“…It strongly grew during the 1960s and the 1970s with the development of new synthesis techniques (i.e., ultrarapid cooling, mechanical-alloying, plasma spray coating, and so on), which have opened the route to new metastable materials with new applications. − Al–Ge is an eutectic metal–semiconductor binary system under thermodynamic equilibrium conditions, standing among the most explored systems due to its similarity with the Al–Si system and to the technological interest of aluminum-based alloys. In addition, the existence of several metastable phases in crystalline and amorphous forms is of interest not only from a fundamental point of view − but also for several fields of application. For example, Al–Ge binary system compounds have been considered as low temperature lead free eutectic soldering/brazing alloys for replacing Au or Au–Si solders in microelectronic devices, , as bonding in electromechanical applications, , as solar absorbers, or for their superconducting properties .…”