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

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.

2014 ◽  
Vol 887-888 ◽  
pp. 289-293
Author(s):  
Jing Chang Zhao ◽  
Zhen Lai Zhou

(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.


2010 ◽  
Vol 445 ◽  
pp. 55-58 ◽  
Author(s):  
Rintaro Aoyagi ◽  
Makoto Iwata ◽  
Masaki Maeda

(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.


2011 ◽  
Vol 211-212 ◽  
pp. 152-155
Author(s):  
Chun Huy Wang

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.


2006 ◽  
Vol 320 ◽  
pp. 39-42 ◽  
Author(s):  
Satoru Matsuzawa ◽  
Yuji Hiruma ◽  
Rintaro Aoyagi ◽  
Hajime Nagata ◽  
Tadashi Takenaka

The piezoelectric properties of Nd and V cosubstituted bismuth titanate ceramics, (Bi4-y,Ndy)1-(x/12)(Ti3-x,Vx)O12 [BNTV-y (x=0.01, y=0.00~1.00)] , are investigated. Furthermore, the grain orientation effects of BNTV-y ceramics on their piezoelectric properties are studied by the hot forging (HF) method. The electromechanical coupling factor, k33, of ordinarily fired (OF) BNTV-y0.75 ceramic was 0.21, which is one of the highest k33 values for bismuth layer-structured ferroelectrics (BLSFs). On the other hand, the k33 of the grain oriented (HF) BNTV-y0.25 ceramic was 0.30.


2012 ◽  
Vol 512-515 ◽  
pp. 1351-1354
Author(s):  
Chun Huy Wang

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(Na0.93K0.07)0.5TiO3 [NKN-BNKT]. (Na0.5K0.5)NbO3 with 2 ~ 6 mol% Bi0.5(Na0.93K0.07)0.5TiO3 has been prepared following the conventional mixed oxide process. A morphotropic phase boundary (MPB) between orthorhombic (O) and rhombohedral (R) was found at the composition 0.98NKN-0.02BNKT 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 0.98NKN-0.02BNKT ceramics were 1040, 47% and 48%, respectively.


2011 ◽  
Vol 230-232 ◽  
pp. 12-15
Author(s):  
Chun Huy Wang

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(Na0.80K0.20)0.5TiO3[NKN-BNKT]. (Na0.5K0.5)NbO3with 2 ~ 6 mol% Bi0.5(Na0.80K0.20)0.5TiO3has been prepared following the conventional mixed oxide process. A morphotropic phase boundary (MPB) between orthorhombic (O) and tetragonal (T) was found at the composition 0.97NKN-0.03BNKT with correspondingly enhanced dielectric and piezoelectric properties. The electromechanical coupling factor and dielectric constant are higher for compositions near the MPB. The dielectric constant (εr), planar coupling coefficient (kp) and thickness coupling coefficient (kt)of 0.97NKN-0.03BNKT ceramics were 1483, 32% and 31%, respectively.


2014 ◽  
Vol 1061-1062 ◽  
pp. 91-95
Author(s):  
Rui Zhu Zhang ◽  
Wen Peng Guo ◽  
Gao Lei Zhao

(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.


2011 ◽  
Vol 687 ◽  
pp. 228-232
Author(s):  
Yong Jie Zhao ◽  
Yu Zhen Zhao ◽  
Rong Xia Huang ◽  
Rong Zheng Liu ◽  
He Ping Zhou

(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.


2011 ◽  
Vol 284-286 ◽  
pp. 1375-1380 ◽  
Author(s):  
Ming Cheng Chure ◽  
Ping Cheng Chen ◽  
Long Wu ◽  
Bing Huei Chen ◽  
King Kung Wu

In the poling process of PZT ceramics, the poling temperature is a critical condition. When the poling temperature is too low, no matter how high is the poling field and how long is the poling time, the planar electromechanical coupling factor kpis lower. When the poling temperature is higher enough, the kpcan reach to a saturated value with a lower poling field and short poling time. The variation of dielectric constant with the poling conditions is the same as that of planar electromechanical coupling factor. When poling with a low temperature, the dielectric constant after poling is lower than 1400. When poling with higher temperature, no matter how high is the poling field and how long is the poling time, the dielectric constant after poling is higher than 1500.


2010 ◽  
Vol 03 (01) ◽  
pp. 35-39 ◽  
Author(s):  
CHEOL-WOO AHN ◽  
CHEE-SUNG PARK ◽  
SHASHANK PRIYA

We propose the design and synthesis of a polycrystalline sintered composite microstructure that leads to improved stability of piezoelectric response as a function of temperature in ( K , Na ) NbO 3 (KNN) based ceramics. The microstructure consists of matrix and island both of which have different composition and surface area. The matrix had much larger surface area and smaller orthorhombic to tetragonal transition temperature (T O-T ) than island. The composition corresponding to 0.99( K 0.48 Na 0.48 Li 0.04)( Nb 0.98 Sb 0.02) O 3-0.01 BaTiO 3 ( KNLNS-BT , T O-T ~ 33° C ) was selected as matrix while ( K 0.5 Na 0.5) NbO 3 ( KNN , T O-T ~ 206° C) was selected as island. The results show the flat electromechanical coupling factor from room temperature until ~ 300°C.


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