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

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.

scholarly journals Microstructure and dielectric properties of (Ba,Sr)TiO3 thin film produced by the polymeric precursor method

2000 ◽  
Vol 15 (5) ◽  
pp. 1176-1181 ◽  
Author(s):  
F. M. Pontes ◽  
E. B. Araujo ◽  
E. R. Leite ◽  
J. A. Eiras ◽  
E. Longo ◽  
...  
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Spin Coating ◽  
Dissipation Factor ◽  
Heating Process ◽  
Polymeric Precursor Method ◽  
Polymeric Precursor ◽  
Precursor Method ◽  
Chemical Homogeneity ◽  
Bst Thin Films

BaxSr1−xTiO3 (x 4 0.6) (BST) thin films were successfully prepared on a Pt(111)/TiO2/SiO2/Si(100) substrate by spin coating, using the polymeric precursor method. BST films with a perovskite single phase were obtained after heat treatment at 700 °C. The multilayer BST thin films had a granular structure with a grain size of approximately 60 nm. A 480-nm-thick film was obtained by carrying out five cycles of the spin-coating/heating process. Scanning electron microscopy and atomic force microscopy analyses showed that the thin films had a smooth, dense, crack-free surface with low surface roughness (3.6 nm). At room temperature and at a frequency of 100 kHz, the dielectric constant and the dissipation factor were, respectively, 748 and 0.042. The high dielectric constant value was due to the high microstructural quality and chemical homogeneity of the thin films obtained by the polymeric precursor method.

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.

Strain Evaluation of GaAs Layers Grown on Ultrahigh-Pressure-Annealed Strain-Free GaAs-On-Si Structures

1997 ◽  
Vol 486 ◽  
Author(s):  
Takehito Jimbo ◽  
Hiroshi Ishiwara
Keyword(s):  
Chemical Vapor ◽  
Xrd Analysis ◽  
Gaas Layer ◽  
Ultrahigh Pressure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Si Substrates ◽  
Gaas On Si ◽  
Gaas Films ◽  
Regeneration Effect

AbstractIn order to form strain-free GaAs films on Si substrates, GaAs-on-Si structures have been formed by molecular beam epitaxy (MBE) or metalorganic chemical vapor deposition (MOCVD) and subsequently annealed under ultrahigh pressure at 2 GPa. The samples were then reannealed at atmospheric pressure in order to investigate the regeneration effect of strain in the GaAs films. It was found from X-ray diffraction (XRD) analysis and photoluminescence (PL) measurement that in the reannealed samples the strain near the surface of GaAs film was smaller than that near the interface with Si. Finally, additional GaAs layers were grown using MBE on both as-grown and strain-free GaAs-on-Si structures and it was found that the residual strain in the GaAs layer on strain-free GaAs-on-Si structure was smaller than in the as-grown case.

Influence of Oxidizing Atmosphere on Crystalline Phase Formation and Microstructural Properties of Mixed Cerium-Zinc Oxides Obtained by Polymeric Precursor Method

2014 ◽  
Vol 798-799 ◽  
pp. 75-78
Author(s):  
L.L.M. Sales ◽  
R.A. Candeia ◽  
Fernando A.P. Cunha ◽  
Jesana Moura Silva ◽  
Alexsandra Cristina Chaves ◽  
...  
Keyword(s):  
Surface Area ◽  
Mixed Oxides ◽  
Rietveld Method ◽  
Xrd Analysis ◽  
Polymeric Precursor Method ◽  
Microstructural Properties ◽  
Polymeric Precursor ◽  
Precursor Method ◽  
Oxidizing Atmosphere ◽  
Catalytic Application

This paper presents the synthesis, characterization and influence of oxidizing atmosphere in the calcinations and sintering processes on microstructural properties of mixed oxides of Cerium and Zinc, obtained by the polymeric precursor method, aiming at a subsequent catalytic application. The material was submitted to calcinations and sintering at 900 and 1050 °C. The samples were characterized by XRD analysis techniques, surface area by BET method and refined by the Rietveld method. The results of X-ray diffraction showed that interest phase was formed, indicating that the method for obtaining the phase is effective. The results of surface area for the system calcined in air were 85 m2/g and 65 m2/g for the system subjected to oxidizing atmosphere both at 900°C, in the same temperature. It was observed that the temperature increase leads to an increase in crystallite size. This fact is in line with other studies in the literature.

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.

Physical Characterization of K-Doped 0.9PMN-0.1PT Synthesized by an Association of the Columbite Route and the Polymeric Precursor Method

2005 ◽  
Vol 498-499 ◽  
pp. 669-675
Author(s):  
A.A. Cavalheiro ◽  
Juliana C. Bruno ◽  
M.A. Zaghete ◽  
José Arana Varela
Keyword(s):  
Grain Size ◽  
Perovskite Phase ◽  
Rietveld Method ◽  
Size Control ◽  
Xrd Analysis ◽  
Polymeric Precursor Method ◽  
Polymeric Precursor ◽  
Structural Refinement ◽  
Precursor Method ◽  
Columbite Precursor

The solid solution 0.9PbMg1/3Nb2/3O3-0.1PbTiO3 is one of the most widely investigated relaxor ceramic, because of its high dielectric constant and low sintering temperatures. PMN-PT powders containing single perovskite phase were prepared by using a Ti-modified columbite precursor obtained by the polymeric precursor method. Such precursor reacts directly with stoichiometric amount of PbO to obtain pyrochlore-free PMNPT powders. The structural effects of K additive included in the columbite precursor and 0.9PMN-0.1PT powders were also studied. The phase formation at each processing step was verified by XRD analysis, being these results used for the structural refinement by the Rietveld method. It was verified the addition of K in the columbite precursor promotes a slight increasing in the powder crystallinity. There was not a decrease in the amount of perovskite phase PMN-PT for 1mol% of K, and the particle and grain size were reduced, making this additive a powerful tool for grain size control.

scholarly journals Preparation of 0.055BaZrO3–0.935(K0.45Na0.5Li0.05)NbO3–0.01(Bi0.5Na0.5)TiO3 piezoelectric thin films from precursor solution by Pechini method

2017 ◽  
Vol 07 (02) ◽  
pp. 1750014 ◽  
Author(s):  
Liqiang Liu ◽  
Tomoaki Karaki ◽  
Tadashi Fujii ◽  
Yuichi Sakai
Keyword(s):  
Thin Films ◽  
Preparation Method ◽  
Pechini Method ◽  
Precursor Solution ◽  
Lead Free ◽  
Polymeric Precursor Method ◽  
Polymeric Precursor ◽  
Precursor Method ◽  
Si Substrates ◽  
Piezoelectric Thin Films

Lead-free piezoelectric thin films of 0.055BaZrO3–0.935(K[Formula: see text]Na[Formula: see text]Li[Formula: see text])NbO3–0.01(Bi[Formula: see text]Na[Formula: see text])TiO3 (BZ–KNLN–BNT) were fabricated on (100)-LaNiO3/SiO2/Si substrates. The Pechini (polymeric precursor) method was carried out to prepare the complicated multi-component precursor solution. This method was suited for controlling the complex components accurately. The films crystallized at 700[Formula: see text]C showed a (100)pc-oriented perovskite structure, whose grain size was about 200[Formula: see text]nm and thickness was about 700[Formula: see text]nm. The Curie temperature [Formula: see text]c of the films was 292[Formula: see text]C that was near to that of the bulk ceramics. The preparation method used in this work provided a possibility for the application of multi-component lead-free piezoelectric films.

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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