Formation of nanostructured ω-Al7Cu2Fe crystalline phase by the ball milling technique

Crystalline ω-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 ω-Al7Cu2Fe phase have been studied by X-ray diffraction employing Rietveld method, Mössbauer spectroscopy and vibrating sample magnetometry. The results indicate that the average grain size of the synthesized sample (ω-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 ω-phase. Magnetic measurements show a weak ferromagnetic behavior with Ms = 0.46 emu.g − 1 for the bulk ω-phase. After the milling process this value increases to Ms = 1.50 emu.g − 1 due to the formation and growth of a magnetic interstitial region after reducing the average grain size of the sample.