Effect of Treatment Process on the Structure and Properties of Sr0.48Ba0.24Ca0.28TiO3-Based Varistor Ceramics

2007 ◽  
Vol 336-338 ◽  
pp. 775-778
Author(s):  
Yu Xing Xu ◽  
Zi Long Tang ◽  
Zhong Tai Zhang ◽  
Li Hai Xu
Keyword(s):  
Dielectric Constant ◽  
Electrical Properties ◽  
Dielectric Loss ◽  
Treatment Process ◽  
Oxidation Temperature ◽  
Structure And Properties ◽  
Defect Reactions ◽  
Effect Of Treatment

Sr0.48Ba0.24Ca0.28TiO3-based varistor ceramics with an excellent capacitor-varistor multifunctional characteristics (V1mA = 11 ~ 49 ν.mm-1, α = 6.1 ~ 11.3, ε r max=3.5×105, tanδmin = 5%) were prepared using conventional solid method. The effect of oxidation temperature and time on structure and electrical properties were investigated. The results show that with increasing the oxidation temperature from 800°C to 900°C, the varistor voltage V1mA and non-linearity coefficient α defining varistor characteristics increase linearly, while the dielectric constant ε r and dielectric loss tanδ decrease linearly. There exists an optimum α value when the specimens were oxidized at 850°C for 3h. This behavior was explained through various defect reactions of dopants.

Microwave and Electrical Properties of Zr-Doped SrTiO3 for Dielectric Resonator Antenna Application

2018 ◽  
Vol 280 ◽  
pp. 142-148 ◽  
Author(s):  
Norhizatol Fashren Muhamad ◽  
Rozana Aina Maulat Osman ◽  
Mohd Sobri Idris ◽  
Faizal Jamlos ◽  
Nor Azura Malini Ahmad Hambali
Keyword(s):  
Dielectric Constant ◽  
Electrical Properties ◽  
Dielectric Loss ◽  
Dielectric Resonator ◽  
Ceramic Powder ◽  
Experimental Studies ◽  
Orthorhombic Phase ◽  
Solid State Reaction Method ◽  
Dielectric Resonator Antenna ◽  
Conventional Solid State Reaction

Present investigation provides experimental studies on cylindrical dielectric resonator antennas (CDRAs) fabricated from SrTi1-xZrxO3ceramic with different substitution of Zr in place of Ti for (0 ≤ x ≤1). Ceramic powder were prepared using conventional solid state reaction method. X-ray Diffraction exposes physical properties Zr-doped SrTiO3which exhibit phase transition from cubic, tetragonal to orthorhombic phase. The electrical properties such as dielectric constant (εr) and dielectric loss (tan δ) were studied in variation of temperatures and frequencies. At room temperature the dielectric constant decreased from 240 to 21 with increase of Zr content however the amazing result was obtained for multiband antenna by Zr content. The dielectric loss obtain shows very low loss value roughly below 0.07 for all samples. The variations of return loss, resonance frequency and bandwidth of CDRAs at their respective resonant frequencies are studied experimentally.

Study on Microstructure and Properties of BTBY Piezoelectric Ceramics with High Curie Temperature

2010 ◽  
Vol 156-157 ◽  
pp. 1541-1544
Author(s):  
Bo Li ◽  
Feng Gao ◽  
Liang Liang Liu ◽  
Bei Xu
Keyword(s):  
Dielectric Constant ◽  
Grain Size ◽  
Electrical Properties ◽  
Dielectric Loss ◽  
Curie Temperature ◽  
Grain Morphology ◽  
High Curie Temperature ◽  
Microstructure And Properties ◽  
New Phase ◽  
Dielectric Relaxor

