A NEW PHASE IN THE INTERMETALLIC AU-CU SYSTEM

A new phase in the Au-Cu system has been found by means of high-resolu tion transmission electron microscopy and further investigation by ele ctron-energy-loss spectroscopy. It developed during room-temperature i rradiation of ordered Cu3Au along [110] and [100] with 400 keV electro ns. The composition of the new phase is close to Au0.5Cu0.5. The cryst al structure is proposed to be either b.c.c. (a = 0.330 + 0.002 nm) or cubic primitive (a = 0.233 +/- 0.002 nm).