Formation of nanostructured ω-Al 7Cu 2 Fe crystalline phase by the ball milling technique

Crystalline omega-Al7Cu2Fe bulk samples were prepared by arc furnace and then by means of milling, the average grain size of these samples is reduced to the nanometer scale. The structural and magnetic properties of the nanostructured omega-Al7Cu2Fe phase have been studied by X-ray diffraction employing Rietveld method, Mossbauer spectroscopy and vibrating sample magnetometry. The results indicate that the average grain size of the synthesized sample (omega-phase) rapidly decreases from 79 to 12 nm after 5 h of milling. Furthermore, the hyperfine parameters of the nanostructured samples are higher than the values for the bulk omega-phase. Magnetic measurements show a weak ferromagnetic behavior with M (s) = 0.46 emu.g (-aEuro parts per thousand 1) for the bulk omega-phase. After the milling process this value increases to M (s) = 1.50 emu.g (-aEuro parts per thousand 1) due to the formation and growth of a magnetic interstitial region after reducing the average grain size of the sample.