Effect of Small Amount BaTiO3 on Properties of K0.02Na0.98NbO3 Ceramics with Various Sintering Temperature Prepared by Molten Salt Method

2016 ◽  
Vol 718 ◽  
pp. 129-132
Author(s):  
Chompoonuch Warangkanagool
Keyword(s):  
Molecular Weight ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Barium Titanate ◽  
Molten Salt ◽  
Sintering Temperature ◽  
Maximum Density ◽  
Molten Salt Method ◽  
Sodium Niobate ◽  
Potassium Sodium Niobate

In the research, the properties of potassium sodium niobate – barium titanate [(1-x)K0.02Na0.98NbO3–(x)BaTiO3: (1-x)KNN–(x)BT] ceramics prepared by molten salt method with various molecular weight of BT or x are 0 and 0.05 were investigated. The calcined powders of pure K0.02Na0.98NbO3 and (0.95) K0.02Na0.98NbO3-(0.05) BaTiO3 were pressed and sintered at 1250 – 1325 °C and 1225 – 1300 °C for 2h, respectively. It was found that, the samples showed phase structure changing from monoclinic to orthorhombic with small amount BaTiO3 addition. The densification of K0.02Na0.98NbO3 ceramics and dielectric properties were improved with the addition of BaTiO3. The (0.95)K0.02Na0.98NbO3–(0.05)BaTiO3 ceramics sintered at 1250 °C showed maximum density and dielectric constant (∼8035), which was even comparable with that of K0.02Na0.98NbO3 ceramics sintered at 1225 – 1300 °C.

Physical, Dielectric Properties and Micro-Hardness of the (Ba0.90Ca0.10)0.90(Na0.50Bi0.50)0.10TiO3 Ceramics Prepared by Molten Salt Method

2018 ◽  
Vol 283 ◽  
pp. 132-139
Author(s):  
Chompoonuch Warangkanagool
Keyword(s):  
Dielectric Properties ◽  
Molten Salt ◽  
Heating Rate ◽  
Sintering Temperature ◽  
Molten Salt Method ◽  
Micro Hardness ◽  
Fluid Medium ◽  
Grain Sizes ◽  
Knoop Indentation ◽  
Lcr Meter

In this study, the physical properties, dielectric properties, and micro-hardness of (Ba0.90Ca0.10)0.90(Na0.50Bi0.50)0.10TiO3 or BCT-NBT ceramics prepared by molten salt method with various sintering temperatures were investigated. The powders were calcined at 500-1100°C for 4 h with heating rate of 5°C/min. It was found that the optimum calcination condition was 1000°C for 4 h. These powders were pressed and sintered at 1200-1400°C for 3 h with a heating rate of 5°C/min. The microstructure was examined by scanning electron microscope (SEM). The density of the sintered samples was measured by Archimedes method with distilled water as the fluid medium. Dielectric properties were examined by LCR meter. The micro-hardness of the BCT-NBT ceramics was determined using the Vickers and Knoop indentation techniques. The results showed that the average grain sizes increased with increasing sintering temperatures. At sintering temperatures higher than 1200°C, the fracture mode changed from partial intra-granular to mainly intra-granular. The sintering temperature at which the density, dielectric and hardness properties were maximal was 1350°C. The highest density was about 5.4 g/cm3, and the Vickers and Knoop micro-hardnesses were 6.6 and 6.4 GPa, respectively. The dielectric constant at the Curie temperature was 3682 and the dielectric loss was 0.01 at 1 kHz frequency.

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.

Influence of CuO Additive on Density and Dielectric Properties of Ba(Zr0.05Ti0.95)O3 Ceramics Prepared by Molten Salt Method

2020 ◽  
Vol 302 ◽  
pp. 115-121
Author(s):  
Chompoonuch Warangkanagool
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Molten Salt ◽  
Room Temperature ◽  
Molten Salt Method ◽  
Distilled Water ◽  
Fluid Medium ◽  
Lcr Meter ◽  
Room Temperature Dielectric Constant

