SOLID STATE PHENOMENA
·
2018
·
IF 0
Li Qian Cheng,Mei Feng,Kai Chen
Single crystalline lead-free (K, Na)NbO3 (KNN) nanostructures have attracted much attention for the high piezoelectricity and environmental compatibility. Especially, the plate-like KNN structures are supposed to be utilized in the synthesis of textured KNN-based ceramics. The KNN plate-like templates were prepared by a two-step molten salt reaction. The layered-perovskite Bi2.5Na3.5Nb5O18 (BNN5) was first prepared by using Bi2O3, Nb2O5, Na2CO3, NaCl as raw materials. The BNN5 precursors possess high aspect ratio with an average size of 15 - 20 μm in width and 0.5 - 1 μm in thickness. Then Bi element in the BNN5 was replaced by Na/K through topochemical reaction, and KNN plate-like products which have anisotropic crystal structure were fabricated. It should be emphasized that piezoresponse force microscopy (PFM) was used to confirm three-dimensional (3-D) morphology, while piezoelectric properties of single crystalline KNN platelets were acquired simultaneously. The as-synthesized KNN structures are expected to play an important role in the study of textured KNN ceramics. Meanwhile, the methodology investigated in this paper can also be applied for further fundamental studies on KNN system as well as other lead-free piezoelectric materials.
研究领域:
材料科学
·
无机化学
✓ 已验证
产品关联
DOI
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2021
·Vol. 104
·期 8
·4119-4130
·
IF 3.784
Yu Huang,Liang Shu,Suwei Zhang,Zhen Zhou,Yue-Yu-Shan Cheng,Biaolin Peng,Lisha Liu,Yuanyuan Zhang,Xuping Wang,Jing-Feng Li
With the development of advanced electrical and electronic devices and the requirement of environmental protection, lead-free dielectric capacitors with excellent energy storage performance have aroused great attention. However, it is a great challenge to achieve both large energy storage density and high efficiency simultaneously in dielectric capacitors. This work investigates the energy storage performance of sol-gel-processed (K,Na)NbO 3 -based lead-free ferroelectric films on silicon substrates with compositions of 0.95(K 0.49 Na 0.49 Li 0.02 )(Nb 0.8 Ta 0.2 )O 3 -0.05CaZrO 3 - x mol% Mn (KNN-LT-CZ5- x mol% Mn). The appropriate amount of Mn-doping facilitates the coexistence of orthorhombic and tetragonal phases, suppresses the leakage current, and considerably enhances the breakdown strengths of KNN-LT-CZ5 films. Consequently, large recoverable energy storage density up to 64.6 J cm −3 with a high efficiency of 84.6% under an electric field of 3080 kV cm −1 are achieved in KNN-LT-CZ5-5 mol% Mn film. This, to the best of our knowledge, is superior to the majority of both the lead-based and lead-free films on silicon substrates and thus demonstrates great potentials of (K,Na)NbO 3 -based lead-free films as dielectric energy storage materials.
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry C
·
2019
·Vol. 7
·期 23
·6914-6923
·
IF 6.641
Yi-Xuan Liu,Hao-Cheng Thong,Chunlin Zhao,Qing Liu,Xingyu Xu,Ke Wang,Jing-Feng Li
The understanding of certain basic issues in (K,Na)NbO3 (KNN)-based systems is still missing, one of which being the influence of ZrO2 addition on the behaviors of KNN-based solid solutions at trace levels possibly introduced during the process of material preparation. Herein, KNN solid solutions with trace ZrO2 addition (0, 0.01, 0.05, and 0.1 mol%) were prepared by a normal sintering method. The dielectric permittivity and the piezoelectric coefficient d33 reach the maximum (εr = 497 and d33 = 139 pC N−1) with 0.1 mol% ZrO2 addition. Moreover, the microscopic results supported by PFM are in agreement with those from the macroscopic perspective. To establish the relationship among the ZrO2 addition contents, the induced defects and the properties of the solid solutions, a related defect model is proposed to support the experimental observation and the origin of induced defects is discussed. The results demonstrate that the properties of the KNN solid solutions can be closely affected by trace zirconia addition.
