scholarly journals Effect of Nb on barium titanate prepared from citrate solutions

2002 ◽  
Vol 34 (1) ◽  
pp. 63-71 ◽  
Author(s):  
Biljana Stojanovic ◽  
C.R. Foschini ◽  
M.A. Zaghete ◽  
F.O.S. Vieira ◽  
C.O. Paiva-Santos ◽  
...  
Keyword(s):  
Phase Composition ◽  
Barium Titanate ◽  
Strong Dependence ◽  
Polymeric Precursor Method ◽  
Microstructure Development ◽  
Polymeric Precursor ◽  
X Ray Diffraction ◽  
Precursor Method ◽  
X Ray ◽  
Doped Barium Titanate

The influence of the addition of dopants on the microstructure development and electrical properties of BaTiO3 doped with 0.2, 0.4, 0.6, 0.8 mol% of Nb and 0.01 mol% of Mn based compounds was studied. Doped barium titanate was prepared using the polymeric precursor method from citrate solutions. The powders calcined at 700?C for 4 hours were analysed by infrared (IR) spectroscopy to verify the presence of carbonates, and by X-ray diffraction (XRD) for phase formation. The phase composition, microstructure and dielectric properties show a strong dependence on the amount of added niobium.

XRD Analysis and Morphological Studies of Spin Coated LiNbO3 Nano Photonic Crystal Prepared for Optical Waveguide Application

2016 ◽  
Vol 1133 ◽  
pp. 457-461 ◽  
Author(s):  
Makram A. Fakhri ◽  
Y. Al-Douri ◽  
Uda Hashim ◽  
Evan T. Salim
Keyword(s):  
Spin Coating ◽  
Xrd Analysis ◽  
Polymeric Precursor Method ◽  
Polymeric Precursor ◽  
X Ray Diffraction ◽  
Precursor Method ◽  
X Ray ◽  
Si Substrates ◽  
Morphological Studies ◽  
Pechini Process

Lithium niobate nanostructured thin films were deposited on (100) N-type Si substrates. Spin coating technique was used employed the polymeric precursor method (Pechini process) . The prepared films were Annealing in static air and oxygen atmosphere was performed at 500 _C for 2 h. X-ray diffraction analysis and SEM properties was carried out for films prepared at different mol concentration (0.25,0.50,0.75,1.00) Mol%. The results show a good enhancement in both structural and surface morphology of the films with increasing the concentration

Silver-Doped Zirconia Nanoparticles as Possible Bactericide in Water Filters

2014 ◽  
Vol 798-799 ◽  
pp. 69-74
Author(s):  
Ermerson Ney Leite Rodrigues ◽  
Edson Jansen Pedrosa Miranda Jr. ◽  
M.M. Oliveira
Keyword(s):  
Bactericidal Activity ◽  
Uv Light ◽  
Colony Growth ◽  
Polymeric Precursor ◽  
X Ray Diffraction ◽  
Precursor Method ◽  
X Ray ◽  
Activity Test ◽  
Water Filters ◽  
Zirconia Nanoparticles

The objectives of this study were to produce ZrO2-based nanoparticles doped with silver, using the polymeric precursor method (Pechini), and to verify their bactericidal activity againstEscherichiacoliandStaphylococcusaureus. Zirconium and silver oxides were chosen due to their bactericidal activity. The oxides were characterized by X-ray diffraction and field emission gun-scanning electron microscopy. The support for the oxides was a porous surface used in gravity filters. The method was not effective against the bacteriumEscherichiacoliin the sample subjected to UV light for 45 min, since it did not eliminate the bacterium, and did not inhibit colony growth and formation. However, the bactericidal activity test proved effective againstStaphylococcusaureus, eliminating the bacterium when the sample was subjected to UV light for 45 min, thus preventing colony growth and formation.

BaMnTiO3 Synthesized by the Oxalate and Impregnation Methods

2008 ◽  
Vol 55-57 ◽  
pp. 81-84
Author(s):  
Pusit Pookmanee ◽  
P. Ketwong ◽  
Sukon Phanichphant
Keyword(s):  
Barium Titanate ◽  
Barium Chloride ◽  
Hexagonal Structure ◽  
Impregnation Method ◽  
Final Solution ◽  
X Ray Diffraction ◽  
Mixed Powder ◽  
X Ray ◽  
Doped Barium Titanate ◽  
Mn Doped

Barium titanate (BaTiO3) was synthesized by the oxalate method with the starting precursors as barium chloride and potassium titanium oxalate with mole ratio of 1:1. Precipitate was obtained after adding oxalic acid until the pH of the final solution was 4. The precipitate was milled and calcined at 700 oC for 2h. Mn-doped barium titanate (BaMnTiO3) was prepared by the impregnation method. Barium titanate calcined at 700 oC was mixed with 2 and 4 mole % of Mn from manganese chloride. The mixed powder was calcined at temperatures of 800 oC and 900 oC for 2h. The phase of BaMnTiO3 was studied by X-ray diffraction (XRD). Hexagonal structure of Ba(Mn0.33Ti0.67)O2.84 was obtained after calcination at 900 oC for 2h with 2 and 4 mole % of Mn. The morphology and chemical composition were investigated by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The particle size of Ba(Mn0.33Ti0.67)O2.84 powder was in the range of 50-60 nm with irregular in shape. The elemental composition of barium, manganese, titanium and oxygen showed the characteristic X-ray energy values.

