Chemical Processing of BaTiO3 Based ceramics

1986 ◽  
Vol 72 ◽  
Author(s):  
J. L. Rehspringer ◽  
J. C. Bernier
Keyword(s):  
Dielectric Properties ◽  
Chemical Processing ◽  
Grain Sizes ◽  
Oxalate Precipitation

AbstractFor multilayers capacitors, submicron BaTiO3 powders are synthetised by chemical routes including gels. Three routes are described, oxalate precipitation, alkoxide gels and carboxyalkoxide polymerisations. Powders characteristics, relations between grain sizes, agglomerates, sintering capabilities and dielectric properties are discussed

Preparation of barium titanate ceramics from amorphous fine particles of the Ba–Ti–O system and its dielectric properties

1995 ◽  
Vol 10 (2) ◽  
pp. 306-311 ◽  
Author(s):  
S. Wada ◽  
T. Suzuki ◽  
T. Noma
Keyword(s):  
Dielectric Properties ◽  
Barium Titanate ◽  
Curie Temperature ◽  
Decomposition Method ◽  
Fine Particles ◽  
Nitrate Solution ◽  
Pressing Method ◽  
Calcination Temperatures ◽  
Grain Sizes ◽  
Titanate Ceramics

Using titanium nitrate solution stabilized by chelation, amorphous fine particles of the Ba-Ti-O system were prepared by the mist decomposition method in air. After calcination of these particles, barium titanate ceramics were prepared using the hot uniaxial pressing method, and various properties were investigated. As a result, the grain sizes could be controlled over the range from 58 nm to 187 nm by the sintering temperatures and/or the calcination temperatures, keeping the density almost constant. Moreover, the dielectric properties of the samples showed that the relative permittivity decreased with decreasing grain size, and Curie temperature also shifted to lower temperatures in the same way. In this study, we first found that Curie temperature existed in the barium titanate ceramics with grain sizes from 58 to 147 nm.

Microstructure and Dielectric Properties of LixTixNi1-2xO Thin Films

2008 ◽  
Vol 368-372 ◽  
pp. 1817-1819
Author(s):  
Cui Hua Zhao ◽  
Bo Ping Zhang ◽  
Yong Liu ◽  
Song Jie Li
Keyword(s):  
Thin Films ◽  
Dielectric Properties ◽  
Spin Coating ◽  
Sol Gel ◽  
Dielectric Constants ◽  
Co Doping ◽  
Grain Sizes ◽  
Uniform Microstructure ◽  
Coating Method ◽  
High Dielectric

LixTixNi1-2xO (x =0, 10 and 20 at. %) thin films with 200 nm in thickness were deposited on Pt/Ti/SiO2/Si (100) by a sol-gel spin-coating method. All samples have a uniform microstructure. The grain sizes grew from 100 nm to 300 nm by co-doping Li and Ti. The LiTiNiO thin films consist of NiO, NiTiO3 and Li2NiO2, while the Li-free thin films consist of NiO, NiTiO3 and NiTi0.99O3. The dielectric properties of the LiTiNiO thin films improved obviously by co-doping Li and Ti, but excess Li increases the amount of Li2NiO2 phase and decreases the dielectric properties. The dielectric constants at 100 Hz for the Li0.1Ti0.1Ni0.8O and Li0.2Ti0.2Ni0.6O thin films are 506 and 388 respectively. Appropriate co-doping contents of Li and Ti are important to obtain a high dielectric property.

Effect of Sintering Temperature on Dielectric Properties of CaCu3Ti4O12 Ceramics Prepared by Mechanochemical Process

2014 ◽  
Vol 974 ◽  
pp. 157-161
Author(s):  
Masturah Mohamed ◽  
Mahesh Talari ◽  
Mohd Salleh Mohd Deni ◽  
Azlan Zakaria
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Sintering Temperature ◽  
Processing Conditions ◽  
Dielectric Measurements ◽  
Frequency Range ◽  
Grain Sizes ◽  
Barrier Capacitance ◽  
Different Temperatures ◽  
Increasing Temperature

CaCu3Ti4O12(CCTO) is well known to have colossal dielectric constant in the range of 105.It is widely accepted that this phenomenon may be attributed to internal layer barrier capacitance (IBLC) model. The dielectric properties of CCTO were reported to be strongly dependent on the processing conditions and grain size. In this work, CCTO samples with different grain sizes were produced by varying sintering temperature in order to investigate IBLC effect on dielectric properties of CCTO. The samples were sintered at four different temperatures, (T=1100°C, 1050°C, 1000°C and 950°C). Dielectric measurements were carried out for the samples in the frequency range of 102– 106Hz using impedance spectrometer. Electron micrographs showed that increasing temperature promoted the grain growth of CCTO while sintering. The internal crystalline defects are seen to play major role by increasing the grain conductivity in dipole formation and increased the dielectric constant of the samples.

