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

The magnetic and structural properties of the Fe"0","7"0Si"0","3"0 alloy are analyzed by using X-ray diffraction and Mossbauer spectrometry. The samples were prepared by mechanical alloying in a planetary ball mill pulverisette 5 during 1, 5, 9, 15, 75 and 100h milling, with a ball mass to powder mass relation of 10:1. The X-ray diffraction patterns showed a coexistence of BCC, DO"3 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 5h, then slowly up to 15h, and finally it remains nearly constant. The lattice parameter for each phase remains nearly constant (2838A for the BCC structure). The shape of hyperfine field distributions used to describe the Mossbauer spectra is discussed.