Improved piezoelectric and strain performance of Na2B4O7-doped (Li,K,Na)NbO3 lead-free piezoceramics

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

“…In addition, the bipolar S ‐ E curves of the KNN‐BNZ‐LF1000 x ceramics are plotted in Figure B, in which butterfly‐shaped S ‐ E hysteresis loops were observed for the samples with x ≤ 0.008, and the KNN‐BNZ‐LF6 sample possessed a positive strain of 0.162% and a negative strain of 0.054% under the electric field of 3 kV/mm. When x = 0.01, the KNN‐BNZ‐LF10 sample showed a small negative strain, and the bipolar S ‐ E curves were distinctly different from other samples and exhibited a significant deviation from the typical piezoelectric behavior …”

“…When x = 0.01, the KNN-BNZ-LF10 sample showed a small negative strain, and the bipolar S-E curves were distinctly different from other samples and exhibited a significant deviation from the typical piezoelectric behavior. 41 To study the influence of LaFeO 3 content on the temperature stability of the KNN-BNZ-LF1000x ceramics, the temperature-dependent unipolar S-E curves of the ceramics with x = 0 and x = 0.006 were collected and are presented in Figure 11A,B, respectively. For the sample with x = 0, the unipolar strain first increased and then decreased greatly during the heating process.…”

Outstanding optical temperature sensitivity and dual‐mode temperature‐dependent photoluminescence in Ho3+‐doped (K,Na)NbO3–SrTiO3 transparent ceramics

“…Generally, the phase structure of KNN‐based ceramics can be judged roughly by the (200) peaks at approximately 2θ = 45°‐47° . Only one sharp (200) diffraction peak (inset of Figure ) suggests that the ceramics possess phase structure with similar lattice constants, that is, pseudo‐cubic . It is well‐known that crystal structure can affect the optical transmittance of transparent ceramics.…”

Simultaneously Enhancing Thermal Stable Dielectric Property and Piezoelectric Response in Lead-Free LiNbO3-Modified (K0.5Na0.5)NbO3- (BaNi0.5Nb0.5O3) System

“…Specifically, the densities of as-synthesized ceramics first increase from 4.35 g•cm −3 (x = 0.00) to 4.46 g•cm −3 (x = 0.06), and then decreased to 4.33 g•cm −3 at x = 0.08. The substitution of Li ions would promote the formation of a transient liquid phase during the sintering process, which could benefit grain growth and compact structure (Zhao et al, 2019). The reason for the decrease in density may be due to the appearance of a low-density second phase K 3 Li 2 Nb 5 O 15 (theoretical density: 4.376 g•cm −3 ).…”

“…However, lead-based ceramics have urgent toxicity for the environment and/or human development due to their intrinsic volatility under extreme conditions (Hong et al, 2016;Zheng et al, 2018). The emerging of (K 0.5 Na 0.5 )NbO 3 (KNN)based lead-free system would be a remarkable alternative for these drawbacks due to its high-performance piezoelectric, ferroelectric properties, and high curie temperature (Du et al, 2007b;Ding et al, 2018;Zhao et al, 2019). Furthermore, the piezoelectricity and temperature stability substantially determine the macroscopical performance of ferroelectric materials (Zhao et al, 2007;Sun et al, 2016;Yan et al, 2017Yan et al, , 2018c.…”