1. High-Moment FeCo Magnetic Nanoparticles Obtained by Topochemical H 2 Reduction of Co-Ferrites.
- Author
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Omelyanchik, Alexander, Varvaro, Gaspare, Maltoni, Pierfrancesco, Rodionova, Valeria, Murillo, Jean-Pierre Miranda, Locardi, Federico, Ferretti, Maurizio, Sangregorio, Claudio, Canepa, Fabio, Chernavsky, Petr, Perov, Nikolai, and Peddis, Davide
- Subjects
METAL nanoparticles ,NANOPARTICLE size ,MAGNETIC materials ,MAGNETIC field effects ,MAGNETIZATION measurement ,FERRITES ,MAGNETIC nanoparticles - Abstract
Featured Application: Metallic nanoparticles with a high value of magnetization have potential interest for application in biomedicine, catalysis, composite permanent magnets, and other fields. Cobalt ferrite nanoparticles of different stoichiometries synthesized by a sol–gel autocombustion method were used as a starting material to obtain high-moment Fe
50 Co50 and Fe66 Co34 metal nanoparticles by topochemical hydrogen reduction. Structural and magnetic investigations confirmed the formation of FeCo nanoparticles with crystallite sizes of about 30 nm and magnetization at 0.5 T of ~265 Am2 /kg (0 K), which was larger than the expected bulk value, likely because of the incorporation in the body-centered cubic (bcc) FeCo structure of the residual C atoms present on the surface of the oxide particles. Temperature-dependent magnetization measurements in the H2 atmosphere were also performed to investigate in detail the reduction mechanism and the effect of an external magnetic field on the process efficiency. [ABSTRACT FROM AUTHOR]- Published
- 2022
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