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Epitaxial Growth of Perovskite Strontium Titanate on Germanium via Atomic Layer Deposition
Published on: July 26, 2016
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Study on Ca Segregation toward an Epitaxial Interface between Bismuth Ferrite and Strontium Titanate
Ulrich Haselmann1, Georg Haberfehlner2, Weijie Pei3
1Erich Schmid Institute of Materials Science, Austrian Academy of Sciences, Leoben 8700, Austria.
ACS Applied Materials & Interfaces
|February 15, 2020
Summary
Calcium segregation at interfaces in bismuth ferrite films alters atomic and electronic structures, reducing strain and creating oxygen vacancies. This finding suggests Ca-rich buffer layers could enhance heterostructure functionality.
Area of Science:
- Materials Science
- Solid State Physics
- Nanotechnology
Background:
- Segregation in perovskite oxides can alter material properties and lead to functionality loss.
- Previous studies primarily focused on surface segregation in oxide thin films.
Purpose of the Study:
- Investigate Ca segregation at an in-plane compressively strained heterostructure interface in Ca- and Mn-codoped bismuth ferrite.
- Understand the atomic and electronic structure modifications induced by Ca segregation.
Main Methods:
- Advanced transmission electron microscopy
- X-ray photoelectron spectroscopy
- Density functional theory (DFT) calculations
- Electron energy loss spectroscopy (EELS)
Main Results:
- Observed Ca segregation towards the heterostructure interface.
- Identified interface strain reduction, interplanar spacing variations, and oxygen vacancies.
- DFT calculations supported segregation with oxygen vacancies and charge compensation.
Conclusions:
- Ca segregation significantly impacts the interface's atomic and electronic structure.
- Oxygen vacancy formation is confirmed as part of the segregation process.
- A Ca-rich buffer layer shows potential for improving heterostructure performance.
Keywords:
BiFeO3EELS and EDSatomic-resolution TEMdensity functional theory (DFT)oxide heterostructure interfaceoxygen vacancysegregationMore Related Videos
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