Thursday, November 29, 2012

Synthesis and Crystal Structure of Cubic Ca16Si17N34


Synthesis and Crystal Structure of Cubic Ca16Si17N34

Abstract Image
29/noviembre/2012
Paulina Levario

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 °C. The colorless millimeter-sized crystals of Ca16Si17N34 with a refractive index (n25) = 1.590 were found to be cubic (a = 14.8882 Å) and belong to the space groupF4̅3m (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.

Para mayor información:

Synthesis and Crystal Structure of Cubic Ca16Si17N34

Sandra M. Hick, Mattheu I. Miller, Richard B. Kaner, and Richard G. Blair
Inorganic Chemistry Article ASAP
DOI: 10.1021/ic300627q
Publication Date (Web): November 16, 2012
Copyright © 2012 American Chemical Society

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