单晶晶格的各向异性导致单晶物理性质的各向异性,单晶的物理性质(如:材料热膨胀系数、弹性模量等)随空间方向变化。通过方向相关函数描述单晶物理性质随空间方向的变化,推导出单晶物理性质方向相关函数的一般形式,给出立方单晶和3m单晶物理性质方向相关函数的具体表达式,并将其用于分析单晶柔度系数、弹性模量、压电系数、介电系数随空间方向的变化。
The anisotropy of crystal lattices leads to the anisotropy of physical properties of the crystals. The physical properties of crystals, such as thermal expansion coefficient and elastic modulus, differ in direction. The direction-dependent functions for crystals are introduced to describe the variations of the physical properties in direction. A general expression of the direction-dependent functions for the physical properties of crystals is derived in this paper. Explicit expressions of the direction-dependent functions for cubic crystals and 3m crystals are given. Some applications of the explicit expressions are discussed.