"Lead-free" Piezoelectric Ba(Ti0.94Zr0.06)O3Single Crystals with Electromechanical Coupling Factor (k33) Higher Than 0.8

2014 ◽  
Vol 51 (6) ◽  
pp. 623-628 ◽  
Author(s):  
Jong-Yeb Lee ◽  
Hyun-Taek Oh ◽  
Ho-Yong Lee
Keyword(s):  
Electromechanical Coupling ◽  
Electromechanical Coupling Factor ◽  
Coupling Factor ◽  
Lead Free

Improved Curie Temperature of Li-Doped Lead-Free (K,Na)NbO3 Ceramics Analysis

2014 ◽  
Vol 1061-1062 ◽  
pp. 91-95
Author(s):  
Rui Zhu Zhang ◽  
Wen Peng Guo ◽  
Gao Lei Zhao
Keyword(s):  
Phase Transition ◽  
Curie Temperature ◽  
Electromechanical Coupling ◽  
Piezoelectric Coefficient ◽  
Electromechanical Coupling Factor ◽  
Coupling Factor ◽  
Lead Free ◽  
Tetragonal Symmetry ◽  
Negative Effects ◽  
Li Content

(K,Na)NbO3(KNN)-based lead-free piezoelectric ceramic could be fabricated by ordinary solid sintering method.This paper reported preferable properties of solid solutions (1-x)(Na0.535K0.480)NbO3-xLiNbO3(x=0.050,0.055,0.060,0.065 and 0.070 successively) all sintered at 1060°C.The nonconservation of charge suppressed negative effects caused by evaporations of K&Na and doped Li occupied A sites in ABO3perovskite structure lattices led to the intensification of lattice distortion.XRD result showd phase transition from coexistence of orthorhombic and tetragonal symmetry to tetragonal.Polymorphic phase boundary could be observed when 0.050≤ x≤ 0.060.Coexistence of orthorhombic and tetragonal phases brought improvements of piezoelectric coefficient d33and electromechanical coupling factor kp,whose top values were 162 pC/N and 28.1% in this paper. Positive correlation between the Curie temperature and Li content proved that a distorted crystal lattice needed more energy to accomplish its phase transition from tetragonal to cubic than a normal one.

(1-x)(K0.475Na0.475Li0.05)(Nb0.975Sb0.025)O3-xBiFeO3 Lead-Free Piezoelectric Ceramics with CuO Sintering Aid

2011 ◽  
Vol 687 ◽  
pp. 228-232
Author(s):  
Yong Jie Zhao ◽  
Yu Zhen Zhao ◽  
Rong Xia Huang ◽  
Rong Zheng Liu ◽  
He Ping Zhou
Keyword(s):  
Electrical Properties ◽  
Electromechanical Coupling ◽  
Piezoelectric Materials ◽  
Piezoelectric Ceramics ◽  
Electromechanical Coupling Factor ◽  
Coupling Factor ◽  
Mechanical Quality Factor ◽  
Lead Free ◽  
X Ray Diffraction ◽  
Diffraction Patterns

(1-x) (K0.475Na0.475Li0.05)(Nb0.975Sb0.025)O3-xmolBiFeO3 (x=0, 0.002, 0.004, 0.006, 0.008) doped with 0.8mol%CuO lead-free piezoelectric ceramics were prepared by the solid state reaction technique. X-ray diffraction patterns suggested that all the ceramics presented perovskite structure. The compositional dependence of the phase structure and the electrical properties of the ceramics were studied. The ceramic (x=0.002) near room temperature exhibited excellent electrical properties (piezoelectric constant d33=172pC/N, planar electromechanical coupling factor kp=0.43, and dielectric constant =418). A relatively high mechanical quality factor (Qm=200) was also obtained in this particular composition. All these results revealed that this system might become a promising candidate for lead-free piezoelectric materials.

