TY - JOUR
T1 - Strain Engineering for Anion Arrangement in Perovskite Oxynitrides
AU - Oka, Daichi
AU - Hirose, Yasushi
AU - Matsui, Fumihiko
AU - Kamisaka, Hideyuki
AU - Oguchi, Tamio
AU - Maejima, Naoyuki
AU - Nishikawa, Hiroaki
AU - Muro, Takayuki
AU - Hayashi, Kouichi
AU - Hasegawa, Tetsuya
N1 - Funding Information:
This study was supported by the Core Research for Evolutional Science and Technology (CREST) program of the Japan Science and Technology Agency (JST) and Grants-in-Aid for Scientific Research (nos. 15H01043 and 12J08258) from the Japan Society for the Promotion of Science (JSPS). Synchrotron radiation experiments were performed at SPring-8 with the approval of the Japan Synchrotron Radiation Research Institute (JASRI; proposal nos. 2013B1328, 2014A1437, and 2015B1338).
Publisher Copyright:
© 2017 American Chemical Society.
PY - 2017/4/25
Y1 - 2017/4/25
N2 - Mixed-anion perovskites such as oxynitrides, oxyfluorides, and oxyhydrides have flexibility in their anion arrangements, which potentially enables functional material design based on coordination chemistry. However, difficulty in the control of the anion arrangement has prevented the realization of this concept. In this study, we demonstrate strain engineering of the anion arrangement in epitaxial thin films of the Ca1-xSrxTaO2N perovskite oxynitrides. Under compressive epitaxial strain, the axial sites in TaO4N2 octahedra tend to be occupied by nitrogen rather than oxygen, which was revealed by N and O K-edge linearly polarized X-ray absorption near-edge structure (LP-XANES) and scanning transmission electron microscopy combined with electron energy loss spectroscopy. Furthermore, detailed analysis of the LP-XANES indicated that the high occupancy of nitrogen at the axial sites is due to the partial formation of a metastable trans-type anion configuration. These results are expected to serve as a guide for the material design of mixed-anion compounds based on their anion arrangements.
AB - Mixed-anion perovskites such as oxynitrides, oxyfluorides, and oxyhydrides have flexibility in their anion arrangements, which potentially enables functional material design based on coordination chemistry. However, difficulty in the control of the anion arrangement has prevented the realization of this concept. In this study, we demonstrate strain engineering of the anion arrangement in epitaxial thin films of the Ca1-xSrxTaO2N perovskite oxynitrides. Under compressive epitaxial strain, the axial sites in TaO4N2 octahedra tend to be occupied by nitrogen rather than oxygen, which was revealed by N and O K-edge linearly polarized X-ray absorption near-edge structure (LP-XANES) and scanning transmission electron microscopy combined with electron energy loss spectroscopy. Furthermore, detailed analysis of the LP-XANES indicated that the high occupancy of nitrogen at the axial sites is due to the partial formation of a metastable trans-type anion configuration. These results are expected to serve as a guide for the material design of mixed-anion compounds based on their anion arrangements.
KW - X-ray absorption near-edge structure
KW - coordination chemistry
KW - epitaxial thin film
KW - oxynitride
KW - perovskite
KW - strain engineering
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U2 - 10.1021/acsnano.7b00144
DO - 10.1021/acsnano.7b00144
M3 - Article
C2 - 28347140
AN - SCOPUS:85018656594
VL - 11
SP - 3860
EP - 3866
JO - ACS Nano
JF - ACS Nano
SN - 1936-0851
IS - 4
ER -