Niobium-germanium (Nb3Ge) is an intermetallic chemical compound of niobium (Nb) and germanium (Ge). It has A15 phase structure.
It is a superconductor with a critical temperature of 23.2 K.
Sputtered films have been reported to have an upper critical field of 37 teslas at 4.2 K. [1]
Nb3Ge was discovered to be a superconductor in 1973 [2] and for 13 years (until the discovery in 1986 of the cuprate superconductors) it held the record as having the highest critical temperature. [3]
It has not been as widely used for superconductive applications as niobium–tin or niobium–titanium.
Niobium-germanium-aluminium has an upper critical field of about 10 teslas. [4]