Open AccessSuperparamagnetic Sub-5 nm Fe@C Nanoparticles: Isolation, Structure, Magnetic Properties, and Directed Assembly
Author(s) -
YuHuang Wang,
Wei Wei,
Daniel Maspoch,
Jinsong Wu,
Vinayak P. Dravid,
Chad A. Mirkin
Publication year - 2008
Publication title -
nano letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.853
H-Index - 488
eISSN - 1530-6992
pISSN - 1530-6984
DOI - 10.1021/nl8020768
Subject(s) - superparamagnetism , nanoparticle , materials science , coercivity , squid , nanotechnology , magnetic nanoparticles , characterization (materials science) , carbon nanotube , particle size , magnetometer , particle (ecology) , chemical engineering , magnetization , condensed matter physics , magnetic field , ecology , oceanography , physics , quantum mechanics , geology , engineering , biology
A method for isolating single crystalline sub-5 nm carbon coated iron nanoparticles (Fe@C NPs) from a carbon nanotube matrix has been developed. The isolation of such particles allows for their characterization by high resolution electron microscopy methods and SQUID magnetometry. While the NPs are superparamagnetic at room temperature, at 10 K they exhibit a coercivity nearly 30 times greater than that of commercial Fe3O4 NPs of comparable size. A novel nanotemplate directed assembly method for manipulating the particles at the individual particle level is also reported.