Piezoelectric performances of <001> -textured (Ag,K)NbO3 ceramics

Abstract

AgNbO₃-based ceramics have become a research hotspot due to their antiferroelectric or ferroelectric properties. Herein, <001> -textured (Ag_0.9K_0.1)NbO₃ ceramics with high texture degree of 90.2 % were obtained by the template grain growth technology with NaNbO₃ templates, which display good piezoelectric coefficients (d₃₃) of 94 pC/N and large piezoelectric voltage coefficient (g₃₃) of 39 × 10⁻³ Vm/N at room temperature, with enhancements of 62 % and 182 % than the non-textured ones. Furthermore, the d₃₃ reaches 266 pC/N at the orthorhombic-tetragonal phase boundary and maintains 186–200 pC/N within the temperature range of 150–250 ℃ with a variation of less than 10 %. Due to the high texture degree, the positive strain is increased to 0.15 % in the textured (Ag_0.9K_0.1)NbO₃ ceramics. A microscopic piezoelectric response with an amplitude of 465 pm at 8 V was obtained, which provides direct evidence for the better piezoelectric properties of the textured ceramics from a microscopic perspective.