Modulation of manganite thin-film properties by strontium titanate excitons

ORAL

Abstract

A comprehensive investigation of the optical, electronic and magnetic properties of La0.7Sr0.3MnO3 films on SrTiO3 (LSMO/STO) and other substrates is conducted using multiple experimental techniques. There is a significant difference in the optical properties of LSMO/STO even in the case of 87.2nm-thick LSMO/STO as compared to those of LSMO on other substrates. We observed interesting excitonic features in the LSMO/STO thin-film at ~4eV. This could be due to formation of anomalous charged excitonic complexes. Based on spectral-weight transfer analysis, anomalous excitonic effects from STO strengthen the electronic-correlation in LSMO films. This results in optical spectral changes related to intrinsic Mott-Hubbard properties in the manganite films. While lattice strain influences the optical properties of the LSMO thin-films, strong e-e and e-h interactions from the substrate play a significant role as well.

*This work is supported by Singapore Ministry of Education (MOE2015-T2-2-065, MOE2015-T2-1-099, MOE2015-T2-2-147, and MOE2016-T2-1-054), Singapore National Research Foundation under its Competitive Research Funding (NRF-CRP 8-2011-06 and NRF-CRP15-2015-01), NUS-YIA, FRCs (R-144-000-379-114 and R-144-000-368-112), and NUS Core Support C-380-003-003-001.

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Presenters

  • Chi Sin Tang

    • NUS Graduate School of Integrative Sciences & Engineering, National University of Singapore

Authors

  • Chi Sin Tang

    • NUS Graduate School of Integrative Sciences & Engineering, National University of Singapore

  • Xinmao Yin

    • Department of Physics, National University of Singapore

  • Le Wang

    • Pacific Northwest Natl Lab
    • Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory

  • Andrew Thye Shen Wee

    • Department of Physics, National University of Singapore

  • Junling Wang

    • School of Materials Science and Engineering, Nanyang Technological University

  • Andrivo Rusydi

    • Department of Physics, National University of Singapore