scholarly journals WHAT CAN BE EXPECTED FROM LEAD-FREE PIEZOELECTRIC MATERIALS?

2010 ◽  
Vol 03 (01) ◽  
pp. 5-13 ◽  
Author(s):  
DRAGAN DAMJANOVIC ◽  
NAAMA KLEIN ◽  
JIN LI ◽  
VIKTOR POROKHONSKYY
Keyword(s):  
Domain Wall ◽  
Phase Boundary ◽  
Morphotropic Phase Boundary ◽  
Wall Motion ◽  
Electromechanical Coupling ◽  
Piezoelectric Properties ◽  
Piezoelectric Materials ◽  
Domain Wall Motion ◽  
Lead Free

The reasons for the lower piezoelectric properties in the most studied lead-free piezoelectrics, modified (K, Na)NbO 3 and ( Bi 0.5 Na 0.5) TiO 3, are discussed. Contributions from domain wall motion and properties at the morphotropic phase boundary are considered and are compared to those in PZT. Lead-free, non-piezoelectric solutions to electromechanical coupling are discussed.

Na/K RATIOS DEPENDENCE OF PIEZOELECTRIC AND FERROELECTRIC PROPERTIES IN (K1-xNax)NbO3 LEAD-FREE CERAMICS

2011 ◽  
Vol 01 (04) ◽  
pp. 471-478 ◽  
Author(s):  
HONGLIANG DU ◽  
SHAOBO QU ◽  
ZHUO XU ◽  
XIAOYONG WEI ◽  
WANCHENG ZHOU ◽  
...  
Keyword(s):  
Solid State ◽  
Phase Boundary ◽  
Morphotropic Phase Boundary ◽  
Piezoelectric Properties ◽  
Ferroelectric Properties ◽  
Lead Free ◽  
Obvious Effect ◽  
Lead Free Ceramics ◽  
Solid State Sintering

In order to clarify the Na/K ratios dependence of piezoelectric properties, ( K 1-x Na x) NbO 3 ceramics were prepared by conventional solid-state sintering at x = 0.4–0.6 with a smaller compositional interval (0.02 mol). The results demonstrate that the Na/K ratios have obvious effect on piezoelectric and ferroelectric properties of ( K 1-x Na x) NbO 3 ceramics. Piezoelectric and ferroelectric properties show the maximum (d33 = 147 pC/N, kp = 0.40, and Pr = 24 μC/cm2) at x = 0.54, which is not consistent with conventional viewpoint. The reasons should be attributed to the existence of a phase boundary at x = 0.54 mol, which is similar to the morphotropic phase boundary in Pb(Zr,Ti)O3 ceramics.

Piezoelectric properties of lead-free (Na0.5Bi0.5)TiO3–(Na0.5K0.5)NbO3–BaTiO3 ceramics

2008 ◽  
Vol 23 (1) ◽  
pp. 115-120 ◽  
Author(s):  
Seung-Ho Lee ◽  
Chang-Bun Yoon ◽  
Sung-Mi Lee ◽  
Hyoun-Ee Kim ◽  
Kyung-Woo Lee
Keyword(s):  
Crystal Structure ◽  
Phase Boundary ◽  
Morphotropic Phase Boundary ◽  
Microstructural Evolution ◽  
Piezoelectric Properties ◽  
Lead Free ◽  
Cubic Phase ◽  
Lead Free Ceramics ◽  
Wide Range

The microstructural evolution and piezoelectric properties of lead-free ceramics (0.98-x)(Na0.5Bi0.5)TiO3–x(Na0.5K0.5)NbO3–0.02BaTiO3 (0 ⩽ x ⩽ 0.98, abbreviated as (0.98-x)NBT–xNKN–0.02BT) were investigated. The effects of the amount of NKN on the crystal structure, microstructural evolution, and piezoelectric properties were examined. The 0.93NBT–0.05NKN–0.02BT ceramics having a lower NKN content gave good performances with piezoelectric properties of d33 = 140 pC/N and kp = 21%, because of the soft additive Nb5+ ions at the B sites. However, a paraelectric cubic phase was observed in the wide range of compositions between x = 0.1 and x = 0.9. At a higher NKN content of x > 0.9, a morphotropic phase boundary (MPB) between the tetragonal and orthorhombic phases was found in the 0.015NBT–0.965NKN–0.02BT ceramics, and the piezoelectric properties were enhanced (d33 = 135 pC/N, kp = 29%). The piezoelectric properties of this system were closely related to its crystal structure.

