Microstructure and Piezoelectric Properties of [(K0.5Na0.5)1-xLix](Nb1-yTay)O3 Lead-Free Piezoelectric Ceramics

2010 ◽  
Vol 156-157 ◽  
pp. 1522-1527
Author(s):  
Bei Xu ◽  
Feng Gao ◽  
Bo Li ◽  
Liang Liang Liu ◽  
Zhen Qi Deng
Keyword(s):  
Room Temperature ◽  
Composition Range ◽  
Piezoelectric Properties ◽  
Piezoelectric Ceramics ◽  
Mechanical Quality Factor ◽  
Lead Free ◽  
Mechanical Quality ◽  
Curie Temperature Tc ◽  
Room Temperature Dielectric Constant ◽  
Tetragonal Phase Transition

Li+ and Ta5+ modified lead-free piezoelectric ceramics [(K0.5Na0.5)1-xLix](Nb1-yTay)O3 have been prepared by an ordinary sintering technique. Effect of Li+ and Ta5+ on microstructure and piezoelectric properties of the ceramics was systematically studied. A morphotropic phase boundary between orthorhombic and tetragonal phases is identified in the composition range of (0.02≤x≤0.04, 0.15≤y≤0.25), which can enhance electrical properties of [(K0.5Na0.5)1-xLix](Nb1-yTay)O3 ceramics. The Curie temperature TC of these ceramics is lower than that of pure (K0.5Na0.5)NbO3 ceramics, but the temperature of orthorhombic to tetragonal phase transition TO-T of the former is higher than that of the latter. TC and TO-T both decrease as the content of Ta5+ increases. With the addition of Li+ increasing, TC increases. The optimal piezoelectric properties are obtained at (x, y)=(0.03, 0.20): piezoelectric constant d33 is 192pC/N; the electromechanical coefficient of the planar mode kp is 44%; room temperature dielectric constant εr is 1049, and the corresponding mechanical quality factor Qm is 49.

Influence MnO2 on the Properties of (LixNayK1-x-y)NbO3 Ceramics

2007 ◽  
Vol 336-338 ◽  
pp. 199-202
Author(s):  
Qiang Chen ◽  
De Jun Lan ◽  
Yi Chen ◽  
Du Min Lin ◽  
Xi Yue ◽  
...  
Keyword(s):  
Composition Range ◽  
Sintering Temperature ◽  
Mechanical Quality Factor ◽  
Piezoelectric Constant ◽  
Potassium Niobate ◽  
Sodium Potassium ◽  
Sodium Potassium Niobate ◽  
State Process ◽  
Mechanical Quality ◽  
Curie Temperature Tc

Lead-free piezoelectric ceramics lithium sodium potassium niobate (LixNayK1-x-y)NbO3 (LNKN100x/100y) have been synthesized by a conventional solid state process. The effects of MnO2 addition on the properties of (LixNayK1-x-y)NbO3(x=0.06, y=0.5)(LNKN6/50) ceramics were investigated. It was found that a morphotropic phase boundary (MPB) between orthorhombic and tetragonal phases is in the composition range 0.05<x<0.07. The piezoelectric constant d33 and the planar electromechanical coefficient kp of LNKN6/50 ceramics reach 222pC/N and 39%, respectively. As the amount of MnO2- doped increases, dielectric constant, piezoelectric constant and Curie temperature Tc of LNKN:Mn ceramics decreased, while mechanical quality factor Qm of LNKN6/50:Mn increased prominently compared to pure LNKN6/50 ceramics. The addition of MnO2 can also decrease the sintering temperature effectively of LNKN6/50 ceramics.

