BaTeMo_2O_9晶体单模切割方向的确定

Determination of the Cut Directions of Single Modes of BaTeMo_2O_9 Crystal

为了促进BaTeMo2O9晶体在压电换能器中的应用,该文采用数值计算法研究了该晶体的单模切割方向。在实验数据的基础上,通过求解旋转坐标系下考虑压电效应的Christoffel方程,计算出了该晶体厚度振动模式下的单模,从而确定了晶体的单模切割方向。结果表明,y切和x切分别可获得纯纵模和纯切变模,且机电耦合系分别为0.625 0和0.292 1。(zyl)-θ切(θ可取任意值)也可获得纯切变模,且在θ为27.77°时,机电耦合系数高达0.986 9。同时也确定了相应单模切型下的声波速度。

In order to promote the application of BaTeMo2 O9 crystal in piezoelectric transducer, the cut directions of single modes of BaTeMo2 O9 were studied by numerical calculation. On the basis of the experimental data, single modes of thickness vibration were calculated by solving piezoelectric stiffened Christoffel equation in rotating coordi- nate systems. The cut directions of single modes were determined. The results indicated that a pure longitudinal mode and a pure shear mode could be obtained by y-cut and x-cut with the corresponding electromeehanical coupling constant 0. 625 0 and 0. 292 1, respectively, Pure shear modes could also be acquired by（zyl）-θ cut where the value of 0 was arbitrary. The electromeehanical coupling constant was up to 0. 986 9 when θwas 27.77 degree. In addi- tion, wave velocity corresponding to the cut directions were also presented in detail.