Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8155963 | Journal of Magnetism and Magnetic Materials | 2015 | 10 Pages |
Abstract
The introduction of an oxidation treatment to the synthesis of spherical and core-shell αâ³-Fe16N2/Al2O3 nanoparticles (~62 nm) from plasma-synthesized core-shell α-Fe/Al2O3 nanoparticles has been found to result in a high yield of αâ³-Fe16N2 phase of up to 98%. The oxidation treatment leads the formation of a maghemite phase with open channeled structures along the c-axis, facilitating penetration of H2 and NH3 gases during the hydrogen reduction and nitridation steps. The saturation magnetization and magnetic coercivity of the core-shell αâ³-Fe16N2/Al2O3 magnetic nanoparticles were found to be 156 emu/g and 1450 Oe, respectively. The detailed effects of the oxidation on the formation of αâ³-Fe16N2 phase were investigated by characterizing the morphology (SEM, TEM and BET), elemental composition (EDX, EELS, and XAFS) and magnetic properties (Mössbauer and MSPS) of the prepared particles. The good magnetic properties obtained have the potential for future applications such as rare-earth-free magnetic materials.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Condensed Matter Physics
Authors
Rizka Zulhijah, Asep Bayu Dani Nandiyanto, Takashi Ogi, Toru Iwaki, Keitaro Nakamura, Kikuo Okuyama,