Investigation on Electrical Properties of CaCu3Ti4O12-Modified (Na,Bi)TiO3-BaTiO3 Lead Free Piezoceramics

2014 ◽  
Vol 887-888 ◽  
pp. 289-293
Author(s):  
Jing Chang Zhao ◽  
Zhen Lai Zhou
Keyword(s):  
Electrical Properties ◽  
Electromechanical Coupling ◽  
Piezoelectric Properties ◽  
Piezoelectric Ceramics ◽  
Electromechanical Coupling Factor ◽  
Coupling Factor ◽  
Mechanical Quality Factor ◽  
Lead Free ◽  
Lead Free Ceramics ◽  
Structure Morphology

(Na,Bi)TiO3-BaTiO3lead free piezoelectric ceramics were fabricated with modification of CaCu3Ti4O12additives. The phase structure, morphology, dielectric and piezoelectric properties of prepared samples were investigated, respectively. It was found that CaCu3Ti4O12additives evidently improve the polarization properties of (Na,Bi)TiO3-BaTiO3lead free ceramics and the obtained samples exhibit an excellent piezoelectric properties (electromechanical coupling factorKp=31%, mechanical quality factorQm=151 and piezoelectric constantd33=160pC/N). According to results, the effect of CaCu3Ti4O12additives on electrical properties of (Na,Bi)TiO3-BaTiO3lead free piezoelectric ceramics is discussed.

Effect of DC Poling Field on Domain Behavior in Lead-Free Piezoelectric Ceramics

2010 ◽  
Vol 67 ◽  
pp. 34-41
Author(s):  
Toshio Ogawa ◽  
Masahito Furukawa ◽  
Takeo Tsukada
Keyword(s):  
Electromechanical Coupling ◽  
Bismuth Titanate ◽  
Domain Switching ◽  
Electromechanical Coupling Factor ◽  
Coupling Factor ◽  
Lead Free ◽  
Poling Field ◽  
Lead Free Ceramics ◽  
Titanate Ceramics ◽  
Dielectric And Piezoelectric Properties

Poling characteristics, especially DC poling field (E) dependence of dielectric and piezoelectric properties were investigated to evaluate the domain behavior in lead-free ceramics such as alkali niobate and alkali bismuth titanate ceramics. The domain switching was confirmed by the E to realize minimum dielectric constant (εr), minimum electromechanical coupling factor (k) and maximum frequency constant (fc), because of domain clamping. On the other hand, the domain rotation occurred at the E to obtain maximum εr and minimum fc. These phenomena are observed in the lead-free ceramics as well as PZT ceramics.

Discharge Current Measurement and Depolarization Property of Lead-Free Niobate Piezoceramics

2010 ◽  
Vol 445 ◽  
pp. 51-54 ◽  
Author(s):  
Hitoshi Matsudo ◽  
Kenichi Kakimoto ◽  
Isao Kagomiya
Keyword(s):  
Discharge Current ◽  
Spontaneous Polarization ◽  
Electromechanical Coupling ◽  
Electromechanical Coupling Factor ◽  
Solid State Reaction Method ◽  
Coupling Factor ◽  
Lead Free ◽  
Ion Migration ◽  
Oxygen Ion Migration ◽  
Phase Transition Temperatures

Lead-free Na0.5K0.5NbO3 (NKN) piezoelectric ceramics was synthesized by an ordinal solid state reaction method. The ceramics was electrically poled under 3 kV/mm at 150 oC for 30 min. The discharge current-flow was measured for the poled ceramics at the heating rate of 1 oC/min from room temperature up to 500 oC. The two sharp peaks were observed at 209 and 417 oC. These temperatures were corresponded to orthorhombic-tetragonal (TO-T) and tetragonal-cubic (TC) phase transition temperatures, respectively. The sharp peaks were mainly originated from the decrease of the spontaneous polarization. Additionally, the several large broad patterns were also observed at 280, 363 and 375 oC, According to the electromechanical coupling factor kp, which is the indicative parameter of the polarization, mainly decreased at TO-T and TC. These broad peaks were not associated with the spontaneous polarization. The peaks seem to have been originated from the discharge current of the oxygen ion migration on elevating temperature inside the poled NKN ceramics.

