SINTERING BEHAVIOR AND DIELECTRIC PROPERTIES OF Ba0.985Bi0.01TiO3-Ba0.9955La0.003TiO3 FINE-POWDERS

2013 ◽  
Vol 27 (12) ◽  
pp. 1350081 ◽  
Author(s):  
JING WANG ◽  
SHENGLIN JIANG ◽  
CHUNZHENG WANG ◽  
HAO YAO ◽  
TINGWEI WANG
Keyword(s):  
Dielectric Properties ◽  
Temperature Stability ◽  
Sintering Behavior ◽  
X Ray Diffraction ◽  
Soft Chemistry ◽  
Fine Powders ◽  
Microstructure Evaluation ◽  
Maximum Dielectric Constant ◽  
Composition Inhomogeneity ◽  
Tan Δ

Ba 0.985 Bi 0.01 TiO 3- Ba 0.9955 La 0.003 TiO 3 fine-powders were synthesized by two-step soft chemistry method. Phase analysis and microstructure evaluation conducted by X-ray diffraction and scanning electron microscopy confirmed the provskite structure of the ceramic grain. Different sintering temperatures were considered to optimize the density and dielectric properties. The maximum dielectric constant decreased first, and then increased before dropping again, reflecting the change of relative density. Samples sintered at 1270°C exhibited the best temperature stability due to composition inhomogeneity and compact properties. The dielectric properties of the sample sintered at 1270°C were: ε = ~8,960, tan δ < 0.28, ΔC/C20° C at -55°C, 110°C and 150°C were -5.2%, 13.8% and -12.8%, respectively.

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

2013 ◽  
Vol 03 (04) ◽  
pp. 1350028 ◽  
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.

The effect of Ag electrode processing on (Nb, Ba) doped TiO2 ceramics

1990 ◽  
Vol 5 (7) ◽  
pp. 1530-1537 ◽  
Author(s):  
Chi-Jen Chen ◽  
Jenn-Ming Wu
Keyword(s):  
Dielectric Properties ◽  
Processing Condition ◽  
Temperature Stability ◽  
Relative Dielectric Constant ◽  
Dissipation Factor ◽  
Interface Layer ◽  
X Ray Diffraction ◽  
Ag Electrode ◽  
Ag Paste ◽  
Interface Layers

Since the characteristics of the electrode made from Ag paste greatly affect the dielectric properties of (Nb, Ba) doped TiO2 ceramics, the processing condition, i.e., baking temperature, was investigated. Low melting glass binder contained in Ag paste reacted with TiO2 ceramics to form an interface layer between Ag electrode and TiO2 ceramics during baking. The interface layer was identified as Bi2Ti2O7 by x-ray diffraction (XRD), and the thickness of the Bi2Ti2O7 layer was estimated from line profiles of EPMA and dielectric properties. The interface layers were found to increase with baking temperature. Increased baking temperature lowered the relative dielectric constant and dielectric dissipation factor of TiO2 ceramics, while it raised the resistivity. Controlling the baking condition of the Ag paste electrode on TiO2 ceramics resulted in reasonably good dielectric properties and excellent temperature stability.

Impact of Sr on the performance of BaTi0.9Zr0.1O3–BaTiO3 dielectric powders

2014 ◽  
Vol 28 (14) ◽  
pp. 1450114 ◽  
Author(s):  
Jing Wang ◽  
Guijuan Rong ◽  
Tingwei Wang ◽  
Hao Yao
Keyword(s):  
Dielectric Constant ◽  
Breakdown Strength ◽  
Dielectric Material ◽  
Phase Method ◽  
X Ray Diffraction ◽  
Liquid Phase Method ◽  
Dielectric Performance ◽  
Composition Inhomogeneity ◽  
Tan Δ ◽  
Constant Maximum

BaTi 0.9 Zr 0.1 O 3– Ba 1-x Sr x TiO 3 fine-powders are synthesized by two-step liquid phase method. Phase analysis and microstructure evaluation conducted by X-ray diffraction and scanning electron microscopy confirm the perovskite structure of the ceramic grain. Different Sr content is considered to optimize the density and dielectric performance. The dielectric constant increases and dielectric loss decreases with the rising of Sr content until x = 0.05. At the doping content of 5%, the dielectric constant maximum of 42,430 and excellent Y5V dielectric material can be obtained due to composition inhomogeneity and compact properties. Its dielectric properties are as follows: ε RT = 36,914, tan δ < 0.09, ΔC/C 20° C at -30° C and 80°C are -58.98% and 14.94%, respectively, and the breakdown strength Eb ≥ 5.2 kV ⋅ mm -1.

