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

Authors

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

ORCID IDs

Prescott Evans Andrew J. Yost Shiv Kumar Eike F. Schwier Kenya Shimada Evgeny Tsymbal Xia Hong P. A. Dowben

Date of this Version

2020

Citation

AIP Advances 10, 045027 (2020); doi: 10.1063/1.5135941

Comments

© 2020 Author(s).

Abstract

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.