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

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.

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

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.93-94.251 ◽

2010 ◽

Vol 93-94 ◽

pp. 251-254 ◽

Cited By ~ 1

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.

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

Materials Science Forum ◽

10.4028/www.scientific.net/msf.700.58 ◽

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.

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

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.760-762.705 ◽

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.

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

Asian Journal of Chemistry ◽

10.14233/ajchem.2021.23264 ◽

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).

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

Materials Science-Poland ◽

10.1515/msp-2018-0027 ◽

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.

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Synthesis and Na+ Ion Conductivity of Stoichiometric Na3Zr2Si2PO12 by Liquid-Phase Sintering with NaPO3 Glass

Materials ◽

10.3390/ma14143790 ◽

2021 ◽

Vol 14 (14) ◽

pp. 3790

Author(s):

Yongzheng Ji ◽

Tsuyoshi Honma ◽

Takayuki Komatsu

Keyword(s):

Solid State ◽

Liquid Phase ◽

Sintering Temperature ◽

Liquid Phase Sintering ◽

Ion Conductivity ◽

X Ray Diffraction ◽

Conventional Solid State Reaction ◽

X Ray ◽

Sintering Time ◽

Lower Activation

Sodium super ionic conductor (NASICON)-type Na3Zr2Si2PO12 (NZSP) with the advantages of the high ionic conductivity, stability and safety is one of the most famous solid-state electrolytes. NZSP, however, requires the high sintering temperature about 1200 °C and long sintering time in the conventional solid-state reaction (SSR) method. In this study, the liquid-phase sintering (LPS) method was applied to synthesize NZSP with the use of NaPO3 glass with a low glass transition temperature of 292 °C. The formation of NZSP was confirmed by X-ray diffraction analyses in the samples obtained by the LPS method for the mixture of Na2ZrSi2O7, ZrO2, and NaPO3 glass. The sample sintered at 1000 °C for 10 h exhibited a higher Na+ ion conductivity of 1.81 mS/cm at 100 °C and a lower activation energy of 0.18 eV compared with the samples prepared by the SSR method. It is proposed that a new LPE method is effective for the synthesis of NZSP and the NaPO3 glass has a great contribution to the Na+ diffusion at the grain boundaries.

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Structure and electric properties of cerium substituted SrBi1.8Ce0.2Nb2O9 and SrBi1.8Ce0.2Ta2O9 ceramics

Processing and Application of Ceramics ◽

10.2298/pac1603183a ◽

2016 ◽

Vol 10 (3) ◽

pp. 183-188 ◽

Cited By ~ 5

Author(s):

Mohamed Afqir ◽

Amina Tachafine ◽

Didier Fasquelle ◽

Mohamed Elaatmani ◽

Jean-Claude Carru ◽

...

Keyword(s):

Dielectric Constant ◽

Solid State ◽

Room Temperature ◽

Single Phase ◽

Solid State Reaction Method ◽

X Ray Diffraction ◽

Reaction Method ◽

X Ray ◽

Lcr Meter ◽

Curie Temperature Tc

SrBi1.8Ce0.2Nb2O9 (SBCN) and SrBi1.8Ce0.2Ta2O9 (SBCT) powders were prepared via solid-state reaction method. X-ray diffraction analysis reveals that the SBCN and SBCT powders have the single phase orthorhom-bic Aurivillius structure at room temperature. The contribution of Raman scattering and FTIR spectroscopy of these samples were relatively smooth and resemble each other. The calcined powders were uniaxially pressed and sintered at 1250?C for 8 h to obtaine dense ceramics. Dielectric constant, loss tangent and AC conductivity of the sintered Ce-doped SrBi2Nb2O9 and SrBi2Ta2O9 ceramics were measured by LCR meter. The Ce-doped SBN (SBCN) ceramics have a higher Curie temperature (TC) and dielectric constant at TC (380?C and ?? ~3510) compared to the Ce-doped SBT (SBCT) ceramics (330?C and ?? ~115) when measured at 100Hz. However, the Ce-doped SBT (SBCT) ceramics have lower conductivity and dielectric loss.

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

Journal of Advanced Dielectrics ◽

10.1142/s2010135x13500288 ◽

2013 ◽

Vol 03 (04) ◽

pp. 1350028 ◽

Cited By ~ 1

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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Dielectric Behaviour of Zn/Al-NO3LDHs Filled with Polyvinyl Chloride Composite at Low Microwave Frequencies

Advances in Materials Science and Engineering ◽

10.1155/2014/647120 ◽

2014 ◽

Vol 2014 ◽

pp. 1-6 ◽

Cited By ~ 5

Author(s):

Ethar Y. Salih ◽

Zulkifly Abbas ◽

Samer Hasan Hussein Al Ali ◽

Mohd Zobir Hussein

Keyword(s):

Dielectric Properties ◽

Polyvinyl Chloride ◽

Loss Factor ◽

Room Temperature ◽

Dielectric Measurements ◽

X Ray Diffraction ◽

Microwave Frequencies ◽

X Ray ◽

Essential Properties ◽

Double Hydroxide

Recently, researchers have shown great interest in improving the thermal, mechanical, dielectric, and microwave properties of pure polymers through the use of polymer-based composites. The essential properties of polymer-based composites can be modified by varying the amount of Zn/Al-NO3layered double hydroxide (LDH) added to polyvinyl chloride (PVC). Therefore, by determining the optimal ratio of LDH in the PVC matrix, the dielectric properties of PVC-LDH composites can be improved. An LDH was prepared using the coprecipitation method, while PVC-LDH composites were prepared using tetrahydrofuran (THF) as the solvent. The composites were characterised using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM), and room temperature dielectric measurements were investigated using an RF Impedance/Material Analyzer (Agilent 4291). The results confirmed that the prepared composites were pure. Additionally, the presence of LDH in the PVC matrix was verified. The dielectric measurements showed that an increase in the LDH concentration leads to an increase in the dielectric constant and the dielectric loss factor. When used as dielectric filler in the PVC matrix, the LDH improved the dielectric properties of the fabricated composites. The results indicate that these composites show great potential for use as microwave absorbers at low microwave frequencies.

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