Influence of Sintering Temperatures on the Properties of Lithium Sodium Potassium Niobate Piezoelectric Ceramics

ABSTRACTLithium sodium potassium niobate (Li, Na, K)NbO3 (LNKN) piezoelectric ceramics were prepared by using conventional solid state process. The phase structures of LNKN ceramics were characterized by x-ray diffraction (XRD). The dielectric properties of LNKN ceramics have been also studied at different temperature and frequency. It was found that LNKN ceramics have high Curie temperature Tc(about 460°C), and relatively high piezoelectric constant d33 (∼200pC/N) and high electromechanical coupling coefficient kp(∼0.40). Both of the piezoelectric constant d33 and electromechanical coupling coefficient kp of LNKN ceramics decreased with the increasing of sintering temperature. The piezoelectric property dependence of composition of LNKN ceramics has also been studied.

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

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.336-338.199 ◽

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.

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Effects of LiNbO3-doping on properties of (Na0.535K0.48)NbO3 piezoelectric ceramics with high electromechanical coupling coefficient for application in surface acoustic wave devices

Ceramics International ◽

10.1016/j.ceramint.2017.05.335 ◽

2017 ◽

Vol 43 (14) ◽

pp. 11324-11330 ◽

Cited By ~ 5

Author(s):

Chung-Ming Weng ◽

Cheng-Che Tsai ◽

Cheng-Shong Hong ◽

Jyh Sheen ◽

Sheng-Yuan Chu ◽

...

Keyword(s):

Acoustic Wave ◽

Surface Acoustic Wave ◽

Coupling Coefficient ◽

Electromechanical Coupling ◽

Piezoelectric Ceramics ◽

Electromechanical Coupling Coefficient ◽

Acoustic Wave Devices

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Effect of Li2O Addition on Piezoelectric Properties of NKN-5LT Ceramics

Materials Science Forum ◽

10.4028/www.scientific.net/msf.534-536.1525 ◽

2007 ◽

Vol 534-536 ◽

pp. 1525-1528 ◽

Cited By ~ 1

Author(s):

Min Soo Kim ◽

Dae Su Lee ◽

Eon Cheol Park ◽

Soon Jong Jeong ◽

In Sung Kim ◽

...

Keyword(s):

Electromechanical Coupling ◽

Electromechanical Coupling Factor ◽

Coupling Factor ◽

Potassium Niobate ◽

Sintering Process ◽

Sodium Potassium ◽

Free System ◽

Sintering Aid ◽

Sodium Potassium Niobate ◽

Conventional Sintering

Recently alkali oxide materials, such as sodium - potassium niobate have drawn much attention due to their ultrasonic applicability and are also considered as promising candidates for a piezoelectric lead-free system. However, it is difficult to sinter such NKN-based materials via conventional sintering process. Therefore, in this study, dense 0.95(Na0.5K0.5)NbO3-0.05LiTaO3 (NKN-5LT) ceramics were developed by conventional sintering process. Sintering temperature was lowered by adding Li2O as a sintering aid. The electrical properties of NKN-5LT ceramics were investigated as a function of Li2O concentration. At the addition of 1 mol% Li2O, electromechanical coupling factor (kP) and piezoelectric coefficient (d33) of NKN-5LT ceramics were found to reach the highest values of 0.37 and 250 pC/N, respectively.

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