New lead-free piezoelectric ceramics derived from the K0.5Na0.5NbO3-AgNbO3 solid solution system

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.

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Electrical and Physical Properties of Lead-Free (Na0.5K0.5)NbO3- Bi0.5(Na0.93K0.07)0.5TiO3 Ceramics

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.512-515.1351 ◽

2012 ◽

Vol 512-515 ◽

pp. 1351-1354

Author(s):

Chun Huy Wang

Keyword(s):

Solid Solution ◽

Dielectric Constant ◽

Coupling Coefficient ◽

Electromechanical Coupling ◽

Electromechanical Coupling Factor ◽

Coupling Factor ◽

Lead Free ◽

Solution System ◽

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(Na0.93K0.07)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.

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Piezoelectric and Electrical Properties of Lead-Free (Na0.5K0.5)NbO3- Bi0.5(Na0.80K0.20)0.5TiO3 Ceramics

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.230-232.12 ◽

2011 ◽

Vol 230-232 ◽

pp. 12-15

Author(s):

Chun Huy Wang

Keyword(s):

Solid Solution ◽

Dielectric Constant ◽

Coupling Coefficient ◽

Electromechanical Coupling ◽

Electromechanical Coupling Factor ◽

Coupling Factor ◽

Lead Free ◽

Solution System ◽

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(Na0.80K0.20)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.

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