ATOMIC DISORDER INDUCED BY MECHANICAL MILLING IN THE NB3AU INTERMETALLIC COMPOUND

The behavior of the intermetallic A15 compound Nb3Au in the early stage of mechanical milling was studied. By following the degradation of the superconducting transition temperature and the increase of the lattice parameter as a function of milling time, it was found that Nb3Au exhibits atomic (chemical) disorder due to milling. A value for the ballistic jump frequency of the atoms was assessed. The behavior turns out to be very similar to that of Nb3Sn, although for long milling time Nb3Sn amorphizes, whereas Nb3Au transforms from the A15 structure to the bcc structure.