Interface chemical and electronic properties of LaAlO3/SrVO3 heterostructures

We have studied the chemical and electronic properties of LaAlO3/SrVO3 (SVO) ultrathin films by combining hard x-ray photoemission spectroscopy and transport measurements. We compare single SrVO3 (SVO) ultrathin films and SrVO3 buried below a polar LaAlO3 (LAO) thin layer, both epitaxially grown on...

Full description

Saved in:
Bibliographic Details
Published in:Journal of applied physics 2018-02, Vol.123 (5)
Main Authors: Fouchet, Arnaud, Rault, Julien E., Allain, Mickaël, Bérini, Bruno, Rueff, Jean-Pascal, Dumont, Yves, Keller, Niels
Format: Article
Language:English
Subjects:
Applied physics
Condensed Matter
Electrical resistivity
Electronics
Epitaxial growth
Film thickness
Heterostructures
Organic chemistry
Photoelectric emission
Photoelectron spectroscopy
Physics
Spectrum analysis
Strontium titanates
Thin films
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We have studied the chemical and electronic properties of LaAlO3/SrVO3 (SVO) ultrathin films by combining hard x-ray photoemission spectroscopy and transport measurements. We compare single SrVO3 (SVO) ultrathin films and SrVO3 buried below a polar LaAlO3 (LAO) thin layer, both epitaxially grown on SrTiO3. While ultrathin films (4 unit cells) of SVO do show insulating behavior over the entire temperature range, the LAO/SVO interface has a resistivity minimum at 250 K. When increasing the SVO layer thickness, the minimum is observed to shift to higher temperatures, but the resistivity always stays smaller than that of comparable SVO single films. Hard x-ray photoemission spectroscopy reveals a surface or interface related V5+ component in the V 2p spectra for SVO films and LAO/SVO heterostructures, respectively, attributed to a strongly oxidized component. This chemical reconstruction is weaker in LAO/SVO heterostructures compared to single SVO films. We show that this dead layer in SVO ultrathin films has to be considered when the film thickness reaches the few unit-cells limit and propose solutions on how to prevent this detrimental effect.
ISSN:0021-8979
1089-7550
DOI:10.1063/1.4998004