Preparation of Potassium Niobate–Barium Titanate Ceramics Using Well-Dispersed Nanoparticles and their Dielectric Properties

2011 ◽  
Vol 485 ◽  
pp. 39-42 ◽  
Author(s):  
Kenta Yamashita ◽  
Shigehito Shimizu ◽  
Ichiro Fujii ◽  
Kouichi Nakashima ◽  
Nobuhiro Kumada ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Barium Titanate ◽  
Potassium Niobate ◽  
Conventional Sintering ◽  
Titanate Ceramics ◽  
Sintering Method

ANbO3– BaTiO3(A=K, Na, or K0.5Na0.5) system ceramics were prepared using a conventional sintering method, and their dielectric properties were investigated. It was found that the dielectric constant of KNbO3-BaTiO3and (K0.5Na0.5) NbO3- BaTiO3system ceramics did not strongly depend on temperature between 20 and 400 °C, making them useful for capacitor application.

Grain Size Dependence of the Microstructure and Dielectric Properties of Potassium Niobate-Barium Titanate Ceramics

2013 ◽  
Vol 566 ◽  
pp. 34-37
Author(s):  
Kenta Yamashita ◽  
Ichiro Fujii ◽  
Kouichi Nakashima ◽  
Nobuhiro Kumada ◽  
Yoshihiro Kuroiwa ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Grain Size ◽  
Dielectric Properties ◽  
Barium Titanate ◽  
Size Dependence ◽  
Potassium Niobate ◽  
Titanate Ceramics

In this study, 0.8 KNbO3(KN) -0.2 BaTiO3(BT) ceramics were prepared using KN powder with the diameter of 100 nm and BT powders with the diameter of 100, 300, or 500 nm. The relative densities were more than 96 % of the theoretical densities of the samples. The dielectric constant of the samples was temperature-stable at temperatures between-50 and 300 °C and it was found that the dielectric constant of the 0.8KN-0.2BT ceramics increased as the BT diameter increased.

Broadband Dielectric Spectroscopy Analysis of Dielectric Properties of Barium Titanate Ceramics

2013 ◽  
Vol 744 ◽  
pp. 323-328 ◽  
Author(s):  
Jie Yang ◽  
Xiang Yun Deng ◽  
Jian Bao Li ◽  
Qiang Cai ◽  
Hai Tao Zhang ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Barium Titanate ◽  
Relaxation Model ◽  
Debye Relaxation ◽  
Broadband Dielectric Spectroscopy ◽  
Function Fitting ◽  
Loss Experience ◽  
Titanate Ceramics

The complex dielectric behaviors of ferroelectric barium titanate (BT) ceramics were investigated. The dielectric properties were studied as a function of temperature and frequency using broadband dielectric spectrometer. The results show that the maximum value of dielectric constant occurs at 500nm BT ceramics, which is approximately 7,500; the dielectric loss is lower than 0.03 with the temperature varying from 225 K to 450 K. Dielectric constant and dielectric loss experience three dielectric peaks corresponding to rhombohedral to orthorhombic, tetragonal and cubic transitions. With the frequency ranges from 1 MHz to 1 GHz, the dielectric relaxation is apparently present. The relaxation process obeys Cole-Cole relaxation model at high temperature and conforms to Debye relaxation model when the temperature far lower than Curie temperature. The relaxation time is the order magnitude of ~10-9s obtained by Havriliak-Negami function fitting, which is very consistent with theoretical calculation.

scholarly journals Dependence of the dielectric properties of barium titanate ceramics and a composite based on it on the sintering temperature

2021 ◽  
Vol 24 (1) ◽  
pp. 40-47
Author(s):  
O. V. Malyshkina ◽  
A. I. Ivanova ◽  
Gr. S. Shishkov ◽  
A. A. Martyanov
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Barium Titanate ◽  
Barium Ferrite ◽  
Sintering Temperature ◽  
Pyroelectric Coefficient ◽  
Ceramic Samples ◽  
Barium Titanate Ceramic ◽  
Titanate Ceramics ◽  
Composite Samples

