Polymorphic phase boundaries and enhanced piezoelectric response in extended composition range in the lead free ferroelectric BaTi1−xZrxO3

2013 ◽  
Vol 114 (1) ◽  
pp. 014102 ◽  
Author(s):  
Ajay Kumar Kalyani ◽  
Anatoliy Senyshyn ◽  
Rajeev Ranjan
Keyword(s):  
Composition Range ◽  
Lead Free ◽  
Piezoelectric Response ◽  
Phase Boundaries

(1 − x)(K0.48Na0.52)(Nb0.95−y−zTazSby)O3–xBi0.5(Na0.82K0.18)0.5ZrO3 lead-free ceramics: composition dependence of the phase boundaries and electrical properties

2015 ◽  
Vol 44 (10) ◽  
pp. 4440-4448 ◽  
Author(s):  
Xiang Lv ◽  
Jiagang Wu ◽  
Dingquan Xiao ◽  
Hong Tao ◽  
Yuan Yuan ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Composition Dependence ◽  
Lead Free ◽  
Phase Boundaries ◽  
Phase Structures ◽  
Lead Free Ceramics

In this work, the KNNST-BNKZ-xyz ceramics were obtained, and the composition dependence of their phase structures and electrical properties was discussed.

Piezoelectric Voltage Constant and Sensitivity Enhancements Through Phase Boundary Structure Control of Lead-free (K,Na)NbO3-based ceramics

2021 ◽  
Author(s):  
Min-Ku Lee ◽  
Byung-Hoon Kim ◽  
Gyoung-Ja Lee
Keyword(s):  
Material Parameter ◽  
Perovskite Oxide ◽  
Lead Free ◽  
Boundary Structure ◽  
Voltage Sensitivity ◽  
Phase Boundaries ◽  
Accelerometer Sensor ◽  
Structure Control ◽  
Piezoelectric Charge ◽  
Piezoelectric Voltage

Abstract The piezoelectric voltage constant (g33) is a material parameter critical to piezoelectric voltage-type sensors for detecting vibrations or strains. Here, we report a lead-free (K,Na)NbO3 (KNN)-based piezoelectric accelerometer with voltage sensitivity enhanced by taking advantage of a high g33. To achieve a high g33, the magnitudes of piezoelectric charge constant d33 and dielectric permittivity er of KNN were best coupled by manipulating the intrinsic polymorphic phase boundaries effectively with the help of Bi-based perovskite oxide additives. For the KNN composition that derives benefit from the combination of er and d33, the value of g33 was found to be 46.9 ´ 10-3 V·m/N, which is significantly higher than those (20 - 30 ´ 10−3 V·m/N) found in well-known polycrystalline lead-based ceramics including commercial Pb(Zr,Ti)O3 (PZT). Finally, the accelerometer sensor prototype built using the modified KNN composition demonstrated higher voltage sensitivity (183 mV/g) when measuring vibrations, showing a 29% increase against the PZT-based sensor (142 mV/g).

FLEXOELECTRIC COMPOSITE — A NEW PROSPECT FOR LEAD-FREE PIEZOELECTRICS

2010 ◽  
Vol 03 (01) ◽  
pp. 79-81 ◽  
Author(s):  
BAOJIN CHU ◽  
WENYI ZHU ◽  
NAN LI ◽  
L. ERIC CROSS
Keyword(s):  
Piezoelectric Properties ◽  
Piezoelectric Materials ◽  
Physical Phenomenon ◽  
Mechanical Strain ◽  
Dielectric Materials ◽  
Electric Polarization ◽  
Lead Free ◽  
Piezoelectric Response ◽  
Bst Ceramics ◽  
Better Than

Flexoelectricity describes the physical phenomenon of the generation of electric polarization from mechanical strain gradient in solid insulators. In common dielectric materials, the flexoelectric coefficient is trivially small ~10-10 C/m. In Ba(Sr,Ti)O 3 (BST) ceramics, flexoelectric coefficient up to 10-4 C/m was observed. Such high coefficient makes it possible to design high piezoelectric response flexoelectric composites. In this letter, we will demonstrate that the newly designed flexoelectric composites could have piezoelectric properties better than conventional piezoelectric materials.

