scholarly journals Preparation and Characterization of Nano-Cadmium Ferrite

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
S. M. Ismail ◽  
Sh. Labib ◽  
S. S. Attallah
Keyword(s):  
Particle Size ◽  
Low Temperature ◽  
Sol Gel ◽  
Stable Phase ◽  
X Ray Diffraction ◽  
Economic Point ◽  
Sol Gel Process ◽  
Pure Phase ◽  
Microstructural Studies

Nano-hematite (α-Fe2O3) and nano-cadmium ferrite (CdFe2O4) are prepared using template-assisted sol-gel method. The prepared samples are analyzed using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and Mössbauer spectroscopy techniques for structural and microstructural studies. Nano-α-Fe2O3 with particle size ~60 nm is formed at 500°C, while nano-CdFe2O4 with smaller particle size (~40 nm) is formed at 600°C. It is found that with a simple sol-gel process we can prepare nano-CdFe2O4 with better conditions than other methods: pure phase at lower sintering temperature and time (economic point) and of course with a smaller particle size. So, based on the obtained experimental results, a proposed theoretical model is made to explain the link between the use of the sol-gel process and the formation of nano-CdFe2O4 as a pure phase at low temperature. This model is based on a simple magnetostatic interaction between the formed nuclei within the solution leading to the formation of the stable phase at low temperature.

Synthesis and Characterization of Li-Ti-O Nano-Composites and Their Doped BaTiO3 Based X7R-Type Ceramics

2010 ◽  
Vol 148-149 ◽  
pp. 1575-1579
Author(s):  
Qing Zhang ◽  
Rui Yuan Niu ◽  
Min Wang ◽  
Bin Cui ◽  
Zhu Guo Chang
Keyword(s):  
Particle Size ◽  
Dielectric Properties ◽  
Ph Value ◽  
Sol Gel ◽  
Nano Composites ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Minimum Particle Size ◽  
Sol Gel Process

Li-Ti-O (abbreviated as LTO) nano-composites were synthesized via sol-gel process, and then doped BaTiO3 based X7R type ceramics. The LTO nano-composites and their ceramics were characterized by means of thermaogravimetric, Fourier-transform infrared, X-ray diffraction methods, transmission electron microscopy. We also characterized the dielectric properties of the LTO doped BaTiO3 based ceramics of X7R type. The results indicated that LTO nano-composites were nanometer scale powders. The pH value and calcining temperature had an influence on particle size of LTO sintering aids. At pH about 3 and with calcining at 600 °C, the nano-composites attained minimum particle size (about 10 nm). By adding 0.10 wt% of the LTO nano-composites, the temperature permittivity achieved about 4200 when sintered at 1240 °C for 4 h, and the dielectric properties met X7R standard.

Preparation and Characterization of (Ba0.88Ca0.12)(Zr0.12Ti0.88)O3 Powders and Ceramics Produced by Sol-Gel Process

2010 ◽  
Vol 148-149 ◽  
pp. 1062-1066 ◽  
Author(s):  
Ren Bo Yang ◽  
Wei Guo Fu ◽  
Xiang Yun Deng ◽  
Zhong Wen Tan ◽  
Yan Jie Zhang ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Particle Size ◽  
Piezoelectric Coefficient ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Thermo Gravimetric ◽  
X Ray ◽  
Sol Gel Process

The (Ba0.88Ca0.12)( Zr0.12Ti0.88)O3 powders and piezoelectric ceramics were prepared by sol-gel process. The reaction process was analyzed with the help of thermo gravimetric and differential scanning calorimetry. X-ray diffraction characterized results showed that the structure of the (Ba0.88Ca0.12)( Zr0.12Ti0.88)O3 powders was perovskite structure and the particle size was approximately 37nm. Piezoelectric measurements revealed that Curie temperature and the maximum piezoelectric coefficient d33 is 95°C and 215pm/V, respectively.

scholarly journals Sol-Gel Template Synthesis and Characterization of Lu2O3:Eu3+ Nanowire Arrays

