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Updated: Jun 3, 2026
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Growth and Electrostatic/chemical Properties of Metal/LaAlO3/SrTiO3 Heterostructures
Published on: February 8, 2018
Thermodynamic instability at the stoichiometric LaAlO3/SrTiO3(001) interface
L Qiao1, T C Droubay, V Shutthanandan
1Fundamental and Computational Science Directorate, Pacific Northwest National Laboratory, Richland, WA, USA.
Summary
Stoichiometric lanthanum aluminate (LaAlO3) grown on strontium titanate exhibits significant cation intermixing at the interface. This intermixing is crucial for accurately modeling the interface
Area of Science:
- Materials Science
- Solid State Physics
- Surface Science
Background:
- Epitaxial growth of complex oxides like LaAlO3 on SrTiO3 is key for fabricating advanced electronic devices.
- Understanding interface properties is critical for controlling device functionality.
Purpose of the Study:
- To investigate cation intermixing in stoichiometric epitaxial LaAlO3 grown on TiO2-terminated SrTiO3(001).
- To theoretically and experimentally determine the impact of intermixing on interface electronic properties, specifically the valence band offset.
Main Methods:
- Off-axis pulsed laser deposition for growing epitaxial LaAlO3 films.
- Experimental measurement of the valence band offset.
- Classical and quantum mechanical calculations to assess interface stability.
Main Results:
- Strong cation intermixing was observed at the LaAlO3/SrTiO3 interface.
- The measured valence band offset was determined to be 0.16 ± 0.10 eV.
- Theoretical models require the inclusion of intermixing to accurately predict the valence band offset.
Conclusions:
- Cation intermixing is an inherent feature of LaAlO3/SrTiO3 interfaces grown under these conditions.
- Accurate theoretical descriptions of these interfaces must account for intermixing.
- The valence band offset is directly influenced by the degree of cation intermixing.
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