Trimeron ordering, bandgap and polaron hopping in magnetite

TL;DR

This study uses DFT+U calculations to analyze the low-temperature structure of magnetite, focusing on trimeron ordering, bandgap characteristics, and polaron hopping, to better understand its electronic properties.

Contribution

It provides a detailed ab initio comparison of structural and electronic variations in magnetite, emphasizing the role of trimeron arrangements and polaron dynamics.

Findings

Trimeron ordering influences the electronic structure of magnetite.

The bandgap varies with different structural configurations.

Polaron hopping energies are linked to electronic conductivity.

Abstract

In this work, we apply the DFT+U approach for a detailed ab initio study of the refined structure of the low-temperature phase of magnetite [M. S. Senn et al., Nature 481, 173 (2012)]. We compare the electronic properties of this structure and several alternatives with respect to the presence of trimeron ordering and the bandgap properties. The connection of the trimeron arrangement with site-selective doping of magnetite is discussed. Calculations of the polaron hopping energy allow us to make one step forward toward understanding the complex interplay of polaronic and bandgap contributions to electronic properties of the magnetite.