Microstructure and Characteristics of PbTiO3-PbZrO3-Pb(Mg1/3Nb2/3)O3- Pb(Zn1/3Nb2/3)O3 Ceramics

2007 ◽  
Vol 280-283 ◽  
pp. 175-180
Author(s):  
Chun Huy Wang
Keyword(s):  
Dielectric Constant ◽  
Piezoelectric Ceramic ◽  
Composition Range ◽  
Piezoelectric Properties ◽  
Coupling Factor ◽  
Mechanical Quality Factor ◽  
Optimal Choice ◽  
Mechanical Quality ◽  
Piezoelectric Measurement ◽  
Dielectric And Piezoelectric Properties

The new piezoelectric ceramic of PbTiO3-PbZrO3-Pb(Mg1/3Nb2/3)O3 -Pb(Zn1/3Nb2/3)O3 with composition close to the morphotropic phase boundary was studied. The dielectric and piezoelectric properties of Pb0.96Sr0.04[(Zr1-yTiy)0.74(Mg1/3Nb2/3)0.20(Zn1/3Nb2/3)0.06]O3 were investigated, the composition range examined are 0.47 £ y £ 0.57. From the results of XRD and piezoelectric measurement, it is supposed that the composition with y = 0.51 corresponds to M.P.B. between tetragonal and pseudocubic perovskite. Some developed phenomena or models are introduced and take it to interpret well. After optimal choice of these conditions, the planar coupling factor close to 0.65, mechanical quality factor Qm close to 75, the longitude wave velocity close to 4100 m/s and the poled dielectric constant close to 2600 can be approached in this study.

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.

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.

Physical and Electrical Properties of Lead-Free (Bi0.5Na0.5)TiO3–(Bi0.5K0.5)TiO3 Ceramics

2011 ◽  
Vol 239-242 ◽  
pp. 3240-3243 ◽  
Author(s):  
Chun Huy Wang
Keyword(s):  
Solid Solution ◽  
Coupling Coefficient ◽  
Piezoelectric Properties ◽  
Coupling Factor ◽  
Mechanical Quality Factor ◽  
Lead Free ◽  
Solution System ◽  
Solid Solution System ◽  
Mechanical Quality ◽  
Quality Factor Q

Extending the investigations on (Bi0.5Na0.5)TiO3-based solid solution for lead-free piezoelectric ceramics, this paper consider the complex solid-solution system (Bi0.5Na0.5)TiO3–(Bi0.5K0.5)TiO3[BNT-BKT]. (Bi0.5Na0.5)TiO3with 7~ 30 mol% (Bi0.5K0.5)TiO3ceramics have been prepared following the conventional mixed oxide process. A morphotropic phase boundary (MPB) between rhombohedral (R) and tetragonal (T) was found at the composition 0.82BNT-0.18BKT with correspondingly enhanced piezoelectric properties. The electromechanical planar coupling factor is higher for compositions near the MPB. The mechanical quality factor (Qm), planar coupling coefficient (kp) and thickness coupling coefficient (kt) of 0.82BNT-0.18BKT ceramics were 125, 28.8% and 47.4%, respectively.

Effects of Mn-Doping on the Piezoelectric and Ferroelectric Properties of (Na0.8K0.2)0.5Bi0.5TiO3 Ceramics

2008 ◽  
Vol 368-372 ◽  
pp. 69-71 ◽  
Author(s):  
Xiang Ping Jiang ◽  
Long Zhu Li ◽  
Fu Lan Jiang ◽  
Yan Yan Zheng ◽  
Li Hua Liu
Keyword(s):  
Solid State ◽  
Dielectric Loss ◽  
Grain Growth ◽  
Remnant Polarization ◽  
Piezoelectric Properties ◽  
Ferroelectric Properties ◽  
Mechanical Quality Factor ◽  
Lead Free ◽  
Mn Doping ◽  
Mechanical Quality

Lead-free piezoelectric ceramics of (Na0.8K0.2)0.5Bi0.5TiO3+x wt.% Mn (abbreviated as NBKT-x% Mn, x=0~0.5) were synthesized by solid-state reaction. The grain growth of the ceramics was restrained by Mn-doping at a certain extent. The mechanical quality factor Qm increases and the dielectric loss tanδ decreases with the increase of Mn-doping. Best piezoelectric properties were obtained for the composition of NKBT-0.2%Mn: d33=158 pC·N-1, tanδ=2.9% at 1 kHz, Qm=110 and kp=30%. The P-E loops show that remnant polarization Pr and coercive field Ec decrease slightly with the amount of the Mn2+ increasing up to 0.2wt.% and then increase as the content of Mn2+ increases further. NKBT-0.5wt. % Mn exhibits strong ferroelectricity with remnant polarization Pr = 38μC/cm2.