In this research, the Ba(Zr0.05Ti0.95)O3 powders were prepared by molten salt method. The powders were calcined at 600-1100°C for 3 h with heating rate of 5°C/min. The BZT powders were synthesized by molten salt method to reduce the calcination temperature by up to 300°C. The sintering procedure was carried out at 1250°C for 2 h with a heating/cooling rate of 5°C/min. Phase formation and microstructure were examined by XRD and SEM, respectively. The influence of the CuO additive on density and dielectric properties were investigated. The density of the sintered samples was measured by Archimedes method with distilled water as the fluid medium. Dielectric properties were examined by LCR meter. The BZT+2.0 mol% CuO ceramic sintered at 1250°C showed the highest density of 5.76 g/cm3, and the room temperature dielectric constant and dielectric loss at 1 kHz were 2687 and 0.01, respectively.

Microstructure and Dielectric Properties of Strontium Bismuth Niobium Ceramics Prepared by Molten Salt Method

2011 ◽  
Vol 197-198 ◽  
pp. 589-592
Author(s):  
Bao Rang Li ◽  
Hui Bin Chang ◽  
Peng Lei Chen
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Molten Salt ◽  
Grain Growth ◽  
Curie Point ◽  
Abnormal Grain Growth ◽  
Theoretical Density ◽  
Molten Salt Method ◽  
Evolution Of Microstructure

Strontium Bismuth Niobium (SBN) ceramics was prepared successfully using the powders synthesized from molten salt method. The evolution of microstructure with temperature increasing was studied and the influences of abnormal grain growth on dielectric properties were also presented in this paper. The results showed that pure strontium bismuth niobium ceramics without abnormal grain growth could be formed at 1150°C while the density was almost 95% of the theoretical density. Further investigations on dielectric properties indicated although abnormal grain growth did not shift the Curie point obviously, they lowered the dielectric constant corresponding to the Curie point. The dielectric loss was found to change with the frequency remarkably.

Preparation and dielectric properties of potassium sodium niobate-based solid solutions

2013 ◽  
Vol 49 (8) ◽  
pp. 826-833 ◽  
Author(s):  
G. M. Kaleva ◽  
A. V. Mosunov ◽  
S. Yu. Stefanovich ◽  
E. D. Politova
Keyword(s):  
Dielectric Properties ◽  
Solid Solutions ◽  
Sodium Niobate ◽  
Potassium Sodium Niobate ◽  
Potassium Sodium

Improving dielectric properties of Zn2(Ti0.88Sn0.12)O4 ceramics by using molten-salt method to optimize the microstructure

2019 ◽  
Vol 6 (12) ◽  
pp. 126309
Author(s):  
Xiao Wang ◽  
Xiangchun Liu ◽  
Wen Yan ◽  
Shan Hou ◽  
Ningna Bai ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Molten Salt ◽  
Molten Salt Method

Effect of Sintering Temperature on Dielectric Properties of CaCu3Ti4O12 Ceramics Prepared by Mechanochemical Process

2014 ◽  
Vol 974 ◽  
pp. 157-161
Author(s):  
Masturah Mohamed ◽  
Mahesh Talari ◽  
Mohd Salleh Mohd Deni ◽  
Azlan Zakaria
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Sintering Temperature ◽  
Processing Conditions ◽  
Dielectric Measurements ◽  
Frequency Range ◽  
Grain Sizes ◽  
Barrier Capacitance ◽  
Different Temperatures ◽  
Increasing Temperature

CaCu3Ti4O12(CCTO) is well known to have colossal dielectric constant in the range of 105.It is widely accepted that this phenomenon may be attributed to internal layer barrier capacitance (IBLC) model. The dielectric properties of CCTO were reported to be strongly dependent on the processing conditions and grain size. In this work, CCTO samples with different grain sizes were produced by varying sintering temperature in order to investigate IBLC effect on dielectric properties of CCTO. The samples were sintered at four different temperatures, (T=1100°C, 1050°C, 1000°C and 950°C). Dielectric measurements were carried out for the samples in the frequency range of 102– 106Hz using impedance spectrometer. Electron micrographs showed that increasing temperature promoted the grain growth of CCTO while sintering. The internal crystalline defects are seen to play major role by increasing the grain conductivity in dipole formation and increased the dielectric constant of the samples.

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.

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