In this paper, we compare the structure and dielectric properties of the samples of barium titanate ceramics that have been sintered at temperatures of 1100, 1150, 1200, 1250 and 1350 °C and dielectric characteristics of the samples of barium titanate (80 vol.%) — barium ferrite (20 vol.%). It is shown that only samples sintered at the temperature of 1250 and 1350 °C have polarization sufficient for the existence of the piezoelectric effect. For the same samples, the pyroelectric coefficient and reversal polarization significantly exceed those for samples sintered at lower temperatures. Analysis of the samples structure confirmed the dependence of the dielectric properties of the barium titanate ceramics on the grain size and, as a consequence, on the sintering temperature. Based on the studies carried out, the optimal temperature (1250 °С) for obtaining composite samples of barium titanate (80 vol.%) — barium ferrite (20 vol.%) was selected. The temperature dependence of the dielectric constant for the composite samples based on barium ferrite — barium titanate with a sintering temperature of 1250 °C is similar to the dependence for the BaTiO3 ceramic samples sintered at 1350 °C. At room temperatures, the permittivity of the composite samples is also significantly higher than that of the barium titanate ceramic samples obtained at the same sintering temperatures. The addition of barium ferrite to the barium titanate not only increased the permittivity of the composite, but also led to a diffusing of the ferroelectric phase transition and a shift in the temperature of the maximum of the dielectric constant by 10 degrees towards high temperatures.

Dielectric Properties of Barium Titanate Ceramics with Nano-Sized Domain

2010 ◽  
Vol 445 ◽  
pp. 27-30 ◽  
Author(s):  
Yoichi Kigoshi ◽  
Saki Hatta ◽  
Takashi Teranishi ◽  
Takuya Hoshina ◽  
Hiroaki Takeda ◽  
...  
Keyword(s):  
Grain Size ◽  
Barium Titanate ◽  
Dipole Polarizability ◽  
Ionic Polarizability ◽  
Grain Sizes ◽  
Conventional Sintering ◽  
Rate Controlled ◽  
Titanate Ceramics ◽  
Sintering Method ◽  
Domain Width

Barium titanate (BaTiO3) ceramics with various grain sizes from 0.7 to 13 μm on average were prepared by a conventional sintering method, a two-step sintering method and a rate controlled two-step sintering method. The permittivity of the ceramics was increased with decreasing grain size to 1.1 μm on average. However, the permittivity of the ceramics was decreased when the grain size was below 1 μm. The field emission scanning electron microscope (FE-SEM) observations revealed that the 90º domain width decreased with decreasing the grain size. By ultrawide range dielectric spectra from kHz to THz range of the BaTiO3 ceramics, the domain contribution to the permittivity was investigated. For the BaTiO3 ceramics with grain sizes over 1 μm, the dipole polarizability and the ionic polarizability were enhanced by high domain-wall density. In contrast, for the BaTiO3 ceramics with grain sizes below 1 μm, these polarizabilities were weakened.

Enhanced Piezoelectric Properties of Barium Titanate-Potassium Niobate Solid Solution System Ceramics by MPB Engineering

2010 ◽  
Vol 445 ◽  
pp. 11-14 ◽  
Author(s):  
Shigehito Shimizu ◽  
Petr Pulpan ◽  
Nobuhiro Kumada ◽  
Daisuke Tanaka ◽  
Masahito Furukawa ◽  
...  
Keyword(s):  
Solid Solution ◽  
Barium Titanate ◽  
Piezoelectric Property ◽  
Potassium Niobate ◽  
Interface Area ◽  
Solution System ◽  
Solid Solution System ◽  
Conventional Sintering ◽  
Two Phases ◽  
Sintering Method

Barium titanate (BaTiO3, BT) - potassium niobate (KNbO3, KN) solid solution system (0.5BT-0.5KN) ceramics with various microstructures were prepared by conventional sintering method and two-step sintering method using BT and KN nanoparticles. Their microstructures were investigated using X-ray diffraction (XRD) measurement and scanning electron microscopy (SEM), and it was confirmed that two ferroelectric phases, i.e., BT-rich tetragonal and KN-rich orthorhombic phases, always coexisted for all ceramics, which suggested that 0.5BT-0.5KN ceramics had “pseudo-morphotropic phase boundary (MPB)” structure. Thus, the control of the interface area between two phases was important to enhance piezoelectric property. Finally, their piezoelectric property was measured, and the apparent piezoelectric constant d33* increased with increasing interface area.

