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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.

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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