Two-Dimensional Polaronic Behavior in the Binary Oxides $m\mathrm{\text{\ensuremath{-}}}{\mathrm{HfO}}_{2}$ and $m\mathrm{\text{\ensuremath{-}}}{\mathrm{ZrO}}_{2}$

Two-Dimensional Polaronic Behavior in the Binary Oxides $m − {HfO}_{2}$ and $m − {ZrO}_{2}$

Keith P. McKenna, Matthew J. Wolf, Alexander L. Shluger, Stephan Lany, and Alex Zunger

Phys. Rev. Lett. 108, 116403 – Published 14 March 2012

Abstract

We demonstrate that the three-dimensional (3D) binary monoclinic oxides ${HfO}_{2}$ and ${ZrO}_{2}$ exhibit quasi-2D polaron localization and conductivity, which results from a small difference in the coordination of two oxygen sublattices in these materials. The transition between a 2D large polaron into a zero-dimensional small polaron state requires overcoming a small energetic barrier. These results demonstrate how a small asymmetry in the lattice structure can determine the qualitative character of polaron localization and significantly broaden the realm of quasi-2D polaron systems.

Received 30 November 2011

DOI:https://doi.org/10.1103/PhysRevLett.108.116403

Authors & Affiliations

Keith P. McKenna^1,2,*, Matthew J. Wolf³, Alexander L. Shluger^2,3, Stephan Lany⁴, and Alex Zunger⁵

¹Department of Physics, University of York, Heslington, York YO10 5DD, United Kingdom
²WPI-AIMR, Tohoku University, 2-1-1, Katahira, Aoba-ku, Sendai 980-8577, Japan
³Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT, United Kingdom
⁴National Renewable Energy Laboratory, Golden, Colorado 80401, USA
⁵University of Colorado, Boulder, Colorado 80309, USA