Crystallization Behavior in Precursor-Modified Sol-Gel Lead

1992 ◽  
Vol 284 ◽  
Author(s):  
Titanate Powders ◽  
Wei-Heng Shie ◽  
Qing Lu ◽  
Wan Y. Shih
Keyword(s):  
Crystallite Size ◽  
Crystallization Behavior ◽  
Sol Gel ◽  
Weight Percent ◽  
Titanium Isopropoxide ◽  
Structural Units ◽  
X Ray ◽  
Nucleation Sites ◽  
Gel Processing ◽  
Gel Network

ABSTRACTThe molecular structure of precursors in sol-gel processing of PbTiO3 is modified via β-diketone substitution for the isopropyl groups of titanium isopropoxide. Crystallite size and crystallization behavior are studied using x-ray diffractometry and differential thermal analysis. The crystallite size decreases with increasing amount of β-diketone substitution. Whereas the weight percent of crystalline phase first decreases and then increases with increasing β-diketone substitution. Our results indicate that the β-diketone substitution reduces the size of the structural units in the gel network resulting in smaller crystallite size and more nucleation sites in the powders produced.

Surface Morphology of Anatase TiO2 Thin Film by Sol-Gel Method

2006 ◽  
Vol 517 ◽  
pp. 135-140 ◽  
Author(s):  
N. Al-Jufairi
Keyword(s):  
Sol Gel ◽  
Titanium Isopropoxide ◽  
Optical Microscope ◽  
Processing Route ◽  
Coating Process ◽  
Coating Films ◽  
Anatase Structure ◽  
Interferometric Technique ◽  
Structure Phase ◽  
Gel Processing

Sol-gel processing route has been used for the production of thin films from titanium isopropoxide (TIP). The surface properties and statistics results have been characterized by AFM; the coating process has been examined using SEM and optical microscope. The structure phase of TiO2 has been analyzed by XRD; the composition of TiO2 has been estimated through EDS; the thickness of film has been measured by polarized microscope in an interferometric technique. The coating films are always crystallined in the anatase structure with circular particles in nanometer size.

Structure and Morphology Properties of Nanosized La0.75K0.05Ba0.05Sr0.15MnO3 Manganite

2020 ◽  
Vol 860 ◽  
pp. 106-111
Author(s):  
Dhawud Sabilur Razaq ◽  
Budhy Kurniawan ◽  
Ikhwan Nur Rahman ◽  
Dicky Rezky Munazat
Keyword(s):  
Bond Length ◽  
Crystallite Size ◽  
Sintering Temperature ◽  
Bond Angle ◽  
Sol Gel ◽  
Rhombohedral Structure ◽  
Phase Purity ◽  
X Ray ◽  
Structure And Morphology ◽  
Scanning Electron

Nanosized La0.75K0.05Ba0.05Sr0.15MnO3 manganite have been synthesized using sol-gel method. Afterwards, the samples were sintered at eight different temperature ranging from 650 to 1000 °C. Phase purity, crystal structure and the morphology of the sample have been examined using X-Ray Diffractometer (XRD) and Scanning Electron Microscope. It has been found that different higher sintering temperature greatly affect the phase purity and crystallite size of the sample. Regardless of the sintering temperature, all the samples crystallized in rhombohedral structure with R-3c space group. The crystallite size of the samples is found to increase from 41.59 nm up to 73.42 nm as the sintering temperature increases. Further analysis from XRD result shows that sintering temperature also affect the average Mn-O bond length and Mn-O-Mn bond angle of the sample. The average Mn-O bond length is found to increase while the average Mn-O-Mn bond angle tends to decrease as sintering temperature increases. SEM measurement shows that various grain size ranging from ~100 nm up to ~ 350 nm exists in all the sample regardless the sintering temperature.

Sol-gel processing of nanocrystalline haematite thin films

1997 ◽  
Vol 12 (6) ◽  
pp. 1441-1444 ◽  
Author(s):  
L. Armelao ◽  
A. Armigliato ◽  
R. Bozio ◽  
P. Colombo
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Raman Spectroscopy ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Single Particles ◽  
X Ray ◽  
Transmission Electron ◽  
Gel Processing

The microstructure of Fe2O3 sol-gel thin films, obtained from Fe(OCH2CH3)3, was investigated by x-ray diffraction (XRD), transmission electron microscopy (TEM), and Raman spectroscopy. Samples were nanocrystalline from 400 °C to 1000 °C, and the crystallized phase was haematite. In the coatings, the α–Fe2O3 clusters were dispersed as single particles in a network of amorphous ferric oxide.

