TY - JOUR
T1 - In-gap state generated by La-on-Sr substitutional defects within the bulk of SrTiO3
AU - Aiura, Yoshihiro
AU - Ozawa, Kenichi
AU - Tezuka, Yasuhisa
AU - Minohara, Makoto
AU - Samizo, Akane
AU - Bando, Kyoko
AU - Kumigashira, Hiroshi
AU - Mase, Kazuhiko
N1 - Funding Information:
Y. A. would like to thank Dr Hideaki Iwasawa for his efforts on analysis and preparation of the ARPES spectra, and Mr Haruki Kamide, Prof. Yoichi Ishiwata, and Dr Jun-ichi Adachi for their assistances in performing the SXES measurement. Fig. 1 was drawn using the program VESTA.53 The PES, SXES, and XAFS measurements were performed under the approval of the Photon Factory Advisory Committee (Proposal No. 2015S2-005, 2017G058, 2017G694 and 2017G685). This work was supported in part by Grants-in-Aid for Scientific Research (Grant No. 16H03867 and 18J11854) from Ministry of Education, Culture, Sports, Science, and Technology of Japan.
Publisher Copyright:
© 2019 the Owner Societies.
PY - 2019
Y1 - 2019
N2 - Local distortion in the conduction pathway has a significant influence on the conducting properties of oxides. The electronic states induced in the band gap of SrTiO3 by La doping were investigated using photoemission spectroscopy (PES) and soft X-ray emission spectroscopy (SXES); moreover, the local distortion in the conduction pathway was examined using extended X-ray absorption fine structure (EXAFS). An itinerant state and a localized state were observed as a metallic state and an in-gap state, respectively, in the PES spectra and as inelastic peaks in the SXES spectra. This implied that the itinerant state and the in-gap state coexisted within the bulk. From EXAFS results, it was observed that La doped into SrTiO3 substituted Sr and locally distorted the conduction pathway. The results showed that some electrons doped by La-on-Sr substitution are trapped/localized by the local distortion in the conduction pathway, whereas the remaining doped electrons itinerate in the pristine conduction pathway with no distortion.
AB - Local distortion in the conduction pathway has a significant influence on the conducting properties of oxides. The electronic states induced in the band gap of SrTiO3 by La doping were investigated using photoemission spectroscopy (PES) and soft X-ray emission spectroscopy (SXES); moreover, the local distortion in the conduction pathway was examined using extended X-ray absorption fine structure (EXAFS). An itinerant state and a localized state were observed as a metallic state and an in-gap state, respectively, in the PES spectra and as inelastic peaks in the SXES spectra. This implied that the itinerant state and the in-gap state coexisted within the bulk. From EXAFS results, it was observed that La doped into SrTiO3 substituted Sr and locally distorted the conduction pathway. The results showed that some electrons doped by La-on-Sr substitution are trapped/localized by the local distortion in the conduction pathway, whereas the remaining doped electrons itinerate in the pristine conduction pathway with no distortion.
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U2 - 10.1039/c9cp02307k
DO - 10.1039/c9cp02307k
M3 - Article
C2 - 31215560
AN - SCOPUS:85068997237
SN - 1463-9076
VL - 21
SP - 14646
EP - 14653
JO - Physical Chemistry Chemical Physics
JF - Physical Chemistry Chemical Physics
IS - 27
ER -