Preparation of Barium Strontium Titanate Ceramics via Combustion Method

2008 ◽  
Vol 55-57 ◽  
pp. 185-188
Author(s):  
Theerachai Bongkarn ◽  
C. Wicheanrat
Keyword(s):  
Crystal Structure ◽  
Perovskite Phase ◽  
Average Particle Size ◽  
Combustion Method ◽  
Cubic Phase ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Pure Perovskite Phase ◽  
Average Grain Size ◽  
Titanate Ceramics

This study concentrated on the crystal structure and microstructure of [(Ba0.75Sr0.25)TiO3; (BST)] ceramics at different firing temperatures. The BST powders were prepared by a combustion method. (CO(NH2)2) was used as a fuel. Crystallinity of the calcined powders was improved by increasing the calcining temperature, as indicated by the increase in intensity of the X-ray diffraction peak. The pure perovskite phase of BST powders was obtained with a calcinations condition of 1200 oC. The a axis lattice constant of BST calcined powders and sintered ceramics were calculated and it was found that the crystal structure is a cubic phase. The microstructure of BST calcined powders and sintered ceramics were analyzed by a scanning electron microscope (SEM). The SEM result indicated that the average particle size and average grain size increased with the increase of calcinations and sintering temperatures, respectively. The apparent density of the samples was measured by the Archimedes method.

Influence of Excess Bi2O3 and Na2Co3 on Crystal Structure and Microstructure of Bismuth Sodium Titanate Ceramics

2011 ◽  
Vol 474-476 ◽  
pp. 1711-1714 ◽  
Author(s):  
Panadda Sittiketkron ◽  
Arrak Klinbumrung ◽  
Theerachai Bongkarn
Keyword(s):  
Crystal Structure ◽  
Dielectric Properties ◽  
Perovskite Phase ◽  
Average Particle Size ◽  
Sodium Titanate ◽  
Solid State Reaction Method ◽  
Lattice Parameter ◽  
Rhombohedral Structure ◽  
Average Particle ◽  
Average Grain Size

This study investigated the influence of excess Bi2O3 and Na2CO3 on the crystal structure, microstructure and dielectric properties of (Bi0.5Na0.5)TiO3 (BNT) ceramics. The BNT ceramics were synthesized using the solid-state reaction method with various excess Bi2O3 and Na2CO3 levels (0, 1, 2, 3 and 4 mol%). The X-ray characterization revealed that all samples had a rhombohedral structure. A pure perovskite phase was obtained in all samples. The lattice parameter a tended to increase with increased excess Bi2O3 and Na2CO3 content in the calcined powders and sintered ceramics. The average particle size increased while, the average grain size tended to decreased with increased of excess Bi2O3 and Na2CO3 content. The depolarization temperature (Td) and the Curie temperature (Tc) were slightly decreased with the increase of excess Bi2O3 and Na2CO3 content. The dielectric properties were related to the density.

Low-temperature fabrication of pyroelectric Ba0.8Sr0.2TiO3 thin films by a sol-gel process

2001 ◽  
Vol 16 (3) ◽  
pp. 778-783 ◽  
Author(s):  
Jian-Gong Cheng ◽  
Jun Tang ◽  
Shao-Ling Guo ◽  
Jun-Hao Chu
Keyword(s):  
Perovskite Phase ◽  
Sol Gel ◽  
Pyroelectric Coefficient ◽  
X Ray Diffraction ◽  
Electrical Measurements ◽  
Pure Perovskite Phase ◽  
Average Grain Size ◽  
Sol Gel Process ◽  
Columnar Grains ◽  
Uncooled Infrared Detectors

Ba0.8Sr0.2TiO3 films were fabricated with a 0.05 M solution by a sol-gel process at temperatures between 550 and 650 °C. Analysis by x-ray diffraction, Raman spectroscopy, and scanning electron microscopy revealed that the films annealed at 650 °C showed pure perovskite phase, tetragonal structure, and columnar grains with an average grain size of 150 nm. Electrical measurements performed on the films annealed at 650 °C showed two dielectric peaks in the dielectric constant–temperature curve, a remnant polarization of 1.4 μC/cm2, a coercive field of 18.3 kV/cm, and good insulating property. The measured pyroelectric coefficient for the films annealed at 650 °C was larger than 3.1 × 10−4 C/m2K at the temperatures ranging from 10 to 26 °C and reached the maximum value of 4.1 × 10−4 C/m2K at 16 °C. The excellent pyroelectric property rendered the Ba0.8Sr0.2TiO3 films annealed at 650 °C promising for uncooled infrared detectors and thermal imaging applications.

