Effect of Sintering Temperatures on Sr-Doped NiO Ceramics

2016 ◽  
Vol 840 ◽  
pp. 61-65 ◽  
Author(s):  
Nurul Nadia Mohd Salim ◽  
Julie Juliewatty Mohamed ◽  
Zainal Arifin Ahmad
Keyword(s):  
Dielectric Constant ◽  
Grain Size ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Size Range ◽  
Sintering Temperature ◽  
Wide Frequency Range ◽  
Frequency Range ◽  
Solid State Method ◽  
State Method

Sr - doped NiO ceramic was prepared using solid state method. The calcination temperature used at 950 oC for 4 hours and the sintering temperatures was varied from 1100 to 1300 oC for 3 hours. The results depict the microstructures increasing in grains size (1-8 μm) by increase of sintering temperatures. The density and porosity testing support the result of microstructures analysis. The larger grains size induced the increase in density and lower in porosity. The dielectric properties is observed in a wide frequency range of (1 - 1 000 MHz). The increase of dielectric constant is associated with the decrease of dielectric loss. The optimum sintering temperature was obtained at 1200 oC depict the grain size range (1 - 2 μm) with highest dielectric constant (1.61 x 103) and lowest dielectric loss (1.15) at 1MHz.

Solid State Sintering and Microstructural Evolution on Wide Frequency Range Dielectric Responses of Mechanically Activated CaTiO3 Ceramics

2015 ◽  
Vol 1107 ◽  
pp. 38-44
Author(s):  
Wong Yick Jeng ◽  
Hassan Jumiah ◽  
Mansor Hashim
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Sintering Temperature ◽  
Microstructural Analysis ◽  
High Energy ◽  
Wide Frequency Range ◽  
Milling Process ◽  
Frequency Range ◽  
Wide Range

The CaTiO3samples were prepared by high-energy ball milling process followed by sintering process from 1040 to 1200°C. X-ray diffraction (XRD), microstructural analysis, and dielectric properties over a wide range of frequency varying from 0.01 Hz to 1 GHz at room temperature were investigated. The formation of a single phase CaTiO3with orthorhombic structure was achieved at 1120°C and above. From a morphological point of view, sintering temperature promoted grain growth. Dielectric properties in the frequency range 0.01 Hz - 1 MHz revealed a relaxation-type process. Interfacial phenomena were the possible physical mechanisms that gave rise to these relaxation-type plots. Extending the frequencies above ~1 MHz yielded a frequency-independent characteristic of dielectric constant (ε'). These turned out to the relatively small dielectric loss (tan δ) values. The origin of the dielectric responses in the frequency range 1 MHz - 1 GHz was attributed to the domination of dipolar polarization. The grain size effect in sintered CaTiO3samples was prominent, notably in dielectric responses above ~1 MHz. Increase in sintering temperature remarkably led to an enhancement in dielectric constant values and reduction in dielectric loss values. Therefore, a significant correlation existed between microstructural features and dielectric properties.

Dielectric Properties of Na2O Doped Cao-B2O3-SiO2 System Glass-Ceramics

2013 ◽  
Vol 750-752 ◽  
pp. 492-496
Author(s):  
Peng Fei Wei
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Sintering Temperature ◽  
Glass Ceramics ◽  
Wide Frequency Range ◽  
Microwave Properties ◽  
Low Dielectric Constant ◽  
Frequency Range ◽  
Low Dielectric

The behavior of dielectric and microwave properties against sintering temperature was been carried out on CaO-B2O3-SiO2glass-ceramics with Na2O addition by XRD and SEM. The results show that 0.5 wt.% Na2O addition is advantageous to improve the dielectric and microwave properties due to increasing the major crystalline CaSiO3. With further increasing Na2O content, α-SiO2is the predominant crystalline phase instead of CaSiO3. The CBS glass-ceramics with 0.5 wt.% Na2O sintered at 875°C has a bulk density of 2.51g·cm-3, and which possesses good dielectric properties:εr=6.2,tanδ=1.9×10-3(10 MHz) and low dielectric constant below 2×10-3over a wide frequency range. The proposed dielectrics can find applications in microwave devices, which require low dielectric loss and low dielectric constant.

