Dielectric properties of Ba0.97Bi0.02TiO3–Ba1−xMgxSn0.02Ti0.98O3 composite ceramics

2016 ◽  
Vol 30 (29) ◽  
pp. 1650363
Author(s):  
Jing wang ◽  
Guijuan Rong ◽  
Liangbin Hao ◽  
Lan Gao ◽  
Haiyan Cheng ◽  
...  

A wet solid-state method was used in this work to produce [Formula: see text]–[Formula: see text] materials. By using core-shell structure nanocubic [Formula: see text] (BMST) decorated [Formula: see text] (BBT) assemblies, a composite capacitor with improved dielectric constant and enhanced breakdown strength was successfully fabricated in contrast with the composite ferroelectric [Formula: see text]–[Formula: see text] (BBT–BST) ceramic. With increasing Mg content, the ceramic capacitors display a stronger performance in its dielectric behavior. The best dielectric properties were obtained in the composition [Formula: see text] = 0.007 with the dielectric constant above 65,000. The dielectric strength of the ceramics was measured by a withstanding voltage tester. The best dielectric strength was achieved in the composition [Formula: see text] = 0.007 with [Formula: see text] = 5.455 kV/mm.

2016 ◽  
Vol 840 ◽  
pp. 8-13
Author(s):  
Hidayani Jaafar ◽  
Zainal Arifin Ahmad ◽  
Mohd Fadzil Ain

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.


2013 ◽  
Vol 575-576 ◽  
pp. 91-94
Author(s):  
Xin You Huang ◽  
Mu Sheng Huang ◽  
Chun Hua Gao ◽  
Zhi Gang Chen

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.


2015 ◽  
Vol 3 (3) ◽  
pp. 30-34
Author(s):  
Hidayani Jaafar ◽  
Sitti Fatimah Mhd Ramle ◽  
Muhammad Azwadi Sulaiman ◽  
Nurul Nadia Aminuddin

The structure and dielectric properties of Barium Zinc Tantalate (BZT) doped by copper oxide (CuO) and calcium oxide (CaO) with a variety of values of mol% doping from 0, 0.1, 0.25, 0.5, 1.0, 1.5 and 2.5 were prepared using a solid state method. A small amount of doping elements increased the relative density. The dielectric constant (?r) value of the BZT significantly improved with the addition of the CuO and CaO for the specimens sintered at 1250°C and it could be explained by the increase of the relative density. The tan ? of the CuO and CaO doped with BZT ceramics is lower than pure BZT ceramics, and decreases as the CuO and CaO content increases. Minimum return loss (dB) shown that the best results are produced when it is doped with 0.25 mol% CaO and 0.5 mol% for CuO sintered at 1250°C.


2019 ◽  
Vol 13 (3) ◽  
pp. 281-286
Author(s):  
Mohamed Afqir ◽  
Amina Tachafine ◽  
Didier Fasquelle ◽  
Mohamed Elaatmani ◽  
Jean-Claude Carru ◽  
...  

Structure and dielectric properties of Eu-doped SrBi2Nb2O9 ceramics (with 0, 20 and 35 at.% of Eu), prepared by the solid-state method and sintering, were investigated. XRD, FTIR and SEM measurements were provided to validate the characteristic structural features of the obtained ceramics. For all samples, the orthorhombic structure was identified through XRD analysis. SEM results confirmed that the fabricated samples have relatively dense structure with rod- and plate-like grains typical for Aurivillius layered structures. Dielectric results showed that the doping with Eu decreases dielectric constant and reduces dielectric loss. Movement of the dielectric peak towards higher temperatures appearing at about 400?C with increase of frequency indicates on relaxor behaviour of the sample with 35 at.% of Eu.


2014 ◽  
Vol 602-603 ◽  
pp. 710-713
Author(s):  
Da Hao Wang ◽  
Hui Ming Ji ◽  
Qian Qian Jia

Ba0.55Sr0.4Ca0.05TiO3-MgO (BSCTM) with Mn2+additive composite ceramics were prepared by the conventional solid state method with BaCO3, SrCO3, CaCO3, MgO and MnCO3as raw materials and B2O3and Li2CO3as sintering agent. The influence of the MnCO3additive on the sinterability and dielectric properties of BSCTM composite ceramics are investigated. The morphologies were analysized by scanning electron microscopy (SEM). The dielectric constant and dielectric loss of ceramics were measured by LCR meter at 1 kHz and 1 MHz. The temperature dependences of dielectric constant were measured by high-low temperature incubator tank and LCR meter at 1 MHz and a temperature range from-55 to 125 °C. The dielectric tunabilities were tested by C-T-V converter and LCR meter at 1 MHz and room temperature (25 °C). SEM results showed that BSCTM ceramics became more compact with the increase of Mn2+content, because Mn2+helped to form more oxygen vacancies for accelerating densification process. The addition of Mn2+largely reduced the dielectric loss while had little effect on dielectric constant. The dielectric constant and dielectric loss of 0.5mol% Mn2+doped BSCTM ceramics were 222 and 0.001, respectively. The dielectric tunability increased at first and then decreased with the increase of Mn2+content. The tunability of 0.5mol% Mn2+doped BSCTM ceramics were 4.04% under a DC electric field of 8.2 kV/cm.


