Effect of Doping Ions on Structure and Electrical Properties of Lead-Free KNN Ceramics

2014 ◽  
Vol 1058 ◽  
pp. 190-195
Author(s):  
Na Yin ◽  
Abolfazl Jalalian ◽  
Zhi Gang Gai ◽  
Lan Ling Zhao ◽  
Xiao Lin Wang
Keyword(s):  
Phase Transition ◽  
Electrical Properties ◽  
Tetragonal Phase ◽  
Room Temperature ◽  
Piezoelectric Properties ◽  
Boundary Region ◽  
Lead Free ◽  
Vibration Modes ◽  
Polymorphic Phase Transition ◽  
Dielectric And Piezoelectric Properties

Doping effect on the lattice parameters, vibration modes, dielectric and piezoelectric properties of LiSbO3, LiTaO3 and LiNbO3 substituted lead-free K0.5Na0.5NbO3 (KNN) ceramics are investigated. All compositions are crystallized in morphotropic phase boundary region. Enhanced piezoelectric and electromechanical response d33 ~176–197 pC/N, kp ~45%–48%, and kt~34%–47% obtained in the doped ceramics are due to the presence of the polymorphic phase transition between orthorhombic and tetragonal phase at room temperature.

Phase Structure, Microstructure and Electrical Properties of Lead-Free (1-x) [Na0.515K0.485]0.94Li0.06(Nb0.99Ta0.01)O3 - BiAlO3 Ceramics

2013 ◽  
Vol 747 ◽  
pp. 781-784 ◽  
Author(s):  
Pornsuda Bomlai
Keyword(s):  
Phase Transition ◽  
Electrical Properties ◽  
Phase Structure ◽  
Piezoelectric Properties ◽  
Perovskite Phase ◽  
Lead Free ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Polymorphic Phase Transition ◽  
Dielectric And Piezoelectric Properties

Lead-free (1-x)[(Na0.515K0.485)0.94Li0.06(Nb0.99Ta0.01)O3]-xBiAlO3 (NKLNT-BA; x = 0, 0.005, 0.010, 0.015, and 0.020) ceramics were fabricated by a conventional mixed-oxide method. The effects of BiAlO3 addition on the phase structure, microstructure and electrical properties of ceramic were then studied. The result indicated that grain size decreased with increasing of BiAlO3 content. In the composition range studied, the perovskite phase with the coexistence of the orthorhombic and tetragonal phases was identified at approximately x 0.005 by the X-ray diffraction analysis and dielectric spectroscopy, which led to a significant enhancement of the piezoelectric properties. The tetragonality increased with further increasing x. The temperature dependence of dielectric properties showed that the addition of BiAlO3 slightly decreased the ferroelectric tetragonal-paraelectric cubic phase transition temperature (TC), but greatly shifted the polymorphic phase transition from the ferroelectric orthorhombic to the ferroelectric tetragonal phase (TOT) to lower room temperature. The dielectric and piezoelectric properties are enhanced for the composition near the orthorhombic-tetragonal polymorphic phase boundary. The unmodified-(Na0.515K0.485)0.94Li0.06(Nb0.99Ta0.01)O3 ceramics exhibit optimum electrical properties (d33 = 225 pC/N and TC = 418°C).

Investigation of the Morphotropic Phase Boundary (MPB) of (1-x-y)BaZrO3-x(K0.45Na0.5Li0.05)NbO3-yBi (Mg0.5Ti0.5)O3

2014 ◽  
Vol 787 ◽  
pp. 242-246
Author(s):  
Rui Lin Wu ◽  
Tomoaki Karaki ◽  
Jiang Tao Zeng ◽  
Liao Ying Zheng ◽  
Wei Ruan ◽  
...  
Keyword(s):  
Phase Boundary ◽  
Morphotropic Phase Boundary ◽  
Tetragonal Phase ◽  
Room Temperature ◽  
Piezoelectric Properties ◽  
Piezoelectric Ceramics ◽  
Solid State Reaction Method ◽  
Lead Free ◽  
Reaction Method ◽  
Dielectric And Piezoelectric Properties

Lead-based piezoelectric ceramics have excellent piezoelectric properties with the compositions near the rhombohedral-tetragonal morphotropic phase boundary (MPB)[1,2]. In these materials, the dielectric and piezoelectric properties show the maximal values at MPB. For lead-free piezoelectric ceramics, finding the MPB area is a promising way to improve their properties. In this paper, the (1-x-y)BaZrO3-x(K0.45Na0.5Li0.05)NbO3-yBi (Mg0.5Ti0.5)O3 lead-free piezoelectric ceramics were prepared by solid-state reaction method, and their piezoelectric properties and dielectric properties were investigated. With the increase of KNLN content, the crystal structure changed from rombohedral phase to tetragonal phase, thus existed a MPB[3,4] between rombohedral and tetragonal phase. At room temperature, the specimen with the composition at MPB (x=0.93, y=0.01) shows the optimal piezoelectric properties (d33=225pC/N and kp=45%), which indicates that this material is a potential lead-free piezoceramic.

