Very low density amorphous phase of zircon
Very low density amorphous phase of zircon
复制标题
锆石的极低密度非晶相
DOI：
10.1016/j.jnoncrysol.2019.03.023
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发表时间：
2019
影响因子：
3.5
通讯作者：
M. Durandurdu
中科院分区：
文献类型：
--
作者：
S. Bolat;M. Durandurdu
采用可靠的从头算分子动力学方法，研究了锆石熔体的快速凝固过程。伴随着非晶化，可察觉到27%的急剧体积膨胀。这个值比在变质锆石中观察到的18%要大得多。如此大的体积膨胀导致Zr原子的平均配位数显著下降，约为5.66，是迄今报道的最低的。另一方面，体积膨胀对硅原子的平均配位数几乎没有影响，即它们保持了它们的四方配位。正如以前的研究所表明的那样，可以观察到SiO4单元的聚合，但我们的模型显示出相对于之前的模拟最高的聚合。基于我们的发现，我们认为我们的模型并不代表变质的锆石，而是一种密度很低的无定形锆石相。
Using a reliableab initiomolecular dynamics method, we investigate the rapid solidification of the zircon melt. Accompanied by amorphization, a drastic volume expansion of 27% is perceived. This value is fairly larger than 18% observed in the metamict zircon. Such a large volume swelling leads to a significant decrease in the mean coordination number of Zr atoms, which is about 5.66 and the lowest one reported so far. On the other hand, the volume expansion is found to have almost no impact on the average coordination number of Si atomsi.e., they maintain their tetragonal coordination. As suggested by earlier investigations, the polymerization of SiO4units is witnessed but our model shows the highest polymerization with respect to the previous simulations. Based on our findings, we propose that our model does not represent the metamict zircon but a very low density amorphous phase of zircon.