Atomic-scale structure and properties of highly stable antiphase boundary defects in Fe<sub>3</sub>O<sub>4</sub>.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 25494005.
- Also identified by DOI 10.1038/ncomms6740 and PMC identifier 4275585.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The complex and intriguing properties of the ferrimagnetic half metal magnetite (Fe<sub>3</sub>O<sub>4</sub>) 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 Fe<sub>3</sub>O<sub>4</sub>, which could be stabilized by strain in films or nanostructures.