Low-Temperature Solution-Mediated Synthesis of Polycrystalline Intermetallic Compounds from Bulk Metal Powders

Abstract

A variety of binary intermetallic compounds of late transition metals with low-melting post-transition metals have been synthesized in bulk quantities by reacting molten metal dispersions with fine metal powders in hot polyalcohol solvents. Fourteen distinct intermetallics were formed using this technique: SbSn, FeSn 2, Cu 6 Sn 5, CoSn 3, Ni 3 Sn 4, FeGa 3, NiGa 4, Cu 9 Ga 4, CoGa 3, Ni 2 In 3, InSb, In 5 Bi 3, InBi, and Bi 3 Ni. Notable among these are a low-temperature phase (α-CoSn 3 ), textured intermetallic powders with anisotropic morphologies (α-CoSn 3 and FeSn 2 ), and superconductors (Bi 3 Ni and In 5 Bi 3 ). Reaction pathway studies suggest that the molten low-melting metals diffuse into the larger higher melting powders, forming intermetallic compounds directly in a liquid-phase medium from bulk-scale powders of the constituent elements.