High-Moment FeCo Magnetic Nanoparticles Obtained by Topochemical H2 Reduction of Co-Ferrites

Autor: Alexander Omelyanchik, Gaspare Varvaro, Pierfrancesco Maltoni, Valeria Rodionova, Jean-Pierre Miranda Murillo, Federico Locardi, Maurizio Ferretti, Claudio Sangregorio, Fabio Canepa, Petr Chernavsky, Nikolai Perov, Davide Peddis
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: Applied Sciences, Vol 12, Iss 4, p 1899 (2022)
Druh dokumentu: article
ISSN: 2076-3417
DOI: 10.3390/app12041899
Popis: Cobalt ferrite nanoparticles of different stoichiometries synthesized by a sol–gel autocombustion method were used as a starting material to obtain high-moment Fe50Co50 and Fe66Co34 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.
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