Effect of Calcination Temperatures on Microstructure and Phase Formation of Ba(Zr0.25Ti0.75)O3 Powders

2008 ◽  
Vol 55-57 ◽  
pp. 205-208 ◽  
Author(s):  
Theerachai Bongkarn ◽  
N. Phungjitt ◽  
Naratip Vittayakorn

In this work, the effect of calcination temperatures on the microstructure and phase formation of Ba(Zr0.25Ti0.75)O3 (BZT) powders were investigated. The BZT powders were prepared via the solid state reaction method under various calcination temperatures. It was found that the second phases such as BaCO3, ZrO2, BaZrO3 and Ba2ZrO4 existed in samples with calcination temperature below 1200 oC. Homogeneity and a highly pure perovskite phase of the BZT powders were obtained with calcination condition at 1300 oC for 4 h. Lattice parameter a and the percentage of cubic perovskite phase tended to increase with increasing calcination temperatures. The TG-DTA results corresponded to the XRD investigation. The microstructures of calcined powders exhibited an almost-spherical morphology and had a porous agglomerated form in all samples. The average particle sizes were increased from 0.2 to 1.1mµ when calcination temperatures were increased from 800 to 1350 oC.

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


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.


2009 ◽  
Vol 421-422 ◽  
pp. 243-246 ◽  
Author(s):  
R. Sumang ◽  
Theerachai Bongkarn

(Pb1-xSrx)TiO3 (PST) (x=0.25, 0.50) powders were synthesized by a mixed oxide solid-state reaction method under various calcination temperatures (600-1100oC). Powder samples were characterized using thermogravimetric (TGA), differential thermal analysis (DTA), x–ray diffractrometer (XRD) and scanning electron microscopy (SEM). The results showed that a single-phase of PST for x=0.25 and 0.50 powders was successfully obtained with a calcination condition of 950 oC for 2 h with a heating/cooling rate of 5oC/min. The TGA-DTA results corresponded to the XRD investigation. The lattice parameter a increased whilst the lattice parameter c decreased with increasing calcination temperatures. The tetragonality of powders decreased with an increase of calcination temperatures. The average particle size of the powders increased with the increase of calcination temperature.


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.


2008 ◽  
Vol 55-57 ◽  
pp. 181-184 ◽  
Author(s):  
Theerachai Bongkarn ◽  
W. Khiawwangthong

In this work, the optimum conditions for the preparation of barium stannate titanate (Ba(Sn0.05Ti0.95)O3 ; BST5) ceramics by solid state reaction method were investigated. The samples were heated at calcination temperatures from 600 to 1200 oC for 4 h and sintering temperatures from 1250 to 1400 oC for 2 h. Thermogravimetric analysis (TGA) and differential thermal analysis (DTA) were used to evaluate the optimum conditions for calcination. The phase formation was carried out by X-ray diffractometer (XRD). The microstructure was studied by using a scanning electron microscope (SEM). It was found that, a high purity of perovskite powders were obtained with a calcinations temperature at 1200 oC. The percent of the perovskite phase and lattice parameter a were increased by increasing the calcination temperatures. The average particle size was increased from 0.6 to 1.0 µm when increasing the calcination temperatures from 600 to 1200 oC. A pure cubic perovskite phase was found in all the sintered samples. The average grain size is in the range of 1.2 to 43.3 µm when increasing of sintering temperatures from 1250 to 1400 oC. The maximum of density and dielectric constant was observed in a 1400 oC sintered pellet.


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.


2016 ◽  
Vol 690 ◽  
pp. 51-56 ◽  
Author(s):  
Manlika Kamnoy ◽  
Piewpan Parjansri ◽  
Uraiwan Intatha ◽  
Sukum Eitssayeam ◽  
Tawee Tunkasiri

The study was conducted to find out the effect of particle sizes of BaTiO3 (BT) seed on the microstructure and electrical properties of (Ba0.85Ca0.15)(Zr0.1Ti0.9)O3 (BCZT) ceramics. The BT seeds were prepared by the molten salt method. Results indicated that the BT seed powder showed a single pure perovskite phase when using a low temperature of ~750°C. The particle sizes of BT seeds increased from ~381 to ~600 nm with increasing heating temperatures from 750 to 900°C. After that, the different BT seeds were mixed with BaCO3, CaCo3, ZrO2 and TiO3 via the solid state reaction method. The mixed powder was calcined and sintered at 1200 °C for 2 h and 1450 °C for 4 h, respectively. The microstructure, phase formation and electrical properties were investigated. All ceramic samples showed a pure perovskite phase. The density and average grain size values of ceramics were in the range of 5.36-5.47 g/cm3 and 9.83-11.86 μm, respectively. The highest values of dielectric constant (εr), piezoelectric constant (d33) were 3393 and 452 pC/N, respectively which obtained at the sample of BT-seed size 372 nm doped.


RSC Advances ◽  
2017 ◽  
Vol 7 (60) ◽  
pp. 37765-37770 ◽  
Author(s):  
Huanhuan Liu ◽  
Long Yuan ◽  
Hui Qi ◽  
Yanyan Du ◽  
Shan Wang ◽  
...  

Reversible thermochromic inorganic materials of Sm3Fe5O12with different particle sizes have been synthesized by a conventional high temperature solid state reaction method (2.51 μm) and sol–gel method (0.16 μm).


2011 ◽  
Vol 497 ◽  
pp. 31-37 ◽  
Author(s):  
Toru Kyomen ◽  
Ryuta Motani ◽  
Minoru Hanaya

Powder of Pr-doped CaTiO3 red phosphor was prepared at 1473 K by a conventional solid-state reaction method with addition of B2O3 or SiO2 as a flux. Primary particle sizes of the prepared samples were increased by using B2O3 flux but decreased by using SiO2 flux. Clear planes, edges, or steps were observed on surfaces of the primary particles. The intensity of photoluminescence induced by irradiation of light with a wavelength longer than ∼350 nm was enhanced about three times by using B2O3 flux. The intensity of photoluminescence induced by irradiation of light with a wavelength shorter than ∼350 nm was enhanced about twice by using either B2O3 or SiO2 fluxes. The origin for the flux effects is discussed.


2018 ◽  
Vol 50 (1) ◽  
pp. 133-138 ◽  
Author(s):  
Lizina Khatua ◽  
Rudrashish Panda ◽  
Avanendra Singh ◽  
Arpan Nayak ◽  
Pravakar Satapathy ◽  
...  

In this work, the ZnO-TiO2 mixed phase nanoparticles were prepared by solid state reaction method by using ZnO and TiO2 powder as precursors. The X-ray diffraction pattern shows a dominant phase of Zinc Orthotitanate (Zn2TiO4). The average particle size (58?18 nm) calculated by the analysing FESEM data closely matches with the particle size calculated by Scherrer?s equation. The calculated average particle size is significantly smaller than the previously published results of nanoparticles, prepared by same method. In the Brunauer-Emmett-Teller (BET) study the specific surface area of the nanoparticles was found as 8.78 m2/g which is similar to the surface area reported in this material prepared by mechanochemical method. The method which we report is simpler and cost effective unlike the previous reported.


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