Study of nanocrystalline FeSi alloys prepared by mechanical alloying

In this work, the refinement of the Fe(94)Si(6) alloy is achieved by mechanical alloying in a high-energy planetary ball mill under argon atmosphere during various milling times up to 10 h. Samples at different milling times were characterized by scanning electron microscope, X-ray diffraction and Mossbauer spectra. After 1 h of milling time, it is observed the refinement and coexistence of two phases: the disordered solid solution of type A(2) (alpha-Fe(Si)) and the ordered solid solution of type B2. The relative concentration of the phase B2 varies with milling time, due to the order-disorder transition. The grain size of the phase A2 decreased most gradually up to 10 nm with increased milling time. Mossbauer spectra show the presence of a ferromagnetic phase with a mean hyperfine field of 30.1 T and a paramagnetic phase with a relative concentration of 6, 5%. (C) 2008 Elsevier B.V. All rights reserved.