钽酸镓镧与石英声表面波传播特性对比研究

Comparison of surface acoustic waves propagation on LGT and quartz substrates

钽酸镓镧(LGT)是近年研制出的新型压电材料。计算了这种材料在不同切向和传播方向的声表面波传播特性,并和石英晶体上相应切向和传播方向的声表面波传播特性进行了对比分析。计算结果表明这种材料的声表面波传播速度一般比石英低1000 m/s左右,和石英一样,具有零温度切向和纯模方向,但它的机电耦合系数K2却远高于石英。还对目前报道的LGT的不同材料常数进行了对比计算,计算结果表明不同材料常数的声表面波传播特性有明显的差异,其中以频率温度系数差异最大。

Langatate (LGT) is a novel piezoelectric crystal, whose structure is similar to that of quartz. The numerical analysis of the propagating characteristics of surface acoustic waves (SAW) on LGT and quartz are presented. The results show that the phase velocity of SAW on LGT is generally about 1000 m/s slower than that on quartz. Like the quartz, there are cuts with zero temperature coefficient and pure module orientations on LGT. Compared with quartz, LGT is with larger electro-mechanical coupling constant (K2). Based on present material constants reported so far, the characteristics of SAW on LGT with different material constants are also calculated. The results show that there are distinct deviations with different material constants, especially the temperature coefficient of frequency (TCF).