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Updated: Aug 3, 2025
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Plasma-assisted Molecular Beam Epitaxy of N-polar InAlN-barrier High-electron-mobility Transistors
Published on: November 24, 2016
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Thickness-Dependent Interface Polarity in Infinite-Layer Nickelate Superlattices
Chao Yang1, Roberto A Ortiz1, Yi Wang1,2
1Max Planck Institute for Solid State Research, Stuttgart 70569, Germany.
Nano Letters
|April 7, 2023
Summary
Interface polarity drives reconstruction in superconducting nickelate films. Thicker NdNiO2/SrTiO3 superlattices exhibit greater cation displacement, crucial for understanding these novel materials.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Solid State Chemistry
Background:
- Interface polarity significantly influences oxide heterointerface properties.
- Reconstruction at NdNiO2/SrTiO3 interfaces is critical for superconductivity in nickelate films, as bulk superconductivity is absent.
Purpose of the Study:
- Investigate the effects of oxygen distribution, polyhedral distortion, elemental intermixing, and dimensionality on NdNiO2/SrTiO3 superlattices.
- Understand the thickness-dependent interface reconstruction caused by polar discontinuity.
Main Methods:
- Utilized four-dimensional scanning transmission electron microscopy (4D-STEM).
- Employed electron energy-loss spectroscopy (EELS).
- Grew NdNiO2/SrTiO3 superlattices on SrTiO3 (001) substrates.
Main Results:
- Observed gradual variation in oxygen content within the nickelate layer.
- Demonstrated thickness-dependent interface reconstruction linked to polar discontinuity.
- Found average cation displacement at interfaces in 8NdNiO2/4SrTiO3 superlattices is twice that in 4NdNiO2/2SrTiO3 superlattices (∼0.025 nm).
Conclusions:
- The study provides crucial insights into atomic and electronic structure modifications at polar NdNiO2/SrTiO3 interfaces.
- Thickness-dependent reconstruction is a key factor in the properties of these superconducting nickelate heterostructures.
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