scholarly journals Composition dependence of dielectric properties in Pb(Zn1∕3Nb2∕3)O3–PbTiO3–BaTiO3 (PZN–PT–BT) relaxor ferroelectric ceramics

2017 ◽  
Vol 07 (02) ◽  
pp. 1750008
Author(s):  
Qiang Gao ◽  
Li Jin ◽  
Yu Cui ◽  
Ye Zhao ◽  
Kun Yu ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Composition Dependence ◽  
Solid State Reaction Method ◽  
Ferroelectric Ceramics ◽  
Dielectric Measurements ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cation Disorder ◽  
Diffusion Phase ◽  
A Site

Perovskite solid solution ceramics of PZN–PT–BT with several compositions were synthesized by solid-state reaction method. X-ray diffraction results indicate pure perovskite structures for all samples. Dielectric measurements show that the implicit Ba(Zn[Formula: see text]Nb[Formula: see text])O3(BZN) composition could broaden the diffusion phase transition (DPT) peaks and lower the [Formula: see text] and [Formula: see text] values. The observed dielectric properties may be caused by the increased cation disorder due to the substitution of barium onto the A-site and titanium onto the B-site.

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.

Structural and Dielectric Properties of Na0.5Bi0.5TiO3 Ferroelectric Ceramics

2012 ◽  
Vol 585 ◽  
pp. 219-223
Author(s):  
Rekha Kumari ◽  
N. Ahlawat ◽  
Ashish Agarwal ◽  
M. Sindhu ◽  
N.N. Ahlawat
Keyword(s):  
Dielectric Properties ◽  
Solid State Reaction Method ◽  
Wide Frequency Range ◽  
Ferroelectric Ceramics ◽  
Frequency Range ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
Reaction Method ◽  
X Ray ◽  
Different Temperatures

Na0.5Bi0.5TiO3 (NBT) ceramics were synthesized by conventional solid state reaction method. Structural and dielectric properties of these ceramics were investigated. Crystalline phase of sintered ceramics was investigated by X-ray diffraction (XRD). The Rietveld refinement of powder X-ray diffraction revealed that the prepared ceramics exhibit the rhombohedral space group R3c. Dielectric properties of Na0.5Bi0. analyzer.5TiO3 (NBT) ceramics were studied at different temperatures in a wide frequency range using impedance

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

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
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.

Temperature Dependence on Dielectric Response of La0.7Ba0.3Mn0.4Ti0.6O3 Ceramic

2015 ◽  
Vol 1107 ◽  
pp. 45-52
Author(s):  
Aaliyawani Ezzerin Sinin ◽  
Walter Charles Primus ◽  
Abdul Halim Shaari ◽  
Zainal Abidin Talib ◽  
Sinin Hamdan
Keyword(s):  
Dielectric Properties ◽  
Temperature Dependence ◽  
Low Frequency ◽  
Sintered Sample ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
Low Frequencies ◽  
X Ray ◽  
Lcr Meter

Ceramic sample of La0.70Ba0.30Mn0.40Ti0.60O3 oxide has been prepared by the conventional solid-state reaction method. The sintered sample was characterized by using x-ray diffraction (XRD) and low frequency LCR meter. XRD result shows that the sample has a cubic structure with the existence of impurity phase. The dielectric properties of La0.70Ba0.30Mn0.40Ti0.60O3 measured from room temperature to 200°C shows that the dielectric permittivity is temperature dependence with strong dispersion at low frequencies. A circuit model based on the universal capacitor response function is also being used to represent the dielectric properties of the sample.

