Effect of C:SiO2 Ratio on Heating Behavior and Photoluminescence Property of SiC by Microwave

2021 ◽  
Vol 13 (4) ◽  
pp. 591-596
Author(s):  
Xin-Yue Zhang ◽  
Qian-Cheng Gao ◽  
Bo-Zhen Song ◽  
Li Guan ◽  
Lei Fan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Field Emission ◽  
Microwave Plasma ◽  
Light Emission ◽  
Photoluminescence Property ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heating Behavior ◽  
Scanning Electron

Coal minerals and tetraethoxysilane were used to prepare SiC by microwave heating. Different C:SiO2 ratios of raw mixed powders were selected to investigate changes in the heating behavior and photoluminescence property. The prepared samples were characterized by X-ray diffraction (XRD) Raman Field-emission scanning electron microscopy (SEM) and X-ray fluorescence spectrophotometer. It was found that distinct heating behavior appeared for different C:SiO2 ratios, including the time taken to reach ~600 °C, performance of the thermal runaway, and heating rate. The changes in the complicated heating behaviors are determined by different microwave coupling, microwave plasma, and E-field intensification effects within samples with different C:SiO2 ratios. When the molar ration of carbon and silicon is 5:1, the intensity of light emission reaches maximum.

scholarly journals Nickel-Doped Cerium Oxide Nanoparticles: Green Synthesis Using Stevia and Protective Effect against Harmful Ultraviolet Rays

Molecules ◽  
2019 ◽  
Vol 24 (24) ◽  
pp. 4424 ◽  
Author(s):  
Mehrdad Khatami ◽  
Mina Sarani ◽  
Faride Mosazadeh ◽  
Mohammadreza Rajabalipour ◽  
Alireza Izadi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cerium Oxide ◽  
Field Emission ◽  
Cerium Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
X Ray Diffraction ◽  
Ni Doping ◽  
X Ray ◽  
Scanning Electron

Nanoparticles of cerium oxide CeO2 are important nanomaterials with remarkable properties for use in both industrial and non-industrial fields. In a general way, doping of oxide nanometric with transition metals improves the properties of nanoparticles. In this study, nickel- doped cerium oxide nanoparticles were synthesized from Stevia rebaudiana extract. Both doped and non-doped nanoparticles were characterized by X-ray diffraction, Field Emission Scanning Electron Microscopy, Energy Dispersive X-ray, Raman spectroscopy, and Vibrating-Sample Magnetometry analysis. According to X-ray diffraction, Raman and Energy Dispersive X-ray crystalline and single phase of CeO2 and Ni doped CeO2 nanoparticles exhibiting fluorite structure with F2g mode were synthesized. Field Emission Scanning Electron Microscopy shows that CeO2 and Ni doped nanoparticles have spherical shape and sizes ranging of 8 to 10 nm. Ni doping of CeO2 results in an increasing of magnetic properties. The enhancement of ultraviolet protector character via Ni doping of CeO2 is also discussed.

Nanostructured CaWO4, CaWO4:Eu3+ and CaWO4:Tb3+ Particles: Sonochemical Synthesis and Luminescent Properties

2008 ◽  
Vol 8 (3) ◽  
pp. 1183-1190 ◽  
Author(s):  
Chunxia Li ◽  
Cuikun Lin ◽  
Xiaoming Liu ◽  
Jun Lin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Field Emission ◽  
Spherical Particles ◽  
X Ray Diffraction ◽  
Blue Emission Band ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Nanostructured CaWO4, CaWO4:Eu3+, and CaWO4:Tb3+ phosphor particles were synthesized via a facile sonochemical route. X-ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, photoluminescence, low voltage cathodoluminescence spectra, and photoluminescence lifetimes were used to characterize the as-obtained samples. The X-ray diffraction results indicate that the samples are well crystallized with the scheelite structure of CaWO4. The transmission electron microscopy and field emission scanning electron microscopy images illustrate that the powders consist of spherical particles with sizes from 120 to 160 nm, which are the aggregates of even smaller nanoparticles ranging from 10 to 20 nm. Under UV light or electron beam excitation, the CaWO4 powder exhibited a blue emission band with a maximum at 430 nm originating from the WO2−4 groups, while the CaWO4:Eu3+ powder showed red emission dominated by 613 nm ascribed to the 5D0 → 7F2 of Eu3+, and the CaWO4:Tb3+ powders showed emission at 544 nm, ascribed to the 5D4 → 7F5 transition of Tb3+. The PL excitation and emission spectra suggest that the energy is transferred from WO2−4 to Eu3+CaWO4:Eu3+ and to Tb3+ in CaWO4:Tb3+. Moreover, the energy transfer from WO2−4 to Tb3+ in CaWO4:Tb3+ is more efficient than that from WO2−4 to Eu3+ in CaWO4:Eu3+. This novel and efficient pathway could open new opportunities for further investigating the novel properties of tungstate materials.

