TY - JOUR
T1 - Melting of Oxygen Vacancy Order at Oxide-Heterostructure Interface
AU - Hirai, Kei
AU - Aso, Ryotaro
AU - Ozaki, Yusuke
AU - Kan, Daisuke
AU - Haruta, Mitsutaka
AU - Ichikawa, Noriya
AU - Kurata, Hiroki
AU - Shimakawa, Yuichi
N1 - Funding Information:
*E-mail: shimak@scl.kyoto-u.ac.jp. ORCID Ryotaro Aso: 0000-0002-1599-2300 Yuichi Shimakawa: 0000-0003-1019-2512 Present Address §The Institute of Scientific and Industrial Research, Osaka University, Osaka 567-0047, Japan (R.A.). Author Contributions K.H., D.K., N.I., and Y.S. conceived and designed the study. K.H., Y.O., N.I., and D.K. fabricated the sample and measured the physical properties. R.A., M.H., and H.K. performed the STEM observation and EELS spectroscopy experiments. All of the authors contributed to the interpretation and discussion of the experimental results. K.H., R.A., M.H., D.K., H.K., and Y.S. wrote the manuscript. Funding This work was partially supported by Grants-in-Aid for Scientific Research (Grant Nos. 15K13670, 16H02266, 16K13665, and 17K19177) and by a grant for the Integrated Research Consortium on Chemical Sciences from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan. The work was also supported by the Japan Society for the Promotion of Science (JSPS) Core-to-Core Program (A) Advanced Research Networks and the Japan Science and Technology Agency (JST) CREST program. Support was also provided by the Nippon Sheet Glass Foundation for Materials Science and Engineering, and the Sumitomo Foundation.
Publisher Copyright:
© 2017 American Chemical Society.
PY - 2017/9/6
Y1 - 2017/9/6
N2 - Modifications in oxygen coordination environments in heterostructures consisting of dissimilar oxides often emerge and lead to unusual properties of the constituent materials. Although lots of attention has been paid to slight modifications in the rigid oxygen octahedra of perovskite-based heterointerfaces, revealing the modification behaviors of the oxygen coordination environments in the heterostructures containing oxides with oxygen vacancies have been challenging. Here, we show that a significant modification in the oxygen coordination environments - melting of oxygen vacancy order - is induced at the heterointerface between SrFeO2.5 (SFO) and DyScO3 (DSO). When an oxygen-deficient perovskite (brownmillerite structure) SrFeO2.5 film grows epitaxially on a perovskite DyScO3 substrate, both FeO6 octahedra and FeO4 tetrahedra in the (101)-oriented SrFeO2.5 thin film connect to ScO6 octahedra in DyScO3. As a consequence of accommodating a structural mismatch, the alternately ordered arrangement of oxygen vacancies is significantly disturbed and reconstructed in the 2 nm thick heterointerface region. The stabilized heterointerface structure consists of Fe3+ octahedra with an oxygen vacancy disorder. The melting of the oxygen vacancy order, which in bulk SrFeO2.5 occurs at 1103 K, is induced at the present heterointerface at ambient temperatures.
AB - Modifications in oxygen coordination environments in heterostructures consisting of dissimilar oxides often emerge and lead to unusual properties of the constituent materials. Although lots of attention has been paid to slight modifications in the rigid oxygen octahedra of perovskite-based heterointerfaces, revealing the modification behaviors of the oxygen coordination environments in the heterostructures containing oxides with oxygen vacancies have been challenging. Here, we show that a significant modification in the oxygen coordination environments - melting of oxygen vacancy order - is induced at the heterointerface between SrFeO2.5 (SFO) and DyScO3 (DSO). When an oxygen-deficient perovskite (brownmillerite structure) SrFeO2.5 film grows epitaxially on a perovskite DyScO3 substrate, both FeO6 octahedra and FeO4 tetrahedra in the (101)-oriented SrFeO2.5 thin film connect to ScO6 octahedra in DyScO3. As a consequence of accommodating a structural mismatch, the alternately ordered arrangement of oxygen vacancies is significantly disturbed and reconstructed in the 2 nm thick heterointerface region. The stabilized heterointerface structure consists of Fe3+ octahedra with an oxygen vacancy disorder. The melting of the oxygen vacancy order, which in bulk SrFeO2.5 occurs at 1103 K, is induced at the present heterointerface at ambient temperatures.
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U2 - 10.1021/acsami.7b08134
DO - 10.1021/acsami.7b08134
M3 - Article
C2 - 28791864
AN - SCOPUS:85028932567
VL - 9
SP - 30143
EP - 30148
JO - ACS applied materials & interfaces
JF - ACS applied materials & interfaces
SN - 1944-8244
IS - 35
ER -