scholarly journals Preparation and dielectric properties of BaBi1.8Ln0.2Nb2O9 (Ln = Ce, Gd) ceramics

2018 ◽  
Vol 36 (1) ◽  
pp. 46-50
Author(s):  
Mohamed Afqir ◽  
Amina Tachafine ◽  
Didier Fasquelle
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Orthorhombic Structure ◽  
X Ray Diffraction ◽  
Main Subject ◽  
Reaction Route ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
Ft Ir

AbstractThe main subject of the presented research is to investigate the dielectric properties of BaBi1.8Ln0.2Nb2O9 (Ln = Ce, Gd) ceramics prepared by conventional solid state reaction route. The materials were examined using XRD and FT-IR methods. Moreover, the AC conductivity, dielectric constant and dielectric loss of the ceramics were determined. X-ray diffraction confirmed that all these compounds crystallize in an orthorhombic structure. Fourier transform infrared spectroscopy study confirmed the presence of two characteristic vibration bands located at around 617 cm-1 and 818 cm-1 for BaBi2Nb2O9. The experimental results show that the substitution of Bi by Ce or Gd causes a decrease in Curie temperature, dielectric constant and dielectric loss.

Preparation and Properties of CCTO-BCTO Ceramics with Ultrahigh Dielectric Constant

2013 ◽  
Vol 760-762 ◽  
pp. 705-708
Author(s):  
La Chen ◽  
Wei Li ◽  
Zhao Xian Xiong ◽  
Chun Xiao Song ◽  
Hong Qiu
Keyword(s):  
Electron Microscopy ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
X Ray Diffraction ◽  
Optimum Amount ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
Impedance Characteristics ◽  
Lcr Meter ◽  
Scanning Electron

Ceramics of (1-x)CaCu3Ti4O12-xBi2/3Cu3Ti4O12, i.e., CCTO-BCTO, with x=0, 0.01, 0.1 and 0.25, respectively, were prepared via the conventional solid-state reaction. The phase structure of the ceramics was identified by X-ray diffraction. The microstructure of the sample was observed with scanning electron microscopy. Dielectric properties and impedance spectroscopy were measured using a LCR Meter, in which 0.9CCTO-0.1BCTO displayed highest dielectric constant (584108) and lowest dielectric loss (0.42) at 1kHz among the four kinds of specimens. Based on series of experimental results, an optimum amount of x was able to improve the dielectric properties of CCTO-BCTO, through adjusting the impedance characteristics of the grain and grain boundary.

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.

scholarly journals Dielectric Properties of 0.95 ( )-0.05 Composites

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Rekha Rani ◽  
Parveen Kumar ◽  
J. K. Juneja ◽  
K. K. Raina ◽  
Chandra Prakash
Keyword(s):  
Dielectric Properties ◽  
Lead Zirconate Titanate ◽  
Nickel Ferrite ◽  
Lead Zirconate ◽  
X Ray Diffraction ◽  
Reaction Route ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
Magnetoelectric Composites ◽  
Solid State Reaction Route

We report studies on dielectric properties of magnetoelectric composites of La-substituted lead zirconate titanate (PLZT) and zinc-doped nickel ferrite (NZF) with compositional formula 0.95 Pb1-3x/2LaxZr0.65Ti0.35O3-0.05 Ni0.8Zn0.2Fe2O4(, 0.01, 0.02, and 0.03). The materials were synthesized by conventional solid state reaction route. The presence of individual phases (PLZT and NZF) was confirmed by using X-ray diffraction technique. Dielectric properties were studied as a function of temperature and frequency. Significant improvement was observed in dielectric properties with addition of La.

Effects of La-Dopant on Phase, Microstructure and Dielectric Properties of Bi4Ti3O12 Ceramics

2010 ◽  
Vol 93-94 ◽  
pp. 251-254 ◽  
Author(s):  
Pasinee Siriprapa ◽  
Anucha Watcharapasorn ◽  
Sukanda Jiansirisomboon
Keyword(s):  
Dielectric Constant ◽  
Grain Size ◽  
Dielectric Properties ◽  
Solid State ◽  
Diffraction Analysis ◽  
Solid State Reaction ◽  
Preferred Orientation ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
X Ray

Bi4-xLaxTi3O12 (where x = 0, 0.25, 0.50, 0.75 and 1) powders and ceramics were prepared using conventional solid state reaction and sintering procedures. The calcination was carried out at 750 °C for 4 h and sintering was done at 1150 °C for 4 h. The density of all ceramics was found to be comparable regardless of La concentration. X-ray diffraction analysis showed that preferred orientation of ceramic grains was reduced with addition of La ions. This reduced preferred orientation was accompanied by a decrease in grain size. The temperature dependence of dielectric constant showed a decrease in Tc with increasing La concentration.

scholarly journals Steady nature of dielectric behaviour in Sm1.5Sr0.5NiO4 – CCTO composites

2019 ◽  
Vol 5 (4) ◽  
pp. 145-150
Author(s):  
Kevin Abraham ◽  
A. K. Thomas ◽  
Jini Thomas ◽  
K. V. Saban
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Solid State ◽  
Loss Factor ◽  
Dielectric Behaviour ◽  
Dielectric Studies ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
Practical Applications

