Fabrication and Characterization of Perovskite SrZrO3 Ceramics through a Combustion Technique

2009 ◽  
Vol 421-422 ◽  
pp. 223-226 ◽  
Author(s):  
Atthakorn Thongtha ◽  
Theerachai Bongkarn

Perovskite SrZrO3 ceramics were successfully prepared via a combustion technique. The effect of calcination temperatures (900-1400oC) and sintering temperatures (1400-1650oC) on phase and morphology evolution of perovskite SrZrO3 ceramics were studied. The highest purity of perovskite phase powder was obtained at 1250 oC and the purity of the perovskite phase of SrZrO3 ceramics were detected in the samples sintered at 1550 oC for 6 h. The SEM results showed the average particle size (84-214 nm) and the average grain size (0.35-2.09 µm) of samples increased with the increase of firing temperatures. The shrinkage of the ceramics increased as the sintering temperatures increased. The maximum density was ~98.4% of the theoretical density for the sample sintered at 1550 oC for 6 h.

2008 ◽  
Vol 55-57 ◽  
pp. 173-176 ◽  
Author(s):  
C. Wattanawikkam ◽  
Theerachai Bongkarn

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.


2011 ◽  
Vol 474-476 ◽  
pp. 1711-1714 ◽  
Author(s):  
Panadda Sittiketkron ◽  
Arrak Klinbumrung ◽  
Theerachai Bongkarn

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.


2009 ◽  
Vol 421-422 ◽  
pp. 247-250 ◽  
Author(s):  
Atthakorn Thongtha ◽  
Kritsana Angsukased ◽  
Theerachai Bongkarn

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.


2011 ◽  
Vol 284-286 ◽  
pp. 839-843 ◽  
Author(s):  
Li Li Wang ◽  
Jin Chen ◽  
Guang Cheng Yang ◽  
Fu De Nie

A carbonate precursor with high sintering activity was prepared by co-precipitation method under ultrasonic radiation. This precursor precipitant completely transformed to pure YAG phase after being calcined at 900 °C for 4 h. The properties of YAG nanopowders obtained under different synthetic process were studied by XRD, TG-DSC, FT-IR and SEM. The results show that the ultrasonic radiation can fine the precursor and reduce its agglomeration. YAG nanopowders with an average particle size of about 60 nm were obtained and particles were sphere-shaped with good dispersity.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Negin Mohammadi ◽  
Zahra Khakpour ◽  
Amir Maghsoudipour ◽  
Aida Faeghinia

The perovskite Lanthanum Strontium Cobalt Ferrite (LSCF) is investigated as the cathode material used in intermediate-temperature solid oxide fuel cells (IT-SOFCs). In the present study, La0.6−xDyxSr0.4Co0.2Fe0.8O3−δ (x = 0, 0.3, 0.6) was synthesized through the coprecipitation method. The obtained precipitate was calcined at 500, 700, 900, and 1000°С. Phase characterization of the synthesized LSCF and LDySCF powder before and after heat treatment at 700°С was carried out by X-ray diffraction (XRD) analysis. XRD patterns revealed that the perovskite phase was obtained at 700°С in all calcined samples. Chemical bond study to investigate the synthesis process was conducted using the Fourier transform infrared spectroscopy technique. Thermal analysis of DTA and TG has been utilized to investigate how the calcination temperature affects the perovskite phase formation. According to the STA results, the perovskite phase formation started at 551°С and completed at 700°С. The density values of synthesized powders were 6.10, 6.11, and 6.37 g·cm−3for the undoped and doped samples calcined at 700°С. Powder morphology was studied by field emission scanning electron microscopy (FE-SEM). The micrographs showed the spherical-shaped particles with the average particle size of 24–131 nm.


