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Ito, Takanori*; Shirasaki, Saori*; Fujie, Yoshinori*; Kitamura, Naoto*; Idemoto, Yasushi*; Osaka, Keiichi*; Hirosawa, Ichiro*; Igawa, Naoki
Denki Kagaku Oyobi Kogyo Butsuri Kagaku, 77(2), p.161 - 168, 2009/02
Times Cited Count:3 Percentile:8.20(Electrochemistry)We analyzed the mechanism of mixed conduction due to electrons and oxygen ions in (LaSr
)MnO
and (Ba
Sr
)(Co
Fe
)O
through the Rietveld refinement and maximum entropy method analyses of neutron and synchrotron X-ray diffractions. It was found that Mn-O plane in (La
Sr
)MnO
has a strong, isotropic covalent bond that enables conduction of electrons. The (Co, Fe)-O2 plane with a covalent bond and a low concentration of oxygen vacancies in (Ba
Sr
)(Co
Fe
)O
can also conduct electrons. On the other hand, the (Ba, Sr)-O1 plane in (Ba
Sr
)(Co
Fe
)O
, which has a high concentration of oxygen vacancies, large isotropic displacement parameter, and a strong ionic bond, is responsible for the diffusion of oxygen ions.
Ito, Takanori*; Nishida, Yuki*; Tomita, Aya*; Fujie, Yoshinori*; Kitamura, Naoto*; Idemoto, Yasushi*; Osaka, Keiichi*; Hirosawa, Ichiro*; Igawa, Naoki
Solid State Communications, 149(1-2), p.41 - 44, 2009/01
Times Cited Count:36 Percentile:77.47(Physics, Condensed Matter)The crystal structure and charge density of (BaSr
)(Co
Fe
)O
were investigated by the Rietveld refinement method and the maximum entropy method by using neutron and synchrotron X-ray diffraction. The crystal structure was refined by using the split atom model to cation sites with the space group,
. The site occupancies of O1(4
) and O2(8
) sites were 0.59 and 0.87, respectively. It was found that the (Co, Fe)-O2 plane in the sample has anisotropic covalent and ionic bands, and that the (Ba, Sr)-O1 bond was ionic with a low charge density.