晶体物理性质的空间轴转动对称性

Spatial Axial Rotation Symmetry of Physical Properties of Crystals

用群论方法导出具有ＳＯ（２）群对称性的一般三阶、四阶张量形式；进而给出具有这种对称性的压电、线性电光、二阶非线性极化、弹光、二次电光、电致伸缩、弹性及三阶非线性极化系数矩阵的一般形式。指出含有４度或６度转轴的非中心对称晶类的压电、线性电光及二阶非线性极化性质，以及所有六方晶类的弹光、二次电光、电致伸缩、弹性及三阶非线性极化性质具有关于晶体中唯一高次轴的任意旋转对称性。对所得结果作了讨论。

The forms of the general third and fourth rank tensors having the symmetry of the group SO(2) are derived with the help of group theoretical methods, hence, the general forms of the piezoelectric, linear electro optic, second order nonlinear susceptibility, elastooptical, second order electrooptical, electrostrictive,elastic, third order nonlinear susceptibility matrices having such a symmetry are given.It is indicated that the piezoelectric, linear electrooptic and second order nonlinear polarization properties for the non centrosymmetrical classes with a tetrad or hexad rotation axis, as well as the elastooptical,second order electrooptical, electrostrictive, elastic and third order nonlinear polarization properties for all the hexagonal classes, have arbitrary rotation symmetry with respect to the unique higher fold axis in the classes. The result is discussed.