A new reduction–diffusion method for preparing submicron-sized Sm₂Fe₁₇N₃ was developed. First, submicron-sized α-Fe/Sm₂O₃ composite precursors with good dispersibility were prepared directly by ultrasonic spray pyrolysis and hydrogen reduction (USP-HR). Then, the precursor was successfully converted into Sm₂Fe₁₇N₃ powder by Ca reduction–diffusion and nitridation. The results displayed that the precursor prepared by USP-HR was a monodisperse homogeneous composite of spherical particles of α-Fe and Sm₂O₃. α-Fe and Sm₂O₃ exist in an intercalated structure in the composite spherical particles. This creates conditions for the preparation of ultrafine Sm₂Fe₁₇N₃ particles with uniform sizes and dispersity. The results show that Sm₂Fe₁₇N₃ is a single-phase, composed of submicron-sized particles with no other impurity phases. The physical property measurement system shows that the coercivity of 0.616 ± 0.347 µm particles reaches 14.7 kOe.

中文翻译：

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超声喷雾热解-氢还原（USP-HR）及其后的还原扩散过程制备亚微米级Sm2Fe17N3细粉

开发了一种新的还原扩散法制备亚微米尺寸的Sm ₂ Fe ₁₇ N ₃。首先，通过超声喷雾热解和氢还原（USP-HR）直接制备具有良好分散性的亚微米级α -Fe / Sm ₂ O ₃复合前体。然后，通过钙还原扩散和氮化将前体成功转化为Sm ₂ Fe ₁₇ N ₃粉末。结果表明，USP-HR制备的前驱体为α -Fe和Sm ₂ O ₃球形颗粒的单分散均质复合物。α-Fe和Sm ₂ O ₃以插层结构存在于复合球形颗粒中。这为制备具有均匀尺寸和分散性的Sm ₂ Fe ₁₇ N ₃超细颗粒创造了条件。结果表明，Sm ₂ Fe ₁₇ N ₃是单相的，由亚微米级颗粒组成，没有其他杂质相。物理性能测定系统表明，0.616±0.347的矫顽力μ m个粒子达到14.7千奥斯特。