scholarly journals Structure evolution, dielectric, and conductivity behavior of (K0.5Na0.5)NbO3-Bi(Zn2/3Nb1/3)O3 ceramics

2021 ◽  
Author(s):  
Tianxiang Yan ◽  
Kaiyuan Chen ◽  
Chengqi Li ◽  
Min Liu ◽  
Jie Wang ◽  
...  
Keyword(s):  
Orthorhombic Phase ◽  
Structure Evolution ◽  
X Ray Diffraction ◽  
Solid State Method ◽  
Low Dielectric ◽  
Lead Free Ceramics ◽  
Temperature Ranges ◽  
Xrd Patterns ◽  
Diffuse Phase ◽  
Conductivity Behavior

Abstract(1−x)K0.5Na0.5NbO3−xBi(Zn2/3Nb1/3)O3 ((1−x)KNN−xBZN, x = 0.010, 0.015, 0.020, 0.025, and 0.030) lead-free ceramics were fabricated via a traditional solid-state method. The crystal structure, microstructure, dielectric, and conductivity behavior of this system were studied. Combined with X-ray diffraction (XRD) patterns, Rietveld refinement, and dielectric spectroscopy, an orthorhombic phase was determined for x = 0.010, an orthorhombic-tetragonal mixed phase was identified for x = 0.015, and a rhombohedral symmetry appears in 0.020 ⩽ x ⩽ 0.030. Both 0.98KNN−0.02BZN and 0.975KNN−0.025BZN ceramics exhibit stable permittivity and low dielectric loss tangent (tanδ) in wide temperature ranges owing to the combination of rhombohedral-tetragonal step-like feature and the diffuse phase transition from tetragonal to cubic. The activation energies of dielectric relaxation and conductivity behavior at high temperatures initially decrease slightly, then drop sharply, and finally decline slowly, which could be attributed to microstructure morphologies and the concentration of oxygen vacancies.

PRELIMINARY CHARACTERISTIC OF ELECTRICAL NON-LINEARITY CO DOPED CAMNO3-ZNO BASED VARISTOR CERAMICS

2016 ◽  
Vol 78 (3) ◽  
Author(s):  
Muhamad Azman Zulkifli ◽  
Mohd Sabri Mohd Ghazali ◽  
Wan Rafizah Wan Abdullah ◽  
Azmi Zakaria ◽  
Zakiyah Ahmad
Keyword(s):  
Zinc Oxide ◽  
Nonlinear Coefficient ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
Solid State Method ◽  
As Doping ◽  
Conventional Solid State Method ◽  
Calcium Manganite ◽  
Xrd Patterns ◽  
Calcium Manganite Camno3

Zinc oxide based varistor are widely used as circuit protective devices by literally absorbs these dangerous surge and spikes or grounding this unwanted magnitudes. In this research, zinc oxide is added with 20 mol% calcium manganite (CaMnO3) as an additive and cobalt oxide (Co3O4) as doping material. Citrate-gel method is used as fabrication method compared to conventional solid-state method. This compound (ZnO-CaMnO3-Co3O4) undergoes pre-sintering at 500 °C for 2 hours. In the sintering process, sintering temperature at 1300 °C, while the sintering time are setting at 1.5 hours. X-ray diffraction (XRD) patterns show the components and phases of the compounds. The change of functional group was observed by Fourier Transform Infrared (FTIR). I-V characteristic shows the value of nonlinear coefficient in the range of 1.0-2.0.  

Structural, dielectric, ferroelectric and impedance spectroscopic studies on Ba1−xSrxTiO3(0.15 ≤ x ≤ 0.35)

2019 ◽  
Vol 33 (17) ◽  
pp. 1950193 ◽  
Author(s):  
Shukdev Pandey ◽  
Om Parkash ◽  
Devendra Kumar
Keyword(s):  
Equivalent Circuit Model ◽  
Solid State Reaction Method ◽  
Spectroscopic Studies ◽  
Frequency Range ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
X Band ◽  
Xrd Patterns ◽  
Diffuse Phase

