Highly dense and ultra-hard Stishovite phase is the most stable form of SiO₂. It is formed when fused silica is subjected to extreme pressures (>34 GPa). In this communication, we report nucleation of the Stishovite phase in shock-loaded soda-lime glass (SLG) samples at a remarkably low compressive stress of 7 GPa. Although it falls within the reported Hugoniot Elastic Limit of SLG between 2.5 and 7 GPa, it is significantly below the crystallization threshold of 34 GPa observed for fused silica. SLG plates were shock loaded by impacting them at 1–2.5 km/s using a table-top experimental setup in which 1 mm-dia Al micro flyer plates of 25–50 μm thickness were generated and propelled using a top-hat Nd:YAG laser pulse of 8 ns duration. The shocked samples were imaged using High Resolution Transmission Electron Microscopy (HRTEM) and further analyzed using Selected Area Electron Diffraction and FFT analyses. All samples showed nucleation of 4 nm Stishovite crystals distributed within the amorphous SLG matrix. The stress state was determined by directly measuring the flyer speed, particle velocity, and shockwave speed by using a state-of-the-art Photonic Doppler Velocimeter (PDV).

高密度和超硬的 Stishovite 相是最稳定的 SiO ₂形式. 它是在熔融石英经受极端压力 (>34 GPa) 时形成的。在这篇通讯中，我们报告了冲击载荷钠钙玻璃 (SLG) 样品中 Stishovite 相在 7 GPa 的极低压缩应力下的成核。尽管它属于所报告的 SLG 的 Hugoniot 弹性极限在 2.5 到 7 GPa 之间，但它明显低于熔融石英观察到的 34 GPa 结晶阈值。SLG 板通过使用桌面实验装置以 1-2.5 km/s 的速度撞击它们来承受冲击载荷，其中产生 1 mm 直径的 25-50 μm 厚度的 Al 微型飞板，并使用顶帽 Nd:YAG 推进8 ns 持续时间的激光脉冲。使用高分辨率透射电子显微镜 (HRTEM) 对电击样品进行成像，并使用选定区域电子衍射和 FFT 分析进行进一步分析。所有样品都显示出分布在无定形 SLG 基质内的 4 nm Stishovite 晶体的成核。应力状态是通过使用最先进的光子多普勒测速仪 (PDV) 直接测量飞行器速度、粒子速度和冲击波速度来确定的。