Preparation and dielectric properties of BaZr0.1Ti0.9O3ceramics with different grain sizes

2006 ◽  
Vol 79 (6-7) ◽  
pp. 389-397 ◽  
Author(s):  
C. E. Ciomaga ◽  
M. T. Buscaglia ◽  
M. Viviani ◽  
V. Buscaglia ◽  
L. Mitoseriu ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Grain Sizes

Developing the Crystalline Structures and Dielectric Properties of Excess Bi2O3-Added 0.95(Na0.5Bi0.5)TiO3-0.05BaTiO3 Ceramics

2011 ◽  
Vol 415-417 ◽  
pp. 981-985
Author(s):  
Ying Hsun Lin ◽  
Ping Shou Cheng ◽  
Yuan Tai Hsieh ◽  
Wen Cheng Tzou ◽  
Chia Ching Wu ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Lattice Constant ◽  
Standard Pattern ◽  
Crystalline Structures ◽  
Lattice Constants ◽  
Grain Sizes ◽  
Refinement Method ◽  
Xrd Patterns

0.95 (Na0.5Bi0.5)TiO3-0.05 BaTiO3 (NBT-BT3) compositions with excess x wt% Bi2O3 (NBT-BT3-x, with x=0, 1, 2, and 3) are sintered at 1200°C. When excess Bi2O3 is added, the NBT-BT3-1 ceramic displays the largest grain sizes, after which the grain sizes apparently decrease as more excess Bi2O3 is added. The lattice constants of calcined NBT-BT3 powder and NBT-BT3-x ceramics are calculated by the Rietveld full-pattern refinement method using the XRD standard pattern of ICSD-154041 and the measured XRD patterns of NBT-BT3-x ceramics. The refined values are compared with the measured XRD patterns to determine the cause of the distortion in the NBT-BT3-x ceramics. We show that NBT-BT3-1 ceramic has the minimum lattice constant a and maximum lattice constant c. The effects of excess Bi2O3 content on the dielectric properties of NBT-BT3-x ceramics are also discussed.

Physical, Dielectric Properties and Micro-Hardness of the (Ba0.90Ca0.10)0.90(Na0.50Bi0.50)0.10TiO3 Ceramics Prepared by Molten Salt Method

2018 ◽  
Vol 283 ◽  
pp. 132-139
Author(s):  
Chompoonuch Warangkanagool
Keyword(s):  
Dielectric Properties ◽  
Molten Salt ◽  
Heating Rate ◽  
Sintering Temperature ◽  
Molten Salt Method ◽  
Micro Hardness ◽  
Fluid Medium ◽  
Grain Sizes ◽  
Knoop Indentation ◽  
Lcr Meter

In this study, the physical properties, dielectric properties, and micro-hardness of (Ba0.90Ca0.10)0.90(Na0.50Bi0.50)0.10TiO3 or BCT-NBT ceramics prepared by molten salt method with various sintering temperatures were investigated. The powders were calcined at 500-1100°C for 4 h with heating rate of 5°C/min. It was found that the optimum calcination condition was 1000°C for 4 h. These powders were pressed and sintered at 1200-1400°C for 3 h with a heating rate of 5°C/min. The microstructure was examined by scanning electron microscope (SEM). The density of the sintered samples was measured by Archimedes method with distilled water as the fluid medium. Dielectric properties were examined by LCR meter. The micro-hardness of the BCT-NBT ceramics was determined using the Vickers and Knoop indentation techniques. The results showed that the average grain sizes increased with increasing sintering temperatures. At sintering temperatures higher than 1200°C, the fracture mode changed from partial intra-granular to mainly intra-granular. The sintering temperature at which the density, dielectric and hardness properties were maximal was 1350°C. The highest density was about 5.4 g/cm3, and the Vickers and Knoop micro-hardnesses were 6.6 and 6.4 GPa, respectively. The dielectric constant at the Curie temperature was 3682 and the dielectric loss was 0.01 at 1 kHz frequency.

