کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1804828 | 1024658 | 2007 | 13 صفحه PDF | دانلود رایگان |

Pre-alloyed Mn50+x−yAl50−xCy (x=0x=0, 2, 4, 6, 8; y=0y=0, 1.7, 3) powders were mechanically milled (MM), and the as-milled powders subsequently annealed at temperatures from 350 to 600 °C to produce the ferromagnetic metastable L10-structured τ-phase. Bulk Mn54Al46 specimens were also annealed under the same conditions for comparison. The effects of the Mn concentration and C additions on phase formation, microstructure, magnetic properties, as well as on the magnetization mechanism of the Mn–Al–C alloys were systematically investigated. It was found that the magnetic properties are strongly dependent both on the fraction of the τ-phase and its microstructure. There exists a strong influence of the microstructural refinement, due to the ball milling, on the rate of ε-phase to τ-phase transformation and on the stability of the τ-phase. The kinetics of formation and subsequent decomposition of the magnetic τ-phase were markedly different in the MM and bulk alloys. Both remanence curves and δM plots showed no exchange coupling among the τ-phase nanograins. The mechanism for the magnetization process was determined to be domain wall pinning.
Journal: Journal of Magnetism and Magnetic Materials - Volume 308, Issue 2, January 2007, Pages 214–226