Nanoporous, high-purity magnesium nitride (Mg3N2) was synthesized with a liquid ammonia-based process, for potential applications in optoelectronics, gas separation and catalysis, since these applications require high material purity and crystallinity, which has seldom been demonstrated in the past. One way to evaluate the degree of crystalline near-range order and atomic environment is electron energy-loss spectroscopy (EELS) in a transmission electron microscope. However, there are hardly any data on Mg3N2, which makes identification of electron energy-loss near-edge structure (ELNES) features difficult. Therefore, we have studied nanoporous Mg3N2 with EELS in detail in comparison to EELS spectra of bulk Mg3N2, which was analyzed as a reference material. The N-K and Mg-K edges of both materials are similar. Despite having the same crystal structure, however, there are differences in fine-structural features, such as shifts and absences of peaks in the N-K and Mg-K edges of nanoporous Mg3N2. These differences in ELNES are attributed to coordination changes in nanoporous Mg3N2 caused by the significantly smaller crystallite size of 2–6 nm compared to the larger (25–125 nm) crystal size in a bulk material.

中文翻译：

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多晶纳米多孔Mg3N2的结构性能和ELNES

纳米多孔高纯度氮化镁（Mg3ñ2) 是用基于液氨的工艺合成的，在光电子学、气体分离和催化方面具有潜在应用，因为这些应用需要高材料纯度和结晶度，而这在过去很少得到证明。评估结晶近程有序度和原子环境的一种方法是透射电子显微镜中的电子能量损失光谱 (EELS)。然而，几乎没有任何关于 Mg 的数据3ñ2，这使得电子能量损失近边结构（ELNES）特征的识别变得困难。因此，我们研究了纳米多孔镁3ñ2与块状镁的 EELS 光谱相比，详细介绍了 EELS3ñ2，作为参考材料进行分析。两种材料的 NK 和 Mg-K 边缘相似。然而，尽管具有相同的晶体结构，但在精细结构特征方面存在差异，例如纳米多孔 Mg 的 NK 和 Mg-K 边缘峰的偏移和缺失3ñ2. ELNES 的这些差异归因于纳米多孔 Mg 的配位变化3ñ2与块状材料中较大的（25-125 nm）晶体尺寸相比，2-6 nm 的微晶尺寸明显更小。