Dielectric properties under dc-bias field of Ba0.6Sr0.4TiO3 with various grain sizes

2002 ◽  
Vol 94 (2-3) ◽  
pp. 164-169 ◽  
Author(s):  
Zhai Jiwei ◽  
Yao Xi ◽  
Cheng Xiaogang ◽  
Zhang Liangying ◽  
Haydn Chen
Keyword(s):  
Dielectric Properties ◽  
Bias Field ◽  
Grain Sizes ◽  
Dc Bias ◽  
Dc Bias Field

HIGH PRESSURE EFFECTS ON ELECTRICAL RESISTIVITY AND DIELECTRIC PROPERTIES OF NANOCRYSTALLINE SnO2

2006 ◽  
Vol 05 (04n05) ◽  
pp. 471-477 ◽  
Author(s):  
P. THANGADURAI ◽  
A. CHANDRA BOSE ◽  
S. RAMASAMY ◽  
R. KESAVAMOORTHY ◽  
T. R. RAVINDRAN
Keyword(s):  
High Pressure ◽  
Dielectric Properties ◽  
Complex Impedance ◽  
Chemical Precipitation ◽  
Pressure Effects ◽  
Precipitation Method ◽  
Grain Sizes ◽  
Electrical And Dielectric Properties ◽  
High Pressure Effects

Rutile structured nanocrystalline tin oxide (nano- SnO 2) was prepared by chemical precipitation method with different grain sizes. Its electrical and dielectric properties were studied using complex impedance spectroscopy under different hydrostatic pressures. These studies showed a transition in nano- SnO 2 under high-pressure. The transition pressures obtained from both the resistivity and dielectric measurements agree with each other and increase considerably with decrease in grain size. In order to find whether the transition under pressure is structural related or not, in situ high pressure Raman spectroscopy was done up to 3.38 GPa at room temperature. No structural change was observed and the transition may be due to the co-operative phenomenon of the change in band gap and better connectivity between grain boundaries.

scholarly journals Effect of ZrO2 Doping on the Microstructure and Dielectric Properties of Ca0.97Y0.03Cu3Ti4-xZrxO12 Ceramics

2021 ◽  
Author(s):  
Haibo YU ◽  
Yanliang WEI ◽  
Xiaolin ZHANG ◽  
Dang WANG ◽  
Yuying ZHANG ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Grain Boundaries ◽  
Single Phase ◽  
Reaction Sintering ◽  
Doping Amount ◽  
Sem Images ◽  
Grain Sizes ◽  
Ceramic Samples ◽  
All Ceramic ◽  
Sintering Method

Abstract Dielectric properties of CaCu3Ti4O12 (CCTO) ceramics were studied by doping amount of Zr4+ donor on the basis of doping Y3+ donor. Ca0.97Y0.03Cu3Ti4-xZrxO12 (x=0, 0.005, 0.010, 0.015, CYCTZO) ceramics were prepared by reaction sintering method, and the phase structure, microstructure and dielectric properties of the ceramics were studied. The single phase CCTO was detected in all ceramic samples. SEM images of samples showed a high density and uniform-sized microstructure, and the average grain sizes of the ceramics was reduced with increasing content of Zr4+ donor. Interestingly, the dielectric constant (εr) was increased significantly while the dielectric loss tangent (tanδ) was decreased with the suitable doping amount of Zr4+. CYCTZO ceramics with x=0.010 exhibited a relatively high εr value of 1.02×105 at 1kHz. Meanwhile, the improved grain boundaries response and dielectric properties were closely related to the strengthened grain boundaries resistance (Rgb). The present results indicate that the εr was improved and the tanδ was reduced by doping Zr4+ donors in Ca0.97Y0.03Cu3Ti4O12 (CYCTO) ceramics and explained that the electrical properties were closely related to the electrical heterogeneity of ceramic grains and grain boundaries.

Low-Temperature Sintering and Dielectric Properties of (Zn1-xMgx)TiO3

2007 ◽  
Vol 546-549 ◽  
pp. 2215-2218 ◽  
Author(s):  
Xiang Chun Liu ◽  
Feng Gao ◽  
Ming Zhao ◽  
Chang Sheng Tian
Keyword(s):  
Dielectric Properties ◽  
Stability Region ◽  
Sintering Temperature ◽  
Hexagonal Phase ◽  
Chemical Processing ◽  
Low Temperature Sintering ◽  
Sintering Aids ◽  
Densification Temperature ◽  
Measuring Frequency ◽  
Dielectric Ceramics

The dielectric ceramics comprised of (Zn1-xMgx)TiO3 (x=0.1~0.5, abbreviated to ZMT) were developed by conventional mixed-oxide method combined with a semi-chemical processing. V2O5 was used as sintering aids to lower the sintering temperature of ceramics. The results showed that the hexagonal phase stability region extended from 900 to 1150°C as the amount of magnesium increased. The densification temperature of ZMT ceramics could be reduced from 1200 to 875°C by V2O5 additions and using semi-chemical processing, the relative density of ZMT ceramics with 1.00wt% V2O5 addition reach 95% at 875°C. The dielectric properties of ZMT were measured at different frequencies and the results showed that there existed a decreasing tendency of the loss tangents (tg δ) with increasing measuring frequency. It is concluded that εr=22 and tg δ= 5.7×10-4 can be obtained for ZMT ceramics at sintering temperature 875°C.

Sign in / Sign up

Export Citation Format

Share Document