Department of Earth and Planetary Materials Science, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan.
Phys Rev Lett. 2010 Jan 15;104(2):025504. doi: 10.1103/PhysRevLett.104.025504.
Acoustic wave velocities of SiO2 glass were measured up to pressures of 207 GPa using newly developed Brillouin scattering spectroscopic techniques to address the nature of pressure-induced structural changes. The acoustic wave velocity data suggests three distinct pressure regimes, two of which correspond to changes in the Si-O coordination number with pressure, and one of which indicates the stability of sixfold-coordinated Si over a broad pressure interval from approximately 40-140 GPa. An anomalous increase in the effect of pressure on velocity at 140 GPa most likely corresponds to the onset of structural densification associated with an increase in coordination number from sixfold to a higher coordination state.
使用新开发的布里渊散射光谱技术，测量了二氧化硅玻璃在高达 207 GPa 的压力下的声波速度，以研究压力诱导结构变化的本质。声波速度数据表明存在三个明显的压力区域，其中两个与 Si-O 配位数随压力的变化相对应，而另一个则表明六配位 Si 在大约 40-140 GPa 的宽压力区间内的稳定性。在 140 GPa 时，压力对速度的影响异常增加，很可能对应于结构致密化的开始，这与 Si 的配位数从六配位增加到更高的配位态有关。