Lead Free (Bi, Na)TiO3–BiAlO3 Ceramics for Piezoelectric Application

2020 ◽  
Vol 15 (4) ◽  
pp. 459-462
Author(s):  
Jae-Hoon Ji ◽  
Don-Jin Shin ◽  
Sang-Kwon Lee ◽  
Sang-Mo Koo ◽  
Jae-Geun Ha ◽  
...  
Keyword(s):  
Electromechanical Coupling ◽  
Piezoelectric Properties ◽  
Piezoelectric Materials ◽  
Lead Free ◽  
Electromechanical Coupling Coefficient ◽  
Substitution Effects ◽  
Sensors And Actuators ◽  
Device Applications ◽  
Piezoelectric Devices ◽  
Piezoelectric Charge

In this research, substitution effects of BiAlO3 with (Bi, Na)TiO3 piezoelectric ceramics was investigated for the sensors and actuators applications. (Bi,Na)TiO3 material has been employed for the piezoelectric devices applications because of their high piezoelectric charge constant, d33, of 88 pC/N, electromechanical coupling coefficient, kp, of 22% and inverse piezoelectric charge constant of 498 pm/V. As a piezoelectric material, (Bi, Na)TiO3 has perovskite structure with tetragonal basis. The improvement of piezoelectric and inverse piezoelectric properties is important for industrial device applications. Therefore, in this research, we have tried to increase functional and electrical properties of (Bi, Na)TiO3 piezoelectric materials by substituting BiAlO3 dopants. As a result, the piezoelectric constant was increased up to 140 pC/N, and the densification was increased up to 5.92 g/cm3 .

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.

LOCAL MICROSTRUCTURE EVOLUTION OF BISMUTH SODIUM TITANATE-BASED LEAD-FREE PIEZOELECTRIC SYSTEMS ACROSS THE MORPHOTROPIC PHASE BOUNDARY REGION

2012 ◽  
Vol 02 (04) ◽  
pp. 1230012 ◽  
Author(s):  
YUN LIU ◽  
RAY L. WITHERS ◽  
JIAN WANG ◽  
LASSE NORÉN ◽  
ANDREW J. STUDER ◽  
...  
Keyword(s):  
Phase Boundary ◽  
Morphotropic Phase Boundary ◽  
Piezoelectric Effect ◽  
Piezoelectric Materials ◽  
Sodium Titanate ◽  
Boundary Region ◽  
Lead Free ◽  
In Situ Neutron Diffraction ◽  
Piezoelectric Performance

Morphotropic phase boundary (MPB) containing piezoelectric systems generally exhibit enhanced piezoelectric performance at compositions within, or close to, the MPB region. The mechanism/s underlying such enhancement, however, are still contentious due to complex micro/nanostructure and apparently inherent local structural variability associated with octahedral tilt disorder/platelet precipitates in such piezoelectric materials. This paper reviews some recent structural analysis results from Bi0.5Na0.5TiO3 (BNT) and other binary, lead-free, piezoelectric materials systems derived from it via electron diffraction and in situ neutron diffraction. The results suggest that intrinsically existing local microstructure (LMS) in BNT essentially continues across the MPB region. The LMS, originating from inherent octahedral tilt disorder, is strongly temperature-, electric field-, pressure- and chemical composition-dependent, and may help to explain a series of phenomena observed in BNT-based binary materials systems, including the enhanced piezoelectric effect in the region of the MPB.

Electrical Properties and Piezoelectric Properties of CaBi2Ta2O9-Based Ceramics

2009 ◽  
Vol 421-422 ◽  
pp. 46-49 ◽  
Author(s):  
Toji Tokusu ◽  
Hirokazu Miyabayashi ◽  
Yuji Hiruma ◽  
Hajime Nagata ◽  
Tadashi Takenaka
Keyword(s):  
Wall Motion ◽  
Remanent Polarization ◽  
Electromechanical Coupling ◽  
Piezoelectric Properties ◽  
Domain Wall Motion ◽  
Electromechanical Coupling Factor ◽  
Coupling Factor ◽  
Higher Temperature ◽  
Increasing Temperature ◽  
Curie Temperature Tc

Electrical and piezoelectric properties of CaBi2Ta2O9-based ceramics have been studied. Temperature dependence of dielectric properties indicated that the Curie temperature, TC, was 923°C. Coercive field, EC, and remanent polarization, Pr, became saturated with increasing temperature. It is expected that higher-temperature than 250°C could promote the domain wall motion during the poling treatment. From resonance and antiresonance measurements, piezoelectric properties such as the maximum phase, max, electromechanical coupling factor, k33, and piezoelectric g constant, g33, were 86.1º, 0.085 and 8.4 × 10-3 V∙m/N, at room temperature, respectively.

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