2009 ◽  
Vol 67 ◽  
pp. 259-264
Author(s):  
D.K. Singh ◽  
R.R. Yadav ◽  
D.K. Pandey

Nanoparticles of chromic oxide (Cr2O3) are widely used in many fields serving as catalysts, wear resistance materials, and advanced colorants. By the reaction system of CrO3 and PVA in aqueous solution, Cr2O3 nanoparticles were prepared via hydrothermal synthesis. We have taken sucrose as reducing agent. The products were loosely agglomerated Cr2O3 particles of 30-80 nm in average particle size calculated from Scherrer’s formula, whose microstructure and the precursor were investigated by SEM. The findings showed that the higher calcination temperatures result in the larger average particle size. Ultrasonic velocity measurements in Cr2O3 nanoparticles suspended in PVA solution were made at different thermal conditions. In the sample Cr2O3+PVA the ultrasonic velocity increases up to 500C and then remains constant. The effort has been made to correlate the ultrasonic velocity/absorption behavior with the magnetic property.


2008 ◽  
Vol 55-57 ◽  
pp. 197-200 ◽  
Author(s):  
Atthakorn Thongtha ◽  
Kritsana Angsukased ◽  
Theerachai Bongkarn

The effect of calcination temperatures (1000-1400 oC) on the phase formation and microstructure of barium strontium zirconate titanate [(Ba0.25Sr0.75)(Zr0.75Ti0.25)O3 ; BSZT] powders were investigated. BSZT powders were prepared and compared by the solid state reaction method and the combustion technique. The higher calcination temperatures increased the percentage of the perovskite phase, but decreased the lattice parameter a. The same crystallographic pure perovskite phase of BSZT powders, which were prepared via the combustion technique were detected above 1300 oC ; which was lower than the calcinations temperature of mixed oxide method by 50 oC. The TGA-DTA results corresponded to XRD investigation. The microstructure of BSZT powders, which were prepared using both techniques, exhibited an almost-spherical morphology and had a porous agglomerated form. The average particle sizes of BSZT powders prepared via the combustion technique (0.13-0.30 µm) and the solid state reaction method (0.18-0.38 µm) were increased with the increase of calcinations temperatures


2020 ◽  
Author(s):  
Negin Mohammadi ◽  
Zahra Khakpour ◽  
Amir Maghsoudipour ◽  
Aida Faeghinia

Abstract The perovskite Lanthanum Strontium Cobalt Ferrite (LSCF) is investigated as the cathode material used in intermediate temperature solid oxide fuel cells (IT-SOFCs). In the present study, La0.6-xDyxSr0.4Co0.2Fe0.8O3-δ(x= 0, 0.3, 0.6) was synthesized through co precipitation method. The obtained precipitate was calcined at500, 700,900and 1000°С. Phase characterization of synthesized LSCF and LDySCF powder before and after heat treatment at 700°Сwas carried out by X-ray diffraction (XRD) analysis. XRD patterns revealed that the perovskite phase was obtained at 700 °С in all calcined samples. Chemical bond study to investigate synthesis process was done using the Fourier transform infrared spectroscopy technique. Thermalanalysis of DTA and TG has been utilized to investigate how the calcination temperature affects the peroveskite phase formation. According to the STA results, the perovskite phase formation started at 551°Сafterwarditcompleted at 700°С.The density values of synthesized powders were 6.10, 6.11 and 6.37g.cm-3for the undoped and doped samples calcined at 700°С. Powder morphology was studied by Field emission scanning electron microscopy. (FE-SEM) micrographs showed the spherical shaped particles with the average particle size of 24-131nm.


2008 ◽  
Vol 55-57 ◽  
pp. 185-188
Author(s):  
Theerachai Bongkarn ◽  
C. Wicheanrat

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.


2011 ◽  
Vol 415-417 ◽  
pp. 617-620 ◽  
Author(s):  
Yan Su ◽  
Ying Yun Lin ◽  
Yu Li Fu ◽  
Fan Qian ◽  
Xiu Pei Yang ◽  
...  

Water-soluble gold nanoparticles (AuNPs) were prepared using 2-mercapto-4-methyl-5- thiazoleacetic acid (MMTA) as a stabilizing agent and sodium borohydride (NaBH4) as a reducing agent. The AuNPs product was analyzed by transmission electron microscopy (TEM), UV-vis absorption spectroscopy and Fourier transform infrared spectroscopy (FTIR). The TEM image shows that the particles were well-dispersed and their average particle size is about 5 nm. The UV-vis absorption and FTIR spectra confirm that the MMTA-AuNPs was stabilized by the carboxylate ions present on the surface of the AuNPs.


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