Micromachines ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 601
Author(s):  
Yahua Hu ◽  
Mu Gu ◽  
Xiaolin Liu ◽  
Juannan Zhang ◽  
Shiming Huang ◽  
...  
Keyword(s):  
Sol Gel ◽  
Nanowire Arrays ◽  
X Ray Diffraction ◽  
Aao Template ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Sol Gel Process ◽  
Optical Luminescence ◽  
Uniform Diameter

Uniform Lu2O3:Eu3+ nanowire arrays were successfully prepared by the sol-gel process using anodic aluminum oxide (AAO) templates. The as-synthesized nanowires are homogeneous, highly ordered, and dense and have a uniform diameter of ~300 nm defined by the AAO templates. The X-ray diffraction and selected area electron diffraction results show that the Lu2O3:Eu3+ nanowires have a polycrystalline cubic structure, and the crystallite size of the Lu2O3:Eu3+ nanowires is confined by the AAO template. The nanowires within the AAO template showed good photoluminescence and X-ray-excited optical luminescence performances for Lu2O3:Eu3+. The emission peaks were attributed to the 5D0 → 7FJ transitions of Eu3+ (J = 0, 1, 2, 3).

Palladium-Silica Organic-Inorganic Membrane Materials via a Sol-Gel Process: Preparation and Properties Calcined under H2 Atmosphere

2017 ◽  
Vol 727 ◽  
pp. 889-894
Author(s):  
Jing Yang ◽  
Lin Yu Li ◽  
Hai Yun Hou ◽  
Zhi Tong
Keyword(s):  
Particle Size ◽  
Sol Gel ◽  
Total Pore Volume ◽  
Energy Dispersive Spectrum ◽  
Bet Surface Area ◽  
Molar Ratio ◽  
Inorganic Membrane ◽  
X Ray Diffraction ◽  
Membrane Materials ◽  
Sol Gel Process

Pd-doped SiO2 organic-inorganic membrane materials were prepared via a sol-gel process. The sol stability is characterized by sol particle size and zeta potential analysis. And the properties of the Pd-doped SiO2 organic-inorganic membrane materials are investigated by X-ray diffraction (XRD), fourier transform infrared (FTIR), energy dispersive spectrum (EDS) analysis and N2 absorption-adsorption measurement. The results showed that the sol particle size distributions are relatively narrow. With the increase of Pd content, the sol particle sizes slightly increase and the zeta potentials decreases until the palladium/tetraethylorthosilicate molar ratio closes to the isoelectric point. After calcined at 350 °C under H2 atmosphere, the added PdCl2 is reduced to metallic Pd0 completely, and the hydrophobic Si−CH3 groups exist in the SiO2 network. The Pd atoms have a lower concentration on the surface and more Pd atoms embedded in the SiO2 matrix. The Pd-doped SiO2 membrane materials calcined at 350 °C with a palladium/tetraethylorthosilicate molar ratio of 0.15 exhibit large BET surface area (up to 683.36 m2/g) and total pore volume (up to 0.386 cm3/g), as well as a mean pore diameter of about 2.26 nm.

Sol-gel derived Ba(Mg1/3Ta2/3)O3 thin films: Preparation and structure

1997 ◽  
Vol 12 (3) ◽  
pp. 596-599 ◽  
Author(s):  
Ji Zhou ◽  
Qing-Xin Su ◽  
K. M. Moulding ◽  
D. J. Barber
Keyword(s):  
Thin Films ◽  
Annealing Temperature ◽  
Volume Fraction ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Sol Gel Process ◽  
Small Grains

Ba(Mg1/3Ta2/3)O3 thin films were prepared by a sol-gel process involving the reaction of barium isopropoxide, tantalum ethoxide, and magnesium acetate in 2-methoxyethanol and subsequently hydrolysis, spin-coating, and heat treatment. Transmission electron microscopy, x-ray diffraction, and Raman spectroscopy were used for the characterization of the thin films. It was shown that the thin films tend to crystallize with small grains sized below 100 nm. Crystalline phase with cubic (disordered) perovskite structure was formed in the samples annealed at a very low temperature (below 500 °C), and well-crystallized thin films were obtained at 700 °C. Although disordered perovskite is dominant in the thin films annealed below 1000 °C, a low volume fraction of 1 : 2 ordering domains was found in the samples and grows with an increase of annealing temperature.

