Revisiting the Al/Al?O? interface: Coherent interfaces and misfit accommodation

Revisiting the Al/Al?O? interface: Coherent interfaces and misfit accommodation

Pilania, G.
Thijsse, B.J.
Hoagland, R.G.
Lazic, I.
Valone, S.M.
Liu, X.Y.

Mechanical, Maritime and Materials Engineering

Materials Science and Engineering

2014-03-27

We study the coherent and semi-coherent Al/?-Al2O3 interfaces using molecular dynamics simulations with a mixed, metallic-ionic atomistic model. For the coherent interfaces, both Al-terminated and O-terminated nonstoichiometric interfaces have been studied and their relative stability has been established. To understand the misfit accommodation at the semi-coherent interface, a 1-dimensional (1D) misfit dislocation model and a 2-dimensional (2D) dislocation network model have been studied. For the latter case, our analysis reveals an interface dislocation structure with a network of three sets of parallel dislocations, each with pure-edge character, giving rise to a pattern of coherent and stacking-fault-like regions at the interface. Structural relaxation at elevated temperatures leads to a further change of the dislocation pattern, which can be understood in terms of a competition between the stacking fault energy and the dislocation interaction energy at the interface. Our results are expected to serve as an input for the subsequent dislocation dynamics models to understand and predict the macroscopic mechanical behavior of Al/?-Al2O3 composite heterostructures.

composites
structural properties
surfaces
interfaces
thin film
atomistic models

http://resolver.tudelft.nl/uuid:69176fc2-bc15-4e62-8490-1b2b85dd1413

https://doi.org/10.1038/srep04485

Nature Publishing Group

2045-2322

Scientific Reports, 4, 2014

Institutional Repository

journal article

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