Synthesis FeCo nanoparticles by NaBH4 reduction in oleylamine

Xia Xua,b, Jihoon Parka,c, Yang-Ki Honga,c, Alan M. Lanea,b*

aCenter for Materials for Information Technology, The University of Alabama, Tuscaloosa, AL

35487 USA.

bDepartment of Chemical and Biological Engineering, The University of Alabama, Tuscaloosa, AL 35487 USA.

cDepartment of Electrical and Computer Engineering, The University of Alabama, Tuscaloosa, AL 35487 USA.

FeCo alloy nanoparticles are of great interest because of their wide applications on catalysis, biomedicine, magnetic resonance imaging (MRI), and data storage. Reducing inorganic salts of iron and cobalt with sodium borohydride (NaBH4) in aqueous solution is a popular synthesis method due to its low cost and easy operation. However, there are several limitations, such as particle agglomeration1, impurity phases (FexB2 and CoxB3) and amorphous product1. To overcome these limitations, we reduced iron and cobalt organic precursors with NaBH4 in an organic solvent. Briefly, iron(III) acetylacetonates (Fe(acac)3), cobalt(II) acetylacetonates (Co(acac)2) and NaBH4 were introduced into oleylamine under a gas mixture of 95% N2 + 5% H2
at room temperature. The mixture was then heated to 300 oC for 10 min. After reaction, the
product was separated and washed for characterization. Fig. 1 shows the TEM image of FeCo nanoparticles with good dispersion and size around 15 nm. X-ray diffraction peaks in Fig. 2 are correctly indexed to body centered cubic (bcc) structure of FeCo alloy. A magnetic hysteresis loop in Fig. 3 shows that the synthesized FeCo nanoparticles have high magnetization (138 emu/g) and low coercivity (192 Oe). This method improves the quality of FeCo nanoparticles synthesized from NaBH4 reduction.
This work was supported by APRA-E/REACT program of US Department of Energy under contract No. DE-AR0000189.
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34, 28.

[3] G. N. Glavee, K. J. Klabunde, C. M. Sorense, G. C. Hadjipanayis, Langmuir., 1993, 9, 162.

* Corresponding author contacted by telephone: +1-205-348-6367, fax: +1-205-348-7558 and email: alane@eng.ua.edu.

1

Fig. 1 TEM image of FeCo nanoparticles Fig. 2 XRD patterns of FeCo nanoparticles

Fig. 3 Magnetic hysteresis loop of FeCo nanoparticles

2