Chemical route to nano-engineered skutterudites

Atomic scale material design provides opportunities for developing thermoelectric materials with significantly improved figures of merit (ZT). The use of small particle size may also increase ZT, because of possible increases in the ratio of electrical conductivity to thermal conductivity and the thermopower. A novel chemical route is described for fabricating multi-component thermoelectric metal alloys as fine nanostructured powders. The different constituents are simultaneously precipitated from aqueous solution-thereby providing a precursor having a precise desired composition and uniform molecular scale mixing. Thermal treatment of the precursor included calcination in air and reduction by hydrogen. Nanophase skutterudite of CoSb/sub 3/ in reasonably high phase purity was thereby produced after thermal treatments at a temperature of 350-550/spl deg/C for only 3-5 hrs. High purity Ni-doped skutterudites of Co/sub 1-x/Ni/sub x/Sb/sub 3/ up to x=0.25 were also produced using this route.