FORMATION OF GAMMA-FE BY MECHANICAL ALLOYING OF CU-FE

A study of the low temperature magnetic behavior of a metastable fcc-F eCu solid solution obtained by mechanical alloying as well as of the s ubsequent annealed product is carried out. The metastable solid soluti on is ferromagnetic and it has a temperature dependence of the magneti zation which follows a T3/2 law. During annealing the metastable phase decomposes into Cu and Fe phases. It has been found that the low temp erature magnetization of this subsequent mixture decreases with respec t to that of the fcc solid solution. Moreover the Mossbauer spectrum o btained shows a paramagnetic Fe phase with the same relative resonant area than the percentage of the decrease in magnetization. These resul ts suggest that after the annealing process, not all the iron is found in the stable and ferromagnetic bcc or a phase, but a noticeable prop ortion probably remains as fcc particles of gamma-Fe.