# Electrochemical ferroelectric switching

Bristowe, N. C. and Stengel, Massimiliano and Littlewood, P. B and Pruneda, J. M and Artacho, Emilio (2012) Electrochemical ferroelectric switching. Physical Review B (Condensed Matter and Materials Physics), 85 (2).

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Official URL: http://link.aps.org/doi/10.1103/PhysRevB.85.024106

## Abstract

Against expectations, robust switchable ferroelectricity has been recently observed in ultrathin (1 nm) ferroelectric films exposed to air [V. Garcia $et$ $al.$, Nature {\bf 460}, 81 (2009)]. Based on first-principles calculations, we show that the system does not polarize unless charged defects or adsorbates form at the surface. We propose electrochemical processes as the most likely origin of this charge. The ferroelectric polarization of the film adapts to the bound charge generated on its surface by redox processes when poling the film. This, in turn, alters the band alignment at the bottom electrode interface, explaining the observed tunneling electroresistance. Our conclusions are supported by energetics calculated for varied electrochemical scenarios.

Item Type: Article 2011AREP; IA63; 03 - Mineral Sciences 03 - Mineral Sciences Physical Review B (Condensed Matter and Materials Physics) 85 Sarah Humbert 07 Oct 2011 17:17 23 Jul 2013 10:02 http://eprints.esc.cam.ac.uk/id/eprint/2190

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