The Effect of B2O3–Li2CO3 Addition on Sintering Behavior and Dielectric Properties of Ba 0.6Sr0.4TiO3 Ceramics

2011 ◽  
Vol 197-198 ◽  
pp. 333-338 ◽  
Author(s):  
Ming Li Li ◽  
Qiong Yu ◽  
Kun Ming Qian ◽  
Song Ji ◽  
Pi Yi Du
Keyword(s):  
Dielectric Properties ◽  
Precipitation Method ◽  
Sintering Behavior ◽  
X Ray Diffraction ◽  
Dense Microstructure ◽  
Barium Strontium ◽  
Mixing Method ◽  
Powder Properties ◽  
Dilatometric Studies ◽  
Co Precipitation

Barium strontium titanate (Ba0.6Sr0.4TiO3: BST) powders were prepared by the oxalate co-precipitation method. The ceramics from thus obtained BST powders with B2O3-Li2CO3 addition were prepared by conventional oxide mixing method. The powders and the ceramics were observed and analyzed by SEM and X-ray diffraction. The effects of B2O3-Li2CO3 addition and powder properties on the sintering behavior and the dielectric properties of BST-based ceramics were investigated. SEM results revealed that the BST powders are micron-sized with cauliflower-shaped rough surface leading the specific surface area reaches 18.52m2/g. In dilatometric studies, the ceramics without B2O3-Li2CO3 addition didn’t produce the desired shrinkage and dense microstructure at relative low temperatures (<1000°C). However, the sintering temperature is decreased to 850°C by addition of small amount (≤3wt %) of B2O3 and Li2CO3. This was also verified in sintered microstructures. The XRD results showed that the main phase of the ceramics was BST without any other crystalline phases of remarkable extent. With increasing of B2O3-Li2CO3 content, the permittivity and the tunability of the ceramics were decreased.

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.

Microwave dielectric properties of (1 − x)Cu3Nb2O8−xZn3Nb2O8 ceramics

2001 ◽  
Vol 16 (5) ◽  
pp. 1465-1470 ◽  
Author(s):  
Dong-Wan Kim ◽  
In-Tae Kim ◽  
Byungwoo Park ◽  
Kug Sun Hong ◽  
Jong-Hee Kim
Keyword(s):  
Solid Solution ◽  
Dielectric Properties ◽  
Microwave Dielectric Properties ◽  
Sintering Behavior ◽  
X Ray Diffraction ◽  
Two Phase ◽  
Sintering Aid ◽  
Microwave Dielectric ◽  
Solid Solution Region ◽  
Solution Region

The sintering behavior and microwave dielectric properties of (1 − x)Cu3Nb2O8−xZn3Nb2O8 have been investigated using dilatometry, x-ray diffraction, and a network analyzer. It was found that (1 − x)Cu3Nb2O8−xZn3Nb2O8 ceramics have a much lower melting temperature than Zn3Nb2O8 ceramics without Cu3Nb2O8 additives. Samples sintered at 900 °C for 2 h exhibited densities >97% of the theoretical density. Cu3Nb2O8 acts as a sintering aid. Two phase regions were identified with increasing Zn3Nb2O8 contents. A Cu3Nb2O8−Zn3Nb2O8 solid solution exists from 0 < x < 0.5 while a mixture of Cu3Nb2O8 and Zn3Nb2O8 exists from 0.5 < x < 1. The microwave dielectric properties correlated to the crystal structure. In Cu3Nb2O8−Zn3Nb2O8 solid solution region, the variation of dielectric properties could be explained by the structure distortion of Cu3Nb2O8 due to electronic anisotropies of Cu2+ cations.