scholarly journals Characterization of Orthorhombicα-MoO3Microplates Produced by a Microwave Plasma Process

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Arrak Klinbumrung ◽  
Titipun Thongtem ◽  
Somchai Thongtem
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Microwave Plasma ◽  
Vibration Modes ◽  
X Ray Diffraction ◽  
Plasma Process ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Scanning Electron

Orthorhombic α-MoO3microplates were produced from (NH4)6Mo7O24·4H2O solid powder by a 900 W microwave plasma for 40, 50, and 60 min. Phase, morphologies, and vibration modes were characterized by X-ray diffraction (XRD), selected area electron diffraction (SAED), scanning electron microscopy (SEM), and Raman and Fourier transform infrared (FTIR) spectroscopy. Sixty min processing resulted in the best crystallization of the α-MoO3phase, with photoluminescence (PL) in a wavelength range of 430–440 nm.

Synthesis of Zinc Doped-Biphasic Calcium Phosphate Nanopowder via Sol-Gel Method

2012 ◽  
Vol 531-532 ◽  
pp. 614-617 ◽  
Author(s):  
Gunawan ◽  
I. Sopyan ◽  
A. Naqshbandi ◽  
S. Ramesh
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Phosphate ◽  
Field Emission ◽  
Biphasic Calcium Phosphate ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gel Technique ◽  
Scanning Electron

Biphasic calcium phosphate powders doped with zinc (Zn-doped BCP) were synthesized via sol-gel technique. Different concentrations of Zn have been successfully incorporated into biphasic calcium (BCP) phases namely: 1%, 2%, 3%, 5%, 7%, 10% and 15%. The synthesized powders were calcined at temperatures of 700-900°C. The calcined Zn-doped BCP powders were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), differential and thermogravimetric analysis (TG/DTA) and field-emission scanning electron microscopy (FESEM). X-ray diffraction analysis revealed that the phases present in Zn-doped are hydroxyapatite, β- TCP and parascholzite. Moreover, FTIR analysis of the synthesized powders depicted that the bands of HPO4 increased meanwhile O-H decreased with an increase in the calcination temperature. Field emission scanning electron microscopy (FESEM) results showed the agglomeration of particles into microscale aggregates with size of the agglomerates tending to increase with an increase in the dopant concentration.

Adsorption and degradation of Congo red on a jarosite-type compound

RSC Advances ◽  
2016 ◽  
Vol 6 (105) ◽  
pp. 102972-102978 ◽  
Author(s):  
Yu Dong ◽  
Ziting Wang ◽  
Xin Yang ◽  
Meiying Zhu ◽  
Rufen Chen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Field Emission ◽  
Congo Red ◽  
X Ray Diffraction ◽  
X Ray ◽  
Type Compound ◽  
Forced Hydrolysis ◽  
Scanning Electron

Natrojarosite particles were prepared by forced hydrolysis. X-ray diffraction and field-emission scanning electron microscopy were used to characterize the resulting products.

Hollow Crystals of BiFeO3 Prepared via a Al3+-Assisted Hydrothermal Method

2012 ◽  
Vol 174-177 ◽  
pp. 516-519
Author(s):  
Yong Gang Wang ◽  
Lin Lin Yang ◽  
Yu Jiang Wang ◽  
Xiao Feng Wang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Hydrothermal Method ◽  
Field Emission ◽  
Growth Mechanism ◽  
Irregular Shape ◽  
Morphology Evolution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

The BiFeO3 hollow crystals were successfully prepared at 200oC by a Al3+assisted hydrothermal method. The structures and morphologies of the as-obtained products were characterized by X-ray diffraction (XRD) and field emission scanning electron microscopy (SEM). A morphology evolution from irregular shape to square, hollow, and sphere-like was observed as the Al ions concentration varied from 0% to 1.5%. The possible growth mechanism of the BiFeO3hollow crystals was also discussed.

