Journal Article Synthesis of single-phase L10-FeNi magnet powder by nitrogen insertion and topotactic extraction

Goto, Sho  ,  Kura, Hiroaki  ,  Watanabe, Eiji  ,  Hayashi, Yasushi  ,  Yanagihara, Hideto  ,  Shimada, Yusuke  ,  Mizuguchi, Masaki  ,  Takanashi, Koki  ,  Kita, Eiji

7p.13216 , 2017-10 , Nature Publishing Group
Tetrataenite (L10-FeNi) is a promising candidate for use as a permanent magnet free of rare-earth elements because of its favorable properties. In this study, single-phase L10-FeNi powder with a high degree of order was synthesized through a new method, nitrogen insertion and topotactic extraction (NITE). In the method, FeNiN, which has the same ordered arrangement as L10-FeNi, is formed by nitriding A1-FeNi powder with ammonia gas. Subsequently, FeNiN is denitrided by topotactic reaction to derive single-phase L10-FeNi with an order parameter of 0.71. The transformation of disordered-phase FeNi into the L10 phase increased the coercive force from 14.5 kA/m to 142 kA/m. The proposed method not only significantly accelerates the development of magnets using L10-FeNi but also offers a new synthesis route to obtain ordered alloys in non-equilibrium states.

Number of accesses :  

Other information