Hydrothermal Synthesis of Nano-Structured Barium Titanate from Metatitanic Acid

2010 ◽  
Vol 434-435 ◽  
pp. 311-313
Author(s):  
Jing Chu ◽  
Dan Yu Jiang ◽  
Na Zhang ◽  
Min Zhang ◽  
Qiang Li
Keyword(s):  
Phase Composition ◽  
Electron Microscope ◽  
Barium Titanate ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
X Ray ◽  
Metatitanic Acid ◽  
Optimal Reaction ◽  
Scanning Electron

Nano-structured Barium Titanate (BaTiO3) was prepared by a hydrothermal method with the reaction between metatitanic acid and an alkaline solution of Ba(OH)2•8H2O. The morphology of as-obtained powders of BaTiO3 was determined by Scanning Electron Microscope, which revealed that well-dispersed nanoparticles were successfully synthesized. The phase composition was analyzed by X-ray diffraction, which shows that cubic phase of Barium Titanate was prepared. The optimal reaction conditions were discussed in detail.

Synthesis of Gadolinium Doped Ceria Ceramic Powder by Polymeric Precursor Method (Pechini)

2014 ◽  
Vol 798-799 ◽  
pp. 182-188 ◽  
Author(s):  
Jesús Mauricio González Martínez ◽  
Rodrigo Arabey Muñoz Meneses ◽  
Cosme Roberto Moreira da Silva
Keyword(s):  
Ceramic Powder ◽  
Doped Ceria ◽  
Polymeric Precursor ◽  
X Ray Diffraction ◽  
Precursor Method ◽  
Calcination Process ◽  
X Ray ◽  
Before And After ◽  
Fluorite Type ◽  
Gadolinium Doped Ceria

The synthesis by polymeric precursors method (Pechini) was used to acquire gadolinium doped ceria forming Ce0,8Gd0,2O1,9 system, reaching high stoichiometric control features and nanosized particles to form dense solid electrolyte of high ionic conductivity. The synthesis was performed with cerium and gadolinium nitrates hexahydrates, citric acid and ethylene glycol. After the pre-calcination at 250°C/18h a resin was obtained like an expanded foam (puff). According to the iterature, this fact indicates that there is a reduction of agglomerates amount in a ceramic powder. A thermogravimetry-differential thermal analysis evaluated the thermal behavior of the resin. Infrared spectroscopy determined the organic matter and nitrates presence, before and after the calcination process. The X-ray diffraction identified the fluorite-type structure and was determined the crystallite size by the Scherrer equation in 22 and 46 nm for the powder calcined respectively at 600 and 800°C. The scanning electron microscopy evaluated the agglomeration degree and the morphology of the powders.

Chemical Synthesis and Sintering Behaviour of Ca3Al206 Obtained by Polymeric Precursor Method

2015 ◽  
Vol 820 ◽  
pp. 143-148 ◽  
Author(s):  
Faili Cintia Tomsen Veiga ◽  
Marciel Gaier ◽  
Cristiane Raubach Ratmann ◽  
Mário Lúcio Moreira ◽  
José Jurado ◽  
...  
Keyword(s):  
Chemical Synthesis ◽  
Refractory Concrete ◽  
Grain Morphology ◽  
Polymeric Precursor Method ◽  
Polymeric Precursor ◽  
X Ray Diffraction ◽  
Precursor Method ◽  
Uniform Size ◽  
Tricalcium Aluminate ◽  
Sintering Behaviour

Tricalcium aluminate (C3A) are used for different applications such as thermal insulation, cement, refractory concrete as binders or binders. The aim of this work is to study the synthesis and sintering behaviour of C3A samples. The chemical synthesis was performed by means of polymeric precursor method from metalic nitrates dissolved in ethylene glycol and citric acid forming a polymeric resin. The evolution of the crystalline phases was accomplished by X ray Diffraction (XRD). Thermogravimetric (TG), Differential Thermal Analysis (DTG) and Thermal Expansion were performed in order to verify the thermal properties of the material. From the characterizations carried out it may be concluded that the synthesis of polymeric precursors via allowed obtaining pure phase of C3A at 1000°C low temperatures. The temperature of 1350°C it possible to obtain materials having grain morphology with uniform size and densely packed.

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