Block-copolymer-templated synthesis of iron, iron–cobalt, and cobalt–nickel alloy nanoparticles

We have produced, by thermal decomposition of organometallic complexes in a bulk film of poly(styrene-b-2-vinyl pyridine (P(S-b-2VP)), nonagglomerated iron, iron–cobalt, and cobalt–nickel alloy nanoparticles. The particles are patterned on the nanoscale: they reside within the P2VP domains of the block copolymer morphology. These results are made possible by the selective sequestration of organometallic complexes into these domains in amounts sufficient to nucleate and grow substantial quantities of nanoparticles, some of which are large enough to show non-zero coercivity at room temperature.