Effect of Sintering Temperature on CuO Doped Barium Zinc Tantalate (BZT) Dielectric Properties

2016 ◽  
Vol 840 ◽  
pp. 8-13
Author(s):  
Hidayani Jaafar ◽  
Zainal Arifin Ahmad ◽  
Mohd Fadzil Ain
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Relative Density ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Solid State Method ◽  
Microwave Dielectric ◽  
Constant E ◽  
State Method ◽  
Tan Δ

The structure and dielectric properties of Barium Zinc Tantalate (BZT) doped by copper oxide (CuO) with a variety of values of mol% doping from 0, 0.1, 0.25, 1.0, 1.5 and 2.5 were prepared using a solid state method. The addition of CuO did not disturb the 1:2 ordering structure of the BZT ceramic. The grain size increased when the addition of doping increased. A small amount of doping elements increased the relative density. The dielectric constant (ɛr) value of the BZT significantly improved with the addition of the CuO for the specimens sintered at 1250°C and it could be explained by the increase of the relative density. The tan δ of the CuO doped with BZT ceramics is lower than pure BZT ceramics, and decreases as the CuO content increases. Meanwhile, for the percentage of bandwidth (%BW) it is shown that the best result is produced when it is doped with 0.25 mol% CuO and sintered at 1250°C. The best microwave dielectric properties obtained were ɛr=70.28, tan δ = 0.024, %BW = 7.83 which occurred for the 0.25 mol% doped CuO and when sintered at 1250°C/4 h.

Structural and dielectric properties of SrFexTi1-xO3 (x = 0.001, 0.005 and 0.01) ceramics

2013 ◽  
Vol 03 (01) ◽  
pp. 1350006
Author(s):  
Zhanwu Yu ◽  
Peng Shi ◽  
Wei Ren ◽  
Xiaoqing Wu ◽  
Xi Yao
Keyword(s):  
Dielectric Constant ◽  
Grain Size ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Leakage Current ◽  
Lattice Constant ◽  
Doping Concentration ◽  
Sintering Temperature ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction

Three different SrFe x Ti 1-x O 3(x = 0.001, x = 0.005, x = 0.01) ceramics were prepared by the conventional solid-state reaction. The crystalline structure, surface morphology and dielectric properties were studied by X-ray diffraction (XRD), scanning electron microscope (SEM) and Agilent 4294A impedance analyzer, respectively. It is shown that both the sintering temperature and doping concentration influence the lattice constant, grain size, dielectric constant and the dielectric loss. When the sintering temperature is higher than 1390°C, the lattice constant, grain size and dielectric constant all decrease with the increase of the doping concentration, except the dielectric loss tangent which shows the opposite trend. Leakage current tests show that the leakage current density falls down with the increase of Fe doping concentration in the given region.

Influence of BaSiO3 Doped on the Properties of BST Capacitor Ceramics

2013 ◽  
Vol 575-576 ◽  
pp. 91-94
Author(s):  
Xin You Huang ◽  
Mu Sheng Huang ◽  
Chun Hua Gao ◽  
Zhi Gang Chen
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Solid State ◽  
Sintering Temperature ◽  
Lattice Parameter ◽  
Solid State Method ◽  
Xrd Study ◽  
Sem Study ◽  
State Method ◽  
Bst Ceramics

The influence of the BaSiO3 dopant on the dielectric properties of (Ba,Sr)TiO3(BST) capacitor ceramics was studied using conventional capacitor ceramics solid state method and XRD , SEM and other analytical methods. The results show that BaSiO3 doping can improve the sintering and microstructure of the capacitor ceramics. SEM study show that BaSiO3 doping can make grain grow uniformly and suppress the grain to grow up, and the structure of ceramics is compact with little pore. XRD study show that there is little SiO2 phase and little influence of BST lattice parameter when BaSiO3 doped amount is 3 mol%.The dielectric properties of BST ceramics doped with 3 mol% BaSiO3 are as follows: dielectric constant (εr) of 1792, which is a little higher than undoped BST ceramics, tanδ of 1%, which is decreased 7.24% compared with undoped BST ceramics, and the sintering temperature decreases 40°C.

Effect of moisture content on dielectric properties of banana leaves and peels in frequency range of 1–20 GHz

Frequenz ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Soumya Sundar Pattanayak ◽  
Soumen Biswas
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Moisture Content ◽  
Measurement Data ◽  
Banana Peel ◽  
Frequency Range ◽  
Proposed Model ◽  
Banana Leaves ◽  
Banana Leaf

Abstract The quality of agricultural products can be remotely sensed and enhanced by determining the dielectric properties. This paper studies the dielectric properties of banana leaf and banana peel over the frequency range 1–20 GHz using the open-ended coaxial probe (OCP) method. A new curve fitting model is proposed to characterize the dielectric properties of banana leaf and banana peel. The different moisture content (MC) levels are considered for both banana leaf and banana peel samples and, their dielectric properties are characterized. Further, the banana leaf and banana peel’s measurement data are compared with the data obtained using the proposed model. In addition, Root Mean Square Error (RMSE) and R-squared (R 2) are calculated to validate the performance of the proposed model. In case of banana leaf at 68.26% MC, the dielectric constant achieves the value of R 2 and RMSE of 0.98 and 0.0648, respectively. Similarly, dielectric loss achieves the value of R 2 and RMSE of 0.88 and 0.0795, respectively. Further, for banana peel at 80.89% MC, the dielectric constant achieves the value of R 2 and RMSE of 0.99 and 0.2989, respectively. Similarly, dielectric loss achieves the value of R 2 and RMSE of 0.96 and 0.6132, respectively.

