Surface Acoustic Wave Propagation in Relaxor-Based Ferroelectric Single Crystals 0.93Pb(Zn_1/3Nb_2/3)O₃−0.07PbTiO₃ Poled along 011_c

Surface acoustic wave (SAW) propagation in relaxor-based ferroelectric single crystals 0.93Pb(Zn_1/3Nb_2/3)O₃−0.07PbTiO₃ (PZN−7%PT ) poled along 011_c has been analyzed theoretically. The results show that PZN−7%PT single crystals have excellent SAW properties, such as low phase velocities, very high electromechanical coupling coefficients and small power flow angles. It is also found that the SAW properties strongly depend on the propagation direction and the characteristic curves of SAW phase velocity, and the electromechanical coupling coefficients are symmetric with respect to θ=90°. Considering all related factors, the X−cut PZN-7%PT single crystal has the best performance. Based on our results, the X−cut PZN-7%PT single crystals poled along 011_c are an excellent candidate for ultra-wide bandwidth low-frequency SAW devices.