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.

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.

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.

scholarly journals Dielectric properties and conductivity of PVdF-co-HFP/LiClO4 polymer electrolytes

2018 ◽  
Vol 96 (7) ◽  
pp. 786-791 ◽  
Author(s):  
Kemal Ulutaş ◽  
Ugur Yahsi ◽  
Hüseyin Deligöz ◽  
Cumali Tav ◽  
Serpil Yılmaztürk ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Polymer Electrolytes ◽  
Room Temperature ◽  
Solid Polymer Electrolytes ◽  
Solid Polymer ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Maximum Conductivity

In this study, it was aimed to prepare a series of PVdF-co-HFP based electrolytes with different LiClO4 loadings and to investigate their chemical and electrical properties in detail. For this purpose, PVdF-co-HFP based electrolytes with different LiClO4 loadings (1–20 weight %) were prepared using solution casting method. X-ray diffraction (XRD), differential scanning calorimetry, and thermogravimetric (TGA) –differential thermal and dielectric spectroscopy analysis of PVdF-co-HFP/LiClO4 were performed to characterize their structural, thermal, and dielectric properties, respectively. XRD results showed that the diffraction peaks of PVdF-co-HFP/LiClO4 electrolytes broadened and decreased with LiClO4. TGA patterns exhibited that PVdF-co-HFP/LiClO4 electrolytes with 20 wt % of LiClO4 had the lowest thermal stability and it degraded above 473 K, which is highly applicable for solid polymer electrolytes. Dielectric constant, dielectric loss, and conductivities were calculated by measuring capacitance and dielectric loss factor of PVdF-co-HFP/LiClO4 in the range from 10 mHz to 20 MHz frequencies at room temperature. In consequence, conductivities of PVdF-co-HFP/LiClO4 increased significantly with frequency for low loading of LiClO4 while they only slightly changed with higher LiClO4 addition. On the other hand, dielectric constant values of PVdF-co-HFP/LiClO4 films decreased with frequency whereas they rose with LiClO4 addition. The dielectric studies showed an increase in dielectric constant and dielectric loss with decreasing frequency. This result was attributed to high contribution of charge accumulation at the electrode–electrolyte interface. The electrolyte showed the maximum conductivity of 8 × 10−2 S/cm at room temperature.

Dielectric Properties of Sintered AIN

1989 ◽  
Vol 167 ◽  
Author(s):  
R. D. Harris ◽  
R. C. Enck ◽  
J. L. Fields
Keyword(s):  
Dielectric Constant ◽  
Dielectric Loss ◽  
Room Temperature ◽  
Dc Resistivity ◽  
Thermally Activated ◽  
Exponential Factors ◽  
Ac Electrical Properties ◽  
Different Sources ◽  
Room Temperature Dielectric Constant ◽  
Product Literature

AbstractWe have initiated a study of the ac electrical properties (dielectric constant and dielectric loss) and the dc resistivity of sintered AIN. For this study, we have used samples purchased commercially as well as samples made by the Carborundum Company, a member of the BP Group. Variations are observed in the room temperature dielectric constant for AIN substrates obtained from different sources. The source-to-source range is from 8.5 to 8.7. This range is lower than the 8.8 to 9.2 that is generally reported in the product literature. Similar source-tosource variations in the room temperature dielectric loss are observed. All of the samples show thermally activated behavior in the dc resistivity. The activation energy observed for all of the samples is similar, EA ∼0.47 eV; however, different pre-exponential factors are apparent. As a result, there are large variations in the measured room temperature resistivities for samples from different sources.

DIELECTRIC PROPERTIES OF CHEMICALLY SYNTHESIZED PbTiO3 NANOCRYSTALS SUITABLE FOR HIGH FREQUENCY DEVICES

2010 ◽  
Vol 24 (23) ◽  
pp. 4547-4554
Author(s):  
K. C. VERMA ◽  
M. SINGH ◽  
N. THAKUR ◽  
N. S. NEGI
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Room Temperature ◽  
Pt Nanoparticles ◽  
X Ray Diffraction ◽  
Chemical Route ◽  
Xrd Pattern ◽  
High Frequency Devices ◽  
Room Temperature Dielectric Constant ◽  
Transmission Scanning Electron Microscopy

PbTiO 3 (PT) nanoparticles have been prepared by chemical route using polyvinyl alcohol (PVA) as an efficient surfactant. The effect of PVA to reduce the particle's sizes of PT has been observed. X-ray diffraction (XRD) pattern shows that the PT nanoparticles are tetragonal with distortion ratio, c/a ~1.061. The average particle's size calculated from XRD and transmission/scanning electron microscopy is ~24 nm for PT powder sintered at 700°C. The nanostructured grains were also observed in PT pellet sintered at 1000°C. The dielectric properties of PT pellet have been measured from room temperature to 200°C and in the frequency range of 0.075 to 10 MHz. The values of room temperature dielectric constant and tanδ are 117 and 0.05 respectively, measured at 0.5 MHz. It is found that the dielectric constant of PT nanoparticles can be controlled up to higher frequency region of 5 MHz.

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.