Effect of H3BO3 Coating on the Microwave Dielectric Properties of BZN Ceramics

2014 ◽  
Vol 906 ◽  
pp. 8-11
Author(s):  
Liu Shuan Yang ◽  
Biao Jin ◽  
Xiao Wang
Keyword(s):  
Dielectric Properties ◽  
Ceramic Composite ◽  
Microwave Dielectric Properties ◽  
Sintering Behavior ◽  
Network Analyzer ◽  
X Ray Diffraction ◽  
Ceramic Specimen ◽  
Coating Technology ◽  
X Ray ◽  
Microwave Dielectric

(Bi1.5Zn0.5)(Zn0.5Nb1.5)O7(BZN) ceramic samples were prepared by solid state reaction. B2O3 was introduced by liquid coating technology with H3BO3 solution in the BZN ceramic specimen to reduce its sintering temperature. The sintering behavior, phase composition and dielectric properties of ceramics were investigated by X-ray diffraction, scanning electron microscopy and vector network analyzer. The (Bi1.5Zn0.5)(Zn0.5Nb1.5)O7 ceramic composite could be sintered well at 900°C for 3h when 0.9M/l H3BO3 was added and showed good dielectric properties of εr=150,Q×f=228,τf=-362ppm/°C.

Dielectric Properties of CaCu3Ti4O12 Synthesized by Different Routes

2014 ◽  
Vol 975 ◽  
pp. 184-188 ◽  
Author(s):  
Tatiane Cristina Porfirio ◽  
Eliana Navarro Santos Muccillo
Keyword(s):  
Dielectric Properties ◽  
Sintering Temperature ◽  
Dielectric Losses ◽  
Electric Permittivity ◽  
X Ray Diffraction ◽  
Soft Chemistry ◽  
X Ray ◽  
Powder Characteristics ◽  
Sintered Materials ◽  
Scanning Electron

The perovskite CaCu3Ti4O12, with giant electric permittivity, was prepared by a soft chemistry route and by the solid state synthesis technique. The main purpose of this work is to verify the effects of the synthesis techniques on the powder characteristics, and the microstructure and dielectric properties of the sintered materials. The synthesized nanopowders were calcined, pressed into pellets and sintered using the same procedures as for the materials prepared by the conventional method. Phase analysis was performed by X-ray diffraction, microstructure observations were carried out by scanning electron microscopy, and the dielectric properties were studied by impedance spectroscopy. The electric permittivity ranged from 11,600 to 27,000 and from 5,000 to 9,000 for specimens prepared by the conventional and the soft chemistry techniques, respectively, and the dielectric losses varied between 0.1 and 1.3 (conventional) and 0.095 and 0.3 (soft chemistry) depending on the sintering temperature.

Effect of Annealing on the Structure and Dielectric Properties in PZT-PCoN Ceramics

2008 ◽  
Vol 55-57 ◽  
pp. 49-52
Author(s):  
Naratip Vittayakorn ◽  
N. Chaiyo ◽  
R. Muanghlua ◽  
A. Ruangphanit ◽  
Wanwilai C. Vittayakorn
Keyword(s):  
Solid Solution ◽  
Dielectric Properties ◽  
Solid State Reaction Method ◽  
Relaxor Ferroelectric ◽  
Dielectric Constants ◽  
X Ray Diffraction ◽  
Reaction Method ◽  
X Ray ◽  
Maximum Dielectric Constant ◽  
Diffraction Patterns

he solid solution between the normal ferroelectric Pb(Zr1/2Ti1/2)O3 (PZT) and relaxor ferroelectric Pb(Co1/3Nb2/3)O3 (PCoN) was synthesized by the solid state reaction method. Sintered PZT-PCoN ceramics were annealed at temperatures ranging from 850 to 1,100°C for 4 h. X-ray diffraction patterns revealed changes of crystalline structure after annealing, which could be correlated to the accompanied changes in dielectric properties. Furthermore, significant improvements in the dielectric responses were observed in this system. After annealing, a huge increase of up to 200% occurred in the dielectric constants, especially near the temperature of maximum dielectric constant.

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