Electronic Structure and Small Hole Polarons in YTiO<sub>3 </sub>

ORAL

Abstract

As a prototypical Mott insulator with ferromagnetic ordering, YTiO3 (YTO) is of great interest in the study of strong electron correlation effects and orbital ordering. Here we report the first molecular beam epitaxy (MBE) growth of YTO films, combined with theoretical and experimental characterization of the electronic structure and charge transport properties. The obstacles of YTO MBE growth are discussed and potential routes to overcome them are proposed. DC transport and Seebeck measurements on thin films and bulk single crystals identify p-type transport with thermally activated transport behavior, with an activation energy of ~ 0.17 eV in thin films, consistent with the energy barrier for small hole polaron migration from hybrid density functional theory (DFT) calculations. Hard X-ray photoelectron spectroscopy measurements (HAXPES) show the lower Hubbard band (LHB) at 1.1 eV below the Fermi level, whereas a Mott-Hubbard bandgap of ~1.5 eV is determined from photoluminescence (PL) measurements. These findings provide critical insight into the electronic band structure of YTO and related materials.

*This work was primarily supported by the U.S. Department of Energy through the University of Minnesota Center for Quantum Materials.

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Presenters

  • Jin Yue

    • Department of Chemical Engineering and Materials Science, University of Minnesota
    • University of Minnesota

Authors

  • Jin Yue

    • Department of Chemical Engineering and Materials Science, University of Minnesota
    • University of Minnesota

  • Nicholas F. Quackenbush

    • Materials Measurement Science Division, National Institute of Standards and Technology

  • Iflah Laraib

    • University of Delaware
    • Department of Materials Science and Engineering, University of Delaware

  • Henry Carfagno

    • Department of Materials Science and Engineering, University of Delaware

  • Sajna Hameed

    • School of Physics and Astronomy, University of Minnesota
    • University of Minnesota
    • School of Physics & Astronomy, University of Minnesota

  • Abhinav Prakash

    • Department of Chemical Engineering and Materials Science, University of Minnesota

  • Laxman Raju Thoutam

    • Department of Chemical Engineering and Materials Science, University of Minnesota

  • James M. Ablett

    • Synchrotron SOLEIL

  • Tien-Lin Lee

    • Diamond Light Source

  • Martin Greven

    • School of Physics and Astronomy, University of Minnesota
    • University of Minnesota
    • School of Physics & Astronomy, University of Minnesota

  • Matthew F Doty

    • Department of Materials Science and Engineering, University of Delaware
    • University of Delaware

  • Anderson Janotti

    • 2- Department of Materials Science and Engineering, University of Delaware
    • University of Delaware
    • Materials Science and Engineering, University of Delaware
    • Department of Materials Science and Engineering, University of Delaware
    • Department of Materials Science & Engineering, University of Delaware

  • Bharat Jalan

    • University of Minnesota
    • Department of Chemical Engineering and Materials Science, University of Minnesota
    • Department of Electrical and Computer Engineering, University of Minnesota