Polymorphic structure evolution and large piezoelectric response of lead-free (Ba,Ca)(Zr,Ti)O3 ceramics

2014 ◽  
Vol 104 (11) ◽  
pp. 112901 ◽  
Author(s):  
Ye Tian ◽  
Xiaolian Chao ◽  
Li Jin ◽  
Lingling Wei ◽  
Pengfei Liang ◽  
...  
Keyword(s):  
Lead Free ◽  
Piezoelectric Response ◽  
Structure Evolution ◽  
Polymorphic Structure

scholarly journals Hybrid Atmosphere Processing of Lead-Free Piezoelectric Sodium Potassium Niobate-Based Ceramics

Ceramics ◽  
2019 ◽  
Vol 2 (3) ◽  
pp. 460-471 ◽  
Author(s):  
Astri Bjørnetun Haugen
Keyword(s):  
Lead Free ◽  
Piezoelectric Response ◽  
Potassium Niobate ◽  
Sodium Potassium ◽  
New Approach ◽  
Sodium Potassium Niobate ◽  
Phase Pure ◽  
High Alkali ◽  
Surface Decomposition ◽  
Air Processing

K0.5Na0.5NbO3-based ceramics, a promising group of lead-free piezoelectrics, are challenging to sinter dense while avoiding alkali evaporation. This work explores hybrid atmosphere processing, a new approach where reducing atmospheres is used during heating to avoid coarsening from alkali carbonates and hydroxides, and oxidizing atmospheres is used during sintering to avoid alkali evaporation. Discs of Li0.06(K0.52Na0.48)0.94Nb0.71Ta0.29O3 with 0.25 mol% Mn (KNNLTM) were sintered in air, N2, 9% H2 in N2, or 9% H2 in N2 during heating and air during sintering (hybrid atmosphere processing). The highest density was obtained by sintering in 9% H2 in N2, but resulted in high alkali loss and decomposition of the surface, followed by low piezoelectric response. However, with the hybrid H2/air processing it was possible to both avoid surface decomposition and leakage currently associated with alkali evaporation during sintering in H2, and to obtain a denser, more phase-pure and small-grained KNNLTM ceramic with a higher piezoelectric response than obtained by sintering in air or N2.

Microstructure and Piezoelectric Properties of (0.996-x) K0.5Na0.5NbO3 - 0.004 BiFeO3 - x LiSbO3 Ceramics

2012 ◽  
Vol 531-532 ◽  
pp. 632-635
Author(s):  
Min Hong Jiang ◽  
Xin Yu Liu ◽  
Guo Hua Chen ◽  
Jia Feng Ma ◽  
Gui Sheng Zhu ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Phase Boundary ◽  
Pore Size ◽  
Mixed Oxide ◽  
Phase Structure ◽  
Composition Range ◽  
Piezoelectric Properties ◽  
Lead Free ◽  
Compositional Dependence ◽  
Tan Δ

(0.996-x) K0.5Na0.5NbO3- 0.004 BiFeO3- x LiSbO3 (x =0.00, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07) lead-free piezoelectric ceramics were prepared by the conventional mixed oxide method. The compositional dependence of the phase structure and the electrical properties of the ceramics were studied. A morphotropic phase boundary between the orthorhombic and tetragonal phases was identified in the composition range of 0.03 < x < 0.06. With the content of LS increases, the size of the pores significantly decreases. However, adding larger amount of LS makes the pore size increase slightly. The (0.996-x)KNN-0.004 BF-xLS(x=0.05) ceramics possess good electrical properties: d33 = 280 pC/N, kp = 53.3%, Tc = 345 °C, εr = 1613, Tan δ =2.07%. These results show that the ceramic is a promising lead-free piezoelectric material.

Piezoelectric and Ferroelectric Properties of KNbO3 Added Bi0.5Na0.5TiO3 Ceramics

2017 ◽  
Vol 751 ◽  
pp. 384-389 ◽  
Author(s):  
Puripat Kantha ◽  
Phathaitep Raksa ◽  
Muangjai Unruan ◽  
Tawee Tunkasiri ◽  
Panupong Jaiban ◽  
...  
Keyword(s):  
Mixed Oxide ◽  
Room Temperature ◽  
Ferroelectric Phase ◽  
Ferroelectric Properties ◽  
Lead Free ◽  
Piezoelectric Response ◽  
Rhombohedral Structure ◽  
Rhombohedral Symmetry

The fabrication of lead-free (1-x)Bi0.5Na0.5TiO3 - xKNbO3 or (1-x)BNT-xKN ceramics where x = 0.00, 0.05, 0.10, and 0.15 was carried out by the modified two-step mixed oxide method. The effects of KNbO3 on structure, piezoelectric and ferroelectric properties were systematically investigated. XRD results revealed that the (1-x)BNT-xKN ceramics with low KN content of x less than 0.05 contained ferroelectric phase with a rhombohedral symmetry while the ceramics with x = 0.05 possessed pseudocubic structure. The higher KN content (x ≥ 0.10) ceramics had symmetries rhombohedral structure. At room temperature, the highest Pr and low Ec were obtained when the composition of x = 0.05. Moreover, the results showed the moderate KN addition could enhance the piezoelectric response. The d33 of 0.95BNT-0.05KN reached as high as 125 pC/N.

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