Title :
The preparation of Co/Fe alloy fine particles from HFeCo3(CO)12
Author :
Lambrick, D.B. ; Mason, N. ; Hoon, S.R. ; Kilner, M. ; Chapman, J.N.
Author_Institution :
Dept. of Phys., Durham Univ., UK
fDate :
3/1/1988 12:00:00 AM
Abstract :
The preparation and properties of magnetic fluids containing fine particles of Co/Fe ´alloys´ are reported. The alloy nature of single particles has been confirmed by local area energy-dispersive X-ray analysis at very high spatial resolution in transmission electron microscopy. These particles have been prepared by the decomposition of a mixed-metal organometallic precursor, HFeCo3(CO)12, in the presence of surfactants. Two principal compositions have been observed, one of 3:1 Co:Fe as in the precursor molecule and another of 8:1 Co:Fe. Electron microscopy has also revealed mean particle diameters in the range 6-8 nm and narrow size distributions. In the case of one fluid, the proportion of metal atoms in the precursor converted to metal in the ferromagnetic state is estimated to be approximately 84% before oxidation. The kinetics of the decomposition show differences in detail compared to those of Co4(CO)12.
Keywords :
X-ray chemical analysis; cobalt alloys; ferromagnetic properties of substances; iron alloys; magnetic fluids; magnetic properties of fine particles; powder metallurgy; transmission electron microscope examination of materials; CoFe; HFeCo3(CO)12; decomposition; ferromagnetic state; fine particles; local area energy-dispersive X-ray analysis; magnetic fluids; transmission electron microscopy; Cobalt alloys; Electron microscopy; Iron alloys; Magnetic analysis; Magnetic liquids; Magnetic properties; Oxidation; Spatial resolution; State estimation; Transmission electron microscopy;
Journal_Title :
Magnetics, IEEE Transactions on
