Sol-Gel Processing and Structure Development of Lead Titanate Particles

1994 ◽  
Vol 346 ◽  
Author(s):  
John S. Wright ◽  
Lorraine Falter Francis
Keyword(s):  
Lead Titanate ◽  
Isopropyl Alcohol ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Amorphous Structure ◽  
Spherical Particles ◽  
Internal Surfaces ◽  
Reflectance Ftir ◽  
Gel Processing ◽  
Gel Network

ABSTRACTSpherical particles of lead titanate, PbTiO3, (PT) were prepared from partially hydrolyzed alkoxide solutions modified with benzoic acid. Modified and aged alkoxide solutions were added dropwise to isopropyl alcohol, forming particles (0.2 to 1.0 μm in diameter). FTIR spectroscopy results demonstrate chelation of the PT alkoxide which prevented the formation of an extended gel network. Diffuse reflectance FTIR (DRIFT) spectra indicate the benzoate ligands are present until 450°C; TGA results show significant weight loss at 450°C. PT particles crystallize into the perovskite phase at =450°C, as determined by DTA and XRD. The relatively low crystallization temperature may be due to the effect of benzoate ligands on amorphous structure and presence of internal surfaces.

ChemInform Abstract: Preparation of Undoped Lead Titanate Ceramics via Sol-Gel Processing.

ChemInform ◽  
2010 ◽  
Vol 30 (19) ◽  
pp. no-no
Author(s):  
Sunuk Kim ◽  
Myong-cheol Jun ◽  
Soon-cheol Hwang
Keyword(s):  
Lead Titanate ◽  
Sol Gel ◽  
Titanate Ceramics ◽  
Gel Processing

PVP-Mediated Crystallization of Perovskite Phase in the PMN-PT Thin Films Prepared by Sol-Gel Processing

2010 ◽  
Vol 93 (3) ◽  
pp. 686-691 ◽  
Author(s):  
Zehui H. Du ◽  
Tianshu S. Zhang ◽  
Minmin M. Zhu ◽  
Jan Ma
Keyword(s):  
Thin Films ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Gel Processing

Structural, Dielectric and Pyroelectric properties of Lanthanum modified Lead Titanate Thin Films

2004 ◽  
Vol 811 ◽  
Author(s):  
Sonalee Chopra ◽  
Seema Sharma ◽  
T.C. Goel ◽  
R.G. Mendiratta
Keyword(s):  
Thin Films ◽  
Lead Titanate ◽  
Mechanical Stability ◽  
Perovskite Phase ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Microstructural Analysis ◽  
Pyroelectric Coefficient ◽  
Structural Investigations ◽  
Glass Substrates

ABSTRACTFerroelectric lead lanthanum titanate (Pb1−xLaxTi1−x/4O3) (PLTx) thin films (x=0.04,0.08 and 0.12) have been prepared by sol-gel spin coating process on ITO coated 7059 Corning glass substrates. Investigations have been made on the crystal structure, surface morphology, dielectric and ferroelectric properties of the thin films. For a better understanding of the crystallization mechanism, the structural investigations were carried out at various annealing temperatures (350°C, 450°C, 550°C and 650°C). Characterization of these films by X-ray diffraction shows that the films annealed at 650°C exhibit tetragonal structure with perovskite phase. Replacement of lanthanum in lead titanate results in reduction of tetragonal ratio (c/a), resulting in better mechanical stability. Microstructural analysis of the films are carried out by taking the Atomic Force Microscope (AFM) pictures. AFM images are characterized by slight surface roughness with a uniform crack free, densely packed structure. Dielectric, pyroelectric and ferroelectric studies carried out on these films have been reported. Dielectric constant and pyroelectric coefficient increase while Curie temperature decreases with increase in La content. The pyroelectric figures of merit of the films have also been calculated which suggest that 8% lanthanum is best suited material for pyroelectric detectors owing to its high pyroelectric coefficient (∼ 29nC/cm2 K), high voltage responsivity (∼420Vcm2/J), high detectivity (∼1.04×10−5Pa−1/2) and low variation of pyrocoefficient with temperature.

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.

Synthesis of Ag-Containing CaO-SiO2 Gel and its Apatite Forming Ability in Simulated Body Fluid

2013 ◽  
Vol 587 ◽  
pp. 56-59 ◽  
Author(s):  
S.B. Cho ◽  
G.J. Yoon ◽  
E.M. An ◽  
Y.J. Kim ◽  
T.N. Kim ◽  
...  
Keyword(s):  
Simulated Body Fluid ◽  
Spherical Particle ◽  
Body Fluid ◽  
Antibacterial Property ◽  
Sol Gel ◽  
Spherical Particles ◽  
Silver Standard ◽  
Standard Solution ◽  
Gel Processing

We reported the apatite-forming ability of CaO-SiO2 spherical particles obtained through a sol-gel processing. In this study, we synthesized the CaO-SiO2 containing silver (Ag) ions using silver standard solution to induce antibacterial property and evaluated the effects of Ag on their apatite forming ability in a simulated body fluid (SBF). The particles with 30CaO·70SiO2 starting composition in Ag standard solution with range 0 to 500 ppm Ag content were synthesized through the sol-gel processing. The prepared 30CaO·70SiO2 could be obtained as spherical particles with regardless of Ag contents. The prepared Ag-contained 30CaO·70SiO2 particles formed apatite on their surfaces after soaking in SBF regardless of Ag contents. Consequently, Ag-contained 30CaO·70SiO2 spherical particle could be obtained without decrease of its apatite forming ability.