研究领域:
材料科学
·
陶瓷材料
✓ 已验证
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2021
·Vol. 105
·期 1
·461-468
·
IF 3.784
Baoyu Deng,Yiming Ma,Tianxiang Chen,Huajing Wang,Jinfeng Lin,Cong Lin,Xiao Wu,Chunlin Zhao,Tengfei Lin,Min Gao,Xinghua Zheng,Changqing Fang
Dense (K, Na)NbO 3 ceramics are successfully fabricated via the cold sintering process at 350°C under a uniaxial pressure of 400 MPa for 4 h. Equimolar KOH and NaOH solutions were utilized as a transient alkaline flux. The microstructure and dielectric properties were studied in detail. Scanning electron microscope and the relative densities reveal dense structures of the ceramics. After post-annealing at 800°C for 1 h, the ceramics show good electrical performance. The relative dielectric permittivity is 829 (at 10 kHz) at room temperature, and the piezoelectric constant ( d 33 ) reaches up to 148 pC/N. The cold sintering technique with equimolar KOH and NaOH solutions as a transient alkaline flux endow KNN ceramics with excellent dielectric and piezoelectric properties, showing a potential way to fabricating other KNN-based ceramics at low temperature.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Zhihao Dong,Peiyao Zhao,Xiao Ma,Limin Guo,Longtu Li,Xiaohui Wang
To reconcile the contradiction between piezoelectric property and its temperature stability, the preparation of composite piezoceramics using multiple components has become an emerging direction. Herein, (K,Na)NbO 3 -based piezoceramics are adopted to prepare high-performance laminated composite ceramics inspired by the lamination composite strategy, and sintered in the reducing atmosphere to meet the development of multilayer piezoelectric actuators with base metal internal electrodes. By adjusting the composition ratio, a high inverse piezoelectric coefficient d 33 * of 1065 pm/V (@ 2 kV/mm) is obtained in the two-component composite ceramics, which fluctuated less than ± 6% in the range of 25–160 °C. In the three-component composite ceramics, a higher d 33 * value of 1326 pm/V (@ 2 kV/mm) is achieved and maintained > 90% until 150 °C. The electric-field-induced strain performances of laminated composite ceramics significantly exceed those of their basic components, which is related to the piezoresponse gain provided by the internal interfaces. The excellent temperature stabilities come from the more diffused phase transition temperature range formed by the complementation of multiple components. The combination of ultrahigh strain performance, high temperature stability, and good fatigue resistance, together with sintering in the reducing atmosphere, constitutes an important step to promote the application of (K,Na)NbO 3 -based multilayer piezoelectric actuators.
研究领域:
材料科学
·
陶瓷工程
·
电陶瓷
✓ 已验证
DOI
高影响因子
ACS Applied Electronic Materials
·
2026
·
IF 4.7
Yi Han,Yichao Wang,Dong Liu,Xiang Hui,Xiaoshuang Ma,Pengju Sun,Jianqiang Li,Zhipeng Xing,Zhenfu Zhang,Li-Feng Zhu
(K,Na)NbO3-based ceramics are promising lead-free piezoelectrics due to their excellent piezoelectric coefficient (d33) and high Curie temperature (Tc), but their poor mechanical properties limit high-reliability applications. To address this issue, 0.97K0.5Na0.5Nb0.95Sb0.05O3-0.03Bi0.5Na0.5ZrO3-0.5%wtBiFeO3-xZrO2(KNNS-xZrO2) textured ceramics were developed. Excessive ZrO2 improved mechanical performance, while <001>-oriented samples exhibited strong piezoelectricity. At x = 0.01, the ceramics achieved high values in the KNN system: d33 ∼ 326 pC·N−1, Hv ∼ 8.46 ± 0.14 GPa, E ∼ 172 ± 4 GPa, and fracture toughness KIC ∼ 1.70 ± 0.09 MPa·m1/2. Based on these outstanding properties, a KNNS-0.01ZrO2 piezoelectric wristband was fabricated to monitor human heart rate, producing stable current signals under different motion states. This work provides insights for reliable piezoelectric sensors and actuators.
