Enhanced piezoelectric performance in Na_0.5Bi_4.5Ti₄O₁₅‐based bismuth‐layered ceramics by Nb/Mn doping modification

Abstract

In this work, Na0.5Bi4.5Ti3.94–xMn0.06NbxO15+y bismuth‐layered ferroelectric ceramics were prepared by a solid‐state reaction method. The effect of Nb5+ content on crystal morphology, electrical properties, and piezoelectric performance were systematically investigated. The results show that the introduction of Nb5+ into Na0.5Bi4.5Ti3.94–xMn0.06NbxO15+y ceramics to replace Ti4+ increases the ratio of b/a lattice parameter, leading to the TiO6 octahedral distortion and the structural transformation tendency from the orthorhombic to tetragonal phase, which facilitates dipole movements of Na0.5Bi4.5Ti3.94–xMn0.06NbxO15+y ceramics. Therefore, the ferroelectric properties of Na0.5Bi4.5Ti3.94–xMn0.06NbxO15+y ceramics are improved, and an enhanced piezoelectric coefficient of 30 pC/N combining great temperature stability with d33 value higher than 25 pC/N in the temperature range of 25°C–450°C has been realized in Na0.5Bi4.5Ti3.94–xMn0.06NbxO15+y ceramics with x = 0.08 mol. Our work provides a good model for designing lead‐free ultrahigh Curie temperature piezoelectric devices that can be practically applied in extremely harsh environments.

Effectively improved piezoelectricity in high-temperature Arrhenius CBT ceramics by modifying potential energy profile and spontaneous polarization

“…Furthermore, the Ps of CBT ceramics is designed to be improved by substitution at B-site. Substituting Nb and Mn ions have been reported to increase d33 of BLSFs by enhancing polarization [23,24], which prompts the selection of dual-ions (Nb2/3Mn1/3) as substitutes for Ti at the B-site. By combining the substitution of (Nb2/3Mn1/3) at B-site and (Na1/2Bi1/2) at A-site in CBT ceramics, significant enhancements in piezoelectricity are achieved through the flatting potential energy profile and the augmentation of Ps.…”

Decoding intrinsic and extrinsic contributions for high piezoelectricity of CBT-based piezoelectric ceramics

“…[1][2][3] As core materials of high temperature piezoelectric sensors, bismuth layer-structured ferroelectrics (BLSFs) possess low dielectric loss, high mechanical quality factor, high thermal stability and high Curie temperature (T C ), which enable them to be widely used in such applications. [4][5][6] The chemical formula of BLSFs is (Bi 2 O 2 ) 2+ (A mÀ1 B m O 3m+1 ) 2À , consisting of two layers of (Bi 2 O 2 ) 2+ with m number perovskite-like layers between them. 7 However, the limitation of the spontaneous polarization (P s ) direction by the (Bi 2 O 2 ) 2+ layer leads to low piezoelectric activity of BLSFs.…”