Synthesis and Characterization of Barium Strontium Titanate Nanocrystalline Powders Prepared by Direct Reactive Precipitation Method from Solution

2013 ◽  
Vol 634-638 ◽  
pp. 2301-2306 ◽  
Author(s):  
Qi An Zhu ◽  
Yao Wu ◽  
Xu Feng Sun ◽  
Xian Tan ◽  
Kai Zhan ◽  
...  
Keyword(s):  
Strontium Titanate ◽  
Barium Strontium Titanate ◽  
Ethanol Solution ◽  
Nanocrystalline Powders ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Tetrabutyl Titanate ◽  
Cubic Phase ◽  
Hydroxyl Groups ◽  
Barium Strontium

Barium strontium titanate nano powders were prepared by mixing ethanol solution of tetrabutyl titanate with an aqueous solution of Ba(OH)2•8H2O and Sr(OH)2•8H2O with a certain molar ratio of barium to strontium at 40°C－95°C. The products were characterized by thermogravimetry (TG), Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), transmission electron microscope (TEM) and atomic force microscopy (AFM). The results show that the powders prepared with the reactant concentration of 0.8M are spherical in particle shape with the grain size of 50nm－65nm. When the annealing temperature of the powders is higher than 906°C, the hydroxyl groups existed in barium strontium titanate lattice are removed. XRD analysis demonstrate that the as-prepared powders are cubic phase. All the diffraction peaks are shifted towards higher diffraction angles and the lattice parameter a calculated decreases linearly with serial decrease of the molar ratio of barium to strontium.

scholarly journals Effects of mechanical activation on the formation and sintering kinetics of barium strontium titanate ceramics

2020 ◽  
Vol 52 (4) ◽  
pp. 371-385
Author(s):  
Darko Kosanovic ◽  
Nebojsa Labus ◽  
Jelena Zivojinovic ◽  
Adriana Peles-Tadic ◽  
Vladimir Blagojevic ◽  
...  
Keyword(s):  
Mechanical Activation ◽  
Strontium Titanate ◽  
Barium Strontium Titanate ◽  
Cubic Phase ◽  
Sintering Kinetics ◽  
Barium Strontium ◽  
Short Period ◽  
Sintered Powder ◽  
Titanate Ceramics ◽  
Kinetics Of

The influence of mechanical activation on the formation, sintering kinetics and morphology was investigated in sintered barium strontium titanate (BST) ceramics with different Ba-to-Sr ratios. Initial powders were mechanically activated for 20 and 120 min, leading to mechano-chemical reaction and formation of BaxSr1-xTiO3 phases. Agglomeration was found to represent an important factor in the process of formation of BaxSr1-xTiO3 phases around 800?C and during sintering. It reduces the effectiveness of mechanical activation on formation of BaxSr1-xTiO3 phases beyond the short period (20 min), while in the process of sintering, prolonged mechanical activation (120 min) leads to a significant reduction in sintering temperature and the corresponding value of activation energy. In addition, all three systems show a phase transformation around 1100?C, attributed to the hexagonal-to-cubic phase transition. Morphology of the final sintered ceramics can be correlated primarily with the state of the pre-sintered powder, where mechanically activated powders with smaller particle size produced more compact and less porous final product.

OPTICAL AND STRUCTURAL PROPERTIES OF NANO-SIZED BARIUM STRONTIUM TITANATE (Ba0.6Sr0.4TiO3) THIN FILM

2008 ◽  
Vol 22 (09) ◽  
pp. 693-700 ◽  
Author(s):  
S. BOBBY SINGH ◽  
H. B. SHARMA ◽  
H. N. K. SARMA ◽  
SUMITRA PHANJOUBAM
Keyword(s):  
Thin Films ◽  
Strontium Titanate ◽  
Barium Strontium Titanate ◽  
Sol Gel ◽  
Processing Technique ◽  
Cubic Phase ◽  
Bst Thin Films ◽  
Barium Strontium ◽  
Free Films ◽  
Quartz Substrates

Barium strontium titanate ( Ba 0.6 Sr 0.4 TiO 3) or BST thin films on quartz substrates have been prepared by using a modified sol-gel processing technique. The starting materials are barium 2-ethylhexanoate Ba[CH 3( CH 2)3 CH(C 2 H 5) CO 2]2, strontium 2-ethylhexanoate Sr[CH 3( CH 2)3 CH(C 2 H 5) CO 2]2 and titanium (IV) isopropoxide Ti[CH 3 CH 3 CHO ]4. The precursors Ti[CH 3 CH 3 CHO ]4 except were synthesized in the laboratory. Transparent and crack-free films were fabricated on quartz substrates by spin coating. The as-fired films were found to be amorphous, which crystallized to cubic phase after annealing at 550°C in air for 1 hr. In this paper, we report the structural and optical properties of BST thin films prepared by the modified sol-gel process.

A phase shifter on a slot line loaded with varactors designed on the basis on nanodimensional films of barium-strontium titanate

2007 ◽  
Vol 52 (11) ◽  
pp. 1300-1304 ◽  
Author(s):  
Vas. M. Mukhortov ◽  
S. I. Masychev ◽  
Yu. I. Golovko ◽  
A. V. Chub ◽  
Vl. M. Mukhortov
Keyword(s):  
Strontium Titanate ◽  
Barium Strontium Titanate ◽  
Phase Shifter ◽  
Slot Line ◽  
Barium Strontium

Structural, thermal and optoelectrical properties of pure and gadolinium doped barium strontium titanate for DSSC applications

2021 ◽  
Author(s):  
S. Karthikeyan ◽  
P. Thirunavukkarasu ◽  
S. Surendhiran ◽  
Y.A. Syed Khadar ◽  
A. Balamurugan ◽  
...  
Keyword(s):  
Strontium Titanate ◽  
Barium Strontium Titanate ◽  
Barium Strontium
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