Cracking diamond anvil cells by compressed nanographite sheets near the contact edge
Cracking diamond anvil cells by compressed nanographite sheets near the contact edge
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DOI：
10.1063/1.2001161
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发表时间：
2005-07
影响因子：
4
通讯作者：
Bin Zhang;Wanlin Guo
中科院分区：
文献类型：
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作者：
Bin Zhang;Wanlin Guo
通过分子动力学模拟，发现金刚石砧细胞（DAC）中的均匀冷压缩纳米石墨片在约17 GPa时由软相转变为硬相。硬相的抗压强度可达150 GPa左右。有限元分析表明，与纳米石墨片接触的金刚石砧片沿界面边界处出现高应力集中。当石墨样品中的平均压力为17 GPa （[W]）时，在直径约为0.2μm的环形区域内，集中压应力可以超过金刚石的强度。[j].科学通报，2004,(1):1 - 2。在窄环内，纳米石墨片形成超硬碳相，导致接触边缘附近的DAC开裂。
Uniformly cold-compressed nanographite sheets in diamond anvil cells (DAC) are found to transform from soft into hard phase at about 17 GPa using molecular dynamics simulations. The hard phase can reach the compressive strength of about 150 GPa. Finite element analyses show that high stress concentrations occur along the boundary of interface on the diamond-anvil culets contacted with the nanographite sheets. The concentrated compressive stress can exceed the strength of diamond in a ring region with the width about 0.2μm, when the average pressure in the graphite sample is 17 GPa as in [W. L. Mao et al., Science 302, 425 (2003)]. Within the narrow ring, superhard carbon phase can be formed from the nanographite sheets, which leads to cracking of the DAC near the contact edge.