Tourmaline is a kind of non-central symmetric crystal with complex chemical composition and structure.It has piezoelectricity.At present,the influence of internal microstructures in tourmaline on its piezoelectricity has rarely been researched.In order to deeply explore the influence of internal microstructures in tourmaline on its piezoelectricity,the relationships between internal microstructure factors(bond length,bond angle)and piezoelectricities of elbaite and dravite have been explored in the study.Based on the piezoelectricity test of tourmaline and the X-ray diffraction test of tourmaline single crystal,we have calculated the distortion parameters of the crystal structure and the inherent electric dipole moments,and have analyzed the relationship between the piezoelectricity of tourmaline and the microstructures within tourmaline crystal.It was found that the cation radiuses of dominant elements in the Y position of tourmaline affected distortion parameters of the bond length and bond angle of the Y polyhedron,affected the distortion degree of the Y polyhedron,further affected the distortion of other polyhedrons in tourmaline crystal,and finally resulted in the intensity change of piezoelectricity of tourmaline.The results show that tourmaline with relatively high Li content has relatively high distortion parameters of the Y polyhedron and relatively strong piezoelectricity.In addition,due to the structure rotating symmetrically around the c-axis of tourmaline,the inherent electric dipole moments provided in directions of the a-axis and the b-axis are offset,resulting in that the piezoelectricity of the c-axis direction was much stronger than those of the a-axis and b-axis for the same kind of tourmaline,.It was also found that the piezoelectric intensity of tourmaline was positively correlated with the inherent electric dipole moment of tourmaline,indicating that it is meaningful to use the inherent electric dipole moment for studying the piezoelectricity of tourmaline.This study provided a new idea for exploring the influence mechanism of microstructure on the piezoelectricity intensity of natural minerals or man-made materials by using the structural parameter calculation.
关键词
电气石/压电性/晶体内微结构/X-射线单晶衍射
Key words
tourmaline/piezoelectricity/crystal microstructure/X-ray diffraction of single crystal
维普
万方数据