✓ 已验证
DOI
高影响因子
Nature Communications
·
2021
·Vol. 12
·期 1
·1-9
·
IF 14.919
Gao Xiaoyi,Cheng Zhenxiang,Chen Zibin,Liu Yao,Meng Xiangyu,Zhang Xu,Wang Jianli,Guo Qinghu,Li Bei,Sun Huajun,Gu Qinfen,Hao Hua,Shen Qiang,Wu Jinsong,Liao Xiaozhou,Ringer Simon P.,Liu Hanxing,Zhang Lianmeng,Chen Wen,Li Fei,Zhang Shujun
(K,Na)NbO 3 based ceramics are considered to be one of the most promising lead-free ferroelectrics replacing Pb(Zr,Ti)O 3 . Despite extensive studies over the last two decades, the mechanism for the enhanced piezoelectricity in multi-elements doped (K,Na)NbO 3 ceramics has not been fully understood. Here, we combine temperature-dependent synchrotron x-ray diffraction and property measurements, atomic-scale scanning transmission electron microscopy, and first-principle and phase-field calculations to establish the dopant–structure–property relationship for multi-elements doped (K,Na)NbO 3 ceramics. Our results indicate that the dopants induced tetragonal phase and the accompanying high-density nanoscale heterostructures with low-angle polar vectors are responsible for the high dielectric and piezoelectric properties. This work explains the mechanism of the high piezoelectricity recently achieved in (K,Na)NbO 3 ceramics and provides guidance for the design of high-performance ferroelectric ceramics, which is expected to benefit numerous functional materials.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
PubMed
高影响因子
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
·
2022
·
IF 4.644
Weipeng Liu,Benwei Zhou,Hualong Wang,Chengjun Li,Yi Du,Chuanbing Cheng
Compositional fluctuation of the K and Na elements during the preparation process becomes a major issue for (K,Na)NbO 3 (KNN) lead-free ceramics to maintain relatively stable electrical properties. The raw material Bi 2 O 3 is more sensitive to high temperature. To improve electrical properties, it is more necessary to compensate the volatile Bi. In this work, the 0.96K 0.48 Na 0.52 Nb 0.96 Sb 0.04 O 3 -0.04Bi 0.5*(1+ x ) Na 0.5 ZrO 3 ( x = −0.05, −0.02, 0.00, 0.02, 0.05, and 0.08) ceramics were selected as basis material. The excess Bi can increase the phase fraction of the T phase and decrease oxygen vacancy content, which effectively enhance the extrinsic contribution of the piezoelectric response. The electromechanical properties were optimized by excess Bi, and the optimal properties ( d 33 = 522 pC/N, k p = 58.9%, T c = 235 °C) were obtained in the ceramic with x = 0.05. The present work provides new guidelines for enhancing the piezoelectric performance of KNN ceramics by a simple method, which can be applied to other lead-free piezoelectric ceramic systems.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
Scientific Reports
·
2016
·Vol. 6
·期 1
·1-12
·
IF 5.228
Huan Yu,Wang Xiaohui,Koruza Jurij,Wang Ke,Webber Kyle G.,Hao Yanan,Li Longtu
Miniaturization of domains to the nanometer scale has been previously reported in many piezoelectrics with two-phase coexistence. Despite the observation of nanoscale domain configuration near the polymorphic phase transition (PPT) regionin virgin (K 0.5 Na 0.5 )NbO 3 (KNN) based ceramics, it remains unclear how this domain state responds to external loads and influences the macroscopic electro-mechanical properties. To this end, the electric-field-induced and stress-induced strain curves of KNN-based ceramics over a wide compositional range across PPT were characterized. It was found that the coercive field of the virgin samples was highest in PPT region, which was related to the inhibited domain wall motion due to the presence of nanodomains. However, the coercive field was found to be the lowest in the PPT region after electrical poling. This was related to the irreversible transformation of the nanodomains into micron-sized domains during the poling process. With the similar micron-sized domain configuration for all poled ceramics, the domains in the PPT region move more easily due to the additional polarization vectors. The results demonstrate that the poling process can give rise to the irreversible domain configuration transformation and then account for the inverted macroscopic piezoelectricity in the PPT region of KNN-based ceramics.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2022
·
IF 24.319
Xi-xi Sun,Ruichen Li,Zhiwei Yang,Nan Zhang,Chao Wu,Junhua Li,Yulin Chen,Qiang Chen,Jing Zhang,Hongjian Yan,Xiang Lv,Jiagang Wu
