Structure and electrical properties of (0.965 − x)(K_0.48Na_0.52)NbO₃–xBiGaO₃–0.035(Bi_0.5Na_0.5)ZrO₃ piezoelectric ceramics

Abstract

0.965 À x)(K 0.48 Na 0.52 )NbO 3 -xBiGaO 3 -0.035(Bi 0.5 Na 0.5 )ZrO 3 [(0.965 À x)KNN-xBG-BNZ] lead-free piezoelectric ceramics were prepared using normal sintering for improving the piezoelectric properties and temperature stability of KNN-based ceramics. The effects of the BiGaO 3 (BG) content on their phase structure, microstructure, and piezoelectric properties were investigated. Orthorhombic-tetragonal phase coexistence has been found in the ceramics with the composition range of 0 # x # 0.001, and the coexistence of rhombohedral, orthorhombic and tetragonal phases at room temperature was obtained with 0.002 # x # 0.006. Then enhanced piezoelectric properties and a high Curie temperature (e.g., d 33 ¼ 312 pC N À1 , k p $ 44%, and T C $ 341 C) were observed. All the results show this system of potassium-sodium niobate-based ceramics demonstrates promising potential in practical applications.

Emerging new phase boundary in potassium sodium-niobate based ceramics

“…With the addition of Sb, KNN-based ceramics with NPB can exhibit a combination of ''high d 33 and moderate T c '', [23][24][25][26]28,29,31,[41][42][43][44][45]55,57,59,60,[63][64][65][66]97,103, while the counterparts without Sb can show a combination of ''high T c and moderate d 33 ''. 27,62,[146][147][148][149][150][151][152][153][154][155][156][157][158][159][160][161][162][163][164][165] Therefore, in addition to the construction of the phase boundary, the composition design should also be fully considered when pursuing high piezoelectric properties. In other words, the NPB can provide a high platform, while the composition design determines the maximum level of piezoelectric properties of KNN-based ceramics.…”

Study of diffuse phase transition and relaxor ferroelectric behavior of Ba0.97Bi0.02Ti0.9Zr0.05Nb0.04O3 ceramic

“…These compounds present several polymorphic phase transitions used to correlate important dielectric/ferroelectric properties, such as variations in polymorphic phase transition temperatures, permittivity, and dielectric loss with chemical doping and ceramic microstructure. [13][14][15] Incorporating Bi 3+ in to this structure at Ba site was reported in many works and assumed that the relaxor behavior is induced by heterovalent substitution can be explained by the random-eld-induced domain state. [16][17][18][19] Moreover, other researchers studied the effect of doping at Ti 4+ site using more stable chemical ions and larger ionic size as Zr 4+ .…”

Enhanced piezoelectricity and temperature stability in LaFeO3‐modified KNN‐based lead‐free ceramics

“…Recently, inspired by the excellent piezoelectric properties in lead‐based ceramics with morphotropic phase boundaries (MPBs), the construction of polymorphic phase boundaries (PPTs) has been widely accepted as an effective way to improve the piezoelectric performance in KNN‐based ceramics. Additives, such as Sb 5+ , Bi 0.5 Na 0.5 ZrO 3 , CaZrO 3 , and BaHfO 3 , were introduced into KNN‐based ceramics to tune the R‐O and O‐T phase transition temperatures . For instance, a series of K 0.48 Na 0.52 NbO 3 ‐Bi 0.5 Na 0.5 ZrO 3 ‐based material systems were fabricated in pioneering works, in which the appropriate amount of Bi 0.5 Na 0.5 ZrO 3 content was consistently found to be approximately 4 mol%.…”