Hyperfine Interactions

, 237:73 | Cite as

Observation of photoexcitation of Fe-oxide grown on TiO2(100) by visible light irradiation

  • Taizo Kawauchi
  • Naoki Nagatsuka
  • Katsuyuki Fukutani
Article
Part of the following topical collections:
  1. Proceedings of the International Conference on the Applications of the Mössbauer Effect (ICAME 2015), Hamburg, Germany, 13-18 September 2015

Abstract

Electronic excitation of materials is of fundamental and technological importance and interest in terms of photoinduced phase transition, photovoltaics, and photocatalysis. In the present study, photoexcitation of Fe2O3 epitaxially grown on rutile TiO2(100) was investigated with conversion electron Mössbauer spectroscopy (CEMS) under dominantly visible-light irradiation. 57Fe was deposited on the substrate at a substrate temperature of 973 K, and the resulting film was characterized by RHEED and XPS. After deposition of Fe on TiO2(100), it was found that Fe was oxidized to Fe 3+, and the structure was analyzed to be the rhombohedral phase of Fe2O3. While the CEMS spectrum without light irradiation showed a quadrupole splitting of 0.80 mm/s with an isomer shift of +0.25 mm/s, an additional component with a quadrupole splitting of 0.85 and an isomer shift of +0.67 mm/s was observed under light irradiation. The latter component corresponds to a reduced state of Fe at the octahedral site surrounded by oxygen atoms. The lifetime of this photoexcited state is discussed.

Keywords

Photoexcitation Fe2O3 TiO2 Visible light CEMS 

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Copyright information

© Springer International Publishing Switzerland 2016

Authors and Affiliations

  • Taizo Kawauchi
    • 1
  • Naoki Nagatsuka
    • 1
  • Katsuyuki Fukutani
    • 1
  1. 1.Institute of Industrial ScienceThe University of TokyoTokyoJapan

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