Unexpected metal-insulator transition in thick Ca1-xSrxVO3 film on SrTiO3 (100) single crystal

Makoto Takayanagi, Takashi Tsuchiya, Wataru Namiki, Shigenori Ueda, Makoto Minohara, Koji Horiba, Hiroshi Kumigashira, Kazuya Terabe, Tohru Higuchi

研究成果: Article査読

2 被引用数 (Scopus)

抄録

Epitaxial Ca1-xSrxVO3 (0 ≦ x ≦ 1) thin films were grown on (100)-oriented SrTiO3 substrates by using the pulsed laser deposition technique. In contrast to the previous report that metal-insulator transition (MIT) in Ca1-xSrxVO3 (CSVO) was achieved only for extremely thin films (several nm thick), MIT was observed at 39, 72, and 113 K for films with a thickness of 50 nm. The electronic structure was investigated by hard and soft X-ray photoemission spectroscopy (HX-PES and SX-PES). The difference between these PES results was significant due to the variation in an escape depth of photoelectrons of PES. While HX-PES showed that the V 2p3/2 spectra consisted of four peaks (V5+, V4+, V3+, and V2+/1+), SX-PES showed only three peaks (V5+, V4+, and V3+). This difference can be caused by a strain from the substrate, which leads to the chemical disorder (V5+, V4+, V3+, and V2+/1+). The thin film near the substrate is affected by the strain. The positive magnetoresistance is attributed to the effect of electron-electron interactions in the disorder system. Therefore, the emergence of MIT can be explained by the electron-electron interactions from the chemical disorder due to the strain.

本文言語English
論文番号133106
ジャーナルApplied Physics Letters
112
13
DOI
出版ステータスPublished - 2018 3 26
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ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

フィンガープリント 「Unexpected metal-insulator transition in thick Ca<sub>1-</sub><sub>x</sub>Sr<sub>x</sub>VO<sub>3</sub> film on SrTiO<sub>3</sub> (100) single crystal」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。

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