In-gap state generated by La-on-Sr substitutional defects within the bulk of SrTiO3. Issue 27 (19th June 2019)

• Record Type: Journal Article
• Authors: Aiura, Yoshihiro; Ozawa, Kenichi; Tezuka, Yasuhisa; Minohara, Makoto; Samizo, Akane; Bando, Kyoko; Kumigashira, Hiroshi; Mase, Kazuhiko
• Is Part Of: Physical chemistry chemical physics. Volume 21:Issue 27(2019)
• Page Start: 14646
• Page End: 14653
• Publication Date: 2019-06-19
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/c9cp02307k
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : La-on-Sr substitution defects in SrTiO3 generate electrons and simultaneously cause local distortion in the conduction pathway. Abstract : 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.