Two-Step Sintering, Microstructure and Electrical Properties of (Ba, Ca)(Ti, Zr)O3 Lead-Free Ceramics

2015 ◽  
Vol 749 ◽  
pp. 79-83
Author(s):  
Pornsuda Bomlai
Keyword(s):  
Phase Transition ◽  
Grain Size ◽  
Electrical Properties ◽  
Piezoelectric Properties ◽  
Orthorhombic Phase ◽  
Lead Free ◽  
Lead Free Ceramics ◽  
Average Grain Size ◽  
Sintering Method ◽  
Dielectric And Piezoelectric Properties

In this work, the (Ba1-xCax)(Ti1-yZry)O3 lead-free ceramics were prepared by the two-step sintering method, and effects of Ca and Zr contents on phase structure, densification, microstructure, and electrical properties were investigated. It was found that all samples showed orthorhombic phase. The highest density of 5.84 ± 0.01 g/cm3 was achieved in x = 0.05, y = 0.05 sample. The average grain size, phase transition temperature, dielectric and piezoelectric properties significantly decreased by introducing of the Ca/Zr content. The ceramics with a small amount of Ca and Zr maintain good piezoelectric properties, and a lower dielectric loss. The composition with x = 0.05, y = 0.025 demonstrated optimum electrical properties of d33 ∼211 pC/N, TC ∼ 119 °C, εr ∼ 1788, and tanδ ∼ 0.04.

Dielectric, Piezoelectric, Pyroelectric Properties and Polymorphic Phase Transition of 0.95 (KXNa1-X) NbO3-0.05LiSbO3 Lead-Free Ferroelectric Ceramics

2013 ◽  
Vol 377 ◽  
pp. 161-165
Author(s):  
Yang Yang Zhang ◽  
Jin Ping Zhang ◽  
Er Ping Wang ◽  
Sheng Lin Jiang ◽  
Lin Lu
Keyword(s):  
Phase Transition ◽  
Transition Temperature ◽  
Electrical Properties ◽  
Room Temperature ◽  
Lead Free ◽  
Ferroelectric Ceramics ◽  
Polymorphic Phase Transition ◽  
Lead Free Ceramics ◽  
Enhanced Properties ◽  
Tetragonal Phase Transition

0.95 (KXNa1-X) NbO3-0.05 LiSbO3(KNN-LS-X) (X=0.4-0.5) lead-free ceramics were prepared by conventional solid method. The effect of K/Na ratio on the dielectric, piezoelectric, pyroelectric and polymorphic phase transition was studied. The results show that the electrical properties strongly depend on the K/Na ratio. The KNN-LS-X(X=0.45) ceramics exhibit enhanced properties (εr=891.267,d33=222pC/N,Kp=0.43517,Qm=64.72,p=15×10-4C/m2K). Enhanced electrical properties of the KNN-LS-X (X=0.45) ceramics could be attributed to the effect of K/Na ratio modifying the polymorphic orthorhombic-tetragonal phase transition temperature to room temperature, which could make KNN-LS-X (X=0.45) ceramics use as a new ferroelectric sensor.

DIELECTRIC AND PIEZOELECTRIC PROPERTIES OF (K,Na)NbO3-BASED PIEZOELECTRIC CERAMICS

2011 ◽  
Vol 01 (03) ◽  
pp. 345-349 ◽  
Author(s):  
ERIC A. PATTERSON ◽  
DAVID P. CANN
Keyword(s):  
Phase Transition ◽  
Solid State ◽  
Room Temperature ◽  
Single Phase ◽  
Piezoelectric Properties ◽  
Lead Free ◽  
Maximum Strain ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dielectric And Piezoelectric Properties

Solid solutions based on Li , Ta and Sb -doped (K0.5Na0.5)NbO3 (KNN) lead-free perovskite systems were created using standard solid-state methods. X-ray diffraction was used to confirm that all compositions were single phase and to verify the phase transition from tetragonal to cubic at TC = 302° C . The three compositions examined, originally developed by Saito and Li , were shown to be strongly ferroelectric with sharp peaks in permittivity present at the Curie temperature. The optimum composition had loss tangent values below 5% up to 100 kHz at room temperature. Bipolar hysteresis measurements showed high values for both maximum polarization (25 and 21 μC/cm2) and remenant polarizations (20 and 16 μC/cm2) for undoped and 0.2 wt% CuO -doped samples. Maximum strain values of greater than 0.23% were observed.

scholarly journals Effects of sintering temperature on structure and electrical properties of (Na0.48k0.473Li0.04Sr0.007)(Nb0.883Ta0.05Sb0.06Ti0.007)O3 piezoelectric ceramics

2021 ◽  
Vol 15 (1) ◽  
pp. 79-86
Author(s):  
Cheng-Shong Hong ◽  
Yi-Tian Hong
Keyword(s):  
Phase Transition ◽  
Electrical Properties ◽  
Diffuse Phase Transition ◽  
Piezoelectric Properties ◽  
Sintering Temperature ◽  
Piezoelectric Ceramics ◽  
Polymorphic Phase Transition ◽  
Dielectric And Piezoelectric Properties ◽  
Diffuse Phase