The composite materials of 0.5 Sm1.5Sr0.5NiO4, 0.5 CCTO and 0.75 Sm1.5Sr0.5NiO4, 0.25 CCTO mixtures were prepared through the conventional solid state reaction in an attempt to obtain good dielectric properties for practical applications. The structural properties were determined by powder X-ray diffraction and single phases were obtained for Sm1.5Sr0.5NiO4 and CaCu3Ti4O12 compounds. The dielectric studies analysed over a range of frequencies (100 KHz–10 MHz) and temperatures (30 to 200 °C) revealed a desired dielectric constant values with a low steady nature of dielectric loss factor. Through impedance spectroscopy, the attained dielectric behaviour was due to the highly insulating grain boundaries at lower frequencies and semiconducting grains at higher frequencies.

scholarly journals Studying the Effect of Titania Additions on some properties of Porcelain

2018 ◽  
Vol 28 (2) ◽  
pp. 169
Author(s):  
Abbas K. Saadon
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Titanium Oxide ◽  
Loss Tangent ◽  
Dielectric Loss Tangent ◽  
Raw Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Manufacturing Method

The paper presents the production of porcelain for the ceramic by inexpensive natural raw materi-als, the principal raw materials of porcelain composition was selected consisting of 50% kaolin, 25% feldspar, 25% silica, the sample synthesized were characterize by X-ray diffraction (XRD) technique, than study the effect additives at different concentration form titanium oxide (𝑇𝑖𝑂2 )at (2, 5, 10, 15, 20) wt% on some physical and dielectric properties of porcelain. The samples are prepared by the conventional manufacturing method. The physical and dielectric properties of porcelain show that change considerably with the sub-stituent sample. It was found that the increase of the titanium oxide (𝑇𝑖𝑂2 ) additives of all our sample produce increasing in dielectric constant and bulk density, while decreasing with open porosity and dielectric loss tangent.

scholarly journals Steady nature of dielectric behaviour in Sm1.5Sr0.5NiO4 – CCTO composites

2019 ◽  
Vol 5 (4) ◽  
pp. 145-150
Author(s):  
Kevin Abraham ◽  
A. K. Thomas ◽  
Jini Thomas ◽  
K. V. Saban
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Solid State ◽  
Loss Factor ◽  
Dielectric Behaviour ◽  
Dielectric Studies ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
Practical Applications

The composite materials of 0.5 Sm1.5Sr0.5NiO4, 0.5 CCTO and 0.75 Sm1.5Sr0.5NiO4, 0.25 CCTO mixtures were prepared through the conventional solid state reaction in an attempt to obtain good dielectric properties for practical applications. The structural properties were determined by powder X-ray diffraction and single phases were obtained for Sm1.5Sr0.5NiO4 and CaCu3Ti4O12 compounds. The dielectric studies analysed over a range of frequencies (100 KHz–10 MHz) and temperatures (30 to 200 °C) revealed a desired dielectric constant values with a low steady nature of dielectric loss factor. Through impedance spectroscopy, the attained dielectric behaviour was due to the highly insulating grain boundaries at lower frequencies and semiconducting grains at higher frequencies.

Phase Development and Dielectric Properties of 0.98BaTiO3-0.02Ba (Mg1/3Nb2/3) O3 Ceramic

2011 ◽  
Vol 700 ◽  
pp. 58-62
Author(s):  
Rachanusorn Roongtao ◽  
Supagorn Rugmai ◽  
Wanwilai C. Vittayakorn
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Loss Factor ◽  
X Ray Diffraction ◽  
Phase Purity ◽  
X Ray ◽  
Phase Development ◽  
Scanning Electron

The 0.98BaTiO3-0.02Ba (Mg1/3Nb2/3) O3ceramics has been synthesized through a conventional mixed-oxide by using BT nanopowder and BMN micropowder. The phase purity of the powders and the ceramics was examined using X-ray diffraction (XRD). The 0.98BT-0.02BMN powders were sintered to 92% of the theoretical density at a temperature of 1300 °C for 2 h. The microstructure of the sintered surface was investigated using scanning electron microscopy (SEM). The dielectric constant (εr) and loss factor (tanδ) of the sintered pellets at Curie temperture were 3000 and 0.015, respectively.

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.

scholarly journals Effect of TeO2 addition on the dielectric properties of CaCu3Ti4O12 ceramics derived from the oxalate precursor route

2013 ◽  
Vol 03 (04) ◽  
pp. 1350028 ◽  
Author(s):  
P. Thomas ◽  
K. B. R. Varma
Keyword(s):  
Dielectric Properties ◽  
Dielectric Loss ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
Oxalate Precursor ◽  
X Ray ◽  
Practical Applications ◽  
Low Dielectric ◽  
Precursor Route ◽  
Tan Δ

CaCu 3 Ti 4 O 12 (CCTO) ceramics which has perovskite structure gained considerable attention due to its giant permittivity. But it has high tan δ (0.1 at 1 kHz) at room temperature, which needs to be minimized to the level of practical applications. Hence, TeO 2 which is a good glass former has been deliberately added to CCTO nanoceramic (derived from the oxalate precursor route) to explore the possibility of reducing the dielectric loss while maintaining the high permittivity. The structural, morphological and dielectric properties of the pure CCTO and TeO 2 added ceramics were studied using X-ray diffraction, Scanning Electron Microscope along with Energy Dispersive X-ray Analysis (EDX), spectroscopy and Impedance analyzer. For the 2.0 wt.% TeO 2 added ceramics, there is a remarkable difference in the microstructural features as compared to that of pure CCTO ceramics. This sample exhibited permittivity values as high as 7387 at 10 KHz and low dielectric loss value of 0.037 at 10 kHz, which can be exploited for the high frequency capacitors application.

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