The lattice strains in a specimen (cubic system) compressed nonhydrostatically in an opposed anvil device
The lattice strains in a specimen (cubic system) compressed nonhydrostatically in an opposed anvil device
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DOI：
10.1063/1.352809
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发表时间：
1993
影响因子：
3.2
通讯作者：
Ashutosh Kumar Singh
中科院分区：
文献类型：
--
作者：
Ashutosh Kumar Singh
使用各向异性弹性理论推导出晶格应变的一般表达式，该表达式对应于在对置砧装置中非流体静力压缩的多晶样品（立方系统）上的X射线衍射测量。各种衍射几何的表达式作为该方程的特殊情况出现。使用各向同性弹性理论计算的应变对应于试样中的宏观应变，并且可以通过使各向异性因子2（S11-S12）/S44=1从本方程获得。此外，它示出的晶格应变的宏观应变（在方向上的晶格应变）由偏应力分量产生的比率取决于米勒指数（hkl）的晶格平面和弹性各向异性因子。只有当构成试样的微晶是弹性各向同性的时，这个比率才是统一的，并且随着微晶的各向异性的增加而增加。
A general expression has been derived using anisotropic elasticity theory for the lattice strain which corresponds to the x‐ray diffraction measurement on the polycrystalline specimen (cubic system) compressed nonhydrostatically in an opposed anvil device. The expressions for the various diffraction geometries emerge as the special cases of this equation. The strain calculated using isotropic elasticity theory corresponds to the macroscopic strain in the specimen, and can be obtained from the present equation by letting the anisotropy factor 2(S11−S12)/S44=1. Further, it is shown that the ratio of the lattice strain to the macroscopic strain (in the direction of the lattice strain) produced by the deviatoric stress component depends on the Miller indices (hkl) of the lattice planes and the elastic anisotropy factor. This ratio is unity only if the crystallites constituting the specimen are elastically isotropic, and increases with increasing anisotropy of the crystallites.