弛豫铁电0.24PIN-0.47PMN-0.29PT单晶声表面波性能研究

Surface Acoustic Waves Properties of 0.24PIN-0.47PMN-0.29PT Relaxor Ferroelectric Single Crystals

随着信息技术的迅速发展,对声表面波器件的要求也进一步提高。为寻找性能更加优异的声表面波器件基底材料,本文利用分波解法对室温下[001]c及[011]c极化弛豫铁电0.24PIN-0.47PMN-0.29PT单晶的声表面波性能进行研究。利用[001]c及[011]c极化弛豫铁电0.24PIN-0.47PMN-0.29PT单晶的弹性、压电及介电性能参数,通过求解克里斯托弗方程计算了晶体声表面波相速度、机电耦合系数及能流角随传播角度的变换关系。结果表明,沿[011]c方向极化的0.24PIN-0.47PMN-0.29PT单晶声表面波性能要优于沿[001]c极化的单晶。[011]c极化0.24PIN-0.47PMN-0.29PT单晶的声表面波机电耦合系数显著高于沿[001]c极化单晶。同时沿[011]c极化0.24PIN-0.47PMN-0.29PT单晶的声表面波能流角的最大值也明显小于[001]c极化单晶。因此,沿[011]c方向极化的0.24PIN-0.47PMN-0.29PT单晶兼具优异的声表面波性能及温度稳定性,更适合于实际应用。

With the rapid development of the information technology,the requirements for surface acoustic wave devices are also increased.In order to find substrate materials with excellent surface acoustic wave performances,a detail theoretical analysis was conducted on the surface acoustic wave properties in 0.24PIN-0.47PMN-0.29PT single crystals along[001]c and[011]c at room temperature using the partial wave method.The relaxor ferroelectric single crystals xPb(In1/2Nb1/2)O3-yPb(Mg1/3Nb2/3)O3-(1-x-y)PbTiO3 with compositions near the morphotropic phase boundary have comparably large piezoelectric and electromechanical properties and much higher Curie temperature.From the complete sets of elastic,piezoelectric and dielectric properties of[001]c and[011]c poled 0.24PIN-0.47PMN-0.29PT single crystals,the orientational dependence of surface acoustic wave phase velocities,electromechanical coupling coefficients and power flow angles was calculated by the Christoffel equation with semi-infinite boundary conditions.The results indicate that 0.24PIN-0.47PMN-0.29PT single crystals along[011]c has better surface acoustic wave properties than the 0.24PIN-0.47PMN-0.29PT single crystals along[001]c.It is very apparent that the surface acoustic wave electromechanical coupling coefficient for 0.24PIN-0.47PMN-0.29PT single crystal along[011]c is dramatically higher compared to along[001]c single crystal.Also,maximum power flow angle for 0.24PIN-0.47PMN-0.29PT single crystals along[011]c is apparently bigger than 0.24PIN-0.47PMN-0.29PT single crystals along[001]c.Therefore,the 0.24PIN-0.47PMN-0.29PT single crystal along[011]c with excellent surface acoustic wave properties and temperature stability is very suitable in making surface acoustic wave devices.