TY - JOUR
T1 - First-principles calculation on oxygen ion migration in alkaline-earth doped La2GeO5
AU - Linh, Tran Phan Thuy
AU - Sakaue, Mamoru
AU - Aspera, Susan Meñez
AU - Alaydrus, Musa
AU - Wungu, Triati Dewi Kencana
AU - Linh, Nguyen Hoang
AU - Kasai, Hideaki
AU - Mohri, Takahiro
AU - Ishihara, Tatsumi
N1 - Funding Information:
This work was supported in part by the JST (Japan Science and Technology Agency) through the ALCA (Advanced Low Carbon Technology Research and Development) Program ‘Development of Novel Metal–Air Secondary Battery Based on Fast Oxide Ion Conductor Nano Thickness Film’ and Strategic Japanese–Croatian Cooperative Program on Materials Science ‘Theoretical modeling and simulations of the structural, electronic and dynamical properties of surfaces and nanostructures in materials science research’. It was also supported in part by the MEXT (Ministry of Education, Culture, Sports, Science and Technology) through the G-COE (Special Coordination Funds for the Global Center of Excellence) program ‘Atomically Controlled Fabrication Technology’, Grant-in-Aid for Scientific Research on Innovative Areas Program (2203-22104008) and Scientific Research (A) (24246013) and (C) (22510107) programs. It was also supported in part by the Osaka University Joining and Welding Research Institute Cooperative Research Program. Some of the calculations presented here were performed using the computer facilities at the following institutes: the super computer centers of Institute of Solid State Physics (ISSP) of the University of Tokyo and Yukawa Institute for Theoretical Physics (YITP) of Kyoto University, High Energy Accelerator Research Organization (KEK) under support of its Large Scale Simulation Program (no. 12/13-10), Cyber-media center (CMC) of Osaka University and the National Institute for Fusion Science (NIFS). TPTL is grateful to the Ministry of Education and Training of Vietnam for the scholarship grant, and acknowledges the Faculty of Basic Science, Hue University of Agriculture and Forestry for giving her the opportunity to pursue her studies at Osaka University.
Publisher Copyright:
© 2014 IOP Publishing Ltd.
PY - 2014
Y1 - 2014
N2 - By using first-principles calculations based on the density functional theory, we investigated the doping effects of alkaline-earth metals (Ba, Sr and Ca) in monoclinic lanthanum germanate La2GeO5 on its oxygen ion conduction. Although the lattice parameters of the doped systems changed due to the ionic radii mismatch, the crystal structures remained monoclinic. The contribution of each atomic orbital to electronic densities of states was evaluated from the partial densities of states and partial charge densities. It was confirmed that the materials behaved as ionic crystals comprising of cations of La and dopants and anions of oxygen and covalently formed GeO4. The doping effect on the activation barrier for oxygen hopping to the most stable oxygen vacancy site was investigated by the climbing-image nudged elastic band method. By tracing the charge density change during the hopping, it was confirmed that the oxygen motion is governed by covalent interactions. The obtained activation barriers showed excellent quantitative agreements with an experiment for the Ca- And Sr-doped systems in low temperatures as well as the qualitative trend, including the Ba-doped system.
AB - By using first-principles calculations based on the density functional theory, we investigated the doping effects of alkaline-earth metals (Ba, Sr and Ca) in monoclinic lanthanum germanate La2GeO5 on its oxygen ion conduction. Although the lattice parameters of the doped systems changed due to the ionic radii mismatch, the crystal structures remained monoclinic. The contribution of each atomic orbital to electronic densities of states was evaluated from the partial densities of states and partial charge densities. It was confirmed that the materials behaved as ionic crystals comprising of cations of La and dopants and anions of oxygen and covalently formed GeO4. The doping effect on the activation barrier for oxygen hopping to the most stable oxygen vacancy site was investigated by the climbing-image nudged elastic band method. By tracing the charge density change during the hopping, it was confirmed that the oxygen motion is governed by covalent interactions. The obtained activation barriers showed excellent quantitative agreements with an experiment for the Ca- And Sr-doped systems in low temperatures as well as the qualitative trend, including the Ba-doped system.
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U2 - 10.1088/0953-8984/26/25/255503
DO - 10.1088/0953-8984/26/25/255503
M3 - Article
AN - SCOPUS:84984917587
VL - 26
JO - Journal of Physics Condensed Matter
JF - Journal of Physics Condensed Matter
SN - 0953-8984
IS - 25
M1 - 255503
ER -