Experimental evidence for the structural models of Re2 Na nd Re2C from micro-Raman spectroscopy
Experimental evidence for the structural models of Re2 Na nd Re2C from micro-Raman spectroscopy
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DOI：
10.1103/physrevb.86.014114
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发表时间：
2012-07
影响因子：
3.7
通讯作者：
A. Friedrich;B. Winkler;K. Refson;V. Milman
中科院分区：
文献类型：
--
作者：
A. Friedrich;B. Winkler;K. Refson;V. Milman
利用微拉曼光谱和基于密度泛函理论的理论计算，研究了六方Re2N氮化铼和Re2C碳化铼在常温和高压下的高压、高温相的振动特性。这些数据证实了最近提出的Re2N结构模型。解决了Re2C中碳位置的模糊性。我们发现re2na和re2c的结构是同型的，在Re原子的六边形堆叠中，N和C原子占据相同的三角棱柱空间。研究了压力对振动特性的影响，发现re2na和re2c的拉曼活性模态Gr¨uneisen参数在1.1 ~ 1.6之间。
The vibrational properties of the high-pressure, high-temperature phases of hexagonal Re2N rhenium nitride and Re2C rhenium carbide are reported from micro-Raman spectroscopy at ambient and high pressure and from theoretical calculations based on density functional theory. These data confirm the structural model of Re2N proposed recently. The ambiguity of the location of the carbon position in Re2C is resolved. We show that the structures of Re2 Na nd Re 2C are isotypic, with the N and C atoms occupying the same trigonal prismatic voids in the hexagonal stacking of Re atoms. The effect of pressure on vibrational properties is investigated, and mode Gr¨ uneisen parameters of the Raman-active modes are found to be between 1.1 and 1.6 for both Re2 Na nd Re 2C.