scholarly journals Dielectric characterization of the system Sr1-xGdxTi1-xCoxO3 (x = 0.10) using impedance spectroscopy

2010 ◽  
Vol 7 (2) ◽  
pp. 499-504
Author(s):  
H. S. Tewari ◽  
P. K. Sakharkar
Keyword(s):  
Dielectric Properties ◽  
Impedance Spectroscopy ◽  
Room Temperature ◽  
Sintering Temperature ◽  
Solid State Reaction Method ◽  
Electrical Behavior ◽  
Cooling Rates ◽  
Impedance Analyzer ◽  
Dielectric Characterization

The structure of ceramic grain boundaries, boundary composition, the boundary charge and associated space charge controls the dielectric and electrical behavior of ceramics. Various methods were researched and applied to increase the dielectric constant by formation of insulating layers between semi-conducting grains. In this communication, we are reporting the effect of cooling rates from sintering temperature to room temperature on dielectric properties of the resulting ceramics in the system, Sr1-xGdxTi1-xCoxO3 with x = 0.10. All the samples in this system were prepared by conventional high temperature solid state reaction method. The samples were cooled at different cooling rates from sintering temperature to room temperature. The capacitance and dielectric loss were measured as a function of frequency and temperature using HP 4192A LF impedance analyzer. The samples cooled from different cooling rates from sintering temperature show interesting dielectric properties due to formation of insulating layers between grains. The impedance spectroscopy is used successfully in explaining the dielectric properties of these materials.

Effect of Sintering Temperature on Structure and Dielectric Properties of Lead Free K0.5Na0.5NbO3 Prepared via Hot Isostatic Pressing

2017 ◽  
Vol 888 ◽  
pp. 42-46 ◽  
Author(s):  
Fatin Khairah Bahanurdin ◽  
Julie Juliewatty Mohamed ◽  
Zainal Arifin Ahmad
Keyword(s):  
Grain Size ◽  
Dielectric Properties ◽  
Room Temperature ◽  
Sintering Temperature ◽  
Hot Isostatic Pressing ◽  
Solid State Reaction Method ◽  
Lead Free ◽  
Tangent Loss ◽  
Isostatic Pressing ◽  
Tan Δ

In this research, alkaline niobate known as K0.5Na0.5NbO3 (KNN) lead-free piezoelectric ceramic was synthesis by solid state reaction method which pressing at different sintering temperatures (1000 °C and 1080 °C) prepared via hot isostatic pressing (HIP)). The effect of sintering temperature on structure and dielectric properties was studied. The optimum sintering temperature (at 1080 °C for 30 minutes) using hot isostatic pressing (HIP) was successfully increase the density, enlarge the particle grain size in the range of 0.3 µm – 2.5 µm and improves the dielectric properties of K0.5Na0.5NbO3 ceramics. The larger grain size and higher density ceramics body will contribute the good dielectric properties. At room temperature, the excellent relative permittivity and tangent loss recorded at 1 MHz (ɛr = 5517.35 and tan δ = 0.954), respectively for KNN1080HIP sample. The KNN1080HIP sample is also exhibits highest relative density which is 4.485 g/cm3. The ɛr depends upon density and in this work, the density increase as the sintering temperature increase, which resulting the corresponding ɛr value also increases.

scholarly journals Preparation, crystal structure, and dielectric characterization of Li2W2O7 ceramic at RF and microwave frequency range

2017 ◽  
Vol 07 (01) ◽  
pp. 1720001 ◽  
Author(s):  
Jinwu Chen ◽  
Chunchun Li ◽  
Dan Wang ◽  
Huaicheng Xiang ◽  
Liang Fang
Keyword(s):  
Dielectric Properties ◽  
Single Phase ◽  
Microwave Dielectric Properties ◽  
Microwave Frequency ◽  
Solid State Reaction Method ◽  
Frequency Range ◽  
Conventional Solid State Reaction ◽  
Dielectric Characterization ◽  
Microwave Dielectric