Effect of Sintering Temperature on the Structure and Piezoelectric Properties of Lead-Free 0.97K0.5Na0.5NbO3-0.03AlFeO3 Ceramics

2014 ◽  
Vol 602-603 ◽  
pp. 822-825
Author(s):  
Ling Peng ◽  
Min Hong Jiang ◽  
Zheng Fei Gu ◽  
Gang Cheng
Keyword(s):  
Low Temperature ◽  
Electromechanical Coupling ◽  
Piezoelectric Properties ◽  
Sintering Temperature ◽  
Electromechanical Coupling Factor ◽  
Coupling Factor ◽  
Lead Free ◽  
Promising Candidate ◽  
Ceramic Process ◽  
Structure Density

Lead-free piezoelectric 0.97 K0.5Na0.5NbO3-0.03 AlFeO3(KNN-AF) ceramics were prepared at low temperature of 980 °C to 1020 °C by the conventional ceramic process. The effect of sintering temperature on the crystal structure, density and electrical properties of the ceramics was investigated. The results indicate that KNN-AF ceramics sintered at an low temperature of 1000 °C exhibit high electrical and piezoelectric properties, with piezoelectric constantd33=116ρC/N, and electromechanical coupling factorkp= 32.9%, polarization (Pr) wasPr=21.8 μC/cm2and curie temperatureTC=382°C. This also indicates that KNN-AF ceramics are promising candidate materials for lead-free piezoelectric applications.

Dielectric and Piezoelectric Properties of (Na,Ba)(Nb,Ti)O3 Lead-Free Piezoelectric Ceramics

2010 ◽  
Vol 445 ◽  
pp. 55-58 ◽  
Author(s):  
Rintaro Aoyagi ◽  
Makoto Iwata ◽  
Masaki Maeda
Keyword(s):  
Crystal Structure ◽  
Solid Solution ◽  
Dielectric Properties ◽  
Room Temperature ◽  
Electromechanical Coupling ◽  
Piezoelectric Properties ◽  
Electromechanical Coupling Factor ◽  
Coupling Factor ◽  
Lead Free ◽  
Dielectric And Piezoelectric Properties

(Na1-xBax)(Nb1-xTix)O3 (NNBTx; x=0.0-0.21) solid-solution ceramics were synthesized and their crystal structure, dielectric properties and piezoelectric properties were investigated. The crystal structure at room temperature of NNBTx varied from orthorhombic to tetragonal with increasing BaTiO3 content x. The phase boundary between orthorhombic and tetragonal at room temperature was confirmed BT content between x=0.08 and 0.09. For x>0.05, it was found that the Curie temperature was decreased with increasing x. The highest electromechanical coupling factor, kp, and the largest piezoelectric constant, d33, were obtained at x=0.09-0.10.

Dielectric and Piezoelectric Properties of Lead-Free (Na0.5K0.5)NbO3- Bi0.5(Na0.85K0.15)0.5TiO3 Ceramics

2011 ◽  
Vol 211-212 ◽  
pp. 152-155
Author(s):  
Chun Huy Wang
Keyword(s):  
Solid Solution ◽  
Dielectric Constant ◽  
Coupling Coefficient ◽  
Electromechanical Coupling ◽  
Piezoelectric Properties ◽  
Electromechanical Coupling Factor ◽  
Coupling Factor ◽  
Lead Free ◽  
Solid Solution System ◽  
Dielectric And Piezoelectric Properties

