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Bulk and Thin Film Synthesis of Compositionally Variant Entropy-stabilized Oxides
Published on: May 29, 2018
Formation of metastable structures by phase separation triggered by initial composition gradients in thin films
Prabhat K Jaiswal1, Kurt Binder, Sanjay Puri
1Institut für Physik, Johannes Gutenberg-Universität Mainz, Staudinger Weg 7, D-55099 Mainz, Germany.
The Journal of Chemical Physics
|August 18, 2012
Summary
Simulations reveal that thin film phase separation can form unexpected layered structures. A moderate concentration gradient, however, surprisingly promotes the desired equilibrium state with perpendicular domain walls, useful for material production.
Area of Science:
- Materials Science
- Chemical Engineering
- Computational Physics
Background:
- Phase separation is crucial for creating materials with specific properties.
- Thin films exhibit unique behavior due to surface and confinement effects.
- Understanding phase separation kinetics is key to controlling material morphology.
Purpose of the Study:
- Investigate phase separation kinetics in binary mixtures within thin films.
- Analyze the impact of initial concentration gradients on morphology.
- Explore the formation of metastable layered structures versus equilibrium domain patterns.
Main Methods:
- Utilized Cahn-Hilliard-Cook model simulations.
- Studied a binary (A,B) mixture in a thin film of thickness D.
- Implemented an initial concentration gradient perpendicular to the film and neutral surfaces.
Main Results:
- Observed the formation of long-lived metastable layered structures under certain conditions.
- Identified a competition between bulk domain growth and surface-directed spinodal decomposition.
- Found that a moderate perpendicular concentration gradient facilitates the approach to equilibrium with perpendicular domain walls.
Conclusions:
- Initial concentration gradients can lead to non-equilibrium layered structures in thin films.
- A moderate perpendicular gradient can overcome this and promote the desired equilibrium morphology.
- This finding offers potential applications in the fabrication of layered materials.
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