Composition and electric field driven studies on modified NBT-based lead-free ceramics

Abstract

A considerable increase in the c/a ratio, tilt angle, octahedral strain, and Ti-Ti distance with an application of electric field was observed for all the compositions in (1-x) (Na0.5Bi0.5TiO3).x(Ba0.85Ca0.15Ti0.90Zr0.10O3) ceramics. In the x = 0.09 sample, a P4bm phase (∼45 %) was observed which reduced to ∼ 15 % upon poling. The tilt angle modifies the A1 phonon mode at 784 cm−1 upon substitution and application of the electric field. Incorporating Ba0.85Ca0.15Ti0.90Zr0.10O3 increased the maximum dielectric permittivity (εm) from ∼ 2466 (x = 0) to ∼ 3231 (x = 0.09). The degree of diffuseness (γ) also increased with substitution from ∼ 1.384 (x = 0) to ∼ 1.980 (x = 0.09). With poling the value of γ was observed to decrease for each composition. The transformation from a compressive octahedral strain to a tensile one increased the piezoelectric coefficient (d33). The d33 value increased from ∼ 70 (x = 0) to ∼ 120 (x = 0.06). © 2023 Elsevier B.V.