Comparative High-Resolution X-Ray Diffraction Analysis of GaN/AlGaN Heterostructure on Al2O3 and Si (111) Substrate Grown by Plasma Assisted Molecular Beam Epitaxy

2015 ◽  
Vol 1754 ◽  
pp. 129-134
Author(s):  
Sanjay Kr. Jana ◽  
Saptarsi Ghosh ◽  
Syed Mukulika Dinara ◽  
Apurba Chakraorty ◽  
D. Biswas
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Resolution ◽  
Molecular Beam Epitaxy ◽  
Field Emission ◽  
Molecular Beam ◽  
X Ray Diffraction ◽  
Reciprocal Space Mapping ◽  
X Ray ◽  
Scanning Electron

AbstractThe work presents a comparative study on GaN/AlGaN type-II heterostructures grown on c-plane Al2O3 and Si (111) substrates by Plasma Assisted Molecular Beam Epitaxy. The in-depth structural characterizations of these samples were performed by High-Resolution X-Ray Diffraction, X-ray Reflectivity and Field Emission Scanning Electron Microscopy. The in-plane and out-of plane strains were determined from measured c- and a-lattice parameters of the epilayers from reciprocal space mapping of both symmetric triple axis (002) and asymmetric grazing incidence (105) double axis mode. The mosaicity parameters like tilt and correlation lengths were also calculated from reciprocal space mapping. Moreover, the twist angle was measured from skew symmetric off axis scan of (102), (103), and (105) planes along with (002) symmetric plane. The defect density were measured from the full width at half maxima of skew symmetric scan of (002) and (102) reflection planes. Also, the strained states of all the layers were analyzed and corresponding Al mole fraction was calculated based on anisotropic elastic theory. The thicknesses of the layers were measured from simulation of the nominal structure by fitting with X-ray Reflectivity experimental curves and also by comparing with cross sectional Field Emission Scanning Electron Microscopy micrographs.

scholarly journals Heterogeneous Cu–Fe oxide catalysts for preferential CO oxidation (PROX) in H2-rich process streams

RSC Advances ◽  
2020 ◽  
Vol 10 (59) ◽  
pp. 35792-35802
Author(s):  
Venkata D. B. C. Dasireddy ◽  
Krish Bharuth-Ram ◽  
Darko Hanzel ◽  
Blaž Likozar
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Carbon Monoxide ◽  
Co Oxidation ◽  
Field Emission ◽  
Oxide Catalysts ◽  
X Ray Diffraction ◽  
Preferential Co Oxidation ◽  
X Ray ◽  
Scanning Electron

Fe loading in Cu–Fe phases and its effect on carbon monoxide oxidation in H2-rich reactant streams were investigated with the catalyst material phases characterized by Field Emission Scanning Electron Microscopy, X-ray diffraction studies and Mössbauer Spectroscopy.

Selected Interlayer of Diamond Deposition on γ-TiAl Intermetallic Compounds Prepared by Microwave-Plasma Assisted CVD

2009 ◽  
Vol 631-632 ◽  
pp. 425-430
Author(s):  
Saleh B. Abu Suilik ◽  
Masayuki Ohshima ◽  
Toshimitsu Tetsui ◽  
Kazuhiro Hasezaki
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Diamond Coatings ◽  
X Ray Diffraction ◽  
Diamond Deposition ◽  
X Ray ◽  
Nano Crystalline ◽  
Scanning Electron

Several diamond coatings were performed on -TiAl substrates by a microwave-plasma assisted CVD, which were made directly to the substrate and indirectly to the TiC, Ti5Si3, Al2O3+TiO2 and Si layers on the substrate. The direct coatings suffered from severe delamination and cracks. The deposited layers on TiC and Ti5Si3 layers partially delaminated, while those on Al2O3+TiO2 and Si layers adhered well without delamination. All the diamond films deposited were characterized using scanning electron microscopy, Raman spectroscopy, and X-ray diffraction. Raman spectra showed that poly- and nano-crystalline diamond films were obtained for the coatings of -TiAl.

A Rational Way to Prepare BaTiO3 Ceramics

2012 ◽  
Vol 535-537 ◽  
pp. 797-800
Author(s):  
Liang Luo ◽  
Yan Jun Zhu ◽  
Ling Ling Song ◽  
Xiao Bo Zhang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Phase Composition ◽  
Solid State ◽  
Field Emission ◽  
Solid State Reaction ◽  
X Ray Diffraction ◽  
One Pot ◽  
X Ray ◽  
Scanning Electron

A facile one-pot hydrothermal method has been developed for synthesis of porous and non-porous BaTiO3 ceramics using Ba(OH)2.8H2O, BaCO3 as barium source. In this paper, we research the effect of different barium source on the nanostructure of BaTiO3 ceramics in a solid state reaction, and the results indicated that the two different morphologies of BaTiO3 ceramics can be easily prepared by using these two different barium source. The phase composition and morphology of the as-obtained products were investigated by X-ray diffraction and field emission scanning electron microscopy (SEM).

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