Compositions with x = 0.15, 0.20, 0.25, 0.30 and 0.35 were synthesized in the system [Formula: see text] using conventional solid state reaction method and characterized by X-Ray Diffraction (XRD), Raman spectroscopy and Scanning Electron Microscopy (SEM). Tetragonal phase was confirmed in all the samples using Rietveld refinement of the XRD patterns and observation of their Raman spectra. Dielectric and impedance measurements were carried out in the temperature range 300–723 K in the frequency range 1 Hz to 1 MHz. The samples exhibit diffuse phase transition (DPT). Equivalent circuit model involving combination of Constant Phase angle Elements (CPE) and resistances (R) was developed which represents the data well. Expressions for the values of resistances (R) were established in terms of composition and temperature empirically. P-E loops indicated normal ferroelectric behavior for all the samples. Dielectric constant was also measured in the frequency range 8–12 GHz in the X band of microwaves.

Electrocaloric properties of Sr and Sn doped BCZT lead-free ceramics

2020 ◽  
Vol 91 (2) ◽  
pp. 20905
Author(s):  
Satyanarayan Patel ◽  
Manish Kumar
Keyword(s):  
Electric Fields ◽  
Perovskite Phase ◽  
Entropy Change ◽  
Lead Free ◽  
X Ray Diffraction ◽  
Solid State Method ◽  
Sn Doping ◽  
Adiabatic Temperature Change ◽  
Lead Free Ceramics ◽  
Pure Perovskite Phase

In the present work, the electrocaloric (EC) effect in lead-free Sr and Sn doped (Ba0.85Ca0.075Sr0.075)(Zr0.1Ti0.88Sn0.02)O3 ceramic prepared by solid-state method has been investigated. The phase purity and pure perovskite phase formation with Sr and Sn doping is confirmed by X-ray diffraction. The adiabatic temperature change ΔT (due to the EC effect), entropy change (ΔS) and refrigeration capacity (RC) are estimated under various electric fields. The maximum peak values of ΔT, ΔS and RC are found as 1.5 K, 1.8 J/kg.K and 2.75 J/kg, respectively under the applied electric field of 33 kV/cm at 305 K. It is also observed that the ΔT, ΔS and RC decreases with an increase in applied temperature. Moreover, the estimated values of EC properties are significantly high which indicates that fabrication of Sr and Sn doped lead-free ceramics can be advantageous for EC applications.

Synthesis and Performance of LiCo1/3Mn1/3Ni1/3O2 Cathode Material for Lithium-Ion Battery

2011 ◽  
Vol 399-401 ◽  
pp. 1491-1495
Author(s):  
Huan Liu ◽  
Yao Chun Yao ◽  
Yong Mei Li ◽  
Hui Hua Yi ◽  
Yong Nian Dai
Keyword(s):  
Electrochemical Performance ◽  
Cathode Material ◽  
Discharge Capacity ◽  
Raw Materials ◽  
Lithium Ion ◽  
X Ray Diffraction ◽  
Solid State Method ◽  
Excellent Electrochemical Performance ◽  
And Performance ◽  
Xrd Patterns

The layered cathode material for Li-ion batteries was synthesized by mechanical activation-high temperature solid state method. XRD and electrochemical measurements were used to characterize the structure and electrochemical performance of the product. The X-ray diffraction (XRD) patterns reveal that the material is crystallized to layered a-NaFeO2structure. The cathode material with excellent electrochemical performance was obtained by sintering the mixed raw materials with n (Li)/n (M) =1.11. The initial discharge capacity was 128mAh/g at a current density of 20mA/g between 2.7-4.2V and the discharge capacity retention was 96% after 50 cycles.

Dielectric Properties and Microstructure of Y-Al-Ga-Si Co-Doped Barium Titanate Ceramics

2014 ◽  
Vol 602-603 ◽  
pp. 700-704
Author(s):  
Min Jia Wang ◽  
Qi Long Zhang ◽  
Xin Hui Zhao ◽  
Hui Yang
Keyword(s):  
Dielectric Properties ◽  
Dielectric Loss ◽  
Barium Titanate ◽  
X Ray Diffraction ◽  
Solid State Method ◽  
Low Dielectric ◽  
Doped Barium Titanate ◽  
Titanate Ceramics ◽  
Functional Components ◽  
Co Doped

