Surface Acoustic Wave Propagation in Relaxor-Based Ferroelectric Single Crystals 0.93Pb(Zn _1/3 Nb _2/3 )O ₃ -0.07PbTiO ₃ Poled along [011] _c

Abstract

Surface acoustic wave (SAW) propagation in relaxor-based ferroelectric single crystals 0.93Pb(Zn 1/3 Nb 2/3)O3-0.07PbTiO3 (PZN-7%PT) poled along [011] 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 = 90 ∘. Considering all related factors, the-cut PZN-7%PT single crystal has the best performance. Based on our results, the-cut PZN-7%PT single crystals poled along [011] are an excellent candidate for ultra-wide bandwidth low-frequency SAW devices.

Relaxor-based ferroelectric single crystals: Growth, domain engineering, characterization and applications

“…The electromechanical coupling factor was found to be much higher than that of traditional piezoelectric materials. The power flow angle (PFA) can be zero in certain directions, which makes this crystal system a promising material for future SAW devices with much smaller size and enhanced performance [348,349,350,351]. …”

Enhancement of Ultrasonic Transducer Bandwidth by Acoustic Impedance Gradient Matching Layer

“…At present, the optimal acoustic impedance gradient distribution of the matching layer is still not clear; it requires a volume ratio of high-impedance filler powder to gradually decrease along the direction of the acoustic wave propagation and achieve a large and smooth acoustic impedance span in a very thin thickness range [ 29 , 30 , 31 , 32 , 33 , 34 , 35 ]. In this paper, we confirmed the ideal acoustic impedance distribution mode and the thickness of the matching layer by simulation and realized this distribution by using nano tungsten powder with high acoustic impedance and epoxy resin to create a kind of anisotropic inhomogeneous material.…”