Superparamagnetic MFe2O4 (M = Fe, Co, Mn) Nanoparticles: Tuning the Particle Size and Magnetic Properties through a Novel One-Step Coprecipitation Route

• Type: Article in International Scientific Journal
• Date: 2012

Authors

Clara Pereira (Author) FCUP; Andre M Pereira (Author) FCUP; Carlos Fernandes (Author) Other; Mariana Rocha (Author) Other; Ricardo Mendes (Author) Other; Maria Paz Fernandez Garcia (Author) FCUP; Alexandra Guedes (Author) FCUP; Pedro B Tavares (Author) Other; Jean Marc Greneche (Author) Other; Joao P Araujo (Author) FCUP; Cristina Freire (Author) FCUP

Journal

Title: Chemistry of Materials

Vol. 24

Pages: 1496-1504

ISSN: 0897-4756

Publisher: American Chemical Society

Indexing

ISI Web of Knowledge - 431 Citations

Scopus - 490 Citations

Scientific classification

FOS: Engineering and technology > Materials engineering

Other information

Authenticus ID: P-002-AZS

DOI: 10.1021/cm300301c

Abstract (EN): Superparamagnetic ferrite nanoparticles (MFe2O4, where M = Fe, Co, Mn) were synthesized through a novel one-step aqueous coprecipitation method based on the use of a new type of alkaline agent: the alkanolamines isopropanolamine and diisopropanolamine. The role played by the bases on the particles' size, chemical composition, and magnetic properties was investigated and compared directly with the effect of the traditional inorganic base NaOH, The novel MFe2O4 nanomaterials exhibited high colloidal stability, particle sizes in the range of 4-12 nm, and superparamagnetic properties. More remarkably, they presented smaller particle sizes (up to 6 times) and enhanced saturation magnetization (up to 1.3 times) relative to those prepared with NaOH. Furthermore, the nanomaterials exhibited improved magnetic properties when compared with nanoferrites of similar size synthesized by coprecipitation with other bases or by other methods reported in the literature. The alkanolamines were responsible for these achievements by acting both as alkaline agents and as complexing agents that controlled the particle size during the synthesis process and improved the spin rearrangement at the surface (thinner magnetic "dead" layers). These results open new horizons for the design of water-dispersible MFe2O4 nanoparticles with tuned properties through a versatile and easily scalable coprecipitation route.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 9