Sound velocities and refractive index of densified a-SiO2 to 25 GPa.
Sound velocities and refractive index of densified a-SiO2 to 25 GPa.
复制标题
致密化 a-SiO2 的声速和折射率至 25 GPa。
DOI：
--
复制
发表时间：
1993
期刊：
影响因子：
--
通讯作者：
Grimsditch
中科院分区：
文献类型：
--
作者：
Polian;Grimsditch
利用布里渊散射，我们测量了[ital a]-SiO[sub 2]的两个独立弹性模量，压力增加和减少可达25 GPa。对于下降压力，剪切常数表现出与先前报道的纵向模态相似的不可逆行为。虽然在给定压力下的体积模量可以通过测量的弹性常数来计算，但致密化过程中发生的不可逆变化排除了通过压缩性的积分来计算密度作为压力函数的可能性。密度的估计是从测量的折射率间接得到的。
Using Brillouin scattering we have measured the two independent elastic moduli of [ital a]-SiO[sub 2] with increasing and decreasing pressures up to 25 GPa. For descending pressures the shear constant shows irreversible behavior similar to that previously reported for the longitudinal mode. Although the bulk modulus at a given pressure can be evaluated from the measured elastic constants, the irreversible changes which occur on densification preclude the possibility of evaluating the density as a function of pressure by an integration of the compressibility. An estimate of the density is obtained indirectly from the measured refractive index.