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Title: Strontium ruthenate–anatase titanium dioxide heterojunctions from first-principles: Electronic structure, spin, and interface dipoles

Abstract

The epitaxial integration of functional oxides with wide band gap semiconductors offers the possibility of new material systems for electronics and energy conversion applications. We use first principles to consider an epitaxial interface between the correlated metal oxide SrRuO{sub 3} and the wide band gap semiconductor TiO{sub 2}, and assess energy level alignment, interfacial chemistry, and interfacial dipole formation. Due to the ferromagnetic, half-metallic character of SrRuO{sub 3}, according to which only one spin is present at the Fermi level, we demonstrate the existence of a spin dependent band alignment across the interface. For two different terminations of SrRuO{sub 3}, the interface is found to be rectifying with a Schottky barrier of ≈1.3–1.6 eV, in good agreement with experiment. In the minority spin, SrRuO{sub 3} exhibits a Schottky barrier alignment with TiO{sub 2} and our calculated Schottky barrier height is in excellent agreement with previous experimental measurements. For majority spin carriers, we find that SrRuO{sub 3} recovers its exchange splitting gap and bulk-like properties within a few monolayers of the interface. These results demonstrate a possible approach to achieve spin-dependent transport across a heteroepitaxial interface between a functional oxide material and a conventional wide band gap semiconductor.

Authors:
;  [1]
  1. Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, 1206 W Green Street, Urbana, Illinois 61801 (United States)
Publication Date:
OSTI Identifier:
22597768
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 120; Journal Issue: 3; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ALIGNMENT; DIPOLES; ELECTRONIC STRUCTURE; ENERGY CONVERSION; EPITAXY; FERMI LEVEL; HETEROJUNCTIONS; INTERFACES; RUTHENIUM COMPOUNDS; SCHOTTKY BARRIER DIODES; SEMICONDUCTOR MATERIALS; SPIN; STRONTIUM OXIDES; TITANIUM OXIDES

Citation Formats

Ferdous, Naheed, and Ertekin, Elif, E-mail: ertekin@illinois.edu. Strontium ruthenate–anatase titanium dioxide heterojunctions from first-principles: Electronic structure, spin, and interface dipoles. United States: N. p., 2016. Web. doi:10.1063/1.4958861.
Ferdous, Naheed, & Ertekin, Elif, E-mail: ertekin@illinois.edu. Strontium ruthenate–anatase titanium dioxide heterojunctions from first-principles: Electronic structure, spin, and interface dipoles. United States. doi:10.1063/1.4958861.
Ferdous, Naheed, and Ertekin, Elif, E-mail: ertekin@illinois.edu. 2016. "Strontium ruthenate–anatase titanium dioxide heterojunctions from first-principles: Electronic structure, spin, and interface dipoles". United States. doi:10.1063/1.4958861.
@article{osti_22597768,
title = {Strontium ruthenate–anatase titanium dioxide heterojunctions from first-principles: Electronic structure, spin, and interface dipoles},
author = {Ferdous, Naheed and Ertekin, Elif, E-mail: ertekin@illinois.edu},
abstractNote = {The epitaxial integration of functional oxides with wide band gap semiconductors offers the possibility of new material systems for electronics and energy conversion applications. We use first principles to consider an epitaxial interface between the correlated metal oxide SrRuO{sub 3} and the wide band gap semiconductor TiO{sub 2}, and assess energy level alignment, interfacial chemistry, and interfacial dipole formation. Due to the ferromagnetic, half-metallic character of SrRuO{sub 3}, according to which only one spin is present at the Fermi level, we demonstrate the existence of a spin dependent band alignment across the interface. For two different terminations of SrRuO{sub 3}, the interface is found to be rectifying with a Schottky barrier of ≈1.3–1.6 eV, in good agreement with experiment. In the minority spin, SrRuO{sub 3} exhibits a Schottky barrier alignment with TiO{sub 2} and our calculated Schottky barrier height is in excellent agreement with previous experimental measurements. For majority spin carriers, we find that SrRuO{sub 3} recovers its exchange splitting gap and bulk-like properties within a few monolayers of the interface. These results demonstrate a possible approach to achieve spin-dependent transport across a heteroepitaxial interface between a functional oxide material and a conventional wide band gap semiconductor.},
doi = {10.1063/1.4958861},
journal = {Journal of Applied Physics},
number = 3,
volume = 120,
place = {United States},
year = 2016,
month = 7
}
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