Behavior of sodium borosilicate glasses under compression using molecular dynamics.
Behavior of sodium borosilicate glasses under compression using molecular dynamics.
复制标题
使用分子动力学研究硼硅酸钠玻璃在压缩下的行为。
DOI：
10.1063/1.4929785
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
S. Ispas
中科院分区：
文献类型：
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作者：
D. Kilymis;J. Delaye;S. Ispas
我们已经进行了经典的分子动力学模拟，以研究在压缩下的变化，在本地和中等范围内的结构性质的三个钠硼硅酸盐玻璃与不同的钠含量。这些玻璃已被等静压压缩至20 GPa，然后减压，以分析影响致密化的不同机制，以及在完整的压缩/减压循环后结构的永久性修改。结果表明，原子堆积是决定玻璃致密化程度的主要因素，也是决定玻璃永久致密化的主要因素。在压缩过程中，体积模量线性增加至约15 GPa，并且对于更高的压力更快，这种行为反映在B和Na的平均配位的增加速率上。在不同压力下的径向分布函数在循环过程中有助于量化的基本结构单元的扭曲量，在压缩过程中的Na-Na和Na-O键长的显着缩短。随后的分解成基本Voronoi体积的玻璃状基质验证了高压缩性的Na丰富的地区。
We have performed classical molecular dynamics simulations in order to study the changes under compression in the local and medium range structural properties of three sodium borosilicate glasses with varying sodium content. These glasses have been isostatically compressed up to 20 GPa and then decompressed in order to analyze the different mechanisms that affect densification, alongside with the permanent modifications of the structure after a full compression/decompression cycle. The results show that the atomic packing is the prominent characteristic that governs the amount of densification in the glass, as well as the setup of the permanent densification. During compression, the bulk modulus increases linearly up to approximately 15 GPa and more rapidly for higher pressures, a behavior which is reflected on the rate of increase of the average coordination for B and Na. Radial distribution functions at different pressures during the cycle help to quantify the amount of distortions in the elementary structural units, with a pronounced shortening of the Na-Na and Na-O bond lengths during compression. A subsequent decomposition of the glassy matrix into elementary Voronoi volumes verifies the high compressibility of Na-rich regions.