| abstract |
There is disclosed a method of making unsupported particles of a base metal selected from the group consisting of iron, cobalt, and nickel, which comprises combining an aqueous solution or suspension of a base metal salt, a strong base so that the resulting combination has an effective hydroxide ion concentration, and a reducing agent, which is then subjected to an autocatalytic reaction at about atmospheric pressure to form a precipitate of the metal. The unsupported base metal particles exhibit an anisometric morphology, generally platetlet or disk-shaped, and have a relatively high aspect or width to thickness ratio, which is preferably three or greater, exhibit ferromagnetic properties, and one or more of these base metals may be formed to exhibit a single magnetic domain. The resulting precipitate of metal particles may be formed as an agglomerate as by subjecting the precipitate to aging or to external means. |