2016 ◽  
Vol 840 ◽  
pp. 61-65 ◽  
Author(s):  
Nurul Nadia Mohd Salim ◽  
Julie Juliewatty Mohamed ◽  
Zainal Arifin Ahmad

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.


2015 ◽  
Vol 241 ◽  
pp. 226-236 ◽  
Author(s):  
Neha Solanki ◽  
Rajshree B. Jotania

Influence of Ca substitution on structural, magnetic and dielectric properties of Ba3Co2-xCaxFe24O41(where x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0), prepared by Sol-Gel auto-combustion method, has been investigated in present studies. The obtained powder was sintered at 950 oC for 4 hrs. in the static air atmosphere. Structural analysis of Ca-doped Ba3Co2-xCaxFe24O41powders revealed pure Z-type hexaferrite phase at low temperature. The frequency dependent dielectric constant (Єʹ) and magnetic properties such as remanent magnetization (Mr), saturation magnetization (Ms) and coercivity (Hc) were studied. It is observed that coercivity increased gradually with increase in calcium content. The real dielectric constant (Єʹ) and dielectric loss tangent (tan δ) were studied in the frequency range of 20Hz to 2MHz. The dielectric parameters for all samples show normal dielectric behavior as observed in hexaferrites. Contents of Paper


2012 ◽  
Vol 512-515 ◽  
pp. 828-831 ◽  
Author(s):  
Wei Dong ◽  
Chang An Wang ◽  
Lei Yu ◽  
Shi Xi Ouyang

Porous Si3N4/SiO2/BN composite ceramics with high strength and low dielectric constant were prepared by dry-pressing process and pressureless sintering at 1750°C for 1.5 h in flow nitrogen. The influences of BN content on microstructure, porosity, mechanical and dielectric properties of the porous Si3N4/SiO2/BN composite ceramics were discussed. The results showed that the porous Si3N4/SiO2/BN composite ceramics with porosity ranging from 29% to 48% were fabricated by adjusting the content of BN. The flexural strength of the porous Si3N4/SiO2/BN composite ceramics was 78215 MPa. The dielectric constant of the porous Si3N4/SiO2/BN composite ceramics was 3.9~5 at 1 MHz.


2021 ◽  
Vol 9 (38) ◽  
pp. 13439-13446
Author(s):  
Nur Amira Farhana Mohamed Saadon ◽  
Nurliyana Mohd Ali ◽  
Norazila Ibrahim ◽  
Zakiah Mohamed

Sr2Ni1−xMgxWO6 (0.00 ≤ x ≤ 0.06) polycrystalline samples were prepared using a solid state method and the structural, optical and dielectric properties of the samples were studied using XRD, UV-vis, FTIR and EIS respectively.


2019 ◽  
Vol 8 (3) ◽  
pp. 234
Author(s):  
Nasr Hadi ◽  
Tajdine Lamcharfi ◽  
Farid Abdi ◽  
Nor-Said Echtoui ◽  
Ahmed Harrach ◽  
...  

<p class="Abstract"><span lang="EN-US">The influences of calcination temperature and doping with cobalt in A–site on structural and dielectric properties of CaCu<sub>3-x</sub>Co<sub>x</sub>Ti<sub>4</sub>O<sub>12</sub> (CCCxTO, x = 0.00, 0.02 and 0.10) ceramics sintered at 1050 <sup>0</sup>C for 8h were investigated. The ceramic samples are prepared by the conventional solid-state method using high purity oxide powders, and they are calcined at 850 °C, 950 °C and 1050 <sup>0</sup>C for 4h. The X-ray diffraction (XRD) analysis of pure and doped CCTO samples calcined at 950 °C and 1050 <sup>0</sup>C showed no traces of any other secondary phases, while impurity phases alongside CCTO phase in the x=0.00 sample calcined at 850 <sup>0</sup>C was observed. Scanning electron microscopy (SEM) investigation showed an increase in grain size with increasing of Co content and calcining temperature. Dielectric measurements indicated that the dielectric constant of the pure CCTO calcined at 1050 <sup>0</sup>C/4h has a low value in the frequency range of 1kHz up to 1MHz, whereas the substitution of Co up to x = 0.10 into CCTO caused a huge increase in the dielectric constant value of the calcined samples which is equal to 153419 and 18957 at 950 <sup>°</sup>C and 1050 <sup>0</sup>C respectively. The complex impedance analysis of all samples shows a decrease in resistance with an increasing temperature, which suggests a semiconductor nature of the samples.</span></p>


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