SMALL ALLOY PARTICLES FORMED BY COREDUCTION OF SOLUBLE PRECURSORS WITH ALKALIDES OR ELECTRIDES IN APROTIC-SOLVENTS

Soluble compounds of transition metals and post-transition metals in dimethyl ether or tetrahydrofuran are rapidly reduced at -30-degrees-C by dissolved alkalides or electrides to produce metal particles with crystallite sizes from < 3 to 15 nm. When two different metal salts are used, alloys or intermetallic compounds form as indicated by X-ray photoelectron spectroscopy. Confirmation by electron diffraction can be made in the case of air-stable samples. Stoichiometric amounts of the alkalide [e.g. K+(15-crown-5)2K-] or electride [e.g. K+(15-crown-5)2e-] are used, and can be prepared separately or in situ. Elements used in this work range from Ta to Te. Especially with active metals, organic decomposition products are formed along with the metal particles.