title: A density functional theory investigation of the electronic structure and spin moments of magnetite.
abstract: We present the results of density functional theory (DFT) calculations on magnetite, Fe3O4, which has been recently considered as electrode in the emerging field of organic spintronics. Given the nature of the potential applications, we evaluated the magnetite room-temperature cubic [Formula: see text] phase in terms of structural, electronic, and magnetic properties. We considered GGA (PBE), GGA +U(PBE +U), and range-separated hybrid (HSE06 and HSE(15%)) functionals. Calculations using HSE06 and HSE(15%) functionals underline the impact that inclusion of exact exchange has on the electronic structure. While the modulation of the band gap with exact exchange has been seen in numerous situations, the dramatic change in the valence band nature and states near the Fermi level has major implications for even aqualitativeinterpretation of the DFT results. We find that HSE06 leads to highly localized states below the Fermi level while HSE(15%) and PBE +Uresult in delocalized states around the Fermi level. The significant differences in local magnetic moments and atomic charges indicate that describing room-temperature bulk materials, surfaces and interfaces may require different functionals than their low-temperature counterparts.
authors.affiliation: School of Chemistry and Biochemistry and Center for Organic Photonics and Electronics, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, USA; School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0245, USA.
authors.forename: Junghyun
authors.initials: J
authors.lastname: Noh
authors.affiliation: Department of Chemistry, Faculty of Science, King Abdulaziz University, PO Box 80203, Jeddah 21589, Kingdom of Saudi Arabia.
authors.forename: Osman I
authors.initials: OI
authors.lastname: Osman
authors.affiliation: Department of Chemistry, Faculty of Science, King Abdulaziz University, PO Box 80203, Jeddah 21589, Kingdom of Saudi Arabia.
authors.forename: Saadullah G
authors.initials: SG
authors.lastname: Aziz
authors.affiliation: School of Chemistry and Biochemistry and Center for Organic Photonics and Electronics, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Winget
authors.affiliation: School of Chemistry and Biochemistry and Center for Organic Photonics and Electronics, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, USA; Department of Chemistry, Faculty of Science, King Abdulaziz University, PO Box 80203, Jeddah 21589, Kingdom of Saudi Arabia.
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Brédas
keywords: DFT; ferrimagnetism; inverse spinel structure; magnetite; spintronics