Abstract
Directional solidification of Au–Co eutectic produces an aligned array of fcc cobalt rods in a gold matrix. The cobalt becomes finer, but more lamellar, as growth rate increases. Intrinsic coercive force increases with increasing growth rate, reaching 330 Oe at 2.1×10−1 cm/sec. Coercive forces up to 925 Oe are produced by subsequent wire drawing. Analysis of the magnetization curves indicates that deformation transforms the cobalt from fcc to hcp.