Ultra-high electro-strain and low hysteresis lead-free piezoelectric ceramics obtained by a novel texture engineering strategy

Abstract

Two problems plague the field of electro-strain research: low electro-strain performance and high hysteresis. These two key factors are often difficult to optimise simultaneously. Therefore, a novel texture engineering strategy is proposed to obtain ultra-high strain while effectively reducing strain hysteresis. Synergistically optimized textured ceramics with a high degree of orientation in <001> direction were achieved by improving the preparation process based on the conventional TGG method through a heterogeneous template distinct from the ceramic substrate. Finally, the normalized strain of 951 pm/V at 40 kV/cm is obtained in the BNT-based lead-free system, and the strain hysteresis is only 43 %. At the same time, a series of in-situ electric field structural characterization reveal the source of high strain and low hysteresis of the textured ceramics: heterogeneous templates caused high polarization and formed a large number of PNRs. This result is of great significance for the study of electro-strain in lead-free piezoelectric materials and the development of actuators.