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.

Effect of Fungicide Treatment on Dielectric Properties of a Vegetable Seed

2015 ◽  
Vol 5 (2) ◽  
Author(s):  
Vishal Singh Chandel ◽  
Atiq UR Rahmanm ◽  
J. P. Shukla ◽  
Rajiv Manohar ◽  
Mohd. Shafi Khan
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Moisture Content ◽  
Considerable Change ◽  
Frequency Range ◽  
Dielectric Parameters ◽  
Hewlett Packard ◽  
Fungicide Treatment ◽  
Vegetable Seed

Effect of fungicides' (thiram, captan, carbendazim, bagalol) treatment on dielectric constant and dielectric loss of a vegetable seed, namely the brinjal at given moisture content and bulk density was examined using Hewlett-Packard (HP-4194A) impedance/gain phase analyzer over the frequency range of 0.01 to 10 MHz and temperature range of 30-450C. Julabo (temperature controller, F-25, Germany) was used for keeping the temperature of seeds constant. Study showed that fungicide treatment cast considerable change in dielectric parameters namely the dielectric constant and dielectric loss.

Dielectric Properties of Eucalyptus urophylla Under an Ultra-Wide Frequency Range

2020 ◽  
Vol 12 (8) ◽  
pp. 1236-1241
Author(s):  
He Xia ◽  
Wang Yong ◽  
Li Yunyan ◽  
Wei Yanqiang ◽  
Quan Peng ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Dielectric Loss ◽  
Dielectric Permittivity ◽  
Loss Factor ◽  
Wide Frequency Range ◽  
Dielectric Loss Factor ◽  
Regression Equations ◽  
Eucalyptus Urophylla ◽  
Frequency Range ◽  
Tangential Directions

Dielectric properties of Eucalyptus urophylla wood were measured by using a network analyzer over an ultrawide frequency range between 0.2 GHz and 20 GHz. The effects of moisture content (MC), temperature and frequency on the dielectric permittivity and the dielectric loss factor of Eucalyptus urophylla were investigated along different grain directions. The results showed that the dielectric permittivity along with the dielectric loss factor increased significantly with the elevation in MC. At the frequency of 2380 MHz with the MC increasing from 0% to 100%, the dielectric permittivity along different grain directions (including longitudinal, radial and tangential directions) increased by 180%, 110% and 112%, respectively, while the loss factor along these three directions increased by 1642%, 3703% and 5058%, respectively. In addition, the increase in dielectric properties of Eucalyptus urophylla wood was determined with the temperature elevating. When the temperature elevated from 20 °C to 140 °C, the dielectric permittivity at 2380 MHz along the longitudinal, radial and tangential directions, increased by 19%, 14% and 15%, respectively, while the loss factor increased by 133% at most. As the radio frequency increased, the dielectric permittivity of wood decreased. Regression equations satisfactorily described the dielectric properties of wood along different grain directions with different moisture contents.

Low Temperature Sintering and Microwave Dielectric Properties of Zinc Titanate Ceramics for LTCC Applications

2008 ◽  
Vol 368-372 ◽  
pp. 179-182
Author(s):  
Zong Chi Liu ◽  
Dong Xiang Zhou ◽  
Shu Ping Gong
Keyword(s):  
Dielectric Properties ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Sintering Behavior ◽  
Solid State Method ◽  
Zinc Titanate ◽  
Microwave Dielectric ◽  
Conventional Solid State Method ◽  
State Method ◽  
Titanate Ceramics

The effects of CuO-MoO3 addition on the sintering behavior and microwave dielectric properties of ZnO-TiO2 ceramics were investigated. ZnO-TiO2 ceramics were prepared with conventional solid-state method and sintered at temperatures from 850 to 1050 °C. The sintering temperature of ZnO-TiO2 ceramics with CuO-MoO3 addition could be effectively reduced to 950 °C due to the liquid phase effects resulting from the additives. A proper amount of CuO-MoO3 addition could effectively improve the densification and microwave dielectric properties of ZnO-TiO2 ceramics. ZnO-TiO2 ceramics with 3 wt% addition sintered at 950 °C for 4 h exhibited better microwave dielectric properties as follows: εr of 26.8, a Q×f value of 16780 GHz at 5.42 GHz, and a τ f value of +34.7 ppm/°C.

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