Fabrication of Iron Carbide and Nitride Ceramics with Controlled Magnetic Properties by the Non-Oxide Sol-Gel Process

2012 ◽  
Vol 512-515 ◽  
pp. 1429-1433
Author(s):  
Xun Lao ◽  
Xiao Yan ◽  
Jiao Xie ◽  
Ya Li Li
Keyword(s):  
Magnetic Properties ◽  
Sol Gel ◽  
Iron Carbide ◽  
Iron Nitride ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Ferromagnetic Properties ◽  
Sol Gel Process ◽  
Nitride Ceramics ◽  
Carbide Ceramics

The carbodiimide-based non-oxide sol-gel process is a novel route to non-oxide nitride and carbide ceramics. This process has been applied to fabricate ternary or binary silicon based nitride and carbide ceramics. Based on this non-oxide sol-gel process, iron carbide and nitride have been fabricated by reaction of iron trichloride with bis(trimethylsilyl)carbodiimide to form FeCN gel followed by pyrolysis in argon flow at different temperatures. The iron carbide material obtained at 700 °C exhibits hard ferromagnetic properties whereas α-iron along with iron nitride formed at 1300 °C shows soft ferromagnetic properties. Therefore, iron carbide and nitride ceramics with controlled magnetic properties can be obtained along this novel non-oxygen sol-gel process by controlled pyrolysis. The pyrolysis behavior was investigated based on thermal gravimetric analysis coupled with differential scanning calorimetry. The phase structures of the iron carbide and nitride are identified by X-ray diffraction and the magnetic properties of the materials are measured by magnetometer.

Study of Pseudoboehmite Synthesis by Sol-Gel Process

2006 ◽  
Vol 45 ◽  
pp. 260-265 ◽  
Author(s):  
Antônio Hortêncio Munhoz Jr. ◽  
Leila Figueiredo de Miranda ◽  
G.N. Uehara
Keyword(s):  
Sol Gel ◽  
Thermo Gravimetric Analysis ◽  
Ammonium Hydroxide ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Sol Gel Process ◽  
Different Temperatures ◽  
Sol Gel Synthesis

A pseudoboehmite was obtained by sol-gel synthesis using aluminum nitrate as precursor. It was used a 2n full factorial design for studying the effect of the temperature of synthesis, the concentration of ammonium hydroxide, and the radiation dose in the product of sol-gel synthesis. The product of the synthesis was analyzed by scanning electron microscopy, x-ray diffraction of the product (after firing the pseudoboehmite at different temperatures), and it was also analyzed the temperature of endothermic and exothermic transformations using the thermo gravimetric analysis (TG) and differential scanning calorimetry (DSC). The X-ray diffraction data show that α-alumina was obtained at 1100o C.

Nano Composite Membranes of Sulfonated Amine-Poly(ether sulfone)s and SiO2 for Fuel Cell Application

2010 ◽  
Vol 658 ◽  
pp. 392-395 ◽  
Author(s):  
Dong Wan Seo ◽  
Young Don Lim ◽  
Soon Ho Lee ◽  
Md. Monirul Islam ◽  
Hyun Mi Jin ◽  
...  
Keyword(s):  
Sol Gel ◽  
Thermo Gravimetric Analysis ◽  
Composite Membranes ◽  
Exchange Capacity ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Nano Composite ◽  
Fuel Cell Application ◽  
Sol Gel Process ◽  
20 Nm

