Effect of milling on the magnetic properties of Al-Mn obtained by mechanical alloying

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• 作者：Mirna Betancourt^a ; ^b ; ^{betamirna@gmail.com} ; Pedro Silva^c ; Gema Gonzalez^b ; ^{gemagonz@ivic.gob.ve}
• 关键词：Al&ndash ; Mn ; Magnetic properties ; Mechanical alloying
• 刊名：Journal of Alloys and Compounds
• 出版年：2012
• 出版时间：25 September, 2012
• 年：2012
• 卷：536
• 期：supp_S1
• 页码：S296-S299
• 全文大小：401 K

文摘

Al-Mn powders were prepared to obtain the compound Mn₄₂Al₅₈ by mechanical alloying. The powders were milled during different periods (1 h, 5 h, 11.5 h, 15 h, 20 h and 50 h) using a SPEX 8000 mixer mill in nitrogen atmosphere. The materials were characterized by X-ray diffraction (XRD) and magnetic properties at room temperature, using a vibrating sample magnetometer (VSM). XRD shows partial transformation to ¦Á-Mn after only 1 h of milling and a mixture of ¦Á-Mn and ¦Â-Mn after 11.5 h of milling and further milling resulted in transformation to ¦Â-Mn phase with a grain size of 6 nm after 50 h. The change in magnetic properties with milling time is quite dramatic, from a ferromagnetic behavior for ¦Á-Mn(Al) to paramagnetic after 11.5 h of milling and showing again ferromagnetic behavior, with a strong increase of magnetization values of 5.5 emu/g, after 50 h of milling with formation of ¦Â-Mn(Al).