title: Atomic-scale structure and properties of highly stable antiphase boundary defects in Fe3O4.
abstract: The complex and intriguing properties of the ferrimagnetic half metal magnetite (Fe3O4) are of continuing fundamental interest as well as being important for practical applications in spintronics, magnetism, catalysis and medicine. There is considerable speculation concerning the role of the ubiquitous antiphase boundary (APB) defects in magnetite, however, direct information on their structure and properties has remained challenging to obtain. Here we combine predictive first principles modelling with high-resolution transmission electron microscopy to unambiguously determine the three-dimensional structure of APBs in magnetite. We demonstrate that APB defects on the {110} planes are unusually stable and induce antiferromagnetic coupling between adjacent domains providing an explanation for the magnetoresistance and reduced spin polarization often observed. We also demonstrate how the high stability of the {110} APB defects is connected to the existence of a metastable bulk phase of Fe3O4, which could be stabilized by strain in films or nanostructures.
authors.affiliation: 1] Department of Physics, University of York, Heslington, York YO10 5DD, UK [2] WPI-AIMR, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan.
authors.forename: Keith P
authors.initials: KP
authors.lastname: McKenna
authors.affiliation: Department of Physics, University of York, Heslington, York YO10 5DD, UK.
authors.forename: Florian
authors.initials: F
authors.lastname: Hofer
authors.affiliation: Department of Physics, University of York, Heslington, York YO10 5DD, UK.
authors.forename: Daniel
authors.initials: D
authors.lastname: Gilks
authors.affiliation: Department of Physics, University of York, Heslington, York YO10 5DD, UK.
authors.forename: Vlado K
authors.initials: VK
authors.lastname: Lazarov
authors.affiliation: WPI-AIMR, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan.
authors.forename: Chunlin
authors.initials: C
authors.lastname: Chen
authors.affiliation: WPI-AIMR, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan.
authors.forename: Zhongchang
authors.initials: Z
authors.lastname: Wang
authors.affiliation: WPI-AIMR, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Ikuhara