Preparation at Low-Temperature and Characterization of TiO2 Film Used for Solar Cells

2013 ◽  
Vol 537 ◽  
pp. 205-208
Author(s):  
Xiao Qiang Wang ◽  
Yue Liu Li ◽  
Jian Min Wang ◽  
Jing Guo ◽  
Ming Ya Li
Keyword(s):  
Low Temperature ◽  
Fill Factor ◽  
Sol Gel ◽  
Influence Factors ◽  
Raw Material ◽  
Tetrabutyl Titanate ◽  
X Ray Diffraction ◽  
Glass Substrates ◽  
Photoelectric Properties

In this work, nanocrystalline TiO2 powder was prepared by the sol-gel method via tetrabutyl titanate as raw material, non-ion surfactant TO8 as a template. Then the nanocrystalline TiO2 thin film electrodes which were coated on FTO glass substrates via the slurry consiting of TiO2 powder prepared by us and the trabutyl titanate precursor were successfully prepared by using a simple and convenient hydrothermal method at low temperature. The structure and morphology of powders and films were characterized by X-ray diffraction, scanning electric microscopy. The influence factors on the samples were discussed. The photoelectric properties of cells assembled by the films were measured. The results show that, at 25°C and under 1000W/m2 light intensity，open voltage is 708mV, Jsc is 14.648mA/cm2, fill factor is 53.788, the conversion efficiency is 5.5988%.

scholarly journals Structural and Magneto-Optical Characterization of La, Nd: Y2O3 Powders Obtained via a Modified EDTA Sol–Gel Process and HIP-Treated Ceramics

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4928
Author(s):  
Andrzej Kruk
Keyword(s):  
Sol Gel ◽  
Hot Isostatic Pressing ◽  
Rare Earth Ions ◽  
X Ray Diffraction ◽  
Thermal Dependence ◽  
Nanosized Powders ◽  
Verdet Constant ◽  
X Ray ◽  
Sol Gel Process

In this study, pure Y2O3, La0.1Y1.9O3 and La0.1Nd0.12Y1.78O3 nanosized powders were successfully synthesized by a modified sol–gel method. Pure and rare-earth ions doped yttria powders were characterized by X-ray diffraction, scanning electron microscopy and Brunauer–Emmett–Teller methods. The powders were sintered by the hot isostatic pressing process. The highest in-line transmittance of 56% was obtained at 800 nm and increased in the IR region. The influence of the lanthanum and neodymium ions on the physicochemical properties of yttria were discussed. The La-Nd-doped material exhibited a Verdet constant over 4000 deg/T·m at 400 nm and low thermal dependence. An interesting evolution of the Verdet constant across the absorption band with high resolution was studied. A study of the optical and magneto-optical properties of yttria doped with Nd3+ and La3+ is discussed in this paper.

Synthesis and Characterization of Siloxane-Polyurethane Hybrid Materials

2008 ◽  
Vol 396-398 ◽  
pp. 481-484
Author(s):  
Rodrigo Jiménez-Gallegos ◽  
L. Téllez-Jurado ◽  
Luis M. Rodríguez-Lorenzo ◽  
Julio San Román
Keyword(s):  
Hybrid Materials ◽  
Sol Gel ◽  
Proton Nuclear Magnetic Resonance ◽  
X Ray Diffraction ◽  
Organic Part ◽  
Sol Gel Process ◽  
Nmr Techniques ◽  
Ft Ir ◽  
Characterization Of Materials

This paper focuses on the preparation of siloxane-polyurethane hybrid materials using a sol-gel method. The global aim of the project is to tailor mechanical properties, degradability rate, bioactivity and biocompatibility to design scaffolds for musculoskeletal applications. A series of seven hybrid materials were synthesized with varying the proportion of polydimethylsiloxane (PDMS), and Polyurethane (PU). The organic part ratios (by weight) employed were (% PDMS:% PU) 30:0, 35:5, 20:10, 15:15, 10:20, 5:25, and 0:30. The organic part was reacted with constant 70 % TEOS to obtain the hybrid materials. A sol-gel process was selected for the synthesis of the hybrids. The characterization of materials was carried out by the fourier-infrared spectroscopy (FT-IR), x-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electronic microscopy (SEM) and proton nuclear magnetic resonance (1H-NMR) techniques in order to analyze the structure, microstructure and chemical composition of the hybrid materials. Gelification time depends on the proportion of PU used. When no PU is employed, the gel time is 8 hours but it rises up to 18 days for 30 % of polyurethane. Materials range from opaque to translucent but with a greater fragility for greater amounts of polyurethane. No differences in the bonding of materials could be appreciated.

