compounds of germanium with metals. The composition of most germanides is analogous to that of the corresponding silicides and does not follow formal valence rules (KGe, KGe4, BaGe2, Mn5Ge3, UGe3, and so on). The germanides of alkaline and alkaline earth metals, as well as of magnesium, are readily decomposed by water and acids to give germanium hydrides; most germanides of the transition metals resist the action of acids and alkalies. The main method of producing germanides is the melting or sintering of the components. The germanides of alkaline and alkaline earth metals are semiconductors; those of the transition metals have metallic properties. The germanides of niobium and vanadium and of vanadium-based alloys, which become superconductors at relatively high temperatures (Nb3Ge, 6.3° K; Nb3Sn1-xGex, 17.6°-18° K; V3Ge, 6.01° K), are of great interest. Germanides are potentially valuable for making new alloys with special physical properties.
REFERENCESamsonov, G. V., and V. N. Bondarev. Germanidy. Moscow, 1968.
B. A. POPOVKIN