Enhancing Crystallinity and Magnetic Properties of Cobalt Ferrite Nanoparticles via Thermal Oxidation

Abstract: Cobalt ferrite (CFO) nanoparticles (NPs) are highly promising for data storage, energy conversion, permanent magnets, and biomedical applications owing to their exceptional magnetic properties. However, the presence of phase impurities (particularly FeO and CoO) can severely degrade their magnetic properties, hindering their practical use. Here, we present a simple post‐synthesis oxidation approach to address this challenge. Our method involves the thermal decomposition of Fe−Co oleate followed by oxidation using trimethylamine N‐oxide. The results reveal the effective elimination of FeO and CoO impurities and the formation of spinel ferrite crystal structures post‐oxidation with no change in morphology or size. Magnetic measurements demonstrate a significant enhancement in magnetic properties (e. g., magnetic saturation, coercivity, and blocking temperature) in oxidized CFO NPs compared to the non‐oxidized counterparts, indicative of the recovered ferrimagnetic structure upon post‐synthesis oxidation. As expected, the restoration of the ferrimagnetic structure, resulting in improved magnetic anisotropy, led to decreased SAR values as the nanoparticles moved away from the optimal anisotropy range. The study underscores the necessity of post‐synthesis oxidation for ensuring phase purity and enhancing the magnetic properties of CFO NPs, irrespective of the synthesis method. This approach offers a promising route for producing highly functional magnetic nanoparticles for practical applications.

Location
Deutsche Nationalbibliothek Frankfurt am Main
Extent
Online-Ressource
Language
Englisch

Bibliographic citation
Enhancing Crystallinity and Magnetic Properties of Cobalt Ferrite Nanoparticles via Thermal Oxidation ; volume:10 ; number:11 ; year:2024 ; extent:9
ChemNanoMat ; 10, Heft 11 (2024) (gesamt 9)

Creator
Poon, Kingsley
Singh, Gurvinder

DOI
10.1002/cnma.202400168
URN
urn:nbn:de:101:1-2411121318213.479152659525
Rights
Open Access; Der Zugriff auf das Objekt ist unbeschränkt möglich.
Last update
15.08.2025, 7:26 AM CEST

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Associated

  • Poon, Kingsley
  • Singh, Gurvinder

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