The strategy of modulating polarization rotation of potassium sodium-niobate ((K 0.5 Na 0.5 )NbO 3 , KNN) lead-free piezoelectric materials was reported to boost piezoelectric properties and resultant piezocatalytic activities. The effectiveness of modulating polarization rotation was proved by degrading Rhodamine B (RhB) using three KNN-based samples with different phase structures (i.e., orthorhombic (O) phase, orthorhombic-tetragonal (O-T) coexistence phase, and rhombohedral-orthorhombic-tetragonal (R-O-T) coexistence phase). Poled samples with the R-O-T coexistence phase show a reaction rate constant of 0.091 min −1 owing to the easiest polarization rotation, 2.12 times more than that of poled O-phase featured samples with the most difficult polarization rotation. Enhanced piezocatalytic activities primarily originate from the easier polarization rotation and improved carrier concentration, accompanied by the trace of the mechano-charge generation. Therefore, modulating polarization rotation effectively boosts piezocatalysis of KNN-based materials, promising for harnessing natural energy and disease treatment.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
Materialia
·
2026
·
IF 3.1
Fengyun Liu,Jialiang Zhang,Lu Li
(K,Na)NbO₃-based ceramics are widely regarded as a promising type of lead-free piezoelectric materials to replace the current lead-containing ones. However, due to polymorphic phase transitions, achieving a desirable comprehensive piezoelectric performance of high piezoelectric coefficient d ₃₃ and large electromechanical coupling factors k p , k t and k 33 along with good thermal stabilities (which are characterized by minimal temperature dependence and ageing degradation) in them is extremely challenging. The poled and subsequently thermally-stabilized <001>-textured 0.98(K₀.₄₈Na₀.₅₂)₀.₉₉Li₀.₀₁(Nb₀.₉₈Sb₀.₀₂)O₃–0.02(Bi₀.₅₀Na₀.₅₀)ZrO₃ ceramic was recently identified as an effective solution to the issue. It possesses a d ₃₃ of 405 pC/N along with k ₚ ≈ 0.80, k ₜ ≈ 0.60, k ₃₃ ≈ 0.88 at room temperature, and its piezoelectric properties are of weak temperature dependence across a broad operational range and show remarkable retention even after thermal ageing at 250 °C. Particularly, its d ₃₃ has an average of 425 pC/N with the variation ≤ ± 6.5% from room temperature to 100 °C, and its k ₜ keeps almost constant between -60 °C and 110 °C. In general, this ceramic exhibits an outstanding comprehensive performance that well competes to those of benchmark commercial piezoceramics such as PZT-5A and PZT-5H, indicating the great potential for advanced ultrasonic applications. Analysis reveals that the excellent piezoelectric properties originate from the synergistic effect of crystallographic anisotropy and an engineered, dense domain structure of orthorhombic phase. Meanwhile, the remarkable thermal ageing stability is possibly attributed to the relaxed crystal structure and the stabilized domain structure, both facilitated by the repeated orthorhombic-tetragonal phase transitions in the thermal treatment.
✓ 已验证
DOI
高影响因子
Biomaterials Advances
·
2026
·
IF 6.7
Linfeng Fan,Zhiyuan Dai,Xinna Bai,Xudan Liu,Zhangui Tang,Hao Pan,Yan Zhang,Dou Zhang
KNN nanoparticles act as nucleating agents in PVDF films, promoting β-phase formation and enhancing piezoelectric properties. • The piezoelectric field generated by KNN/PVDF film promotes fibroblast migration. • Elevated TGF-β and VEGF expression accelerates angiogenesis and wound healing. Electrical stimulation that mimics endogenous electric fields represents a promising therapeutic strategy for wound healing. In this study, a lead-free piezoelectric composite film was fabricated by incorporating (K,Na)NbO 3 (KNN) ceramics into a polyvinylidene fluoride (PVDF) matrix via tape casting. The introduction of KNN fillers significantly enhanced the β-phase content and piezoelectric output of PVDF. Under ultrasound irradiation, the resulting KNN/PVDF film effectively promoted fibroblast proliferation and migration in vitro, achieving a 54.84% migration rate within 24 h and upregulating key wound-repair genes, including TGF-β and VEGF. In vivo, the composite film markedly accelerated the healing of full-thickness skin defects in rats, promoted neovascularization, and achieved approximately 95% wound closure by day 9. These results demonstrate that the KNN/PVDF composite film provides an effective wireless platform for biomimetic electrical stimulation in tissue regeneration.
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）