Development of "ExchangeCoupled Magnet" based on a new principle- Towards rare-earth free magnet -

这项研究提出了“交换耦合磁体”，在这种磁体中，通过与硬颗粒反铁磁耦合的薄铁磁表面层来防止硬颗粒表面的磁化反转。对Nd-Fe-B磁体的计算机模拟预测，交换耦合的磁体的矫顽力是没有反铁磁耦合的磁体的1.5-2倍。为了获得这样的磁体，铬、锰、铯和钒基合金从快冷的Nd2Fe14B磁粉表面扩散到Nd2Fe14B晶界。然而，我们还没有成功地合成出这样的反铁磁性与Nd_Fe_B偶联的表面层

This investigation proposes the “exchange-coupled magnet”, in which magnetization reversal from the surfaces of a hard grain is prevented by thin ferromagnetic surface layers coupled anti-ferromagnetically with the hard grain. Thecomputer simulation for Nd-Fe-B magnets predicted that the coercivity of the exchangecoupled magnet was 1.5-2 times larger than those without anti-ferromagnetic coupling. In order to achieve such magnets, Cr, Mn, Cy, and V-based alloys were diffused from the surface of rapidly quenched Nd-Fe-B magnet powders into the boundaries between Nd2Fe14Bgrains. However, we have not succeeded to synthesizing such surface layers coupledanti-ferromagneticall with Nd_Fe_B yet