三方系晶体压电性能随空间方向变化的研究

为了研究三方系32和3m点群晶体纵向压电系数及机电耦合系数空间变化规律,介绍了研究32和3m点群晶体宏观物理量空间分布的方法,对这2类晶体纵向压电性能在空间分布上的各自共性分别进行了讨论、归纳和总结.结果表明:32点群晶体的纵向压电及机电耦合系数d₁₁^′和k₁₁^′绝对值在空间上的分布呈6个完全相同的花瓣形状,d₁₁^′和k₁₁^′的最大值与沿x轴的d₁₁和k₁₁的相等;3m点群晶体纵向压电及机电耦合系数d₃₃^′和k₃₃^′的绝对值在空间特殊方向上存在着最大值,沿这些最大值方向,晶体的压电性能提高的幅度较大,而且最大值的方向随晶体的不同而不同.

A Study on Crystal Orientation Dependence of Longitudinal Piezoelectric Properties for Trigonal Crystals

To study the space variation of longitudinal piezoelectric constant and electromechanical fator of 32 and 3 m crystals of trigonal system, the method of studing macroscopic tensor space distribution is introduced. Longitudinal piezoelectric properties in space of the two kinds of crystals are discussed respectively. The results show that, for 32 crystals, the absolute values of the longitudinal piezoelectric constant d'n and electromechanical factor k11′ distribute in space in the shape of 6 petals, and maximum values of d11′ and k11′ are equal to that of d11 and k11 which are along the x-axis; for 3 m crystals, the longitudinal piezoelectric constant d33′ and electromechanical factor k33′ exist the maximum values in special orientation, and along these corresponding directions which depend on the crystals, the longitudinal piezoelectric properties can be greatly enhanced.