High Pressure Behavior of Silicon Clathrates: A New Class of Low Compressibility Materials
High Pressure Behavior of Silicon Clathrates: A New Class of Low Compressibility Materials
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DOI：
10.1103/physrevlett.83.5290
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发表时间：
1999-12
影响因子：
8.6
通讯作者：
Alfonso San-Miguel;P. Kéghélian;X. Blase;P. Mélinon;A. Pérez;J. Itié;A. Polian;E. Reny;C. Cros;M. Pouchard
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文献类型：
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作者：
Alfonso San-Miguel;P. Kéghélian;X. Blase;P. Mélinon;A. Pérez;J. Itié;A. Polian;E. Reny;C. Cros;M. Pouchard
本文用X射线衍射研究了硅笼形物在室温下的高压演化过程，压力可达15 GPa。值得注意的是，没有观察到向金刚石结构的转变，并且笼形物相在11 GPa下直接转变为b-tin金属相。此外，体积模量被发现是90 6 5 GPa，即，只有8 6 5%小于金刚石相的一个。这些结果是在良好的协议与从头计算预测进一步的碳笼形物，如果合成，应小于立方BN的可压缩性。
The high pressure evolution of silicon clathrates is studied at room temperature by x-ray diffraction up to 15 GPa. Remarkably, no transition towards the diamond structure is observed and the clathrate phase transforms directly into the b-tin metallic phase at 11 GPa. Further, the bulk modulus is found to be 90 6 5 GPa, that is, only 8 6 5% smaller than the one of the diamond phase. These results are in good agreement with ab initio calculations which predict further that carbon clathrates, if synthesized, should be less compressible than cubic BN.