Real-space investigation of polarons in hematite Fe₂O₃

Author(s)

Jesus Redondo, Michele Reticcioli, Vit Gabriel, Dominik Wrana, Florian Ellinger, Michele Riva, Giada Franceschi, Erik Rheinfrank, Igor Sokolovic, Zdenek Jakub, Florian Kraushofer, Aji Alexander, Laerte L. Patera, Jascha Repp, Michael Schmid, Ulrike Diebold, Gareth S. Parkinson, Cesare Franchini, Pavel Kocan, Martin Setvin

Abstract

In polarizable materials, electronic charge carriers interact with the surrounding ions, leading to quasiparticle behaviour. The resulting polarons play a central role in many materials properties including electrical transport, optical properties, surface reactivity and magnetoresistance, and polaron properties are typically investigated indirectly through such macroscopic characteristics. Here, noncontact atomic force microscopy (nc-AFM) is used to directly image polarons in Fe2O3 at the single quasiparticle limit. A combination of Kelvin probe force microscopy (KPFM) and kinetic Monte Carlo (KMC) simulations shows that Ti doping dramatically enhances the mobility of electron polarons, and density functional theory (DFT) calculations indicate that a metallic transition state is responsible for the enhancement. In contrast, hole polarons are significantly less mobile and their hopping is hampered further by the introduction of trapping centres.

Organisation(s)

Computational Materials Physics

External organisation(s)

Charles University Prague, Technische Universität Wien, Universität Regensburg (UR)

Publication date

03-2023

Austrian Fields of Science 2012

103015 Condensed matter

Keywords

Portal url

https://ucris.univie.ac.at/portal/en/publications/realspace-investigation-of-polarons-in-hematite-fe2o3(eaecef5c-7a1d-4e36-9295-9fe7743d7195).html