Multilayer ceramic capacitors (MLCC) are important functional components of electronic information technology. The development of AC MLCC requires low dielectric loss and high AC breakdown voltage. In this paper, Y-Al-Ga-Si co-doped barium titanate ceramics were prepared by conventional solid state method. Microstructures, surface morphology and dielectric properties were investigated by X-ray diffraction, SEM, and LCR analyzer, respectively. Y3+ entered into the lattice of BaTiO3, replaced A-sites and B-sites, suppressed grain growth effectively, and made crystal structure change from tetragonal to pseudo-cubic, which reduced dielectric loss and lowered the Curie peak. The sintering characteristic and permittivity can be improved by the incorporation of Al and Ga. BaTiO3 -0.06Y2O3 - 0.02Ga2O3 -0.01Al2O3 -0.01SiO2 ceramics sintered at 1380°C achieved good dielectric properties: εr= ~2223, tanδ =~1.1% (at 1kHz), ΔC/C25 <~15.26% (from 55°C to 150°C).

scholarly journals PRELIMINARY CHARACTERISTIC OF ELECTRICAL NON-LINEARITY CO DOPED CMO-ZNO BASED VARISTOR CERAMIC

2016 ◽  
Vol 78 (3) ◽  
Author(s):  
Muhamad Azman Zulkifli ◽  
Mohd Sabri Mohd Ghazali ◽  
Wan Rafizah Wan Abdullah ◽  
Azmi Zakaria ◽  
Zakiyah Ahmad
Keyword(s):  
Zinc Oxide ◽  
Nonlinear Coefficient ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
Solid State Method ◽  
As Doping ◽  
Conventional Solid State Method ◽  
Calcium Manganite ◽  
Xrd Patterns ◽  
Calcium Manganite Camno3

Zinc oxide based varistor are widely used as circuit protective devices by literally absorbs these dangerous surge and spikes or grounding this unwanted magnitudes. In this research, zinc oxide is added with 20 mol% calcium manganite (CaMnO3) as an additive and Cobalt oxide (CoO) as doping material. Citrate-gel method is used as fabrication method compared to conventional solid-state method. This compound (ZnO-CaMnO3 -CoO) undergoes pre-sintering at 500 °C for 2 hours. In the sintering process, sintering temperature at 1300 °C, while the sintering time are setting at 1.5 hours. X-ray diffraction (XRD) patterns shows the components and phases of the compounds. The change of functional group was observed by Furrier transform infra-red (FTIR). I-V characteristic shows the value of nonlinear coefficient in the range of 1.0-2.0.  

scholarly journals PEMBUATAN DAN KARAKTERISASI KATALIS TIO2/KARBON AKTIF DENGAN METODE SOLID STATE

2015 ◽  
Vol 9 (1) ◽  
pp. 34 ◽  
Author(s):  
Upita Septiani ◽  
Mega Gustiana ◽  
Safni
Keyword(s):  
Solid State ◽  
Wave Number ◽  
Composite Catalyst ◽  
Not Given ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Solid State Method ◽  
X Ray ◽  
Infra Red ◽  
Xrd Patterns

Composite catalyst of TiO2/Activated Carbon (TiO2/AC) had been synthesized with successfully by solid-state method. Synthesis was done by varying the addition of AC 5%, 10% and 15% of the mass of TiO2 was used. Composite catalyst was calcinated at temperature 400°C and characterized by Fourier Transform Infra-Red (FTIR), X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). FTIR spectrum show that the absorption appearedin the regionof C=C at wave number 1600-1800 cm-1, that assumed from AC. From XRD we can see that with variated of AC do not given different XRD patterns significantly, crystal structure of composite catalyst is anatase. SEM images showed that AC prevented the aglomeration of TiO2 that would expand surface area and increased catalytic activity of TiO2.

