Search

Iron nanoparticles were synthesized in situ within the channels of a microchannel glass by differentially pumping across the plate in conjunction with plasma enhanced chemical vapor deposition. The microchannel glass was mounted on a custom designed differentially pumped sample holder, which produced 10 Torr of differential pressure across the 5 μm channels. The iron precursor was ferrocene [(C[sub 5]H[sub 5])[sub 2]–Fe]. The composition and structure of the nanoparticles was determined by electron diffraction to be Fe[sub 3]O[sub 4], where oxidation of the nanoparticles occurred upon exposure to air. Transmission electron microscopy revealed the formation of nanoparticles ranging in size from 150 to 960 nm, which are formed from smaller nanoparticles on the order of 5–10 nm. The large nanoparticles (150–960 nm) grow independently of one another and are largely freestanding within the channels, i.e., they are not highly attached to the channel walls or agglomerated. The magnetic signature of the large nanoparticles is consistent with ferrimagnetic Fe[sub 3]O[sub 4]. The magnetic hysteresis loops of the particles are reminiscent of superparamagnetic behavior, which would suggest that the magnetic coupling between the 5 and 10 nm nanoparticles is weak. A model for nanoparticle formation based on plasma suspension of the Fe nanoparticles inside the glass channels is proposed. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Presents information on a study which synthesized iron nanoparticles in an amorphous boron carbide matrix using plasma enhanced chemical vapor deposition. Nanoparticle synthesis; Experimental details; Results and discussion; Conclusions.