Optimized orientation of PIN-PMN-PT single crystal for enhanced electromechanical properties via anisotropic structural engineering

To enhance the performance of medical ultrasonic transducers, we optimized the cutting angle of length orientation for the [011]-oriented Pb(In_1/2Nb_1/2)O₃-Pb(Mg_1/3Nb_2/3)O₃-PbTiO₃ single crystal (SC) B-mode resonator to maximize the longitudinal vibration (k′₃₃) while suppressing transverse vibration (k₃₁) via anisotropic structural engineering. Experimental results demonstrate that a 60° length orientation along the [100]_c direction achieves a peak k′₃₃ value of 77.8%, corroborating theoretical predictions. This orientation of resonator’s length concurrently delivers a low acoustic impedance (Z′₃₃) of 27.6 MRayl, a broad 3 dB bandwidth of 77.1%, and excellent transmit (TP = 3.24 × 10⁻⁴ m⋅N^−1/2) and receive (RP = 3.77 × 10⁻¹¹ m⋅N^−1/2) efficiencies. The synergy of high electromechanical coupling and reduced clamped dielectric permittivity (ϵ₃₃^S/ϵ₀ < 600) renders this configuration ideal for large-aperture, high-frequency ultrasonic transducers. This work underscores the critical role of crystallographic orientation in tailoring anisotropic electromechanical properties, establishing guidelines of material design for developing high-performance transducers.