Calcium-assisted reduction of cobalt ferrite nanoparticles for nanostructured iron cobalt with enhanced magnetic performance

TitleCalcium-assisted reduction of cobalt ferrite nanoparticles for nanostructured iron cobalt with enhanced magnetic performance
Publication TypeJournal Article
Year of Publication2017
AuthorsQi, B., J. S. Andrew, and D. P. Arnold
JournalJournal of Nanoparticle Research
Volume19
Issue3
Date PublishedJan-03-2017
ISSN1388-0764
Abstract

This paper demonstrates the potential of a calcium-assisted reduction process for synthesizing fine-grain (~100 nm) metal alloys from metal oxide nanoparticles. To demonstrate the process, an iron cobalt alloy (Fe66Co34) is obtained by hydrogen annealing 7-nm cobalt ferrite (CoFe2O4) nanoparticles in the presence of calcium granules. The calcium serves as a strong reducing agent, promoting the phase transition from cobalt ferrite to a metallic iron cobalt alloy, while maintaining high crystallinity. Magnetic measurements demonstrate the annealing temperature is the dominant factor of tuning the grain size and magnetic properties. Annealing at 700 °C for 1 h maximizes the magnetic saturation, up to 2.4 T (235 emu/g), which matches that of bulk iron cobalt.

URLhttp://link.springer.com/10.1007/s11051-017-3797-7
DOI10.1007/s11051-017-3797-7
Short TitleJ Nanopart Res