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.

Calcination Temperature Influence on Ionic Conductivity of Solid Electrolytes

2014 ◽  
Vol 798-799 ◽  
pp. 419-425
Author(s):  
Jesús Mauricio González Martínez ◽  
Licurgo Borges Winck ◽  
Cosme Roberto Moreira da Silva
Keyword(s):  
Infrared Spectroscopy ◽  
Ionic Conductivity ◽  
Calcination Temperature ◽  
Electrical Characterization ◽  
Uniaxial Pressure ◽  
X Ray Diffraction ◽  
Precursor Method ◽  
X Ray ◽  
Microstructure Evaluation ◽  
Fluorite Type

The gadolinia doped ceria was developed in Ce0,8Gd0,2O1,9 composition, with the objective to study the influence of calcination temperature on the ionic conductivity of sintered samples (pellets) used as solid electrolyte for the fuel cells applications. The powder was synthesized by the polymeric precursor method (Pechini) from cerium and gadolinium nitrates hexahydrates, obtaining a polymeric resin characterized by infrared spectroscopy. The heat treatments at 600 and 800°C resulted on oxides formation which have been characterized by infrared spectroscopy and X-ray diffraction for each sample. In each case, the fluorite type structure was identified. The pellets were formed by uniaxial pressure and sintered at 1500°C with relative densities of 93.1 and 89.4% for the samples calcined at 600 and 800°C, respectively. The microstructure evaluation was performed by scanning electron microscopy, and the electrical characterization was carried out by impedance spectroscopy, reaching a conductivity of 1.49x10-4 S/cm at 400°C in this work.

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.

scholarly journals Hydroxyapatite Extracted from Waste Fish Bones and Scales via Calcination Method

2015 ◽  
Vol 773-774 ◽  
pp. 287-290 ◽  
Author(s):  
N. Mustafa ◽  
Mohd Halim Irwan Ibrahim ◽  
Rosli Asmawi ◽  
Azriszul Mohd Amin
Keyword(s):  
Chemical Reaction ◽  
Fish Bone ◽  
Powder Size ◽  
X Ray Diffraction ◽  
Calcination Process ◽  
X Ray ◽  
Calcination Temperatures ◽  
Hydroxyapatite Powder ◽  
Before And After ◽  
Calcination Method

A hydroxyapatite is known as one of vital materials and common use in biomedical field and concentrated in clinical area. In relation to the above, the development of hydroxyapatite powder becomes an attractive research lines due to simplify in produce it. Thus in this paper the researcher stress out about Hydroxyapatite powder gained from the natural sources or so called as the waste of Tilapia bone and scales. The raw bones of and scale were undergo to crushing process to form in powder size (0.2 mm) then analysed by X-ray Diffraction (XRD) to identified the mineralogy of raw bone. Moreover the powder of fish bone and scales also go through to Scanning Electron Microscope (SEM) machine to analyse the microstructure of the powder while EDS act as device to determine the chemical composition of the sample powder. Sample powder then forward calcination process at selected temperature range to as a cheaper method in obtained hydroxyapatite raw sources. The range of calcination temperatures are between 800°C to 1000 °C. The sample preparation were analysed in both condition before and after calcination process by using XRD, SEM and EDS. The HAP crystalline composition of tilapia bones for raw powder and at 800 °C are similar with HAP pattern (JDS 00-009-0432) and the chemical reaction is Ca5(PO4)3(OH) then at temperature 900 and 1000 similar to HAP pattern (JDS 00-055-0592) with chemical reaction equal to Ca10(PO4)6(OH)2.

scholarly journals Influence of mg doping on structural, optical and photocatalytic performances of ceria nanopowders

2017 ◽  
Vol 11 (4) ◽  
pp. 304-310
Author(s):  
Branko Matovic ◽  
Jelena Lukovic ◽  
Bojan Stojadinovic ◽  
Sonja Askrabic ◽  
Aleksandra Zarubica ◽  
...  
Keyword(s):  
Solid Solutions ◽  
Oxygen Vacancies ◽  
Uv Light ◽  
Doped Ceria ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ceria Solid Solutions ◽  
Fluorite Type ◽  
Photocatalytic Performances ◽  
Mg Doped

Nanosized Mg-doped ceria powders were obtained by self-propagating room temperature reaction without using surfactants or templates. X-ray diffraction analysis and field emission scanning microscopy results showed that the doped samples are solid solutions with fluorite-type structure and spherical morphology. Raman spectra revealed an increase in the amount of oxygen vacancies with the increase of Mg concentration. This increasing results in a narrowing of the bandgap of CeO2. The photocatalytic performances of the Mg-doped ceria solid solutions were evaluated by decomposing an organic dye, crystal violet under UV irradiation. The Mg-doped ceria solid solutions exhibit significantly better photocatalytic activity than the pure CeO2 and commercial TiO2. The higher first rate constant of the Mg-doped samples demonstrated that they are much more efficient than TiO2 and CeO2 under UV light. Mg2+ dopant ions and oxygen vacancies play a significant role in the enhancement of photocatalytic performances of the Mg-doped ceria.

scholarly journals Potential Peat Clay for Minerals Source Utilized as Adsorbent and Catalyst

2019 ◽  
Vol 280 ◽  
pp. 04003
Author(s):  
Agus Mirwan ◽  
Meilana Dharma Putra ◽  
Riani Ayu Lestari
Keyword(s):  
Xrd Analysis ◽  
Sem Analysis ◽  
X Ray Diffraction ◽  
Huge Amount ◽  
Calcination Process ◽  
X Ray ◽  
Potential Source ◽  
Before And After ◽  
Flake Structure

