) is a metallic chemical compound
(Nb) and Germanium
(Ge). It has A15 phase
It is a superconductor with a critical temperature of 23.2 kelvins (K).
Spluttered films have been reported to have an upper critical field of 37 Tesla at 4.2 K.
Ge was discovered to be a superconductor in 1971 and for 15 years (until the discovery in 1986 of the cuprate
superconductors) it held the record as having the highest critical temperature .
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 Tesla.