Pressure-Induced Amorphization of Strontium Azide

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• 作者：Hongyang Zhu ; Xue Han ; Peifen Zhu ; Xiaoxin Wu ; Yanmei Chen ; Miaoran Li ; Xuefeng Li ; Qiliang Cui
• 刊名：Journal of Physical Chemistry C
• 出版年：2016
• 出版时间：June 16, 2016
• 年：2016
• 卷：120
• 期：23
• 页码：12423-12428
• 全文大小：538K
• 年卷期：0
• ISSN：1932-7455

文摘

Strontium azide (Sr(N₃)₂) has been studied by in situ high pressure X-ray diffraction at room temperature. Sr(N₃)₂ exhibits anisotropic compressibility due to the orientation and rotation of azide anions. The refinement results and spectra measurements reveal that Sr(N₃)₂ possesses bent azide ions at ambient conditions, differing from the linear azide ions of alkali azides. The bent azide ions further bend and rotate with increasing pressure. These unique properties of bent azide ions play a significant role in the process of electron orbit hybridization and greatly enhance the propensity of nitrogen polymerization. The bulk modulus of Sr(N₃)₂ is 49.1 GPa, which is larger than those of alkali azides and close to those of heavy metal azides. The larger bulk modulus is attributed to the partial covalent bonding character of Sr(N₃)₂. Sr(N₃)₂ transforms into an amorphous phase at relative low pressure compared with alkali azide. This property might induce that Sr(N₃)₂ transforms into polymeric nitrogen more readily than other inorganic azides.