Abstract High phase-purity Sm(Fe0.8Co0.2)11Ti and Sm0.8Zr0.2(Fe0.8Co0.2)11Ti powders with the tetragonal ThMn12 crystal structure have been synthesized by reduction-diffusion method. The average particle size is 1.47 ± 0.82 μm for the Zr-free and 2.29 ± 1.22 μm for the Zr-doped samples. The larger particles are multi-grain, without a chemically distinct grain boundary phase as revealed by TEM investigations. The intrinsic magnetic properties are μ 0 M s = 1.42 ± 0.04 T, μ 0 H a = 9.8 ± 0.4 T for Zr-free and μ 0 M s = 1.37 ± 0.04 T, μ 0 H a = 9.7 ± 0.4 T for Zr-doped samples. Temperature-dependent XRD studies show that the ThMn12-type phase begins to decompose around 500 °C which presents difficulties for further development into fully dense bulk magnets. Successful introduction of grain boundary phase with good wettability has been realized by infiltrating low-melting eutectic alloys, resulting in fully dense bulk samples. However, coercivity remains low, μ0Hc = 0.34 T. The underlying microstructural reasons for not achieving large Hc are discussed.

中文翻译：

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还原扩散法制备的SmFe12基硬磁合金

摘要 采用还原扩散法合成了具有四方晶系ThMn12晶体结构的高相纯度Sm(Fe0.8Co0.2)11Ti和Sm0.8Zr0.2(Fe0.8Co0.2)11Ti粉末。无 Zr 样品的平均粒径为 1.47 ± 0.82 μm，Zr 掺杂样品的平均粒径为 2.29 ± 1.22 μm。较大的颗粒是多晶粒，没有 TEM 研究显示的化学上不同的晶界相。固有磁特性为 μ 0 M s = 1.42 ± 0.04 T，无 Zr 时 μ 0 H a = 9.8 ± 0.4 T，而 Zr 时 μ 0 M s = 1.37 ± 0.04 T， μ 0 H a = 9.7 ± 0.4 T -掺杂的样品。温度相关的 XRD 研究表明，ThMn12 型相在 500 °C 左右开始分解，这给进一步开发成完全致密的块状磁铁带来了困难。通过渗透低熔点共晶合金，成功地引入了具有良好润湿性的晶界相，从而获得了完全致密的块状样品。然而，矫顽力仍然很低，μ0Hc = 0.34 T。讨论了无法实现大 Hc 的潜在微观结构原因。