Organic-inorganic Nano composite membranes were prepared by Sulfonated amine-poly(ether sulfone)s (S-APES)s and SiO2. S-APESs were prepared by nitration, reduction and sulfonation of poly(ether sulfone) (ultrason®-S6010). Poly(ether sulfone) was reacted with ammonium nitrate and trifluoroacetic anhydride to produce the nitrated poly(ether sulfone), and was followed by reduction using tin(Ⅱ)chloride and sodium iodide as reducing agents to give the amino-poly(ether sulfone). The S-APES was obtained by reaction of 1,3-propanesultone and the amino-poly(ether sulfone) (NH2-PES) with sodium methoxide. The different degrees of nitration and reduction of poly(ether sulfone) were successfully synthesized by an optimized process. Organic-inorganic nano composite membranes were obtained by mixing S-APES (45 %) with hydrophilic SiO2 (20 nm, 4-10 %) obtained by sol-gel process. Different contents of SiO2 of the S-APES were studied by FT-IR, 1H-NMR spectroscopy, differential scanning calorimetry (DSC), and thermo gravimetric analysis (TGA). Sorption experiments were conducted to observe the interaction of sulfonated polymers with water and methanol. The ion exchange capacity (IEC), a measure of proton conductivity, was evaluated. The nano composite membranes exhibit conductivities (25 °C) from 3.51 x 10-3 to 4.10 x 10-3 S/cm, water swell from 57.25 to 60.50 %, IEC from 0.68 to 0.73 meq/g, and methanol diffusion coefficients from 2.81 x 10-7 to 3.33 x 10-7 cm2/S at 25 °C.

Preparation and Ferroelectric Properties of Sol-Gel Derived (Ba0.95Ca0.05)TiO3 Ceramics

2011 ◽  
Vol 418-420 ◽  
pp. 362-367
Author(s):  
Xue Liang Yang ◽  
Xiang Yun Deng ◽  
Li Ren Han ◽  
Ren Bo Yang ◽  
Yan Jie Zhang ◽  
...  
Keyword(s):  
Ferroelectric Properties ◽  
Sol Gel ◽  
Hysteresis Loops ◽  
Structural Evolution ◽  
Ferroelectric Ceramics ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Scanning Calorimetry ◽  
Maximum Dielectric Constant ◽  
Sol Gel Process

Ba0.95Ca0.05)TiO3 (BCT) ferroelectric ceramics were prepared from powders synthesized using a sol–gel process. Structural evolution of the BCT dry gels are investigated by thermal gravimetric analysis differential scanning calorimetry. It is found that BCT crystallites can be formed before 800°C. Well-sintered samples are synthesized at 1320°C for 2h. The crystal structure of the BCT ceramics is studied by XRD and ferroelectric properties of the ceramics are characterized by TF analyzer 2000. The Curie temperature Tc of the BCT ceramics is at about 130°C. The maximum dielectric constant (εr) reaches about 13678 at 130°C and hysteresis loops are measured with the temperature range from 25°C to 150°C.

scholarly journals Structural and Magnetic Properties of La0.9Sr0.1MnO3 Nanoparticles Prepared via Sol-gel Process

2019 ◽  
Vol 70 (6) ◽  
pp. 2044-2047
Author(s):  
Alexandru-Horatiu Marincas ◽  
Firuta Goga ◽  
Roxana Dudric ◽  
Crina Suciu ◽  
Alexandra Avram ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Measurements ◽  
Sol Gel ◽  
Thermo Gravimetric Analysis ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Thermo Gravimetric ◽  
X Ray ◽  
Transmission Electron ◽  
Sol Gel Process

In the present paper, nanosized La0.9Sr0.1MnO3 particles were synthesized via a facile modified sol-gel route using two cheap and environmentally friendly organic chemicals, namely sucrose and pectin. The obtained powders were characterized by thermo gravimetric analysis (TGA), X-ray diffraction (XRD), transmission electron microscopy (TEM), and magnetic measurements. The optimal temperature for obtaining nanosized particles was determined as 1000�C and 1h dwell time was enough to obtain crystalline nanoparticles. Magnetic properties of samples calcined with different calcination period were analyzed and both samples shown a transition temperature around 274 K.

Effect of Annealing temperature on the Structural and Magnetic Properties of TbxY3-xFe5O12(x = 0.0, 1.0, 2.0) Thin Films Prepared by Sol-Gel Process

2012 ◽  
Vol 501 ◽  
pp. 236-241 ◽  
Author(s):  
Ftema W. Aldbea ◽  
Noor Bahyah Ibrahim ◽  
Mustafa Hj. Abdullah ◽  
Ramadan E. Shaiboub
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Vibrating Sample Magnetometer ◽  
X Ray ◽  
Garnet Phase ◽  
Sol Gel Process ◽  
Amorphous Structures

