Complete electroelastic set for the (YXt)-45° cut of a KNbO3 single crystal

Abstract

A complete and consistent set (elastic, dielectric, and piezoelectric tensors) of a commercial lead-free (YXt)-45° cut KNbO3 single crystal is reported. These data were obtained using several samples and the resonance-antiresonance method. Particular attention was paid to the consistency of this delivered database. A genetic algorithm with an appropriate criterion was used. Electromechanical characterization revealed a high thickness coupling factor of approximately 60%. These properties make this single crystal a good candidate for several applications such as medical imaging. This complete set provides a basis for simulation designs of such devices integrating this piezoelectric lead-free material, especially for ultrasonic transducers.

Piezoelectric sensitivity and hydrostatic response of novel lead-free 2–0–2 composites with two single-crystal components

“…According to reported data [31] on a 2-2 PZT ceramic / polymer composite, its max PZT ceramics [12] with the lead-free SCs in Table 1, the effective parameters g decrease more intensively [19] than the 2-0-2 composite studied here. We add that for the 2-2 composite based on single-domain KNbO 3 SC [34] from the mm2 symmetry class, the polarisation orientation effect was studied [19] to improve the piezoelectric sensitivity and examine conditions for the large piezoelectric anisotropy.…”

Complete electroelastic set of co doped barium titanate for transducer applications

“…Regardless of this choice, the calculation has to give a unique and similar result. If the result depends on the choice of the subset, the complete set is inconsistent [8,4]. The complete set provided in this paper avoids this important defect.…”

“…In this work, reference values are taken from the Bechmann's results [10] about the complete electroelastic set of barium titanate ceramic because of the similar compositions. The GA attempts to reduce the fitness value p as it is defined in [4]. Relative distances are calculated between both right-and left-hand sides of each intercoefficient relation.…”

“…In this study, a method based on a genetic algorithm is used to optimize the consistency of the full set of material constants through the minimization of a defined criterion. This method has already been applied to KN single crystal characterization [4]. With a BTCaCo disc, a single element tranducer is fabricated and the measured performances are compared with the theoretical behavior to evaluate the efficiency of this leadfree composition.…”

Unified model for the electromechanical coupling factor of orthorhombic piezoelectric rectangular bar with arbitrary aspect ratio

“…Lead-free single crystals are also extensively studied in order to satisfy new international restrictions. 3 Some of these crystals can exhibit orthorhombic structures like the well-known PIN-PMN-PT 4 or the promising lead-free KNbO 3 , 5,6 that brings some difficulties in the optimization and the design of these piezoelectric materials for their integration in ultrasonic transducers. Indeed, in linear or phased arrays, piezoelectric elements shape is a rectangular slender bar with dimensions that depend on the expected transducer's characteristics (operating frequency, resolution, .…”