Extending the investigations on (Na0.5K0.5)NbO3-based solid solution for lead-free piezoelectric ceramics, this paper consider the complex solid-solution system (Na0.5K0.5)NbO3–Bi0.5(Na0.85K0.15)0.5TiO3[NKN-BNKT]. (Na0.5K0.5)NbO3with 2 ~ 6 mol% Bi0.5(Na0.85K0.15)0.5TiO3has been prepared following the conventional mixed oxide process. A morphotropic phase boundary (MPB) between orthorhombic (O) and hexagonal (H) was found at the composition 0.96NKN-0.04BNKT with correspondingly enhanced dielectric and piezoelectric properties. The electromechanical coupling factor and dielectric constant are higher for compositions near the MPB. The dielectric constant (KT33), planar coupling coefficient (kp) and thickness coupling coefficient (kt)of 0.96NKN-0.04BNKT ceramics were 1273, 34% and 38%, respectively.

Influence of Calcined Temperature on the Piezoelectric Properties of (Na0.48K0.47Li0.05)NbO3 Lead-Free Piezoelectric Ceramics Doped with CuO

2013 ◽  
Vol 760-762 ◽  
pp. 763-766 ◽  
Author(s):  
Xin You Huang ◽  
Mu Sheng Huang ◽  
Chun Hua Gao
Keyword(s):  
Electromechanical Coupling ◽  
Piezoelectric Ceramics ◽  
Electromechanical Coupling Factor ◽  
Solid State Reaction Method ◽  
Coupling Factor ◽  
Lead Free ◽  
Comprehensive Properties ◽  
Piezoelectric Strain ◽  
Calcined Temperature ◽  
Sintered Temperature

Na0.48K0.47Li0.05)NbO3(NKLN)Lead-free piezoelectric ceramics doped with CuO were prepared by traditional solid-state reaction method. Influence of calcined temperature on the material phase of NKLN lead-free piezoelectric ceramics doped with CuO by X-ray diffraction (XRD) and the influence of calcined temperature and sintered temperature on the properties of NKLN lead-free piezoelectric ceramics doped with CuO by others analysis method. The results show that the best calcined temperature is got, when calcined temperature is up to 850 °C, the mixed phase disappeares, a single phase perovskites structure is formed. With the increase of calcined temperature, piezoelectric strain constant (d33) planar electromechanical coupling factor (Kp) of NKLN lead-free piezoelectric ceramics increase first and then decrease, while only dielectric loss (tanδ) decreases first and then increases.The best calcined temperature is 850 °C, the best sintered temperature is 1080 °C, the NKLN lead-free piezoelectric ceramics doped with CuO with good comprehensive properties are obtained, whose d33, Kp, tanδ are 85 pC/N, 0.3, 0.038, respectively.

Low-Temperature Sintering of ZnO and B2O3 Co-Doped (K0.5Na0.5)NbO3 Lead-Free Piezoelectric Ceramics

2011 ◽  
Vol 687 ◽  
pp. 315-320 ◽  
Author(s):  
Rong Xia Huang ◽  
Yu Zhen Zhao ◽  
Yong Jie Zhao ◽  
Rong Zheng Liu ◽  
He Ping Zhou
Keyword(s):  
Electromechanical Coupling ◽  
Lattice Distortion ◽  
Sintering Temperature ◽  
Electromechanical Coupling Factor ◽  
Coupling Factor ◽  
Lead Free ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Doping ◽  
High Relative Density

Lead-free K0.5Na0.5NbO3-xwt% (0.4ZnO-0.6B2O3) ceramics were synthesized by conventional ceramics process. The co-doping of ZnO and B2O3 can decrease the sintering temperature of K0.5Na0.5NbO3 ceramics to 1000°C, and the samples show high relative density around 96%. X-ray diffraction (XRD) reveals that Co-doping of ZnO and B2O3 induces lattice distortion. Liquid phase is observed by scanning electron microscopy (SEM), which is resulted from the addition of ZnO and B2O3. The ceramics show better piezoelectric and dielectric properties with planar electromechanical coupling factor kp= 40.7%, piezoelectric constant d33=117pC/N, dielectric constant εT33/ε0=318.6, and loss tangenttanδ=0.034.

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