Detection of decoupled surface and bulk states in epitaxial orthorhombic SrIrO3 thin films

Prescott E. Evans; Takashi Komesu; Le Zhang; Ding-Fu Shao; Andrew J. Yost; Shiv Kumar; Eike F. Schwier; Kenya Shimada; Evgeny Y. Tsymbal; Xia Hong; P. A. Dowben

doi:10.1063/1.5135941

AIP Advances (Apr 2020)

Detection of decoupled surface and bulk states in epitaxial orthorhombic SrIrO3 thin films

Prescott E. Evans,
Takashi Komesu,
Le Zhang,
Ding-Fu Shao,
Andrew J. Yost,
Shiv Kumar,
Eike F. Schwier,
Kenya Shimada,
Evgeny Y. Tsymbal,
Xia Hong,
P. A. Dowben

Affiliations

Prescott E. Evans: Department of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, Theodore Jorgensen Hall, 855 N 16th, University of Nebraska, Lincoln, Nebraska 68588-0299, USA
Takashi Komesu: Department of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, Theodore Jorgensen Hall, 855 N 16th, University of Nebraska, Lincoln, Nebraska 68588-0299, USA
Le Zhang: Department of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, Theodore Jorgensen Hall, 855 N 16th, University of Nebraska, Lincoln, Nebraska 68588-0299, USA
Ding-Fu Shao: Department of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, Theodore Jorgensen Hall, 855 N 16th, University of Nebraska, Lincoln, Nebraska 68588-0299, USA
Andrew J. Yost: Department of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, Theodore Jorgensen Hall, 855 N 16th, University of Nebraska, Lincoln, Nebraska 68588-0299, USA
Shiv Kumar: Hiroshima Synchrotron Radiation Center, Hiroshima University, Higashi-Hiroshima 739-0046, Japan
Eike F. Schwier: Hiroshima Synchrotron Radiation Center, Hiroshima University, Higashi-Hiroshima 739-0046, Japan
Kenya Shimada: Hiroshima Synchrotron Radiation Center, Hiroshima University, Higashi-Hiroshima 739-0046, Japan
Evgeny Y. Tsymbal: Department of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, Theodore Jorgensen Hall, 855 N 16th, University of Nebraska, Lincoln, Nebraska 68588-0299, USA
Xia Hong: Department of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, Theodore Jorgensen Hall, 855 N 16th, University of Nebraska, Lincoln, Nebraska 68588-0299, USA
P. A. Dowben: Department of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, Theodore Jorgensen Hall, 855 N 16th, University of Nebraska, Lincoln, Nebraska 68588-0299, USA

DOI: https://doi.org/10.1063/1.5135941
Journal volume & issue: Vol. 10, no. 4
pp. 045027 – 045027-5

Abstract

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We report the experimental evidence of evolving lattice distortion in high quality epitaxial orthorhombic SrIrO3(001) thin films fully strained on (001) SrTiO3 substrates. Angle-resolved X-ray photoemission spectroscopy studies show that the surface layer of 5 nm SrIrO3 films is Sr–O terminated, and subsequent layers recover the semimetallic state, with the band structure consistent with an orthorhombic SrIrO3(001) having the lattice constant of the substrate. While there is no band folding in the experimental band structure, additional super-periodicity is evident in low energy electron diffraction measurements, suggesting the emergence of a transition layer with crystal symmetry evolving from the SrTiO3 substrate to the SrIrO3(001) surface. Our study sheds light on the misfit relaxation mechanism in epitaxial SrIrO3 thin films in the orthorhombic phase, which is metastable in bulk.

Published in AIP Advances

ISSN: 2158-3226 (Online)
Publisher: AIP Publishing LLC
Country of publisher: United States
LCC subjects: Science: Physics
Website: http://aipadvances.aip.org/

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