Structure and Piezoelectric Properties of (K,Na)NbO3 Ceramics Fabricated from Microwave Hydrothermal Synthesized Powders

2011 ◽  
Vol 412 ◽  
pp. 285-289
Author(s):  
Yue Ming Li ◽  
Zong Yang Shen ◽  
Hu Liu ◽  
Zhu Mei Wang ◽  
Yan Hong
Keyword(s):  
Hydrothermal Method ◽  
Reaction Temperature ◽  
Electromechanical Coupling ◽  
Piezoelectric Properties ◽  
Raw Materials ◽  
Relative Dielectric Constant ◽  
Processing Parameters ◽  
Electromechanical Coupling Coefficient ◽  
Microwave Hydrothermal ◽  
Microwave Hydrothermal Method

First, (K,Na)NbO3 (abbreviated as KNN) powders were synthesized by microwave hydrothermal method using Nb2O5, NaOH and KOH as raw materials. The effects of NaOH/KOH mole ratio and reaction temperature on the structure of KNN powders were studied systematically. Near spherical KNN powders of about 800 nm in diameter can be obtained at the optimized processing parameters as follows: NaOH/KOH mole ratio was 1.40/4.60, reaction temperature was 200 °C. Second, the ceramics were successfully prepared from the microwave hydrothermal synthesized KNN powders under 1090 °C for 2 h. This ceramic sample showed the enhanced piezoelectric properties such as piezoelectric constant d33=142 pC/N and planar electromechanical coupling coefficient kp=38%, in addition to other good properties as relative dielectric constant εr=426, Curie temperature Tc=410 °C, remnant polarization Pr=17.45μC/cm2 and coercive field Ec=1.41 kV/mm, indicating that microwave hydrothermal method can improve the properties of KNN ceramics high efficiently.

PIEZOELECTRIC PROPERTIES OF CEMENT PIEZOELECTRIC COMPOSITES CONTAINING NANO-QUARTZ POWDERS

2020 ◽  
Vol 7 (2) ◽  
Author(s):  
Huang Hsing Pan ◽  
Wei-Ren Lin ◽  
Kuan Huang
Keyword(s):  
Health Monitoring ◽  
Electromechanical Coupling ◽  
Piezoelectric Properties ◽  
Relative Dielectric Constant ◽  
Cement Matrix ◽  
Electromechanical Coupling Coefficient ◽  
Cement Composites ◽  
Piezoelectric Composites ◽  
Structural Health ◽  
Piezoelectric Strain

In order to increase piezoelectric properties of 0-3 type cement piezoelectric composites (piezoelectric cement) developed for structural health monitoring, nano-quartz powders, as the replacement of cement matrix, were added into PZT/cement composites. The piezoelectric cement consists of 50% PZT and 50% cement by volume. Two gradations of PZT inclusions, single-grading and medium-grading, were chosen to fabricate the piezoelectric cement. Nano-quartz powders of 1% to 6% were added to form nano-quartz piezoelectric cement. Experimental results indicate that nano-quartz powders can reduce the porosity of piezoelectric cement. The single-grading piezoelectric cement (PSQ) with 4% nano-quartz powders and the medium-grading one (PMQ) with 2% have the lowest porosity. The maximum values on both piezoelectric strain factor d33 and relative dielectric constant εr always occur at the minimum porosity of nano-quartz piezoelectric cement. Both the PSQ and the PMQ have the optimum d33=104 pC/N. For the PSQ, 4% nano-quartz powders provide a 22% enhancement on thickness electromechanical coupling coefficient Kt. However, the effect of nano-quartz powders displays as less effective to the Kt of the PMQ due to non-uniform distribution of PZT particles. Nano-quartz piezoelectric cement has higher piezoelectric properties able to monitor and detect concrete structural health.

The Effect of Particle Size on the Electromechanical Properties of PZT/PVDF

2009 ◽  
Vol 66 ◽  
pp. 238-241
Author(s):  
Xiao Fang Liu ◽  
Hua Jun Sun ◽  
Ming Wei ◽  
C.X. Xiong
Keyword(s):  
Particle Size ◽  
Piezoelectric Ceramic ◽  
Electromechanical Coupling ◽  
Piezoelectric Properties ◽  
Volume Fraction ◽  
Relative Dielectric Constant ◽  
Connectivity Pattern ◽  
Conventional Solid State Reaction ◽  
Pressing Method ◽  
Dielectric And Piezoelectric Properties

