旋声晶体NaBrO3与NaClO3的弹性研究

用中子相干非弹性散射、沿三个主晶轴方向测量了同构异质晶体NaBrO₃和NaClO₃的声子色散关系。从小波矢区的实验结果获得了沿晶体这些方向的弹性波速及三个独立的弹性常数C₁₁,C₁₂,C₄₄。实验结果表明,尽管这两种晶体在旋声方面表现出十分不同的特性,但是,它们的左旋和右旋圆偏振声子的声速都是在一个特定的平均速度v_(TD)上下均衡的分布,这个平均速度可由 关键词：

A STUDY ON ELASTICITY OF ACOUSTICALLY ACTIVE CRYSTALS NaBrO3 AND NaClO3

The dispersion curves of phonons along three crystallographic axes for isomorphous crystals NaBrO₃ and NaClO₃ have been measured by using coherent inelastic neutron scattering. The velocities of elastic waves along these directions and three independently elestic constants C₁₁,C₁₂ and C₄₄ are deduced from the dispersion curves in the region of small wave vectars. The experimental results verified directly the prediction of portigal's theory that the velocities of left circularly polarized phonons and the right polarized ones distribute on both side of a particular average velocity v_(TD) symmetrically, the value of v_(TD) can be determined uniquely by the velocities on other directions or the zero-order approximative elastic constants.