Synthesis of Nano-Sized SrTiO3 Photocatalyst by Sol-Gel Method

2012 ◽  
Vol 512-515 ◽  
pp. 1673-1676 ◽  
Author(s):  
Wei Zhao ◽  
Jian Jun Yao ◽  
Jing Ya ◽  
Lei E ◽  
Zhi Feng Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Methylene Blue ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Complexing Agent ◽  
Strontium Nitrate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ph Values ◽  
Gel Processing

A sol-gel processing technology was employed to synthesize fine SrTiO3 powder by using strontium nitrate (Sr(NO3)2) , butyl titanate (Ti(OC4H9)4) as precursors, citric acid (C6H8O6) as complexing agent and (ethylene) glycol (C2H6O2) as stabilizer. Prepared the precursors in liquid phase and then calcined the precursors to achieve nano-sized SrTiO3 powders. The microstructure and composition of the as-synthesized samples were characterized by X-ray diffraction (XRD), Scan Electron Microscopy (SEM), and the photocatalytic activity was studied. The results showed that all the SrTiO3 particles were identified as perovskite phase. The pH values, the content of the acetic acid, the heat treat temperature play important roles on the synthesis of the SrTiO3 photocatalyst. When the pH=1, n(Sr(NO3)2 ) : n(Ti(OC4H9)4) = 1 : 1, n(Sr(NO3)2 ) : n(C6H8O6)=1:1.7, the product has better rate of photodegradation for the Methylene Blue under the ultraviolet condition.

Phase development in Si modified sol-gel-derived lead titanate

1993 ◽  
Vol 8 (7) ◽  
pp. 1712-1720 ◽  
Author(s):  
John S. Wright ◽  
Lorraine Falter Francis
Keyword(s):  
Lead Titanate ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Pyrochlore Phase ◽  
Lattice Parameter ◽  
X Ray Diffraction ◽  
Phase Development ◽  
Higher Temperature ◽  
Si Content ◽  
Si Addition

Sol-gel methods were used to prepare chemically modified lead titanate (PT) powders. A PT alkoxide solution was synthesized and doped with Si (2–12 mole%) or with equimolar amounts (2–12 mole%) of Si and Pb through the addition of Si and Pb–Si alkoxide solutions, respectively. PT alkoxide solutions were also prepared with excess Pb and Ti (7 and 10 mole%). Gels were prepared through controlled additions of water. Crystalline phase development of gel-derived powders with heat treatment (400–700 °C) was studied using x-ray diffraction (XRD) and differential thermal analysis (DTA). While PT powders without added Si crystallized directly into a perovskite phase, Si modified materials crystallized first into a pyrochlore phase and at a higher temperature transformed into perovskite. The pyrochlore lattice parameter and the temperature for the transformation to perovskite increased with Si content. In all cases, the crystal structure of the final perovskite phase was not affected by the Si addition. The effect of Si on phase development and mechanisms of transformation is discussed.

Pyrochlore-to-perovskite transformation during rapid heating of sol-gel (Pb,La)TiO3 thin films

1999 ◽  
Vol 14 (11) ◽  
pp. 4302-4306 ◽  
Author(s):  
Miguel Algueró ◽  
M. Lourdes Calzada ◽  
Lorena Pardo
Keyword(s):  
Thin Films ◽  
Phase Transformation ◽  
Thermal Treatment ◽  
Heating Rate ◽  
Lead Titanate ◽  
Perovskite Phase ◽  
Rapid Heating ◽  
Sol Gel ◽  
Pyrochlore Structure ◽  
Gel Method

Phases appearing in lanthanum-modified lead titanate thin films prepared by a diol-based sol-gel method and crystallized by rapid heating were studied. The results clearly indicate that a phase transformation from a pyrochlore structure to the perovskite phase occurs in Pb-deficient films during the thermal treatment, which involves a heating rate higher than 500 °C min−1. The rate of this transformation is a function of the lead content of the films, decreasing as lead volatilizes. Temperatures higher than 650 °C or soak times longer than 2 h make possible the complete pyrochlore-to-perovskite transformation without any lead excess in the films.

Ferroelectric thin films of calcium modified lead titanate by sol-gel processing

1994 ◽  
Vol 13 (24) ◽  
pp. 1804-1805 ◽  
Author(s):  
R. Sirera ◽  
M. L. Calzada ◽  
F. Carmona ◽  
B. Jim�nez
Keyword(s):  
Thin Films ◽  
Lead Titanate ◽  
Sol Gel ◽  
Ferroelectric Thin Films ◽  
Gel Processing
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