Milling time effects on the magnetic and structural properties of the Fe70Si30 system

The magnetic and structural properties of the Fe0.70Si0.30 alloy are analyzed by using X-ray diffraction and Mosssbauer spectrometry. The samples were prepared by mechanical alloying in a planetary ball mill pulverisette 5 during 1, 5, 9, 15, 75 and 100 h milling, with a ball mass to powder mass relation of 10:1. The X-ray diffraction patterns showed a coexistence of BCC, DO3 and FeSi structural phases: however, for 1-5h process, we observed additional peaks Which Correspond to iron and silicon elements. These results indicate us that the alloy is still a non-fully consolidated sample. The grain size decreases drastically from 1 to 5 h, then slowly up to 15 h, and finally it remains nearly constant. The lattice parameter for each phase remains nearly constant (2838 A for the BCC structure). The shape of hyperfine held distributions used to describe the Mossbauer spectra is discussed. (C) 2008 Elsevier Ltd. All rights reserved.