Single phase Li2W2O7 with anorthic structure was prepared by the conventional solid-state reaction method at 550[Formula: see text]C and the anorthic structure was stable up to 660[Formula: see text]C. The dielectric properties at radio frequency (RF) and microwave frequency range were characterized. The sample sintered at 640[Formula: see text]C exhibited the optimum microwave dielectric properties with a relative permittivity of 12.2, a quality factor value of 17,700[Formula: see text]GHz (at 9.8[Formula: see text]GHz), and a temperature coefficient of the resonant frequency of [Formula: see text]232[Formula: see text]ppm/[Formula: see text]C as well as a high relative density [Formula: see text]94.1%. Chemical compatibility measurement indicated Li2W2O7 did not react with aluminum electrodes when sintered at 640[Formula: see text]C for 4[Formula: see text]h.

scholarly journals Study of Sintering Temperature on Dielectric Properties of CaCu3Ti4O12 Materials Prepared by Sol-Gel Method

2020 ◽  
Vol 32 (12) ◽  
pp. 3109-3112
Author(s):  
W. Sue-Aok ◽  
J. Khemprasit
Keyword(s):  
Dielectric Properties ◽  
Room Temperature ◽  
Sintering Temperature ◽  
Sol Gel ◽  
Cross Linking ◽  
Impedance Analyzer ◽  
Sol Gel Process ◽  
Ft Ir ◽  
Ccto Powder ◽  
Tan Δ

CaCu3Ti4O12 (CCTO) powder was prepared by sol-gel process using acetic acid as a solvent and also as cross-linking agent by varying the sintering temperature (1000-1150 ºC) for 3 h. The dried gels were characterized by TG-DTA and FT-IR techniques. The sintered samples were characterized by XRD, SEM techniques and impedance analyzer for dielectric properties measurement. The sample showed the perovskite structure with small amounts of TiO2 and CuO phases. The best dielectric properties (εr = 1.38 × 104 and tan δ = 0.13 at 10 kHz and room temperature) were observed in the CCTO pellets calcined at 800 ºC for 3 h and sintered at 1100 ºC for 3 h.

Effect of Sm-Doping on Magnetic and Dielectric Properties of BiFeO3

2012 ◽  
Vol 501 ◽  
pp. 329-333 ◽  
Author(s):  
R.S.N. Ain ◽  
S.A. Halim ◽  
Mansor Hashim
Keyword(s):  
Dielectric Properties ◽  
Room Temperature ◽  
Spontaneous Magnetization ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Impedance Analyzer ◽  
X Ray ◽  
Multiferroic Bifeo3 ◽  
Average Grain Size ◽  
Magnetic And Dielectric Properties

Polycrystalline Bi1-xSmxFeO3 multiferroic samples in the range 0 ≤ x ≤ 0.1 were prepared via solid state reaction method. The effect of samarium ion (Sm3+) doping at the bismuth site in multiferroic BiFeO3 structure and its relation with magnetic and dielectric properties were investigated. X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Vibrating Sample Magnetometer (VSM) and Impedance Analyzer were used to characterize the structure and the properties of the composition. The XRD results showed that all the compounds are rhombohedral distorted perovskite structure (R3C). The average grain size identified by SEM were 2.61 µm and decreased to 1.18 µm by introducing the element of Sm doping. At room temperature, all samples showed a spontaneous magnetization which was enhanced by doping with Sm3+ ion. The dielectric constant and dielectric loss decreased inversely proportional to the frequency from 102 to 106 Hz.

Dielectric Properties and Raman Spectroscopy in Ca-Substituted Na0.5Bi0.5TiO3 Ferroelectric Ceramics

2011 ◽  
Vol 324 ◽  
pp. 298-301 ◽  
Author(s):  
Roy Jean Roukos ◽  
Olivier Bidault ◽  
Julien Pansiot ◽  
Ludivine Minier ◽  
Lucien Saviot
Keyword(s):  
Raman Spectroscopy ◽  
Dielectric Properties ◽  
Room Temperature ◽  
Rhombohedral Phase ◽  
Xrd Analysis ◽  
Solid State Reaction Method ◽  
Ferroelectric Ceramics ◽  
Dielectric Measurements ◽  
X Ray Diffraction ◽  
X Ray

Lead free Na0.5Bi0.5TiO3 (NBT) and (Na0.5Bi0.5TiO3)1-x(CaTiO3)x (NBT-CT) piezoelectric ceramics with the perovskite structure were studied. The NBT and NBT-CT samples were synthesized using a solid-state reaction method and characterized with X-ray diffraction (XRD), Raman spectroscopy and dielectric measurements for several compositions (x = 0, 0.07, 0.15) at room temperature. The XRD analysis showed a stabilization of a rhombohedral phase at a low concentration of Ca (0 < x <0.15), whereas Raman spectra reveal a strong modification for the sample with x = 0.15. The dielectric properties of these ceramics were studied by measuring impedance in the 79-451K temperature range for unpoled and field cooling with an electric field (FC) conditions.