Structural and Dielectric Properties of Rare Earth (Y, Ho) Doped Ba0.95Ca0.05Ti0.85Zr0.15O3 Ceramics

2014 ◽  
Vol 602-603 ◽  
pp. 728-733 ◽  
Author(s):  
Zheng Bo Shen ◽  
Xiao Hui Wang ◽  
Hui Ling Gong ◽  
Long Tu Li
Keyword(s):  
Rare Earth ◽  
Dielectric Properties ◽  
Barium Carbonate ◽  
X Ray Diffraction ◽  
Solid State Method ◽  
Low Dielectric ◽  
Doping Effects ◽  
Dielectric Ceramics ◽  
Lower Temperature ◽  
Different Content

Ba0.95Ca0.05Ti0.85Zr0.15O3(BCTZ) dielectric ceramics were fabricated by traditional solid-state method, using barium carbonate, calcium carbonate, titanium dioxide and zirconium dioxide as the starting materials. Rare earth dopants have a significant influence on the dielectric properties of BCTZ ceramics. The doping effects of Y and Ho with different content on the dielectric properties and structure were studied respectively. The results reveal that the effects of Y and Ho are similar, they perfer to occpy B site, and they move the dielectric peak to lower temperature, widen the peak and increase the insulation resistivity, thus improve the dielectric properties obviously. The effects were investigated by X-ray diffraction, scanning electron microscope, and dielectric property measurements. After rare earth elements-doping, the BCTZ ceramics satify the Y5V EIA specifications, mainly due to the change of structure. The BCTZ dielectric ceramics with high permittivity over 10,000, high insulation resistivity over 1012Ωcm, low dielectric loss less than 1%, can be applied in multilayer ceramic capacitors (MLCCs).

Pinning Effects on the Dielectric and Ferroelectric Properties of Mn-Doped Ba(Zr0.06Ti0.94)O3 Ceramics

2011 ◽  
Vol 687 ◽  
pp. 354-358 ◽  
Author(s):  
Shu Juan Kuang ◽  
Xin Gui Tang ◽  
Jun Bo Wu ◽  
Yan Ping Jiang ◽  
Qiu Xiang Liu
Keyword(s):  
Ferroelectric Properties ◽  
Orthorhombic Phase ◽  
X Ray Diffraction ◽  
Pinning Mechanism ◽  
X Ray ◽  
Defect Dipole ◽  
Uniform Microstructure ◽  
Lead Free Ceramics ◽  
Process Structure ◽  
Mn Doped

Lead-free ceramics with the composition of Mn-doped Ba(Zr0.06Ti0.94)O3 – xmol%MnO2 (BZT6-xMn, x=0, 1 and 2) have been synthesized by a mixed oxide process. Structure and micrograph characterization were examined using X-ray diffraction (XRD) and scanning electron microscopy (SEM), which revealed that all samples have the orthorhombic phase with dense and the uniform microstructure. The grain size of Mn-doped BZT6 ceramics decreased with increasing MnO2 doping. The effect of MnO2 doping on the dielectric and ferroelectric properties was also investigated. The maximum dielectric permittivity decreased dramatically with increasing MnO2 doping in the BZT6 ceramics. A peculiar double-hysteresis-like loop was observed. Mn ions as acceptor doping occupy the B site of ABO3 in the form of Mn2+ and Mn3+, which brought an increase in the oxygen vacancies concentration. The defect dipole model was explained the pinning mechanism.

CHARACTERIZATION OF POTASSIUM DOPED GdBa2Cu3O7−δ USING RAMAN SPECTROSCOPY AND X-RAY DIFFRACTION

1995 ◽  
Vol 09 (26n27) ◽  
pp. 1739-1752
Author(s):  
PREETHI CICILY THOMAS ◽  
MANOJ KUMAR K. ◽  
V. UNNIKRISHNAN NAYAR ◽  
VIDYALAL V. ◽  
C.P.G. VALLABHAN
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectra ◽  
Tetragonal Phase ◽  
Orthorhombic Phase ◽  
Superconducting Transition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Resistivity Measurements ◽  
Xrd Patterns

Potassium doped and undoped GdBa 2 Cu 3 O 7−δ have been prepared and superconducting transition temperatures between 92 K and 100 K have been determined from resistivity measurements. Raman spectra of doped and undoped samples are identical and they contain bands corresponding to both the superconducting orthorhombic phase and nonsuperconducting tetragonal phase. XRD patterns also reveal both the phases. Raman spectra recorded at 92 K of undoped GdBa 2 Cu 3 O 7−δ and doped GdBa 2 Cu 3 O 7−δ with weight percentages 0.75, 1.00, 1.25 and 1.50 of K shows a softening of the band at 338 cm−1.

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