ELABORATION AND CHARACTERIZATION OF La4Ni3O10 CATHODE MATERIAL (SOFC) BY SOL-GEL PROCESS

2011 ◽  
Vol 1326 ◽  
Author(s):  
Rene Fabian Cienfuegos ◽  
Leonardo Chávez Guerrero ◽  
Sugeheidy Carranza ◽  
Laurie Jouanin ◽  
Guillaume Marie ◽  
...  
Keyword(s):  
Cathode Material ◽  
Sol Gel ◽  
Synthesis Method ◽  
Solid Material ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Metallic Salts ◽  
Sol Gel Process

ABSTRACTThe goal in this study was to synthesize a lanthanum - nickel phase (Ruddlesden-Popper phases) La4Ni3O10. This material was prepared using a polymeric route. An easy synthesis method is presented in order to obtain an economical cathode material, which can be used in Solid Oxide Fuel Cells (SOFC). The polymeric precursors were prepared following the Castillo method. The originality of this work was to optimize the ratio HMTA/ metallic salts from 1 to 6. The obtained powders were characterized by thermal analysis; Differential Scanning Calorimetry (DSC Q10 Instrument TA), Thermogravimetric Analysis (TGA - Q50 Instrument TA-) and X-ray diffractometer (Bruker, D8 Advance diffractometer), in order to determine the crystallized phase. Experiments 5 and 6 did not present coagulation but after few days, solution 5 was transformed into a gel. Gels 2 to 5 were heated in order to obtain a solid material. These powders are characterized by thermogravimetric and thermo-differential methods. The powders obtained at 800, 900 and 1000°C were analyzed by X-ray diffraction and it was found that the temperature to get to the La4Ni3O10 phase was 1000ºC.

Structure and microstructure characterization of the mixed sesquioxides (Gd1−xYbx)2O3and (Gd1−xHox)2O3prepared by sol–gel process

2005 ◽  
Vol 38 (2) ◽  
pp. 306-310 ◽  
Author(s):  
Z. K. Heiba ◽  
L. Arda ◽  
Y. S. Hascicek
Keyword(s):  
Crystallite Size ◽  
Sol Gel ◽  
Average Crystallite Size ◽  
Rare Earth Ions ◽  
X Ray Diffraction ◽  
Refinement Method ◽  
Cationic Distribution ◽  
Sol Gel Process ◽  
Structure And Microstructure

Polycrystalline samples of (Gd1−xYbx)2O3and (Gd1−xHox)2O3(0.0 ≤x≤ 1.0) were synthesized by a sol–gel process. X-ray diffraction data were collected and crystal structure and microstructure analyses were performed using the Rietveld refinement method. All samples were found to have the same crystal system and formed solid solutions over the whole range ofx. For the system (Gd1−xHox)2O3, the cationic distribution over the two non-equivalent sites 8band 24dof the space groupIa\bar{3} were found to be random for all values ofx. For (Gd1−xYbx)2O3, the distribution is random in the range 0.0 <x≤ 0.5 and preferential in the range 0.5 <x≤ 1.0. The lattice parameters are found to vary linearly with the compositionx. Replacing Gd3+and Yb3+, or Gd3+and Ho3+, by each other introduces slight changes in relative atomic coordinates. Crystallite size and microstrain analyses were performed along different crystallographic directions and both are found to vary anisotropically with the composition parameter (x). The obtained values of microstrain are correlated with the distribution of the rare earth ions over the two cationic sites of the structure. The average crystallite size ranges from 45 to 144 nm and the root mean square (r.m.s.) strain from 0.018 to 0.409 × 10−2.

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