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 Sokolović, Zdenek Jakub, Florian Kraushofer, Aji Alexander, Eduard Belas, 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 behavior. The resulting polarons play a central role in many materials properties including electrical transport, interaction with light, surface reactivity, and magnetoresistance, and polarons are typically investigated indirectly through these 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 the mobility of electron polarons can be markedly increased by Ti doping. Density functional theory (DFT) calculations indicate that a transition from polaronic to metastable free-carrier states can play a key role in migration of electron polarons. In contrast, hole polarons are significantly less mobile, and their hopping is hampered further by trapping centers.

Organisation(s)

Computational Materials Physics

External organisation(s)

Charles University Prague, Technische Universität Wien, Czech Academy of Sciences, Jagiellonian University in Krakow, University Hospital Regensburg, Leopold-Franzens-Universität Innsbruck, University of Bologna

Journal

Science Advances

Volume

10

No. of pages

8

ISSN

2375-2548

DOI

https://doi.org/https://arxiv.org/abs/2303.17945

Publication date

11-2024

Peer reviewed

Yes

Austrian Fields of Science 2012

103015 Condensed matter

ASJC Scopus subject areas

General

Portal url

https://ucrisportal.univie.ac.at/en/publications/realspace-investigation-of-polarons-in-hematite-fe2o3(a7ab223f-8f46-4d56-b726-301298c02f40).html