Preparation and Characterization of CaCu3Ti4O12 Ceramics by Cold Isostatic Press Forming

2008 ◽  
Vol 368-372 ◽  
pp. 123-125
Author(s):  
Jie Li ◽  
Hao Xue ◽  
Zhao Xian Xiong
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Room Temperature ◽  
Frequency Range ◽  
Cold Isostatic Press ◽  
Temperature Range ◽  
Press Forming ◽  
Conventional Sintering ◽  
Sintering Method

CaCu3Ti4O12 (CCTO) ceramics were prepared by cold isostatic press (CIP) forming combined with the conventional sintering method. The effects of calcining temperature on properties of CCTO ceramics were investigated. The dielectric properties as the function of temperature at typical frequencies were measured in the temperature range from 243 to 363 K. In addition, the dielectric properties and complex impedances at room temperature were analyzed in a frequency range from 20 Hz to 106 Hz. The results showed that CCTO ceramics with dielectric constant higher than 104 were obtained. Compared with the dry press forming, CCTO ceramics prepared by CIP had more homogeneous grains, less porosity and better dielectric properties.

Preparation of Barium Titanate Porous Ceramics and their Piezoelectric Power Generation Property

2013 ◽  
Vol 566 ◽  
pp. 41-44
Author(s):  
Satoshi Wada ◽  
Yoshikazu Shimura ◽  
Petr Pulpan ◽  
Ichiro Fujii ◽  
Kouichi Nakashima
Keyword(s):  
Power Generation ◽  
Dielectric Constant ◽  
Barium Titanate ◽  
Piezoelectric Properties ◽  
Sintering Temperature ◽  
Porous Ceramics ◽  
Elastic Compliance ◽  
Conventional Sintering ◽  
Sintering Method ◽  
Dielectric And Piezoelectric Properties

Barium titanate (BaTiO3) porous ceramics were prepared by conventional sintering method, and their dielectric and piezoelectric properties were measured using 31-resonators. With decreasing sintering temperature, dielectric constant showed a maximum of 5500 at 1300 °C, while piezoelectric constant and elastic compliance increased. These resonators were developed to unimorph-type vibrators and their instantaneous electric powers were measured. As the results, the maximum electric power of 129 μW was measured for the BaTiO3porous ceramics sintered at 1200 °C, and this value was 20 times greater than that for dense BaTiO3ceramics.

Microstructure Control of Porous Barium Titanate Ceramics and their Sensor Properties

2013 ◽  
Vol 582 ◽  
pp. 32-35
Author(s):  
Kazuki Maeda ◽  
Ichiro Fujii ◽  
Kouichi Nakashima ◽  
Gakuyo Fujimoto ◽  
Kazuhiro Suma ◽  
...  
Keyword(s):  
Barium Titanate ◽  
Pore Structure ◽  
Pore Size ◽  
Figure Of Merit ◽  
Microstructure Control ◽  
Conventional Sintering ◽  
Sensor Properties ◽  
Titanate Ceramics ◽  
The Relationship ◽  
Sintering Method

Porous barium titanate (BaTiO3, BT) ceramics were prepared by a conventional sintering method using two kinds of BT particles. The relationship between pore structure (porosity and pore size) of BT ceramics and their sensor properties was investigated. Since a piezoelectric d33 constant of BT depends largely on the pore structures, the microstructure control of porous BT ceramics is important to improve the figure-of-merit (g33/ρ). In this study, the maximal piezoelectric g33 constant value of 14.8×10-3 V·m·N-1 and the maximal g33/ρ value of 3.14×103 V·m4·N-1·g-1 were recorded at a porosity of approximately 23%.

The Research on the Piezoelectric and Dielectric Properties of Bi0.5(Nak)0.5-BaTiO3 Lead-Free Ceramics

2014 ◽  
Vol 1035 ◽  
pp. 422-425
Author(s):  
Jian Yong Guo ◽  
Tao Sheng Zhou ◽  
Ji Hong Liao
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Perovskite Structure ◽  
Relative Dielectric Constant ◽  
Lead Free ◽  
Reactive Sintering ◽  
Lead Free Ceramics ◽  
Xrd Patterns ◽  
Sintering Method

The Bi0.5(Na1-xKx)0.5-yBaTiO3(BNK-BT) lead-free ceramics have been prepared by the solild reactive sintering method. XRD patterns show the BNK-BT ceramics had a perovskite structure. Piezoelectric and dielectric properties of the ceramics also have been studied. The results show that the samples had the best piezoelectric and dielectric properties when x=0.20, y=0.10. And the maximum of d33is 149 pC/N, while the relative dielectric constant is 1087.

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