Synthesis and Crystal Structure of Cubic Ca16Si17N34

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• 作者：Sandra M. Hick ; Mattheu I. Miller ; Richard B. Kaner ; Richard G. Blair
• 刊名：Inorganic Chemistry
• 出版年：2012
• 出版时间：December 3, 2012
• 年：2012
• 卷：51
• 期：23
• 页码：12626-12629
• 全文大小：261K
• 年卷期：v.51,no.23(December 3, 2012)
• ISSN：1520-510X

文摘

Since the late 1960s, the exact structure of cubic calcium silicon nitride has been a source of debate. This paper offers evidence that the cubic phase CaSiN₂ described in the literature is actually Ca₁₆Si₁₇N₃₄. Presented here is a method for synthesizing single crystals of cubic-calcium silicon nitride from calcium nitride and elemental silicon under flowing nitrogen at 1500 掳C. The colorless millimeter-sized crystals of Ca₁₆Si₁₇N₃₄ with a refractive index (n₂₅) = 1.590 were found to be cubic (a = 14.8882 脜) and belong to the space group F4̅3m (216). The synthesis of bulk, powdered cubic-Ca₁₆Si₁₇N₃₄ from calcium cyanamide and silicon is also discussed. Ca₁₆Si₁₇N₃₄ is a relatively air-stable refractory ceramic. In contrast to the orthorhombic phase of CaSiN₂, in which Ca²⁺ sits in octahedral sites, this cubic phase has Ca²⁺ in cubic sites that makes it an interesting host for new phosphors and gives rise to unique crystal field splitting.