(Co,Fe)Pt nanoparticles by aqueous route; self-assembling, thermal and magnetic properties.

(Co,Fe)Pt alloy nanoparticles of A1-type structure were obtained by reduction of metallic salts by hydrazine in aqueous medium. Sb and Cu were used as additives for the (Co,Pt) and (Fe,Pt) systems, respectively. Sols of CoPt particles capped with oleylamine were obtained in one step by achieving the synthesis in an H2O/hexane two-phase medium. Conversion to an L10 phase was investigated in powders.