SYNTHESIS AND CHARACTERIZATION OF ANISOMETRIC COBALT NANOCLUSTERS

Sonication of aqueous Co2+ and hydrazine resulted in the formation of anisometric (disk-shaped) cobalt nanoclusters that averaged about 100 nanometers in width and 15 nanometers in thickness. Electron diffracti on from single particles revealed that they were oriented (001) crysta ls that conformed to a trigonal or hexagonal unit cell four times the size of the cell adopted by bulk alpha-cobalt. Lorentz microscopy indi cated that these were single-magnetic domain particles, with the axis of magnetization located in the (101) plane, offset at some appreciabl e angle from the [001] axis.