Dielectric properties of normal, reduced, and specially reduced rutile (TiO2) single crystals at room temperature

1969 ◽  
Vol 47 (1) ◽  
pp. 3-6 ◽  
Author(s):  
H. B. Lal ◽  
K. G. Srivastava
Keyword(s):  
Dielectric Constant ◽  
Relaxation Time ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Oxygen Vacancy ◽  
Single Crystals ◽  
Room Temperature ◽  
Interfacial Polarization ◽  
Absorption Peak ◽  
Single Relaxation Time

The variation of the dielectric constant (ε′) and the dielectric loss (ε″) have been studied as a function of frequency (102 to 1010 c.p.s.) for normal (as grown), reduced (heated in vacuum), and specially reduced (heated in vacuum in presence of an asymmetric d.c. field) rutile single crystals parallel to c-axis at room temperature. Dispersions in ε′ have been observed in the frequency ranges 102 to 103 and 107 to 109 c.p.s. for all the samples with absorption peaks in ε″ at 2 × 102 and 6 × 107 c.p.s. Also an extra absorption peak in ε″ has been found at 2 × 104 c.p.s. for the specially reduced sample. The absorption peak at 2 × 102 c.p.s. has been observed by many workers and is typical for interfacial polarization. The peak at 6 × 107 c.p.s. appears to be due to a dipole rotation process with a single relaxation time and is identified as due to relaxation of dipoles formed between Ti3+ and a neighboring oxygen vacancy. The possible mechanism of relaxation for the 2 × 104 c.p.s. absorption peak is also discussed.

Characterization and dielectric properties of sodium fluoride doped talc

Clay Minerals ◽  
2014 ◽  
Vol 49 (4) ◽  
pp. 551-558
Author(s):  
S. Gümüştas ◽  
K. Köseoğlu ◽  
E. E. Yalçinkaya ◽  
M. Balcan
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Firing Temperature ◽  
Room Temperature ◽  
Dielectric Measurements ◽  
Frequency Range ◽  
Detailed Characterization ◽  
Circuit Element

AbstractThe purpose of this paper is to determine the effect of NaF and firing temperature on the dielectric properties (dielectric constant and dielectric loss) of talc, which is used in the electrical and electronic industries as a circuit element. A detailed characterization of the samples was made by XRD, FTIR, SEM and TG-DTG methods. Dielectric measurements were performed in the frequency range from 1 MHz to 80 MHz at room temperature. The dielectric constant value increased with an increase in firing temperature due to the removal of polarizable compounds from the talc structure. The higher dielectric constant values were obtained by addition of NaF. The dielectric loss of NaF doped talc decreased with the increase of firing temperature and increased with the increase of the amount of NaF.

Effect of Al2O3 and MgO Additives on Dielectric Properties of BaZrxTi1-xO3-Based Ceramics

2014 ◽  
Vol 602-603 ◽  
pp. 714-718
Author(s):  
Hong Jun Feng ◽  
Hui Ming Ji ◽  
Xiao Lei Li ◽  
Jian Wang ◽  
Da Hao Wang
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Raw Materials ◽  
Bias Field ◽  
Phase Shifters ◽  
Sem Images ◽  
Solid State Method ◽  
Tunable Capacitors ◽  
Lcr Meter

BaZrxTi1-xO3-based (BZT) ceramics with Al2O3 and MgO addtives were prepared by the conventional solid state method with BaCO3, ZrO2, TiO2, Al2O3 and MgO as raw materials and B2O3 and Li2CO3 as sintering additive. The morphologies were analysized by scanning electron microscopy (SEM). The dielectric constant and dielectric loss of ceramics were measured by LCR meter. The temperature dependences of dielectric constant were measured by high-low temperature incubator tank and LCR meter at 1 MHz and a temperature range-55 to 125 °C. The tunabilities were tested by C-T-V converter and LCR meter at 1 MHz at room temperature. The results show that with the increase of Zr/Ti, BZT ceramic dielectric constant increases, the loss increases, the Curie temperature moves to a lower temperature, and dielectric bias field coordination is relatively lower. The SEM images show that the grain size reaches about 1-2 μm when the sintering temperature is 1100 °C, and the addition of Al2O3 and MgO promote the grain growth and densification of the composite ceramics. The Curie peaks are broadened and depressed with the addition of Al2O3 and MgO. The tunability is improved to 9.59% under a DC electric field of 7.0 kV/cm after the addition of Al2O3. The dielectric constant and dielectric loss of BaZr0.25Ti0.75O3-30wt%Al2O3 and BaZr0.25Ti0.75O3-30wt%MgO are 586, 0.011 and 486, 0.003, respectively. The optimistic dielectric properties make it a promising candidate for the application of tunable capacitors and phase shifters.

scholarly journals AC CONDUCTIVITY AND DIELECTRIC STUDIES OF POLYPYRROLE-PAPAIN COMPOSITE

2019 ◽  
Vol 7 (8) ◽  
pp. 332-338
Author(s):  
Pandey Munish ◽  
Badlani Richa
Keyword(s):  
Dielectric Constant ◽  
Room Temperature ◽  
In Situ Polymerization ◽  
Weight Percent ◽  
Oxidizing Agent ◽  
Dielectric Studies ◽  
Dielectric Constant And Loss ◽  
Lcr Meter ◽  
Room Temperature Dielectric Constant

Enzyme doped polypyrrole polymer were synthesized by in situ polymerization where ferric chloride works as an oxidizing agent. The different weight percent of papain was added at the time of polymerization. The polypyrrole-papain composite of various composition was analyzed for its dielectric and a. c. conductivity by using LCR meter at room temperature. Dielectric constant and loss decreases, with escalation in frequency. The variation in dielectric constant and dielectric loss was also noted with change in papain percentage in pyrrole.

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