Abstract
Mechanical aloying(MA) under the N2 gas atmosphere was capable of amorphizing V70Cu30 powders which is characterized by a positive heat of mixing (ΔHmix=5 kJ/mol). The S(Q) observed by X-ray diffraction gradually changed into the structure characteristic of an amorphous state with increasing milling time. The S(Q) observed by neutron diffraction after 200 hours of milling possesses a mixture of both amorphous and crystal phases. Since the coherent scattering length of the V atom in the neutron diffraction is negligibly small, small crystal peaks shoud be due the Cu crystal. The growth of a new peak at Q=4.25 A-1 in the S(Q) was observed after 40 and 120 hours of milling and then it disappeared after 200 hours of milling. This peak is attributable to the bcc Cu crystal formed by dissolving Cu atoms into the bcc V lattice. The results can be interpreted that the bcc solid solution is formed at the early stage of milling but becomes amorphized due to the gradual incorporation of N atoms in the subsequent stage of milling.
