On the B2 -> fcc transformation of Fe-Rh during deformation

It has been previously reported that deformation of the Fe-Rh intermetallic with B2-type ordered bce structure results in a B2-to-fcc phase transforma tion and that the Fee phase exhibits a low-temperature magnetic behaviour t ypical of a spin glass or a cluster glass. Using transmission electron micr oscopy in conjunction with X-ray diffraction, Mossbauer spectroscopy and ot her previously published data, we show that the B2-to-fcc transformation oc curs before grain refinement and deformation-induced nanocrystallization is completed anti long before the low-temperature magnetic properties show sp in-glass-like behaviour. Not only is a B2-to-bcc solid-solution transformat ion not observed but evidence is found for localized transformations from t he B2 phase to ordered fct L1(0), and it is concluded that the metastable f ee phase must contain strong chemical short-range order (CSRO), which then is progressively reduced by continued deformation in this case by ball mill ing. The continued reduction in the degree of CSRO is related to the develo pment of the spin-glass-like behaviour observed after long milling times.