Gel-derived amorphous cesium-aluminosilicate powders useful for formation of pollucite glass-ceramics

1991 ◽  
Vol 6 (2) ◽  
pp. 217-219 ◽  
Author(s):  
Mari A. Hogan ◽  
Subhash H. Risbud
Keyword(s):  
Electron Microscopy ◽  
Sol Gel ◽  
Glass Ceramics ◽  
Amorphous Powder ◽  
Glass Crystallization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Amorphous Powders ◽  
Gel Processing ◽  
Scanning Electron

Amorphous powders in the Cs2O–Al2O3−SiO2 system were prepared by sol-gel processing. Gels made from TEOS, Al-chelate, and Cs-acetate were dried and calcined to obtain molecularly mixed powders of analyzed compositions in the range useful for conversion to pollucite (CsAlSi2O6) glass-ceramics. X-ray diffraction (XRD), differential thermal analysis (DTA), thermogravimetry (TG), and scanning electron microscopy (SEM) were used to characterize the powders. A typical amorphous powder of analyzed chemical composition (in wt.%) = 28.05Cs2O, 37.77SiO2, and 37.96Al2O3 was found to have a glass transition temperature of 945 °C and a glass crystallization temperature of 1026 °C. Preliminary experimental results of densification and crystallization of the amorphous powders show pollucite/mullite phases to be present.

Microscopic Characterization and Analysis of Electrospun TiO2-PVP and TiO2-PVDF Fibers

2017 ◽  
Vol 264 ◽  
pp. 33-37 ◽  
Author(s):  
Joshua Zheyan Soo ◽  
Bee Chin Ang ◽  
Boon Hoong Ong
Keyword(s):  
Molecular Weight ◽  
Polyvinylidene Fluoride ◽  
Sol Gel ◽  
Titanium Isopropoxide ◽  
Electrospinning Technique ◽  
X Ray ◽  
Suitable Material ◽  
Fibre Network ◽  
Weight Concentration ◽  
Polymer Decomposition

Titanium dioxide (TiO2) is a suitable material to be used in the field of photocatalytic water treatment. In this research, TiO2 membrane fibers were synthesized using a combination of non-aqueous sol gel method and electrospinning technique. Titanium isopropoxide (TTIP) was used as the precursor for the TiO2 filler of the fibers. Both polyvinylpyrrolidone (PVP) and polyvinylidene fluoride (PVDF) were used as the polymer base to obtain the respective membrane fibers. The effects of weight concentration of TTIP as well as the type and molecular weight of the polymer on the morphology of the fibers were studied. Microscopic characterization using field-emission scanning electron microscopy (FESEM) and Energy Dispersive X-Ray (EDX) analysis was performed to obtain the morphology and elemental composition of the fibers. Sub-micron range fibers with a continuous network were generally obtained. Fibers that are subjected to post-electrospinning calcination have a lower fiber diameter. Polymer decomposition is shown to occur during calcination which yielded higher purity TiO2 fibers. The use of higher molecular weight polymers can produce a stronger fibre network for membranes.

MgO-Al2O3-SiO2 Glass-Ceramic Prepared by Sol-Gel Method

2010 ◽  
Vol 92 ◽  
pp. 131-137 ◽  
Author(s):  
Qiu Hua Yuan ◽  
Pei Xin Zhang ◽  
Li Gao ◽  
Hai Lin Peng ◽  
Xiang Zhong Ren ◽  
...  
Keyword(s):  
Glass Ceramic ◽  
Crystallization Behavior ◽  
Glass Powder ◽  
Sol Gel ◽  
Glass Ceramics ◽  
Green Body ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
Sio2 Glass ◽  
X Ray

The crystallization behavior of MgO-Al2O3-SiO2 glass-ceramics by sol-gel technology was investigated by using x-ray diffraction (XRD), differential thermal analysis (DTA), Scanning electron microscopy (SEM). The results showed that: (1)α-cordierite phase was precipitated when the green body was calcined at 1050°C, and α-cordierite of high purity and stability could be formed at 1100°C; (2) Adding an appropriate amount of low melting point glass powder into the green body may provide liquid-phase environment during the sintering process, which will help enhance the tightness density of glass-ceramic, and thus improve its flexural strength.