Frequency dependence and fuel effect on optical properties of nano TiO2-based structures

2016 ◽  
Vol 30 (18) ◽  
pp. 1650247 ◽  
Author(s):  
Mahdi Ghasemifard ◽  
Misagh Ghamari ◽  
Meysam Iziy
Keyword(s):  
Particle Size ◽  
Optical Properties ◽  
Average Particle Size ◽  
Combustion Method ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Nano Tio2 ◽  
Transmission Electron ◽  
Auto Combustion ◽  
Xrd Patterns

TiO2-(Ti[Formula: see text]Si[Formula: see text]O2 nanopowders (TS-NPs) with average particle size around 90 nm were successfully synthesized by controlled auto-combustion method by using citric acid/nitric acid (AC:NA) and urea/metal cation (U:MC). The structure of powders was studied based on their X-ray diffraction (XRD) patterns. The XRD of TS-NPs shows that rutile and anatase are the main phases of TS-NPs for AC:NA and U:MC, respectively. Particle size and histogram of nanopowders were characterized by transmission electron microscopy (TEM) and dynamic light scattering (DLS). Optical properties of TS-NPs were calculated by Fourier transform infrared spectroscopy (FTIR) and Kramers–Kroning (KK) relation. Plasma frequencies of TS-NPs obtained from energy loss functions depend on fuels as a result of changes in crystal structure, particle size distribution, and morphology.

Fabrication of Barium Stannate Tatanate Ceramics via Combustion Technique

2008 ◽  
Vol 55-57 ◽  
pp. 173-176 ◽  
Author(s):  
C. Wattanawikkam ◽  
Theerachai Bongkarn
Keyword(s):  
Perovskite Phase ◽  
Average Particle Size ◽  
Combustion Method ◽  
Lattice Parameter ◽  
Average Particle ◽  
Calcination Temperatures ◽  
Grain Sizes ◽  
Barium Stannate ◽  
Calcined Temperature ◽  
Combustion Technique

The effect of firing temperatures on phase formation and microstructure of barium stannate titanate [Ba(Sn0.1Ti0.9)O3; BST10] ceramics were investigated. BST10 was synthesized via a combustion method, at various calcination and sintering temperatures. It was found that, a single perovskite of BST10 powders was obtained with a calcinations temperature of 1200 oC. The percent of the perovskite phase and the lattice parameter were increased with increasing calcination temperatures. The average particle size was increased from 0.48 to 1.69 µm by increasing the calcined temperature from 600 to 1200 oC. The average grain sizes were increased from 0.99 to 17.77 µm by increasing the sintering temperature from 1250 to 1450 oC. The maximum density and dielectric constant were observed in sintered samples at 1350 oC.

Influences of Firing Temperatures on Phase and Morphology Evolution of (Ba0.25Sr0.75)(Zr0.75Ti0.25)O3 Ceramics Synthesized via Solid-State Reaction Method

2009 ◽  
Vol 421-422 ◽  
pp. 247-250 ◽  
Author(s):  
Atthakorn Thongtha ◽  
Kritsana Angsukased ◽  
Theerachai Bongkarn
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Perovskite Phase ◽  
Average Particle Size ◽  
Solid State Reaction Method ◽  
Lattice Parameter ◽  
Average Particle ◽  
Strontium Zirconate ◽  
Reaction Method ◽  
Average Grain Size

The effect of calcination (1000-1400 oC) and sintering temperatures (1400-1600 oC) on the phase formation and microstructure of barium strontium zirconate titanate [(Ba0.25Sr0.75)(Zr0.75Ti0.25)O3; BSZT] ceramics were investigated. BSZT powders were prepared by the solid-state reaction method. Higher calcination temperatures increased the percentage of the perovskite phase, but decreased the lattice parameter a of BSZT powders. The pure perovskite phase of BSZT powders was detected above the calcination temperature of 1350 oC. The microstructure of BSZT powders exhibited an almost-spherical morphology and had a porous agglomerated form. The average particle size and the average grain size of the ceramics were increased with the increase of calcination and sintering temperatures. The highest density of the samples was 5.42 g/cm3 which was obtained from ceramic sintered at 1550 oC for 2 h.

