ChemInform Abstract: Synthesis of High-Tc Dual-Phase Ag-YBa2Cu3O7-x Superconductor Composite Powders by Sol-Gel Process.

ABSTRACTThe synthesis of mixed oxide ceramic powders that consist of very fine (submicron)-monodisperse particles with uniform composition is desirable in the improvement of existing ceramics and the development of new ceramic materials. Metal alkoxide hydrolysis is a very attractive method for the synthesis of ultrapure composite powders at low temperatures by the sol-gel process.The present study investigates the effects of the hydrolysis of aluminum alkoxides and the condensation products on the growth kinetics and morphology of composite particles containing alumina and titania. Alkoxides of titanium and aluminum are employed; therefore, powders of high purity are produced. Since various solvents are used as media for powder synthesis, the effect of the solvent on particle morphology will also be discussed.

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Effect of Phase Formation on Magnetism of Sol-Gel Derived PbTiO3/(Ni, Pb) Ferrite Composite Powders

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.336-338.706 ◽

2007 ◽

Vol 336-338 ◽

pp. 706-708 ◽

Cited By ~ 3

Author(s):

Yan Ling Dong ◽

Pi Yi Du ◽

Wen Jian Weng ◽

Gao Rong Han

Keyword(s):

Heat Treatment ◽

Ferroelectric Phase ◽

Sol Gel ◽

Initial Permeability ◽

Treatment Temperature ◽

Ferromagnetic Phase ◽

Composite Powders ◽

Structure Morphology ◽

Sol Gel Process

Ferroelectric/ferromagnetic multiphase powdered composites, consisting of PbTiO3 as ferroelectric phase and NiFe2O4 (PbFe12O19) as ferromagnetic phase, were successfully prepared in situ by sol-gel process. The phase structure, morphology and magnetism properties were observed. Biphase powdered ME composite consisting of PbTiO3 and NiFe2O4 is obtained at 700oC. Triphase composite consisting of PbTiO3, NiFe2O4 and PbFe12O19 is obtained above 750oC. With increasing heat-treatment temperature, the particles combine more tightly and the particle size decreases. The saturation magnetization (σs) and the initial permeability (μi) increase with the increase of NiFe2O4 content. The coercive force (Hc) increases with the increase of PbFe12O19 content.

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Photocatalysis for Oxidation of Phenol and Reduction of Inorganic Pollutants by Nanocrystalline TiO2-ZrO2 Powders

Materials Science Forum ◽

10.4028/www.scientific.net/msf.449-452.289 ◽

2004 ◽

Vol 449-452 ◽

pp. 289-292 ◽

Cited By ~ 2

Author(s):

Jae-Kil Han ◽

Sung Min Choi ◽

Ik Hyun Oh ◽

Fumio Saito ◽

Byung Teak Lee

Keyword(s):

Photocatalytic Activity ◽

Sol Gel ◽

Homogeneous Distribution ◽

Particle Sizes ◽

Inorganic Pollutants ◽

Composite Powders ◽

Sol Gel Process ◽

Oxidation Of Phenol ◽

Xrd And Tem

TiO2(1-.ZrO2. (.=- 0.2, 0.4, 0.6 and 0.8) composite powders having a homogeneous distribution and nanocrystalline were successfully synthesized by sol-gel process using titanium iso-propoxide as precursor. The particle sizes of TiO2-ZrO2powders calcined at 600°C were measured ranging from 10nm to 19nm by XRD and TEM. For the comparison of photocatalytic activity, TiO2-ZrO2composite powders were tested in the degradation of phenol and the photoreduction of inorganic pollutants. The degradation of phenol increased with increase the content of anatase TiO2phase.

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