The Nb modified PZT piezoelectric ceramic was synthesized by conventional solid-state reaction, where all of different particle sizes had the same physical properties. 0-3 modified PZT/PVDF composites were formed by hot-pressing method. The particle size effect of modified PZT on the relative dielectric and piezoelectric properties of the composites were investigated. The relative dielectric constant εr, piezoelectric constant d33 and electromechanical coupling factor kp were higher in the composite containing larger PZT particle size. The microstructures of the composites were studied by SEM, the composite with the finer PZT particle size was more homogeneous, but larger particle size was easy to be contacted. In a high volume fraction particle-loaded composite, some piezoelectric ceramic particle appeared to be in contact, as in a 1-3 connectivity pattern. The larger particle size of modified PZT itself could be seen as the grain of modified PZT contact in a 1-3 connectivity pattern and easy to be contacted each other compared to the finer particle size in the composites, thus reducing the resistance of the composites and the poling process became effective, which led to higher properties. The optimal particle size of PZT is about 100μm, the Nb modified PZT/PVDF (volume fraction 70/30) composite show higher dielectric and piezoelectric properties than the others, εr=156.6, d33=69pC/N and kp=0.358.

Effects of Different Sintering Temperature on the Microstructure and Piezoelectric Properties of Pb(Nb2/3Zn1/3)x(Zr52Ti48)1-XO3 Ceramics

2014 ◽  
Vol 1061-1062 ◽  
pp. 83-86
Author(s):  
Hong Wu ◽  
De Yi Zheng
Keyword(s):  
Electrical Properties ◽  
Electromechanical Coupling ◽  
Piezoelectric Properties ◽  
Sintering Temperature ◽  
Electromechanical Coupling Coefficient ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ceramic Samples ◽  
Xrd Patterns ◽  
The Relationship

In this paper, the effects of different sintering temperature on the microstructure and piezoelectric properties of Pb(Nb2/3Zn1/3)0.03(Zr52Ti48)0.97O3(PNZZT) ceramic samples were investigated. The Pb(Nb2/3Zn1/3)0.03(Zr52Ti48)0.97O3 ceramics materials was prepared by a conventional mixed oxide method. In the period of the experiment, the relationship between crystallographic phase and microstructure were analyzed by X-ray diffraction(XRD) and scanning electron microscopy(SEM) respectively. The XRD patterns shows that all of the ceramic samples are with a tetragonal perovskite structure. Along with sintering temperature increased and the x is 0.03, the grain size gradually become big. Through this experiment, it has been found that when the x is 0.03 and sintered at 1130°C for 2 h, the grains grow well, the grain-boundary intersection of the sample combined well and the porosity of the ceramics decreased, an excellent comprehensive electrical properties of the Pb(Nb2/3Zn1/3)0.03(Zr52Ti48)0.97O3 samples can be obtained. Its best electrical properties are as follows: dielectric constant (ε) is 1105, dielectric loss(tg) is 0.017, electromechanical coupling coefficient (Kp) is 0.287, piezoelectric constant(d33) is 150PC/N

DNA-templated microwave-hydrothermal synthesis of nanostructured hydroxyapatite for storing and sustained release of an antibacterial protein

2016 ◽  
Vol 45 (4) ◽  
pp. 1648-1656 ◽  
Author(s):  
Xi Chen ◽  
Bin Yang ◽  
Chao Qi ◽  
Tuan-Wei Sun ◽  
Feng Chen ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Sustained Release ◽  
Hydrothermal Method ◽  
Nanostructured Materials ◽  
Antibacterial Study ◽  
Antibacterial Protein ◽  
Microwave Hydrothermal ◽  
Microwave Hydrothermal Method

Hydroxyapatite nanostructured materials are prepared by a DNA-templated microwave-hydrothermal method and used for IgY loading/release and antibacterial study.

Microwave-hydrothermal method post-treatment of sprayed Ca-P coating

2019 ◽  
Vol 45 (1) ◽  
pp. 874-884 ◽  
Author(s):  
Yangyang Su ◽  
Kezhi Li ◽  
Xiaofei Zhu ◽  
Changcong Wang ◽  
Yunpeng Zhang
Keyword(s):  
Hydrothermal Method ◽  
Post Treatment ◽  
Microwave Hydrothermal ◽  
Microwave Hydrothermal Method

scholarly journals Photoluminescence and Chromaticity Properties of ZnO Nanopowders Made by a Microwave Hydrothermal Method

2011 ◽  
Vol 120 (5) ◽  
pp. 908-910 ◽  
Author(s):  
E. Wolska ◽  
D. Sibera ◽  
B.S. Witkowski ◽  
S.A. Yatsunenko ◽  
I. Pełech ◽  
...  
Keyword(s):  
Hydrothermal Method ◽  
Microwave Hydrothermal ◽  
Microwave Hydrothermal Method
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