Projects per year
Abstract
Polycrystalline metal oxides find diverse applications in areas such as nanoelectronics, photovoltaics and catalysis. Although grain boundary defects are ubiquitous their structure and electronic properties are very poorly understood since it is extremely challenging to probe the structure of buried interfaces directly. In this paper we combine novel plan-view high-resolution transmission electron microscopy and first principles calculations to provide atomic level understanding of the structure and properties of grain boundaries in the barrier layer of a magnetic tunnel junction. We show that the highly [001] textured MgO films contain numerous tilt grain boundaries. First principles calculations reveal how these grain boundaries are associated with locally reduced band gaps (by up to 3 eV). Using a simple model we show how shunting a proportion of the tunnelling current through grain boundaries imposes limits on the maximum magnetoresistance that can be achieved in devices.
Original language | English |
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Article number | 45594 |
Number of pages | 9 |
Journal | Scientific Reports |
Volume | 7 |
DOIs | |
Publication status | Published - 4 Apr 2017 |
Bibliographical note
© The Author(s) 2017Keywords
- Journal Article
Projects
- 1 Finished
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Non-equilibrium electron-ion dynamics in thin metal-oxide
McKenna, K. P. (Principal investigator)
1/01/13 → 30/04/18
Project: Research project (funded) › Research
Datasets
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Atomic structure and electronic properties of MgO grain boundaries in tunnelling magnetoresistive devices
McKenna, K. P. (Creator) & Bean, J. (Creator), University of York, 2017
DOI: 10.15124/e559c66a-a6ec-43b2-b92b-617dcb1ad7af
Dataset