Highly enhanced mechanical quality factor in lead-free (K0.5Na0.5)NbO3 piezoelectric ceramics by co-doping with K5.4Cu1.3Ta10O29 and CuO

2010 ◽  
Vol 64 (14) ◽  
pp. 1577-1579 ◽  
Author(s):  
Beom Chul Park ◽  
In Ki Hong ◽  
Hyun Deok Jang ◽  
Vu Diem Ngoc Tran ◽  
Weon Pil Tai ◽  
...  
Keyword(s):  
Quality Factor ◽  
Piezoelectric Ceramics ◽  
Mechanical Quality Factor ◽  
Lead Free ◽  
Co Doping ◽  
Mechanical Quality

(1-x)(K0.44Na0.52Li0.04)(Nb0.84Ta0.10Sb0.06)O3-xSrTiO3 Lead Free Piezoelectric Ceramics

2008 ◽  
Vol 368-372 ◽  
pp. 1896-1898
Author(s):  
Ming He Cao ◽  
Wan Qiang Wang ◽  
Zhi Yong Yu ◽  
Hua Hao ◽  
Han Xing Liu
Keyword(s):  
Phase Boundary ◽  
Morphotropic Phase Boundary ◽  
Composition Range ◽  
Piezoelectric Properties ◽  
Piezoelectric Ceramics ◽  
Solid State Reaction Method ◽  
Lead Free ◽  
Sintering Behavior ◽  
Reaction Method ◽  
Na Ions

(1-x)(K0.44Na0.52Li0.04)(Nb0.84Ta0.10Sb0.06)O3-xSrTiO3 (KNNT-ST) lead free piezoelectric ceramics have been synthesized by a solid state reaction method. The effect of SrTiO3 content on the piezoelectric properties, sintering behavior and microstructure of (1-x) KNNT-x ST ceramics was investigated. The experimental results showed that the addition of SrTiO3 can restrain the volatilization of Na ions and K ions and improve relative density of the samples. A morphotropic phase boundary between orthorhombic and tetragonal phases is found in the composition range of 0.03<x<0.05. The piezoelectric properties can be enhanced for (1-x) KNNT-x ST ceramics near the morphotropic phase boundary.

Study on the Pressureless Sintering and Properties of (K0.5Na0.5)1-xLixNb1-yTayO3 Lead-Free Piezoelectric Ceramics

2012 ◽  
Vol 512-515 ◽  
pp. 1403-1407
Author(s):  
Hang Fei Hao ◽  
Guo Qiang Tan ◽  
Peng Xiong ◽  
Bo Qin ◽  
Hui Jun Ren
Keyword(s):  
Piezoelectric Properties ◽  
Solid Phase ◽  
Piezoelectric Ceramics ◽  
Mechanical Quality Factor ◽  
Lead Free ◽  
Potassium Sodium Niobate ◽  
Mechanical Coupling ◽  
Polarization Voltage ◽  
Quality Factor Q ◽  
The Relationship

Potassium sodium niobate ((K0.5Na0.5)1-xLixNb1-yTayO3) powers were prepared by solid phase synthesis and (K0.5Na0.5)1-xNb1-yTayO3 lead-free piezoelectric ceramics were fabricated by the pressuerless sintering. The relationship among the powder phase composition and electric properties was studied. The results show that when x=0.5, the sintering temperature is 1050°C,and the polarization voltage is 3 kV/mm, the (K0.5Na0.5)1-xLixNb1-yTayO3 piezoelectric ceramics with the better piezoelectric properties are prepared. (The relative density is 94%, the piezoelectric constant d33=105pC/N, the planar electro-mechanical coupling coefficient kp=0.39, the medium loss tanδ=0.29, the mechanical quality factor Qm=45, and the dielectric constant εr=720). As the increase of the polarization votage, the ceramic piezoelectric properties are increased. When the polarization voltage E=3kV/mm, the polarization tends to be saturation on the whole.

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