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Sr substitution effects on atomic and local electronic structure of Ca 2 AlMnO 5+δ
Author(s) -
Kunisada Yuji,
Saito Genki,
Hayami Kazuki,
Nomura Takahiro,
Sakaguchi Norihito
Publication year - 2019
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.6549
Subject(s) - ionic radius , chemistry , crystallography , electronic structure , ionic bonding , covalent bond , density functional theory , atomic radius , bond length , oxygen , crystal structure , ion , computational chemistry , organic chemistry
We performed the first‐principle calculations based on spin‐polarized density functional theory to investigate the Sr substitution effects on the atomic and local electronic structure of Ca 2 AlMnO 5+δ . The ionic radius of Sr 2+ is larger than that of Ca 2+ ; thus, the lattice expansion occurs with Sr substitution. From the total energy calculations, we found that Sr substitution makes the oxygen‐absorbed phase unstable and realizes the lower operation temperature. From the point of atomic structure, Sr substitution lengthens the bond length between Mn and O atoms connecting Mn and Al atoms in Al tetrahedral (O Mn‐Alt ) in oxygen‐absorbed phase, because the large Sr 2+ prevents the release of the Jahn‐Teller distortion. We also found that the covalent bonding between Mn and O Mn‐Alt atoms weaken with Sr substitution by the local electronic structure analysis, which results in the unstable oxygen‐absorbed phase and weak prepeak and main peak intensity near the onset of O‐K edge ELNES of O Mn‐Alt atoms.