A combined experimental and first principles study of small hole polarons in YTiO<sub>3</sub> thin films

ORAL

Abstract

Rare-earth titanate YTiO3 is a Mott insulator whose electronic structure description has been quite challenging to density functional theory (DFT) calculations within standard (semi)local approximations to the exchange-correlation term. The reported onset of optical absorption in YTiO3 is ~0.6 eV while the calculated Mott-Hubbard gap using hybrid DFT is ~2 eV. Combining experiments on hybrid molecular beam epitaxy (MBE) grown YTiO3 heterostructures with DFT calculations we investigated the electronic and transport properties of YTiO3. We test the performance of the meta-GGA SCAN functional in the description of the electronic structure of YTiO3, comparing the results of hybrid functional and photoemission measurements. We also study the formation, stability and migration of small hole polarons in YTiO3, and compare our findings with the measurements of the Seebeck coefficient and temperature-dependent resistivity. We also carry out a detailed analysis of the effects of the TiO6 octahedral tilt and rotations, and lattice distortions on the Mott-Hubbard gap.

*Theory work was supported by the National Science Foundation Early Career Award Grant No. DMR-1652994. Experimental work supported by the DOE Center for Quantum Materials, University of Minessota.

–

Presenters

  • Iflah Laraib

    • Materials Science and Engineering, University of Delaware

Authors

  • Iflah Laraib

    • Materials Science and Engineering, University of Delaware

  • Jin Yue

    • Chemical Engineering and Materials Science, University of Minnesotta
    • Department of Chemical Engineering and Materials Science, University of Minnesota
    • Chemical Engineering and Materials Science, University of Minnesota - Twin Cities

  • Nicholas F Quackenbush

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

  • Bharat Jalan

    • Chemical Engineering & Materials Science, University of Minnesota
    • University of Minnesota
    • Chemical Engineering and Materials Science, University of Minnesotta
    • Department of Chemical Engineering and Materials Science, University of Minnesota
    • Chemical Engineering and Materials Science, University of Minnesota
    • Department of Chemical Engineering and Materials Science, University of Minnesota-Minneapolis
    • Chemical Engineering and Materials Science, University of Minnesota - Twin Cities

  • Anderson Janotti

    • Materials Science and Engineering, University of Delaware
    • Department of Materials Science and Engineering, University of Delaware
    • University of Delaware
    • Department of Materials Science & Engineering, University of Delaware
    • Department of Material Science and Engineering, University of Delaware
    • Univ of Delaware