Abstract

We have experimentally observed the influence of a magnetic phase transition on the morphological transformation during a thermal oxidation reaction in air due to ionic diffusion process. A Fe ferromagnetic metallic microwire turns into a semiconducting iron oxide microtube when heat treated above the Curie temperature. Electrical transport behavior of Fe microwires measures changes in ionic transport across magnetic transition. Scanning electron microscopy images and x-ray diffraction measurements revealed that the formed microtubes are comprised of a Fe2O3 outer and Fe3O4 inner shells when the sample is heated above the Fe magnetic ordering temperature. This result is closely related to the higher atomic mobility in the paramagnetic state. We discuss the influence of magnetic spin interaction on Fe vacancy formation and the ionic mass transport. Numerical calculations of the vacancy formation energy in both ferromagnetic and paramagnetic states support our experimental observation that enhanced ionic mobility, leaving vacancies behind, is correlated to the vanishing of magnetic spin interactions above TC.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.