Polymorphism, superheating, and amorphization of silica upon shock wave loading and release
Polymorphism, superheating, and amorphization of silica upon shock wave loading and release
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DOI：
10.1029/2002jb002317
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发表时间：
2003-09-10
影响因子：
3.9
通讯作者：
Asimow, PD
中科院分区：
文献类型：
--
作者：
Luo, SN;Ahrens, TJ;Asimow, PD
[ 1]我们提出了一个详细的和定量的检查的热力学和相变机制（包括非晶化）时发生的冲击波加载和卸载的二氧化硅。我们应用Debye-Gruneisen理论计算了石英的Hugoniot和等熵释放路径。石英在15至46 GPa之间转化为方石英（或类似方石英的相），并且固相在其液相线以上的持久性（即，过热）在77和110 GPa之间确认。计算比较有利的冲击和冲击后的温度测量。对于二氧化硅，测量冲击后温度的方法对于预测在释放期间是否实际发生相变不敏感。在压力粒子速度空间中的释放状态的测量进行比较计算的冻结相释放路径。这种比较表明，一个stishovite样相的转变，以较低的密度相，包括石英，液体，或致密的无定形玻璃。当从26 GPa及以上的峰值压力释放时，发生向液体或玻璃的转化。等熵释放假设似乎是近似有效的。本文提出了一个与石英中二氧化硅变质作用有关的冲击压力-温度标度。无论是恢复柯石英，也没有大量的结晶stishovite样相石英冲击加载后预测。预计在15和26 GPa之间的冲击载荷的结晶的stishovite状相的痕量。
[ 1] We present a detailed and quantitative examination of the thermodynamics and phase change mechanisms ( including amorphization) that occur upon shock wave loading and unloading of silica. We apply Debye-Gruneisen theory to calculate both the Hugoniot of quartz and isentropic release paths. Quartz converts to stishovite ( or a stishovite-like phase) between 15 and 46 GPa, and persistence of the solid phase above its liquidus ( i.e., superheating) is confirmed between 77 and 110 GPa. Calculations compare favorably to measurements of shock and post-shock temperatures. For silica, the method of measuring post-shock temperature is insensitive to predicting whether phase transitions actually occur during release. Measurements of release states in pressure-particle velocity space are compared to computed frozen-phase release paths. This comparison suggests transformation of a stishovite-like phase to lower density phases including quartz, liquid, or dense amorphous glass. Transformations to liquid or glass occur upon release from peak pressure of 26 GPa and above. The isentropic release assumption appears to be approximately valid. A shock pressure-temperature scale relating metamorphism of silica in shock-loaded quartz is proposed. Neither recovery of coesite nor substantial quantities of crystalline stishovite-like phases upon shock loading of quartz is predicted. Trace amounts of crystalline stishovite-like phases from shock loading between 15 and 26 GPa are expected.