Electrical and Magnetic Studies of (La0.5-xPrxBa0.5)(Mn0.5Ti0.5)O3 as Multiferroic Material

2012 ◽  
Vol 545 ◽  
pp. 269-274
Author(s):  
Nor Hayati Alias ◽  
Abdul Halim Shaari ◽  
Wan Mohamad Daud Wan Yusoff ◽  
Che Seman Mahmood
Keyword(s):  
Magnetic Properties ◽  
Dielectric Properties ◽  
Solid State ◽  
Room Temperature ◽  
Sintering Temperature ◽  
Multiferroic Material ◽  
Magnetic Studies ◽  
State Technique ◽  
Magnetic And Dielectric Properties ◽  
Synthesized Materials

A new perovskite based titano-manganite (La0.5-xPrxBa0.5)(Mn0.5Ti0.5)O3 at x concentration 0, 0.01, 0.03, 0.05, 0.07 and 0.09 has been successfully prepared by ceramic solid-state technique at sintering temperature of 1300 °C. Dielectric electrical properties of the synthesized materials at frequency ranging from 5 Hz to 1 MHz and magnetic properties have been studied at room temperature. Analyses have been carried out to determine the structural, magnetic and dielectric properties of the synthesized material as a candidate of multiferroic material.

Effect of Process on the Dielectric Properties of BaTiO3-Based X9R Ceramics

2014 ◽  
Vol 906 ◽  
pp. 18-24 ◽  
Author(s):  
Bao Lin Zhang ◽  
Bin Bin Zhang ◽  
Ning Ning Wang ◽  
Jing Ming Fei
Keyword(s):  
Particle Size ◽  
Dielectric Properties ◽  
Milling Time ◽  
Sintering Temperature ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
Sintered Ceramic ◽  
X Ray ◽  
Particle Size Analyzer

The effect of milling time and sintering process on the dielectric properties of BaTiO3-based X9R ceramics was investigated. The characterization of the raw powders and the sintered ceramic was carried out by X-ray diffraction and scanning electron microscopy. The particle size distribution of the mixed powders was examined by Laser Particle Size Analyzer. The results shown that with the milling time extended, the Cruie Peak was depressed, or even disappeared. Moreover, with the rise of sintering temperature, the dielectric constant of the ceramics increased and the dielectric loss decreased gradually. Eventually, by milling for 11h and sintering at 1090°Cfor 2h, good dielectric properties were obtained, which were ε25°C≥ 2526, εr/εr25°C≤± 12% (–55~200°C), tanδ≤1.12% (25°C).

scholarly journals Development of a Microfluidic GHz Impedance Cytometer

2013 ◽  
Vol 80 (12) ◽  
Author(s):  
Niels Haandbæk ◽  
Sebastian C. Bürgel ◽  
Flavio Heer ◽  
Andreas Hierlemann
Keyword(s):  
Dielectric Properties ◽  
Chinese Hamster Ovary ◽  
Cho Cells ◽  
Single Cells ◽  
Chinese Hamster ◽  
Frequency Range ◽  
Cell Nuclei ◽  
Dielectric Characterization ◽  
The Difference

AbstractThis article presents a novel microfluidic impedance cytometer enabling dielectric characterization of single cells at frequencies up to 500 MHz. The dielectric properties of cells at lower frequencies contain information about their size and membrane capacitance. The increased frequency range of the presented cytometer potentially allows for characterization of intracellular components, such as vacuoles or the cell nuclei. We demonstrate the overall capabilities of the cytometer through discrimination of polystyrene beads from Chinese hamster ovary (CHO) cells. The discrimination is based on the difference in dielectric properties at frequencies up to 500 MHz.

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