Interface energetics and atomic structure of epitaxial La{sub 1−x}Sr{sub x}CoO{sub 3} on Nb:SrTiO{sub 3}

Journal Article · Mon Jun 15 04:00:00 EDT 2015 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4922880· OSTI ID:22483063

Yamazaki, Takashi; Aso, Hiroyuki; Kataoka, Yuji; Imanaka, Yoshihiko ^[1]; Ricinschi, Dan ^[2]; Miyata, Yusuke; Yamada, Hiroaki; Fujimura, Norifumi ^[3]

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1. Fujitsu Laboratories, Atsugi, Kanagawa-ken (Japan)
2. Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, 4259-G2-25 Nagatsuta, Midori-ku, Yokohama 226–8502 (Japan)
3. Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531 (Japan)

The energetics at oxide semiconductor/La{sub 1−x}Sr{sub x}CoO{sub 3} heterojunctions, including the respective alignment of the valence and conduction bands, govern charge transfer and have to be determined for the design of future La{sub 1−x}Sr{sub x}CoO{sub 3}-based devices. In this letter, the electronic and atomic structures of epitaxial La{sub 1−x}Sr{sub x}CoO{sub 3} on Nb-doped strontium titanate are revealed by scanning transmission electron microscopy, electron energy loss spectroscopy, and in situ x-ray and ultra violet photoelectron spectroscopies. For LaCoO{sub 3}, a valence band (VB) offset of 2.8 ± 0.1 eV is deduced. The large offset is attributed to the orbital contributions of the Co 3d states to the VB maximum of the LaCoO{sub 3} thin films, with no evidence of interface dipole contributions. The sensitivity of the valence band orbital character to spin state ordering and oxygen vacancies is assessed using density functional theory.

• OSTI ID: 22483063
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 24 Vol. 106; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
DENSITY FUNCTIONAL METHOD
DOPED MATERIALS
ENERGY-LOSS SPECTROSCOPY
EPITAXY
INTERFACES
OXIDES
PHOTOELECTRON SPECTROSCOPY
SEMICONDUCTOR MATERIALS
SENSITIVITY
STRONTIUM TITANATES
THIN FILMS
TRANSMISSION ELECTRON MICROSCOPY
VACANCIES
X RADIATION