Dielectric Properties of Barium Titanate Ceramics Modified by CuO in Different Methods

2012 ◽  
Vol 463-464 ◽  
pp. 276-280 ◽  
Author(s):  
Dan Su ◽  
Yu Wang ◽  
Wan Ping Chen ◽  
Helen Lai Wah Chan ◽  
Li Na Bing
Keyword(s):  
Barium Titanate ◽  
Curie Temperature ◽  
Perovskite Phase ◽  
Hexagonal Phase ◽  
Boundary Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pure Perovskite Phase ◽  
The Difference ◽  
Titanate Ceramics

CuO has been doped solely and together with BaO and SiO2 into barium titanate by mixing and calcination. X-ray diffraction showed that the sample doped by CuO-BaO has stable second hexagonal phase while the samples doped by CuO, CuO-SiO2 were of a pure perovskite phase. For CuO-BaO doping, the Curie temperature was decreased accompanied with higher εmax; while for CuO doping and CuO-SiO2 codoping, the Curie temperature was increased with εmax decreased. The difference can be explained considering that Cu2+ ion could not only incorporate into the BaTiO3 lattice, but also assemble in the boundary phase when CuO was doped solely. Besides, the mechanisms of CuO doping and SiO2 doping could happen at one time.

Synthesis of n-Hexadecylphosphonic Acid-Coated Monodisperse Fe3O4 Superparamagnetic Nanoparticles

2012 ◽  
Vol 512-515 ◽  
pp. 170-173
Author(s):  
Xue Song Tang ◽  
Ming Li
Keyword(s):  
Crystal Structure ◽  
Particle Size ◽  
Drug Loading ◽  
Average Particle Size ◽  
Superparamagnetic Nanoparticles ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Cubic Crystal ◽  
Transmission Electron ◽  
Potential Applications

Monodisperse Fe3O4 Superparamagnetic Nanoparticles Were Synthesized in N-Hexadecylphosphonic Acid/ Cyclohexane/ Water/ Ethanol Microemulsion under Solvothermal Conditions at 100°C. the Crystal Structure and Particle Size of Synthesized Fe3O4 Were Observed by X-Ray Diffraction (XRD) as Well as Transmission Electron Microscopy (TEM). the Results Show that the Nanoparticles Have a Cubic Crystal System and a Average Particle Size of about 10nm. each Nanoparticle Has a Single Crystal Structure. the Surface Chemistry of Synthesized Fe3O4 Nanoparticles Was Characterized by Fourier Transform Infrared Spectroscopy (FTIR), Indicating that the Nanoparticles Were Covered by a Layer of N-Hexadecylphosphonic Acid, which Made the Nanoparticles Totally Lipophilic. Magnetic Properties of the Nanoparticles Were Investigated by Using Vibrating Sample Magnetometer (VSM). the Result Reveals that the Saturation Magnetization (Ms) of the Nanoparticles Is Higher than 40 Emu/G and the Coercive Force Is near to 0. the Monodisperse Fe3O4 Nanoparticles Have Superparamagnetic Property and May Find Potential Applications in many Fields, such as Ferrofluids, Drug Loading and Release, Selective Biomolecular Separation and MRI.

Nanostructured alumina doped TiO2 ceramics for gas sensors

2005 ◽  
Vol 900 ◽  
Author(s):  
Young Jin Choi ◽  
Amit Bandyopadhyay ◽  
Susmita Bose
Keyword(s):  
Particle Size ◽  
Anatase Phase ◽  
Average Particle Size ◽  
Combustion Method ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Auto Combustion ◽  
Average Surface Area

ABSTRACTNanostructured TiO2 based ceramics were synthesized using citrate-nitrate auto combustion method with different concentrations of aluminum oxide as dopant. The powder x-ray diffraction data showed that synthesized TiO2 powders, pure as well as alumina doped TiO2 had anatase phase. Dopant concentration was varied between 0 and 15 wt%. Particle size analysis showed that the particle size was in the range of 50 to 80nm for nanosized TiO2 calcined between 600 and 800°C. Average particle size of doped powders was generally less than pure TiO2. BET specific average surface area was between 10 and 25 m2/g. Doping upto 10wt% alumina is not effective in retarding anatase crystallite growth. The resistance of Al doped TiO2 sample is found to be lower than that of pure TiO2. Al2O3 doped TiO2 sensor was found to be selective to CO sensing at an operating temperature of 600 °C.