EFFECT OF Nb2O5 ON THE ELASTIC BEHAVIOR OF PZT FERROELECTRIC MATERIALS

2002 ◽  
Vol 16 (03) ◽  
pp. 79-85
Author(s):  
Y. PURUSHOTHAM ◽  
O. P. THAKUR ◽  
CHANDRA PRAKASH ◽  
P. VENUGOPAL REDDY
Keyword(s):  
Elastic Moduli ◽  
Solid State Reaction Method ◽  
Ferroelectric Materials ◽  
Ferroelectric Ceramics ◽  
Elastic Behavior ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wave Velocities ◽  
Shear Wave Velocities ◽  
Pulse Transmission

A series of ferroelectric ceramics with the compositional formula PbZr0.52Ti0.48O3 + x wt% of Nb2O5 were prepared by the solid state reaction method. Samples were characterized by studying their X-ray diffraction and dielectric measurements. The longitudinal and shear wave velocities and corresponding elastic moduli were determined at room temperature by using the pulse transmission technique. The values of Young's modulus (E), and the rigidity (n) and bulk (k) moduli were corrected to theoretical density and were found to increase with increasing dopant concentration. The variation of elastic moduli and other elastic parameters such as Debye temperature (θ D ) with composition are explained qualitatively.

scholarly journals Effect of V2O5 B-site substitution on the microstructure, Raman spectrum, and dielectric properties of SrBi2Ta2O9 ceramics

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Chia-Ching Wu ◽  
Cheng-Fu Yang
Keyword(s):  
Raman Spectrum ◽  
Dielectric Properties ◽  
Solid State Reaction Method ◽  
Layered Perovskite ◽  
Scanning Electron Micrographs ◽  
X Ray Diffraction ◽  
Strontium Bismuth Tantalate ◽  
Reaction Method ◽  
X Ray ◽  
Ferroelectric Characteristic

Abstract Strontium bismuth tantalate vanadate [SrBi2(Ta2−xVx)O9, SBTV] ceramics, which are bismuth-layered perovskite ferroelectrics, were synthesized through the solid-state reaction method. The effects of different sintering temperatures and V2O5 contents on the structure of the microstructure, Raman spectrum, and dielectric properties of the SBTV ceramics were investigated. As sintered at high temperature (980–1040 °C) and different V2O5 contents (x = 0.1 − x = 0.4), only disk-like grains of the SBTV ceramics were observed in the scanning electron micrographs. Preferential orientation of the crystals of the SBTV ceramics was confirmed through X-ray diffraction studies. The higher dielectric constant and Curie temperature of the SBTV ceramics compared with those of strontium bismuth tantalite (SrBi2Ta2O9, SBT) ceramics are ascribe to the partial replace of Ta5+ ions by V5+ ions in the B sites. The Curie–Weiss law and the modified Curie–Weiss law were used to discuss the normal-type or relaxor-type ferroelectric characteristic of the SBTV ceramics. The Ta5+ ion replaced by V5+ ion site in SBT ceramics to form SBTV ceramics exerted a pronounced effect on the BO6 mode, as demonstrated by Raman spectrum results.

Dielectric properties anomaly of (1−x)Pb(Ni1/3Nb2/3)O3−xPbTiO3 ceramics near the morphotropic phase boundary

2001 ◽  
Vol 16 (3) ◽  
pp. 834-836 ◽  
Author(s):  
Zhenrong Li ◽  
Liangying Zhang ◽  
Xi Yao
Keyword(s):  
Dielectric Properties ◽  
Phase Boundary ◽  
Morphotropic Phase Boundary ◽  
Composition Range ◽  
The Other ◽  
Dielectric Measurements ◽  
X Ray Diffraction ◽  
Structure Defects ◽  
X Ray ◽  
Dielectric Peak

Dielectric properties and the phase compositions of (1−x)Pb(Ni1/3Nb2/3)O3−xPbTiO3 ceramics were investigated. A morphotropic phase boundary (MPB) in the system between pseudocubic and tetragonal phase regions has been identified to lie in the composition range x = 0.34–0.38 by means of x-ray diffraction and dielectric measurements. The samples of composition lying near the MPB have good dielectric properties, but at the same time, exhibit two dielectric peaks. The possible reasons for the occurrence of dielectric bipeaks are discussed. One dielectric peak is phase transition peak, and the other peak lying in 130–150 °C temperature range is suggested to result from structure defects in the ceramics.

scholarly journals Effects of barium substitution on the sintering behavior, dielectric properties of Ca2Nb2O7 ferroelectric ceramics

