磁場印加による強磁性τ-Mn-Alへの相変態の促進

抄録

The magnetic field effect on phase formations of ferromagnetic Mn-Al (τ-phase) was evaluated. The transformation from ε-phase with hcp-structure to τ-phase was accelerated by annealing in magnetic field. With in-field annealing at 623 K, the magnetization of the sample annealed at 15 T was a maximum of 72.2 A･m²/kg at 1.5 T, which was over 4 times larger than that annealed in a zero field. Meanwhile, the precipitation of non-ferromagnetic β-phase was suppressed by in-field annealing. Magnetic field-induced acceleration of ε-τ transformation and suppression of τ-β transformation were due to the gain of Zeeman energy of τ-phase.

 

Mater. Trans. 58(2017) 1511-1518に掲載．内容理解の簡略化のため，背景，実験方法，結果，考察において文章を修正．Fig. 1とFig. 2を新しくFig. 1にまとめた．Fig. 2は重要な点のみのグラフに変更し簡略化．Fig. 4とFig. 5を重要な点のみに絞り新しくFig. 3にまとめた．Fig. 6 (a)とFig. 6 (b)は比較を容易にするため，一つにまとめFig. 4とした．その他図の一部は章中で詳しく説明し，内容理解において重要でないため省略．

Fig. 4 The annealing time dependence of the saturation magnetization M_s of the samples at 1.5 T.