(1-x)(0.6BIT-0.4BT)-xBiYbO3(BTBY) ceramics with high Curie temperature were prepared by the conventional processing. The effect of BiYbO3 content on the microstructure and electrical properties was investigated. The results show that the main phase of BTBY ceramics is BIT-BT, and a new phase BaBi4Ti4O15 (BBT) appeared. The grain morphology of BTPY ceramics are platelike and the grain size was significantly increased with increasing content of BiYbO3 .Tc of all the BTBY samples are above 440 . The BTBY ceramics show obvious dielectric relaxor characteristic. The dispersion factor γ, the dielectric constant εr, and the dielectric loss tanδ decreased with increasing the content of BiYbO3. When the content of BiYbO3 is 0.06, the optimal properties of BTBY ceramics are obtained, Tc is 457 , εr is 165, tanδ is 0.0223 and d33 is 10 pC·N-1.

Preparation and Characterization of (Sr1−xTix)O3 and (Ba1−xSrx)TiO3 Thin Films using ECR Plasma Assisted MOCVD

1996 ◽  
Vol 433 ◽  
Author(s):  
Kwangsoo No ◽  
Joon Sung Lee ◽  
Han Wook Song ◽  
Won Jong Lee ◽  
Byoung Gon Yu ◽  
...  
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Electrical Properties ◽  
Dielectric Loss ◽  
Leakage Current ◽  
Leakage Current Density ◽  
Current Density ◽  
Breakdown Field ◽  
Carrier Gas ◽  
Ecr Plasma

AbstractBa(TMHD)2, Sr(TMHD)2 and Ti-isopropoxide were used to fabricate the (SrxTi1 x)O3 and (Ba1 x Srx)TiO3 thin films. The decomposition and degradation characteristics of Ba(TMHD)2 and Sr(TMHD)2 with storage time were analyzed using a differential scanning calorimeter (DSC). The thin films were fabricated on Si(p-type 100) and Pt/SiO2/Si substrates with Ar carrier gas using ECR plasma (or without ECR plasma) assisted MOCVD. Experimental results showed that the ECR oxygen plasma increased the deposition rate, the ratio of Sr/Ti, the dielectric constant and the leakage current density of the film. The dependency of the crystallinity and the electrical properties on the Sr/Ti ratio of films were investigated. However, almost of the films deposited with Ar carrier gas had slightly high dielectric loss and high leakage current density and showed non-uniform compositional depth profiles. NH3 gas was also used to decrease the degradation of the MO-sources. Mass spectra in-situ monitoring of source vapors in ECR-PAMOCVD system were obtained. By introducing NH3 as a carrier gas, a significant improvement was achieved in the volatility and the thermal stability of the precursors, and the vaporization temperatures of the precursors were reduced compared to Ar carrier gas. The uniform compositional depth profile, less hydrogen and carbon content and the good electrical properties of (SrxTi1−x)O3 thin films were obtained with NH3 carrier gas. The (Ba1−xSrx)TiO3 thin film were fabricated to have very fine and uniform microstructure, the dielectric constant of 456, the dielectric loss of 0.0128, the leakage current density of 5.01 × 10−8A/cm2 at 1V and the breakdown field of 3.65MV/cm.

Structural and electrical properties of lithium cobalt nanoferrites prepared by sol–gel method

2015 ◽  
Vol 29 (01) ◽  
pp. 1450255
Author(s):  
Victory Maisnam ◽  
Mamata Maisnam ◽  
Sumitra Phanjoubam
Keyword(s):  
Dielectric Constant ◽  
Electrical Properties ◽  
Dielectric Loss ◽  
Ac Conductivity ◽  
Sol Gel ◽  
Interfacial Polarization ◽  
Frequency Variation ◽  
Gel Method ◽  
Sol Gel Method ◽  
Lithium Cobalt

