Fabrication and properties of radially ⟨001⟩C textured PMN-PT cylinders for transducer applications

< 001 >(C) Textured PMN-PT ceramics have electromechanical properties (d(33) = 850-1050 pm/V, k(33) = 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 similar to 5 cm in diameter by similar to 2.5 cm in height and demonstrate scalability of textured ceramic fabrication techniques. The fabricated cylinders are similar to 50 vol.% textured and show high 31-mode electromechanical properties compared to PZT ceramics (d(31) = -259 pm/V, k(31) = 0.43, epsilon(T)(33) = 3000, and Q(m) = 350). Frequency bandwidth is related to the square of the hoop mode coupling coefficient k(h)(2), which is similar to 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. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4730938]