article TOTAL-ENERGY CALCULATIONS AUGMENTED-WAVE METHOD SPACE-CHARGE BASIS-SET BAZRO3 CONDUCTORS DISTRIBUTIONS DIFFUSION DEFECT Barium zirconate Grain boundary Proton conductivity Density functional theory Space charge layer Structural disorder