FAR FROM EQUILIBRIUM PHASE-TRANSITION INDUCED BY SOLID-STATE REACTION IN THE FE-SI SYSTEM

In the first part of this paper, this special issue gives us the opportunity to overview systems which have been mechanically synthesized. In the second part, we report on the far from equilibrium phase transitions induced by mechanical alloying and post-milling isothermal annealing in the Fe-Si system. The end-product structures were characterized using X-ray diffraction patterns. Specific attention was paid to two particular phases exhibiting some very interesting physical properties: Fe(Si) (a crystalline phase exhibiting a magnetic effect) in which extension of the solubility limit of silicon of the crystalline Fe(Si) phase (up to 16 wt.% silicon) was observed, and beta-FeSi2 (a semiconductor-type phase exhibiting a direct optical gap and a thermoelectric power) crystalline phases.