Thin films nanoparticles TbxY3-xFe5O12 (x=0.0, 1.0, 2.0) were prepared by the sol-gel process followed by annealing process at various annealing temperatures of 700° C, 800° C and 900° C in air for 2 h. The results obtained from X-ray diffractometer (XRD) show that the films annealed below 900°C exhibit peaks of garnet mixed with small amounts of YFeO3 and Fe2O3. Pure garnet phase has been detected in the films annealed at 900°C. Before annealing the films show amorphous structures. The particles sizes measurement using the field emission scanning electron microscope (FE-SEM) showed that the particles sizes increased as the annealing temperature increased. The magnetic properties were measured at room temperature using the vibrating sample magnetometer (VSM). The saturation magnetization (Ms) of the films also increased with the annealing temperature. However, different behavior of coercivity (Hc) has been observed as the annealing temperature was increased.

scholarly journals Enhanced Magnetic Properties of BiFeO3 Thin Films by Doping: Analysis of Structure and Morphology

Nanomaterials ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 711 ◽  
Author(s):  
Yilin Zhang ◽  
Yuhan Wang ◽  
Ji Qi ◽  
Yu Tian ◽  
Mingjie Sun ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Sol Gel ◽  
Exchange Interactions ◽  
Ferromagnetic Behavior ◽  
Ferromagnetic Properties ◽  
Structure And Morphology ◽  
Related Diversification ◽  
Lattice Distortions ◽  
Mn Doped

The improvement of ferromagnetic properties is critical for the practical application of multiferroic materials, to be exact, BiFeO3 (BFO). Herein, we have investigated the evolution in the structure and morphology of Ho or/and Mn-doped thin films and the related diversification in ferromagnetic behavior. BFO, Bi0.95Ho0.05FeO3 (BHFO), BiFe0.95Mn0.05O3 (BFMO) and Bi0.95Ho0.05Fe0.95Mn0.05O3 (BHFMO) thin films are synthesized via the conventional sol-gel method. Density, size and phase structure are crucial to optimize the ferromagnetic properties. Specifically, under the applied magnetic field of 10 kOe, BHFO and BFMO thin films can produce obvious magnetic properties during magnetization and, additionally, doping with Ho and Mn (BHFMO) can achieve better magnetic properties. This enhancement is attributed to the lattice distortions caused by the ionic sizes difference between the doping agent and the host, the generation of the new exchange interactions and the inhibition of the antiferromagnetic spiral modulated spin structure. This study provides key insights of understanding the tunable ferromagnetic properties of co-doped BFO.

scholarly journals Irradiation of a Nanocomposite of Pseudoboehmite-Nylon 6,12

2010 ◽  
Vol 71 ◽  
pp. 28-33 ◽  
Author(s):  
Antônio Hortêncio Munhoz Jr. ◽  
Renato Meneghetti Peres ◽  
L.H. Silveira ◽  
Leonardo Gondim Andrade e Silva ◽  
L.F. de Miranda
Keyword(s):  
Sol Gel ◽  
Thermo Gravimetric Analysis ◽  
Mechanical Tests ◽  
Polymeric Matrix ◽  
Nano Particles ◽  
Gravimetric Analysis ◽  
Polymeric Nanocomposites ◽  
X Ray Diffraction ◽  
Inorganic Substances ◽  
Sol Gel Process

Nanocomposites are nanometrical material particles embedded in a specific matrix. The degree of organization of the nanostructures and their properties depend on the nature of the organic and inorganic components of the structure that can generate synergic interactions. Polymeric nanocomposites are related to a class of hybrid materials where inorganic substances of nanometric dimensions are dispersed in a polymeric matrix. In the present work, nanocomposites of nylon 6,12 with different concentrations of pseudoboehmite obtained by sol-gel process were prepared with and without the presence of octadecylamine. After preparation, the samples were irradiated with a 200 kGy radiation dose in an electron accelerator. The pseudoboehmite nano particles were characterized by X-ray diffraction, scanning electron microscopy, differential thermal analysis and thermo gravimetric analysis. The nanocomposites were characterized by thermal and mechanical tests. The addition of pseudoboehmite promoted a reduction of the melting flow during the production of the composites evidencing the interaction of pseudoboehmite with the polymeric matrix, probably modifying its crystalline structure.

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