Lithium cobalt nanoferrites having the compositional formula Li 0.5-x/2 Co x Fe 2.5-x/2 O 4 with x varying from 0.00 to 0.12 in steps of 0.03 were prepared by the chemical sol–gel method. Samples were heated at two different temperatures namely 300°C and 500°C for 4 h. Structural characterization of the samples was done using X-ray diffraction (XRD) technique and confirmed the formation of single phase with spinel structure in all the samples. From the XRD data, the lattice parameter was calculated and found to range from 82.87–83.35 nm while the crystallite size was found to be in the range 17–34 nm. Microstructural studies were carried out using the Scanning Electron Microscopy and revealed the microstructures with grain size ranging from 35–70 nm. Electrical properties like dielectric constant, dielectric loss and AC conductivity for these nanoferrites were investigated. The frequency variation of room temperature dielectric constant, dielectric loss and AC conductivity were studied in the frequency range 100 Hz–1 MHz, and a dispersive behavior was observed, which has been attributed to the Maxwell–Wagner type of interfacial polarization.

Electrical Properties of BaTiO3 Doped with Lanthana and Niobia

2007 ◽  
Vol 280-283 ◽  
pp. 357-360
Author(s):  
M.M. Mosaad ◽  
M.I. Abd El-Ati ◽  
S.A. Olofa ◽  
A. Ismal
Keyword(s):  
Dielectric Constant ◽  
Electrical Resistivity ◽  
Electrical Properties ◽  
Dielectric Loss ◽  
Temperature Range ◽  
Constant E

The electrical resistivity (r), the dielectric constant (e), and the dielectric loss (tan d) were accurately measured in the temperature range 60-200oC for the samples (BaTiO3-La2O3-Nb2O5) with (Nb2O5 = 0.1) wt% and La2O3 = 0.0, 0.1, 0.2, 0.3 and 0.4). It is found that the addition of La content cause increase in resistivity and decrease the dielectric constant.

Influence of Doped Mn, Cu, Ni and Fe on Electrical Properties of SrTiO3 Ceramics

2009 ◽  
Vol 79-82 ◽  
pp. 1603-1606 ◽  
Author(s):  
Ning Zhang Wang ◽  
Sha Sha ◽  
Yu Tian Ma
Keyword(s):  
Dielectric Constant ◽  
Electrical Properties ◽  
Dielectric Loss ◽  
Nonlinear Coefficient ◽  
Lower Dielectric Constant ◽  
Sintering Conditions

MnCO3, CuO, NiO and Fe2O3 doped SrTiO3 multifunction ceramics were fabricated firstly. The microstructure and electrical properties were investigated. The results show that MnCO3 doped ceramic and CuO doped ceramic possess relative higher resistivity (ρ),nonlinear coefficient (α), varistor voltage (V1mA) and relative lower dielectric constant (ε),dielectric loss (tgδ) in contrast with NiO doped ceramic and Fe2O3 doped ceramic with the same contents under the same sintering conditions. The electrical properties among the ceramics doped are different due to the different behaviors of Mn,Cu,Ni and Fe acceptor dopants during the sintering course.

Influence of Sintering Temperature on KNN-BF-LS Piezoelectric Ceramic

2016 ◽  
Vol 859 ◽  
pp. 8-12 ◽  
Author(s):  
Guo Yuan Cheng ◽  
Xing Hua Fu ◽  
Wen Hong Tao ◽  
Yu Zhang ◽  
Wen Xin Ma ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Grain Size ◽  
Dielectric Loss ◽  
Piezoelectric Ceramic ◽  
Electromechanical Coupling ◽  
Sintering Temperature ◽  
Sol Gel ◽  
Electromechanical Coupling Coefficient ◽  
Structure And Properties ◽  
Maximum Value

In this paper, (K0.5Na0.53)0.932Nb0.932O3-0.008BF-0.06LS (abbreviated as KNN-BF-LS) piezoelectric ceramic was prepared by sol-gel method. Structure and properties of ceramics were analyzed.Through analysis of the results, when sintering temperature is 1080°C, ceramic has good perovskite structure. At this temperature, grain size is more uniform, and structure is the most dense. Piezoelectric constant d33, electromechanical coupling coefficient Kp, dielectric constant εr reached the maximum value, respectively, 113pC/N, 0.33, 591. Dielectric loss tanδ reached the minimum 0.11.

