Imperial College London
Portrait Picture

Professor Michael W. Finnis

Faculty of Engineering, Department of Materials

Chair in Materials Theory and Simulation
 
 
 
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Contact

 

+44 (0)20 7594 6812m.finnis Website

 
 
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Location

 

2.27BRoyal School of MinesSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Guhl:2015:10.1016/j.actamat.2015.07.042,
author = {Guhl, H and Lee, HS and Tangney, P and Foulkes, WMC and Heuer, AH and Nakagawa, T and Ikuhara, Y and Finnis, MW},
doi = {10.1016/j.actamat.2015.07.042},
journal = {Acta Materialia},
pages = {16--28},
title = {Structural and electronic properties of sigma7 grain boundaries in alpha-Al2O3},
url = {http://dx.doi.org/10.1016/j.actamat.2015.07.042},
volume = {99},
year = {2015}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Applying simulated annealing with a classical potential followed by screening of low-energy structures with density functional theory, we examined the atomic and electronic structures of the View the MathML source and View the MathML source symmetric tilt grain boundaries in α-Al2O3. The lowest energy View the MathML source boundary exhibits a pronounced pattern of alternating columns of exclusively four- or fivefold coordinated Al atoms, with a grain boundary energy of 1.84 Jm−2. For the View the MathML source boundary, numerous structures were found with energy just below 2.11 Jm−2. Furthermore, by analysing the full set of candidate structures generated by simulated annealing for the two grain boundaries, we find that the number of fivefold coordinated Al atoms tends to increase with grain boundary energy, which we can also correlate with the behaviour of the electronic density of states. On the other hand, we find no systematic trend with energy that might be expected for other quantities, notably the excess volume of the interface. We compare simulated high-resolution transmission electron microscope (HRTEM) images of the lowest energy calculated structures with experimental images. The disparate structural and electronic features of these two boundaries suggest reasons for their very different oxygen diffusion coefficients that have been observed experimentally.
AU  - Guhl,H
AU  - Lee,HS
AU  - Tangney,P
AU  - Foulkes,WMC
AU  - Heuer,AH
AU  - Nakagawa,T
AU  - Ikuhara,Y
AU  - Finnis,MW
DO  - 10.1016/j.actamat.2015.07.042
EP  - 28
PY  - 2015///
SN  - 1359-6454
SP  - 16
TI  - Structural and electronic properties of sigma7 grain boundaries in alpha-Al2O3
T2  - Acta Materialia
UR  - http://dx.doi.org/10.1016/j.actamat.2015.07.042
UR  - https://www.sciencedirect.com/science/article/pii/S1359645415005133
UR  - http://hdl.handle.net/10044/1/25490
VL  - 99
ER  -
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