Elasticity of single-crystal quartz to 10 GPa
Elasticity of single-crystal quartz to 10 GPa
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DOI：
10.1007/s00269-014-0711-z
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发表时间：
2015-03-01
影响因子：
1.4
通讯作者：
Duffy, Thomas S.
中科院分区：
文献类型：
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作者：
Wang, Jue;Mao, Zhu;Duffy, Thomas S.
用布里渊光谱法测定了石英在金刚石砧胞中至10gpa的二阶弹性常数。所有弹性常数都表现出平滑的压力趋势。C（14）和C（66）的大小随压力的减小而减小，而C（44）表现出较弱的压力依赖性。我们测量的弹性常数与先前的密度泛函理论计算比与先前的实验结果更一致。对α -石英的绝热体模量K E-0S(1)和剪切模量G E-0(1)的压力导数屈服值分别为6.2(2)和0.9(1)，计算了骨料弹性模量并与有限应变状态方程拟合。从我们的数据得到的状态方程与静态x射线衍射数据是一致的。我们的数据的有限应变外推预测了Born稳定性准则的违反，表明结构的机械不稳定性，在26 GPa下，这与观察到石英相变和压力诱导非晶化的压力范围大致一致。
The second-order elastic constants of quartz were determined by Brillouin spectroscopy to 10 GPa in a diamond anvil cell. All elastic constants exhibit smooth pressure trends. A decrease in the magnitudes of C (14) and C (66) with pressure is observed, while C (44) shows a weak pressure dependence. Our measured elastic constants are more consistent with previous density functional theory calculations than with earlier experimental results. Aggregate elastic moduli were calculated and fit to a finite-strain equation of state, yielding values for the pressure derivatives of the adiabatic bulk modulus, K E-0S(1), and shear modulus, G E-0(1), of alpha-quartz of 6.2(2) and 0.9(1), respectively. The equation of state obtained from our data is consistent with static X-ray diffraction data. A finite-strain extrapolation of our data predicts a violation of a Born stability criterion, indicating a mechanical instability in the structure, at 26 GPa which is broadly consistent with the pressure range at which a phase transition and pressure-induced amorphization in quartz are observed.