Fabrication and properties of radially 001_C textured PMN-PT cylinders for transducer applications

001_C Textured PMN-PT ceramics have electromechanical properties (d₃₃ 850-1050 pm/V, k₃₃ 0.79-0.83) between those of conventional PZT ceramics and relaxor PMN-PT crystals. In this work, we tailor crystallographic orientation in textured PMN-PT ceramics for transducer designs with non-planar poling surfaces. Specifically, omni-directional cylindrical transducer elements were fabricated using monolithic, radially 001_C textured and poled PMN-PT ceramic. Texture was produced by templated grain growth using NBT-PT templates, which were oriented radially by wrapping green ceramic tapes around a cylindrical mandrel. Finished transducer elements measure ∼5 cm in diameter by ∼2.5 cm in height and demonstrate scalability of textured ceramic fabrication techniques. The fabricated cylinders are ∼50 vol. textured and show high 31-mode electromechanical properties compared to PZT ceramics (d₃₁ -259 pm/V, k₃₁ 0.43, ^T ₃₃ 3000, and Q_m 350). Frequency bandwidth is related to the square of the hoop mode coupling coefficient k_h², which is ∼60 higher in textured PMN-PT cylinders compared to PZT 5H. Finite element simulations show that this parameter may be further increased by improving texture quality to 90 vol. . Radially textured PMN-PT may thus improve performance in omni-directional cylindrical transducers while avoiding the need for segmented single crystal designs.