October 2009, Volume 4, Issue 10, pp 1130-1134,
Open Access This content is freely available online to anyone, anywhere at any time.
Date: 14 Jun 2009
Nearly Monodispersion CoSm Alloy Nanoparticles Formed by an In-situ Rapid Cooling and Passivating Microfluidic Process
An in situ rapid cooling and passivating microfluidic process has been developed for the synthesis of nearly monodispersed cobalt samarium nanoparticles (NPs) with tunable crystal structures and surface properties. This process involves promoting the nucleation and growth of NPs at an elevated temperature and rapidly quenching the NP colloids in a solution containing a passivating reagent at a reduced temperature. We have shown that Cobalt samarium NPs having amorphous crystal structures and a thin passivating layer can be synthesized with uniform nonspherical shapes and size of about 4.8 nm. The amorphous CoSm NPs in our study have blocking temperature near 40 K and average coercivity of 225 Oe at 10 K. The NPs also exhibit high anisotropic magnetic properties with a wasp-waist hysteresis loop and a bias shift of coercivity due to the shape anisotropy and the exchange coupling between the core and the thin oxidized surface layer.
Y. Song et al., Shape and crystallinity shift of nanoparticles formed in a microfluidic reactor. J. Nanopart. Res. (under reviewing)
L.-H. Hung, A.P. Lee, Microfluidic devices for the synthesis of nanoparticles and biomaterials. J. Med. Biol. Eng. 27, 1–6 (2007)
H.S. Carslaw, J.C. Jaeger, Conduction of heat in solids (Clarendon Press, Oxford, 1956), p. 232
J.H.I. Lienhard, Lienhard JHV A heat transfer textbook (Phkigiston Press, Massachusetts, 2003), pp. 203–223
Y. Song, L.L. Henry, W.T. Yang, In situ rapid cooling microfluidic process for the formation of stable cobalt amorphous nanoparticles Langmuir (revised reversion under reviewing)
- Nearly Monodispersion CoSm Alloy Nanoparticles Formed by an In-situ Rapid Cooling and Passivating Microfluidic Process
- Open Access
- Available under Open Access This content is freely available online to anyone, anywhere at any time.
Nanoscale Research Letters
Volume 4, Issue 10 , pp 1130-1134
- Cover Date
- Print ISSN
- Online ISSN
- Additional Links
- Microfluidic reactor
- Industry Sectors
- Author Affiliations
- 1. Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beihang University, 100191, Beijing, China
- 2. Department of Physics, Southern University A & M College, Baton Rouge, LA, 70813, USA