In this study, the effects of sintering temperature on microstructure, dielectric and piezoelectric properties are investigated for the non-stoichiometric (Na0.48K0.473Li0.04Sr0.007)(Nb0.883Ta0.05Sb0.06Ti0.007)O3 (NKLNTSST) piezoelectric ceramics. The results suggest that the piezoelectric properties are enhanced owing to the more normal ferroelectric characteristics, higher density, more uniform grains and presence of polymorphic phase transition regions, which are observed with an increase in the sintering temperature up to 1080?C. The piezoelectric properties are weakened owing to the larger degree of diffuse phase transition and more cationoxygen-vacancy pairs with an increase in the sintering temperature above 1080?C. The best piezoelectric properties including kp = 40%, d33 = 288 pC/N, ?max = 72.12, loss = 2.57%, Ec = 13.45 kV/cm and Pr = 10.23 ?C/cm2 are obtained at the sintering temperature of 1080?C.

Evaluating the polymorphic phase transition in calcium-doped Ba(Zr0.05Ti0.95)O3: a lead-free piezoelectric ceramic

2013 ◽  
Vol 46 (2) ◽  
pp. 324-331 ◽  
Author(s):  
Gurvinderjit Singh ◽  
V. S. Tiwari ◽  
P. K. Gupta
Keyword(s):  
Room Temperature ◽  
Composition Range ◽  
Piezoelectric Properties ◽  
Ferroelectric Ceramic ◽  
Lead Free ◽  
Dielectric Measurements ◽  
Polymorphic Phase Transition ◽  
Tetragonal Crystal ◽  
Tetragonal Crystal Structure ◽  
Dielectric And Piezoelectric Properties

Structural and dielectric investigations were carried out on a perovskite lead-free (Ba1−xCax)(Zr0.05Ti0.95)O3ferroelectric ceramic forx= 0.03, 0.05, 0.08, 0.10, 0.12 and 0.15. The room-temperature structural analysis reveals a crossover from orthorhombic to tetragonal crystal structure nearx= 0.10. A coexistence of tetragonal (P4mm) and orthorhombic (Pmm2) structure is observed in the composition range 0.05 ≤x≤ 0.10. The fraction of tetragonal phase increases from 27% forx= 0.05 to 71% forx= 0.10. The dielectric measurements show that the tetragonal to orthorhombic and rhombohedral to orthorhombic transition temperatures decrease with an increase in Ca2+content, while the cubic to tetragonal transition temperature remains the same. It is also shown that for the tetragonal to orthorhombic transition a phase coexistence occurs over a temperature range of about 18 K. The coexistence range covers room temperature for intermediate compositions:x= 0.05, 0.08 and 0.10. Therefore, higher dielectric and piezoelectric properties are observed in these compositions.

Effect of LiNbO3 on Piezoelectric Properties of K0.5Na0.5NbO3 Ceramics

2010 ◽  
Vol 654-656 ◽  
pp. 2037-2040
Author(s):  
Ming He Cao ◽  
Zhuo Li ◽  
Fan Li ◽  
Hua Hao ◽  
Han Xing Liu
Keyword(s):  
Phase Transition ◽  
Solid State ◽  
Electrical Properties ◽  
Phase Structure ◽  
Composition Range ◽  
Piezoelectric Properties ◽  
Piezoelectric Ceramics ◽  
Lead Free ◽  
Polymorphic Phase Transition ◽  
State Process

Lead-free (1-x)K0.5Na0.5NbO3–xLiNbO3 piezoelectric ceramics have been prepared by a conventional solid state process. The phase structure and the electrical properties of the ceramics were studied. A polymorphic phase transition (PPT) between the orthorhombic and tetragonal phases was identified in the composition range of 0.08<x<0.10. The ceramics near the PPT show better piezoelectric properties. At a level of 10mol% LiNbO3, the sample sintered at 1100oC for 1h exhibits optimal piezoelectric properties.

Dielectric and Piezoelectric Properties of Lead Free (1-x-y)Na1/2Bi1/2TiO3-xBaTiO3-yBiFeO3 Piezoelectric Ceramics

2011 ◽  
Vol 492 ◽  
pp. 194-197 ◽  
Author(s):  
Yue Fang Wang ◽  
Xiu Jie Yi ◽  
Wei Pan ◽  
Guo Zhong Zang ◽  
Juan Du
Keyword(s):  
Electrical Properties ◽  
Dielectric Loss ◽  
Phase Structure ◽  
Perovskite Structure ◽  
Piezoelectric Properties ◽  
Piezoelectric Ceramics ◽  
Lead Free ◽  
Compositional Dependence ◽  
Pure Perovskite Structure ◽  
Dielectric And Piezoelectric Properties

Lead-free (1-x-y)Na1/2Bi1/2TiO3-xBaTiO3-yBiFeO3 ceramics were synthesized by ordinary sintering technique. The compositional dependence of phase structure and electrical properties of the ceramics was systematically investigated. All samples possessed pure perovskite structure. The dielectric and piezoelectric properties of ceramics were investigated with the amount of different BiFeO3 substitutions. The addition of BiFeO3 can not only decrease Ec and Pr but also lead to a significant degradation of the dielectric loss tanδ.

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