The existence of peat clay is scattered in many parts of the world with the huge amount. The high compound of minerals in the peat clay can be potentially used as adsorbent and catalyst. This research aims to study the composition of peat clay and functional group of the compound in the peat clay. The characterization of x-ray fluorescence (XRF), fourier transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), and scanning electron microscope-energy dispersive x-ray (SEM- EDX) were assigned to compare the sample before and after calcination process at 700 oC 120 min. FTIR analysis showed the presence of quartz, kaolinite, hematite, illite in peat clay. The results of XRF analysis showed that chemical composition of peat clay was dominantly in the form of silica oxide (18%), aluminum oxide (7%), and iron oxide (15%). The amount of compounds was observed to increase to be 32%, 18% and 11%, respectively after calcinations. XRD analysis confirmed the presence of this mineral in the peat clay. SEM analysis showed flake structure of peat clay with EDX which indicated composition of the dominant element namely the presence of Al, Si, and Fe before and after calcination. This high amount of minerals in peat clay led to potential source to be utilized as adsorbent for removing the pollutant or as and catalyst for chemical process.

scholarly journals Oxide ionic conductivity and microstructures of Pr and Sm co-doped CeO2-based systems

2018 ◽  
Vol 16 (1) ◽  
pp. 827-832 ◽  
Author(s):  
Aliye Arabacı
Keyword(s):  
Ionic Conductivity ◽  
Sem Analysis ◽  
Doped Ceria ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fluorite Type ◽  
Doped Ceo2 ◽  
Oxide Ionic Conductivity ◽  
Total Ionic Conductivity ◽  
Co Doped

AbstractThe compositions Ce0.80Sm0.2-xPrxO2-δ (x=0-0.12) were prepared through the citrate-nitrate method. The synthesized Pr3+ and Sm3+ co-doped ceria powders with different compositions were calcined at 600°C for 3 h. Phase structure of the calcined powders was characterized by X-Ray diffraction (XRD) analysis.All the calcined samples were found to be ceria based solid solutions of fluorite type structures. The morphology examinations were carried out by scanning electron microscopy (SEM) analysis. Relative density of more than 91% of the theoretical can be achieved by sintering the Ce0.80Sm0.2-xPrxO2-δ pellets at 1400°C for 6 h. The two-probe a.c. impedance spectroscopy was used to study the ionic conductivity of the doped ceria samples. The Ce0.80Sm0.80Pr0.12O1.90 composition showed the highest total ionic conductivity value which is 2.39 × 10−2 S/cm at 600°C.

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 Characterization of nickel doped Zn7Sb2O12 spinel phase using Rietveld refinement

2003 ◽  
Vol 18 (3) ◽  
pp. 219-223 ◽  
Author(s):  
L. Gama ◽  
C. O. Paiva-Santos ◽  
C. Vila ◽  
P. N. Lisboa-Filho ◽  
E. Longo
Keyword(s):  
Crystal Structure ◽  
Rietveld Refinement ◽  
Spinel Phase ◽  
Pechini Method ◽  
Polymeric Precursor ◽  
X Ray Diffraction ◽  
Inverse Spinel ◽  
Precursor Method ◽  
X Ray

Zn7Sb2O12 is known to adopt an inverse spinel crystal structure, in which Zn2+ occupies the eight tetrahedral positions and Sb5+ and Zn2+ randomly occupy the 16 octahedral positions. Samples of Zn7−xNixSb2O12 (x=0, 1, 2, 3, and 4) were synthesized using a modified polymeric precursor method, known as the Pechini method. The crystal structure of the powders was characterized by Rietveld refinement with X-ray diffraction data. The results show that for x=0, 1, and 2 Ni substitutes for Zn2+ in the octahedral sites, and that for x=3 and 4 it is assumed that Ni2+ replaces Zn2+ ions in both the octahedral and tetrahedral positions. It is also observed for x=3 and 4 the formation of two spinel phases.

scholarly journals Microstructural, structural and optical properties of nanoparticles of PbO-CrO3 pigment synthesized by a soft route

Cerâmica ◽  
2015 ◽  
Vol 61 (357) ◽  
pp. 118-125 ◽  
Author(s):  
V. D. Araújo ◽  
M. R. B. Andreeta ◽  
L. J. Q. Maia ◽  
R. M. Nascimento ◽  
F. V. Motta ◽  
...  
Keyword(s):  
Optical Properties ◽  
Diffuse Reflectance ◽  
Microstructural Properties ◽  
Polymeric Precursor ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Precursor Method ◽  
X Ray ◽  
Diffraction Patterns ◽  
Good Agreement

PbCrO4 and Pb2CrO5 particles were synthesized by the polymeric precursor method. Structural and microstructural properties of the particles were characterized by scanning electron microscopy with field emission gun, X-ray diffraction, and Raman spectroscopy techniques. The diffuse reflectance technique was employed to study the optical properties in the 400-700 nm range. The optical bandgap of the samples was obtained indirectly. Colorimetric coordinates L*, a*, b* were calculated for the pigment powders as a function of the heat treatment (400-700 ºC). The powders displayed colors ranging from green to red. X-ray diffraction patterns showed the presence of monoclinic PbCrO4 phase in green samples, while red powders had a monoclinic Pb2CrO5 phase structure. The Raman spectra of the PbCrO4 and Pb2CrO5 powders were in good agreement with those reported in the literature. The synthesized compounds can be used as green and red pigments with high thermal stability.

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