scholarly journals Fabrication and studying the dielectric properties of (polystyrene-copper oxide) nanocomposites for piezoelectric application

2019 ◽  
Vol 8 (1) ◽  
pp. 52-57 ◽  
Author(s):  
Dalal Hassan ◽  
Ahmed Hashim Ah-yasari
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Electrical Properties ◽  
Dielectric Loss ◽  
Copper Oxide ◽  
Electrical Resistance ◽  
Copper Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
Increase With Increase

The preparation of (polystyrene-copper oxide) nanocomposites have been investigated for piezoelectric application. The copper oxide nanoparticles were added to polystyrene by different concentrations are (0, 4, 8 and 12) wt.%. The structural and A.C electrical properties of (PS-CuO) nanocomposites were studied. The results showed that the dielectric constant and dielectric loss of (PS-CuO) nanocomposites decrease with increase in frequency. The A.C electrical conductivity increases with increase in frequency. The dielectric constant, dielectric loss and A.C electrical conductivity of polystyrene increase with increase in copper oxide nanoparticles concentrations. The results of piezoelectric application showed that the electrical resistance of (PS-CuO) nanocomposites decreases with increase in pressure.

scholarly journals The Effects of TDI on Selected Properties of Ester Epoxy Alkyd Varnish

2020 ◽  
Vol 36 (4) ◽  
Author(s):  
Nguyen Trung Thanh
Keyword(s):  
Dielectric Constant ◽  
Electrical Properties ◽  
Dielectric Loss ◽  
Heat Resistance ◽  
Epoxy Resin ◽  
Breakdown Voltage ◽  
Toluene Diisocyanate

This article presents the effects of toluene diisocyanate (TDI) on electrical properties of ester epoxy alkyd varnish. Through testing on breakdown voltage, dielectric constant, block resistivity, Tang (Tg) dielectric loss, the electrical properties of varnish were investigated. When TDI amount increased from to 4 - 10 (w/100w of epoxy resin), the breakdown voltage increased from 21.78 to 65.69 KV/mm. With TDI of 8 - 10 w/w, the dielectric constant was the best, about 2.78 - 3.02. With TDI of 8 w/w, the block resistivity was 6.8.1014 W.cm and Tg dielectric loss was 0.0069. The article also presents the effect of TDI on solvent- and heat resistance of the varnish.

Preparation and Study the Electrical and Optical Properties for (PVA-PEG-Sr2O3) Nanocomposites

2021 ◽  
Vol 19 (10) ◽  
pp. 47-55
Author(s):  
Safa Ahmed Jabbar Al-Rubaye ◽  
Nassar A. Al-lsawi ◽  
Ali R. Abdulridha
Keyword(s):  
Dielectric Constant ◽  
Refractive Index ◽  
Optical Properties ◽  
Electrical Properties ◽  
Dielectric Loss ◽  
Energy Gap ◽  
Antimony Oxide ◽  
Optical And Electrical Properties ◽  
Electrical And Optical Properties ◽  
Constant E

In the presented work, the optical and electrical properties of composite materials (PVA-PEG-Sr2O3) were measured, as the electrical properties were verified at various frequencies in range of 100 Hz-6 MHz. In addition, the experimental results showed that the increase in frequency causes a reduction in the dielectric loss (δ) and dielectric constant (ɛ), and there is an increase in ɛ due to the increase in the content of antimony oxide (Sr2O3). It increases with increasing frequency and decreases with increasing Sr2O3 content in PVA-PEG-Sr2O3 compounds, the result of the optical properties of the nanoparticles (PVA-PEG-Sr2O3) showed that the values transmittance and energy gap were reduced with the increases in the concentrations of Sr2O3 NPs, whereas the values related to extinction coefficient, absorption coefficient, optical conductivity, refractive index, and dielectric constant (imaginary, real) were increased with increase in the concentration of Sr2O3 NPs.

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