Hot-deformed Nd-Fe-B magnets with a larger maximum energy product at higher operating temperature are desirable in a wide range of applications but are very challenging to realize in a common “single phase” structure. Here, we show the macroscopic structural design in hot-deformed magnets by using two kinds of melt-spun powders with/without heavy rare earth. Higher coercivity with a remarkably improved maximum energy product is obtained in the separated multilayer magnet. We find that the multilayer structure can improve the c-axis alignment of platelet-shaped grains in each layer and propose the possible interlayer's long-range magnetic interaction explaining the recoil loop open of designed magnets, coupled with visible field-induced domain evolution. This experimental approach reveals exciting applications of structural design in ultrafine-grained hot-deformed magnets.

中文翻译：

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具有宏观复合结构的热变形Nd-Fe-B磁体

在较高的工作温度下具有较大的最大能量乘积的热变形Nd-Fe-B磁体在广泛的应用中是理想的，但要实现常见的“单相”结构则非常困难。在这里，我们展示了通过使用两种含/不含重稀土的熔纺粉末在热变形磁体中的宏观结构设计。在分离的多层磁体中获得了较高的矫顽力和最大改善的最大能量乘积。我们发现，多层结构可以改善每一层中的薄片状晶粒的c轴排列，并提出可能的中间层的远距离磁相互作用，从而解释了设计磁铁的反冲环开路，以及可见磁场引起的畴演化。