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Updated: May 11, 2026
11:54
Growth and Electrostatic/chemical Properties of Metal/LaAlO3/SrTiO3 Heterostructures
Published on: February 8, 2018
Structure and phase transitions at the interface between α-Al2O3 and Pt
Colin Ophus1, Melissa K Santala, Mark Asta
1National Center for Electron Microscopy, Lawrence Berkeley National Laboratory, Berkeley, CA, USA. cophus@gmail.com
Summary
This study reveals the oxygen-terminated interface between platinum and alumina using advanced microscopy and calculations. A predicted structural phase transition occurs under specific temperature and oxygen conditions.
Area of Science:
- Materials Science
- Surface Science
- Computational Materials Science
Background:
- Understanding metal-oxide interfaces is crucial for catalysis and materials design.
- Platinum (Pt) and alpha-alumina (α-Al2O3) interfaces are relevant in various applications.
- Controlling interface structure impacts material properties.
Purpose of the Study:
- To investigate the atomic structure and thermodynamics of the (111) Pt / basal α-Al2O3 interface.
- To determine the most stable interface termination under varying conditions.
- To predict potential structural phase transitions at the interface.
Main Methods:
- High-resolution electron microscopy (HREM) for structural characterization.
- First-principles calculations based on ab initio thermodynamics.
- Calculation of interfacial excess free energies as a function of temperature (T) and oxygen partial pressure (PO2).
Main Results:
- Experimental and computational results confirm an oxygen-terminated interface.
- Three competing interface terminations were analyzed.
- Interfacial free energy calculations predict a structural phase transition.
Conclusions:
- The interface between (111) platinum and the basal plane of alpha-alumina is oxygen terminated.
- A structural phase transition is predicted within experimentally accessible temperature and oxygen partial pressure ranges.
- This work provides fundamental insights into metal-oxide interface behavior.
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