Properties of Single‐Domain Particles of Cobalt‐Nickel

Single‐domain particles of cobalt‐nickel have been prepared by electrodeposition into mercury, and the intrinsic coercive force observed as a function of particle composition. A marked increase in coercive force occurred in particles having a composition of 87.5% cobalt–12.5% nickel. On the basis of the spherical structure of the particles observed in electron micrographs and from the constancy of the coercive force with packing, crystal anisotropy was assumed to be the principal factor contributing to the coercivity of the cobalt‐nickel particles. An intrinsic coercive force of 1750 oe was achieved, and a minimum crystal anisotropy of −2.4×10⁶ ergs/cc calculated at −196°C for the above composition. Magnets were prepared with a maximum magnetic energy of 1.3×10⁶ gauss‐oe.