Comparison of Milling Techniques to Figure of Merit of 0.98PZT-0.02BYF Piezoelectric Ceramic Energy Harvester

2016 ◽  
Vol 690 ◽  
pp. 218-223
Author(s):  
Piyalak Ngernchuklin ◽  
Arjin Boonruang ◽  
Saengdoen Daungdaw ◽  
Nestchanok Yongpraderm
Keyword(s):  
Ball Milling ◽  
Figure Of Merit ◽  
Perovskite Phase ◽  
Average Particle Size ◽  
Pyrochlore Phase ◽  
Electrical Energy ◽  
High Energy ◽  
Average Particle ◽  
K Value ◽  
Pure Perovskite Phase

Nowadays, the concept of harvesting energy from the environment, for example, thermal, wind, sun, vibration and human activities is much of interest. PZT is one of the materials which show an ability to harness vibration energy and then change to electrical energy. Therefore, the PZT (Pb(Zr0.53Ti0.47)O3) doped with 0.02 mol% BYF (Bi(Y0.7Fe0.3)O3) piezoelectric ceramics has been studied to improve the figure of merit (d33*g33). The PZT and BYF powder systems were prepared by solid state reaction with calcination temperature of 800 and 850 °C for 2 h, respectively. XRD results showed that both powders exhibited pure perovskite phase for PZT and single phase of BYF without pyrochlore phase. Then, the two calcined powders (PZT and BYF) were mixed according to the composition of 0.02 mol% BYF doped PZT by two different milling techniques called conventional ball-milling (CBM) and high energy ball-milling (HBM) for 10 h. The result showed that average particle size obtain from HBM was 1 µm which was smaller than from CBM shown up to a few microns in bimodal mode. The PZT-BYF-HBM ceramics showed higher physical and electrical properties but lower K value. Thus promoting to higher g33 which was equal to 36.89 * 10-3(Vm/N) and FOM was 11,632*10-15(m2/N), while PZT-BYF-CBM had g33 of 26.86* 10-3(Vm/N) and FOM at 8,016*10-15(m2/N), respectively.

Microwave property improvement of Ca[(Li1/3Nb2/3)0.95Zr0.15]O3+δ perovskite by A-site substitution

2016 ◽  
Vol 30 (10) ◽  
pp. 1650123
Author(s):  
Mingzhe Hu ◽  
Gang Xiong ◽  
Zhao Ding
Keyword(s):  
Crystal Structure ◽  
Perovskite Phase ◽  
Microwave Dielectric Properties ◽  
Minor Amount ◽  
Second Phase ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
Microwave Dielectric ◽  
Pure Perovskite Phase ◽  
A Site

The crystal structure and microwave dielectric properties of Ca[(Li[Formula: see text]Nb[Formula: see text])[Formula: see text]Zr[Formula: see text]]O[Formula: see text] ceramic (CLNZ) are tuned by A-site substitution of Sr[Formula: see text] and Ba[Formula: see text] ions in the present paper. The tuning effect on the crystal structure is investigated by the X-ray diffraction (XRD) pattern and it illustrates that single phase of orthorhombic perovskite structure is formed, however, minor amount of BaNb2O6-type second phase is also detected in (Ca[Formula: see text]Ba[Formula: see text])[(Li[Formula: see text]Nb[Formula: see text])[Formula: see text]Zr[Formula: see text]]O[Formula: see text] ceramics (CBLNZ) in the range of [Formula: see text], while pure perovskite phase is obtained in (Ca[Formula: see text]Sr[Formula: see text][(Li[Formula: see text]Nb[Formula: see text])[Formula: see text]Zr[Formula: see text]]O[Formula: see text] ceramics (CSLNZ) in the whole investigation range of [Formula: see text]. With the increase of [Formula: see text] value, the unit cell volumes of both CBLNZ and CSLNZ perovskites gradually expand, which results in the degradation of the vibration bond strength between the B-site ions and oxygen in the perovskites. The microscopic structure related thermal parameters in CSLNZ and CBLNZ perovskites are analyzed in terms of Clausius–Mossotti equation to reveal the original contributors in the temperature coefficients. The results show that both Sr[Formula: see text] and Ba[Formula: see text] substitution can effectively improve the permittivity and [Formula: see text] value, especially, improve the temperature coefficient of CLNZ ceramic in a certain range.

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