Dense and optical transparent CdWO4 films by sol-gel processing for scintillation applications

2007 ◽  
Vol 22 (6) ◽  
pp. 1527-1536 ◽  
Author(s):  
H.M. Shang ◽  
M. Bliss ◽  
S. Heald ◽  
T.K. Sham ◽  
F. Heigl ◽  
...  
Keyword(s):  
Sol Gel ◽  
Tungstic Acid ◽  
Cadmium Nitrate ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Optical Luminescence ◽  
Optically Transparent ◽  
Rapid Sintering ◽  
Gel Processing

In this paper, we report the first successful fabrication of dense and optically transparent cadmium tungstate (CWO) films by sol-gel processing and the study of their optical and x-ray scintillation properties. A new sol-gel processing method was developed using tungstic acid and cadmium nitrate as precursors and hydrogen peroxide as solvent; homogeneous and stable CWO sols were aged at room temperature and used for the preparation of CWO films. A rapid sintering process was investigated and found to be necessary to make dense and optically transparent nanocrystalline CWO films. CWO films were uniform, fully dense, and crack-free, with CWO as the only detectable crystalline phase, as determined by x-ray diffraction. The thickness, density, grain size, and crystallinity of CWO films are all found to be strongly dependent on the sintering conditions and in turn impact the optical and x-ray scintillation properties. Sol-gel-derived dense CWO films demonstrated intense photoluminescence and x-ray excited optical luminescence intensity. The relationships between sol-gel processing, nanostructures, and optical and x-ray scintillation properties are discussed in detail.

Performance Effect of ZnAl2O4 - SiO2 Thin Film for Wireless Patch Antenna Application

2014 ◽  
Vol 28 ◽  
pp. 141-150 ◽  
Author(s):  
Mohd Syafiq Zulfakar ◽  
Huda Abdullah ◽  
Mohammad Tariqul Islam ◽  
Wan Nasarudin Wan Jalal ◽  
Zalita Zainuddin ◽  
...  
Keyword(s):  
Crystallite Size ◽  
Patch Antenna ◽  
Sol Gel ◽  
Average Crystallite Size ◽  
Cubic Phase ◽  
Frequency Range ◽  
Performance Effect ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force

Polycrystalline of (1-x)ZnAl2O4 – xSiO2 compound with compositions of x = 0.00, 0.05, 0.10, 0.15, 0.20 and 0.25 have been prepared using sol-gel method. Structural properties was investigated by atomic force microscopy (AFM) and x-ray diffractometer (XRD). The AFM images analysis showed that the surface roughness of the highest composition had rougher surface compared with other samples. XRD measurement indicated that the crystallite size also increased with average crystallite size around 18 nm with cubic phase had been found. The dielectric permittivity value were measured with frequency range of 1 Hz to 1 MHz. It is showed that the dielectric value decreased as the freqeuncy was applied to the samples. The performance of the patch antenna showed that the antenna resonated at 3.30 GHz and give-13.87 dB with frequency range about 2 – 4 GHz.

Synthesis and Characterization of Cobalt Ferrite Nanoparticles via Sol-Gel Auto Combustion Method

2020 ◽  
Vol 307 ◽  
pp. 58-63
Author(s):  
Che Zaheerah Najeehah ◽  
Kashif Tufail Chaudhary ◽  
Jalil Ali
Keyword(s):  
Crystallite Size ◽  
Spinel Structure ◽  
Cobalt Ferrite ◽  
Sol Gel ◽  
Combustion Method ◽  
Spectral Lines ◽  
Hysteresis Curve ◽  
X Ray ◽  
Tauc Plot ◽  
Auto Combustion

This article reports the synthesis of cobalt ferrite (CoFe2O4) nanoparticles by low-cost sol-gel auto combustion method. The synthesized CoFe2O4 nanoparticles were characterized using X-ray Diffraction (XRD), Field Emission Scanning Electron Microscope (FESEM), Energy Dispersive X-ray (EDX), UV-Visible (UV-Vis), Fourier Transform Infrared Spectroscopy (FTIR) and Vibrating Sample Magnetometry (VSM). The XRD pattern inferred the formation of cubic spinel structure with average crystallite size 35.3 nm. The crystallite size was obtained in the range 32-37.5 nm in FESEM analysis. The elemental composition was confirmed using EDX spectroscopy. The presence of spectral lines at positions 465.57 cm-1 and 577.52 cm-1 associated to stretching vibrations of Co-O in octahedral sites and Fe-O in tetrahedral sites confirmed the spinel structure. The magnetic properties such as saturation magnetization (Ms) 67.79 emu/g, coercivity (Oe) 874.76 Oe and remnant (Mr) 29.07 emu/g were obtained from the hysteresis curve. The bandgap 1.409 eV was obtained for synthesized CoFe2O4 using Tauc plot from UV-Vis absorption spectra.

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