Electronic bonding transition in compressed SiO2 glass
Electronic bonding transition in compressed SiO2 glass
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DOI：
10.1103/physrevb.75.012201
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发表时间：
2007-01-01
影响因子：
3.7
通讯作者：
Chow, Paul
中科院分区：
文献类型：
--
作者：
Lin, Jung-Fu;Fukui, Hiroshi;Chow, Paul
了解高压下无定形和液态二氧化硅的电子结构对于理解其复杂性质至关重要，这些性质包括从岩浆中的二氧化硅熔体到光学、电子和材料科学中的二氧化硅玻璃。在这里，我们提出了氧的K-边缘附近的SiO2玻璃光谱到51 GPa的金刚石压砧单元中使用X-射线拉曼散射获得。下面的拉曼谱图与石英和柯石英的谱图一致，而上面的拉曼谱图与斯氏石英的谱图一致。这种压力引起的光谱变化表明，在10 GPa和22 GPa之间的SiO2玻璃中发生的电子键合跃迁从四重类石英到六重类stishovite配置。与不可逆致密化相反，电子键合转变在减压时是可逆的。所观察到的可逆键合转变和不可逆的致密化要求在压缩SiO2玻璃的转变机制的连贯的理解。
Knowledge of the electronic structure of amorphous and liquid silica at high pressures is essential to understanding their complex properties ranging from silica melt in magma to silica glass in optics, electronics, and material science. Here we present oxygen near K-edge spectra of SiO2 glass to 51 GPa obtained using x-ray Raman scattering in a diamond-anvil cell. The x-ray Raman spectra below similar to 10 GPa are consistent with those of quartz and coesite, whereas the spectra above similar to 22 GPa are similar to that of stishovite. This pressure-induced spectral change indicates an electronic bonding transition occurring from a fourfold quartzlike to a sixfold stishovitelike configuration in SiO2 glass between 10 GPa and 22 GPa. In contrast to the irreversible densification, the electronic bonding transition is reversible upon decompression. The observed reversible bonding transition and irreversible densification call for a coherent understanding of the transformation mechanism in compressed SiO2 glass.