scholarly journals Structure and electrical properties of Eu-doped SrBi2Nb2O9 ceramics

2019 ◽  
Vol 13 (3) ◽  
pp. 281-286
Author(s):  
Mohamed Afqir ◽  
Amina Tachafine ◽  
Didier Fasquelle ◽  
Mohamed Elaatmani ◽  
Jean-Claude Carru ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Xrd Analysis ◽  
Structural Features ◽  
Orthorhombic Structure ◽  
Dense Structure ◽  
Solid State Method ◽  
Dielectric Peak ◽  
State Method ◽  
Dielectric Results

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.

scholarly journals The effects of calcination and doping on structural and dielectric properties of CaCu3-xCoxTi4O12 ceramic

2019 ◽  
Vol 8 (3) ◽  
pp. 234
Author(s):  
Nasr Hadi ◽  
Tajdine Lamcharfi ◽  
Farid Abdi ◽  
Nor-Said Echtoui ◽  
Ahmed Harrach ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Complex Impedance ◽  
Impedance Analysis ◽  
Xrd Analysis ◽  
Secondary Phases ◽  
Solid State Method ◽  
Complex Impedance Analysis ◽  
Oxide Powders ◽  
Increasing Temperature

<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>

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.

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 ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Breakdown Strength ◽  
Dielectric Strength ◽  
Dielectric Behavior ◽  
Composite Ceramics ◽  
Solid State Method ◽  
Composition Formula ◽  
State Method ◽  
Mg Content

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.

scholarly journals Effect of Zinc Doping on the Electrical and Dielectric Properties of CCTO Compound Synthesized by Solid-State Method

2021 ◽  
Vol 33 (9) ◽  
pp. 2000-2006
Author(s):  
M. Slaoui ◽  
N. Gouitaa ◽  
Y. El Issmaeli ◽  
A. Harrach ◽  
F. Abdi ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Solid State ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Solid State Method ◽  
X Ray ◽  
Zn Concentration ◽  
Zinc Doping ◽  
Electrical And Dielectric Properties

In this work, the influence of zinc doping on structural and dielectric properties of CaCu(3-x)ZnxTi4O12 (CCZxTO with x = 0, 2.5, 5, 7.5, 10, 12.5 and 15%) ceramics sintered at 1000 ºC for 8 h was studied. The ceramic samples were prepared by the conventional solid-state and calcined at 1050 ºC for 4 h. The X-ray diffraction (XRD) analysis of pure and Zn-doped CCTO were analyzed by using Rietveld refinement with cubic CCTO phase with no trace impurity phase. The scanning electron microscopy (SEM) investigation showed that for Zn-doped CCTO, the grains distributions were homogenous with average sizes which decreased with increasing of Zn concentration. The dielectric permittivity as function of temperature showed two dielectric anomalies (weakly and strong) and the dielectric constant value largely decreased for x = 2.5%, which is about tree magnitude smaller than the pure ceramic. Then it increased and reached a maximum at x = 10%, which is larger than the value of pure ceramic. And for x > 10%, the dielectric constant decreased for about two magnitude smaller than the ceramic at x = 10%. The cole-cole diagramm for all the samples showed existence of two semi-arcs attributed to the grains and grains boundaries. It was found that the Rg values were much smaller than the Rgb value. This give an evidance on the formation of interior barrier layer capacity (IBLC).

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.

scholarly journals Influence of CaO and CuO on Barium Zinc Tantalate (BZT) Dielectric Properties

2015 ◽  
Vol 3 (3) ◽  
pp. 30-34
Author(s):  
Hidayani Jaafar ◽  
Sitti Fatimah Mhd Ramle ◽  
Muhammad Azwadi Sulaiman ◽  
Nurul Nadia Aminuddin
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Solid State ◽  
Copper Oxide ◽  
Relative Density ◽  
Calcium Oxide ◽  
Return Loss ◽  
Solid State Method ◽  
State Method ◽  
R Value

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.

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.

scholarly journals The effects of calcination and doping on structural and dielectric properties of CaCu3-xCoxTi4O12 ceramic

2019 ◽  
Vol 8 (3) ◽  
pp. 234-244
Author(s):  
Nasr Hadi ◽  
Tajdine Lamcharfi ◽  
Farid Abdi ◽  
Nor-Said Echtoui ◽  
Ahmed Harrach ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Complex Impedance ◽  
Impedance Analysis ◽  
Xrd Analysis ◽  
Secondary Phases ◽  
Solid State Method ◽  
Complex Impedance Analysis ◽  
Oxide Powders ◽  
Increasing Temperature

The influences of calcination temperature and doping with cobalt in A–site on structural and dielectric properties of CaCu3-xCoxTi4O12 (CCCxTO, x = 0.00, 0.02 and 0.10) ceramics sintered at 1050 0C 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 0C for 4h. The X-ray diffraction (XRD) analysis of pure and doped CCTO samples calcined at 950 °C and 1050 0C showed no traces of any other secondary phases, while impurity phases alongside CCTO phase in the x=0.00 sample calcined at 850 0C 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 0C/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 °C and 1050 0C 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.

Structural, optical and dielectric properties of Sr2Ni1−xMgxWO6 (x = 0.00, 0.02, 0.04, and 0.06) double perovskite

2021 ◽  
Vol 9 (38) ◽  
pp. 13439-13446
Author(s):  
Nur Amira Farhana Mohamed Saadon ◽  
Nurliyana Mohd Ali ◽  
Norazila Ibrahim ◽  
Zakiah Mohamed
Keyword(s):  
Dielectric Properties ◽  
Solid State ◽  
Double Perovskite ◽  
Solid State Method ◽  
State Method

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.

scholarly journals The investigation of electrical properties and microstructure of ZnO-doped Ba0.9Sr0.1TiO3 ceramics

2017 ◽  
Vol 07 (01) ◽  
pp. 1750007 ◽  
Author(s):  
Gang Liu ◽  
Wentao Jiang ◽  
Jingyong Jiao ◽  
Li Liu ◽  
Ziyang Wang ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Grain Size ◽  
Dielectric Properties ◽  
Solid State ◽  
Breakdown Strength ◽  
Electrical Breakdown ◽  
Xrd Analysis ◽  
Solid State Reaction Method ◽  
Reaction Method ◽  
Electrical Breakdown Strength

Ba[Formula: see text]Sr[Formula: see text]TiO3 ceramics with or without ZnO have been prepared by traditional solid state reaction method. The XRD analysis showed that the doped Zn[Formula: see text] ions diffused into the BST crystal lattice, resulting in the variation of dielectric properties. Especially the dielectric constant at Curie point decreased with doping ZnO content when it is lower than 0.5[Formula: see text]mol%. Due to the promotion of sintering, doping ZnO can enhance the density of ceramics but increase grain size. However, ZnO is a kind of semiconductor and can lead to the decrease in electrical breakdown strength value.

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