Synthesis and Characterization of Anisometric Cobalt Nanoclusters

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Science  03 Mar 1995:
Vol. 267, Issue 5202, pp. 1338-1340
DOI: 10.1126/science.267.5202.1338


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 diffraction from single particles revealed that they were oriented (001) crystals that conformed to a trigonal or hexagonal unit cell four times the size of the cell adopted by bulk α-cobalt. Lorentz microscopy indicated that these were single-magnetic domain particles, with the axis of magnetization located in the (101) plane, offset at some appreciable angle from the (001) axis.