Structural and Magnetic Properties of Mn-Al-C Alloy Powders by Mechanical Milling

When: Thursday, November 17, 2011 at 12:00 pm
Where: EG 306
Speaker: Dr. Ogheneyunume Obi
Organization: Department of Electrical and Computer Engineering, Northeastern University
Sponsor: Nanogroup Meeting

Mn-Al-C magnets are well known to posses hard magnetic properties without ferromagnetic elements due to their metastable ferromagnetic τ-phase, which has a relative large saturation magnetization of up to 7 kG and high anisotropy field of 40 kOe [1-3]. These materials have gained a lot of attention due to their less expensive component materials in contrast to the high cost of rare earth alloys such as Sm-Co and Nd-Fe-B etc., which makes them more practical in commercial applications as high-performance magnets.


In this work, we fabricated and investigated the structural and magnetic properties of Mn-Al-C (Mn0.53Al0.47-xCx) alloy powders by mechanical milling. The alloy powders were annealed in a tube furnace to form the ferromagnetic τ-phase with magnetic performance. The annealed powders exhibited a high percentage of τ-phases (39-57%), leading to a coercivity of up to 2.2 kOe and a maximum saturation magnetization of 3.3 kG. Magnetic properties were systemetically investigated with different annealing conditions.





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  3. T. Saito, Magnetic properties of Mn-Al-C alloy powders produced by mechanical grinding, Journal of Applied Physics 97, 10F304 (2005) .