2017 ◽  
Vol 07 (02) ◽  
pp. 1750013 ◽  
Author(s):  
Chunchun Li ◽  
Huaicheng Xiang ◽  
Yuandong Qin ◽  
Liang Fang
Keyword(s):  
Phase Transition ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Secondary Phase ◽  
Solubility Limit ◽  
Ferroelectric Ceramics ◽  
Sintering Behavior ◽  
X Ray Diffraction ◽  
Spectroscopy Analysis ◽  
X Ray

Barium-doped Ca2Nb2O7 ceramics were prepared in the form of Ca[Formula: see text]BaxNb2O7 (0 [Formula: see text] 0.6) by solid-state reaction. The solubility limit of barium in Ca2Nb2O7 was found to be [Formula: see text] based on X-ray diffraction and Raman spectroscopy analysis. When [Formula: see text] 0.4, Ca[Formula: see text]BaxNb2O7 solid solutions with a monoclinic perovskites-like layered structure (PLS) were formed, whereas beyond [Formula: see text], a secondary phase CaNb2O6 was detected. The dielectric properties obviously depended on the barium substitution. With increasing barium amount, the dielectric constant increased from 33.5 for pure Ca2Nb2O7 to 38.6 for [Formula: see text] ([Formula: see text][Formula: see text]MHz). The Curie temperature ([Formula: see text] of the [Formula: see text] sample was 1280[Formula: see text][Formula: see text][Formula: see text]5[Formula: see text]C. The phase transition was confirmed to be the second order.

scholarly journals Effect of Zr4+ Content on Crystal Structure, Micromorphology and Dielectric Properties of Ba(Zrx Ti1-X)O3 Ceramics

2019 ◽  
Vol 3 (1) ◽  
Keyword(s):  
Crystal Structure ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Great Influence ◽  
Secondary Phase ◽  
Solid State Reaction Method ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Patterns

Ba(Zrx Ti1-x)O3 ceramics (X=1.5, 2.0, 2.5, 3.0) were prepared by solid-state reaction method. Effect of controlling the ratio of Zr/Ti on the crystal structure, micromorphology and dielectric properties of BZT ceramics. Their crystal structures, morphologies, and electric properties were respectively characterized using X-ray diffraction, scanning electron microscope and impedance analyzer. The X-ray diffraction patterns show that the zirconium titanate ceramic samples behave cubic phase structure and no secondary phase. The ratio of Zr/Ti has a great influence on the crystal structure, microstructure and dielectric properties. As the Zr4+ content increases, the lattice constant increases and the grain size decreases. The dielectric constant is the largest when the Zr content is 15%. As the Zr4+ content increases, the dielectric constant decreases gradually, and the Curie temperature moves toward the low temperature region.

Effect of (Ba1−xLax)TiO3 and (Pb1−xLax)TiO3 dopants in optical and dielectric properties of PMN-based transparent ceramics

2019 ◽  
Vol 33 (33) ◽  
pp. 1950408
Author(s):  
M. Ghasemifard ◽  
M. Ghamari ◽  
S. Samarin ◽  
J. F. Williams
Keyword(s):  
Dielectric Properties ◽  
Hot Pressing ◽  
Optical Transmittance ◽  
Transparent Ceramics ◽  
Dielectric Measurements ◽  
X Ray Diffraction ◽  
X Ray ◽  
Combination Methods ◽  
Average Optical Transmittance

A relaxor electroceramic [Formula: see text]–[Formula: see text]–0.30-[Formula: see text] (PMN–PLT–BLT) with [Formula: see text] = 0.25, 0.50 and 0.75 was synthesized using the two combination methods of auto-combination and hot-pressing. Characterization of the crystal phase, microstructure, optical and dielectric properties of PMN–PLT–BLT was made primarily by X-ray diffraction and TEM and SEM methods. The pure perovskite crystals (rhombohedral and tetragonal) prepared at [Formula: see text] for 2 h calcination were revealed by using X-ray diffraction. The average optical transmittance of these electroceramics in the range between 450 nm and 900 nm is higher than 60% while in the IR region reached 100%. The PMN–PLT–BLT with [Formula: see text] = 0.75 displays the highest transparency around 70% near 1100 nm. The microstructures and dielectric measurements show that these three electroceramics have densities of about 98.8% and exhibit a normal relaxation characteristic.

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