Infrared spectroscopy of CeO2 nanoparticles using Bergman’s spectral representation: effects of phonon confinement and lattice strain

2021 ◽  
Author(s):  
Inigo González de Arrieta ◽  
Leire del Campo ◽  
Domingos De Sousa Meneses
Keyword(s):  
Infrared Spectroscopy ◽  
Cerium Oxide ◽  
Dielectric Function ◽  
Lattice Strain ◽  
Spectral Representation ◽  
Ceo2 Nanoparticles ◽  
Phonon Confinement ◽  
Function Model

The dielectric function of a cerium oxide nanopowder has been investigated by infrared spectroscopy. The use of Bergman’s spectral representation and a semi-quantum dielectric function model allows an accurate retrieval...

Synthesis and Characterization of Cerium Oxide (CeO2) Nanoparticles

2009 ◽  
Vol 609 ◽  
pp. 189-194 ◽  
Author(s):  
C. Benmouhoub ◽  
A. Kadri ◽  
N. Benbrahim ◽  
S. Hadji
Keyword(s):  
Crystallite Size ◽  
Cerium Oxide ◽  
Ceo2 Nanoparticles ◽  
Precipitation Method ◽  
Synthesis And Characterization

Nanoparticles of cerium oxide (CeO2) are synthesized with cerium (III) nitrates (Ce(NO3)3, 6H2O) by precipitation method in ammonium hydroxyl solution (NH4OH). The influence of several parameters such as nature of the solvent, synthesizing temperature and the calcination on the crystallite size is studied by XRD, TEM and BET methods. The results show that both calcinations and synthesizing temperature affect the particles size. Also, the nature of solvent has a great effect on the morphology of CeO2 nanoparticles.

Optical properties of cerium oxide (CeO2) nanoparticles synthesized by hydroxide mediated method

2018 ◽  
Author(s):  
Mawlood Maajal Ali ◽  
Hadeel Salih Mahdi ◽  
Azra Parveen ◽  
Ameer Azam
Keyword(s):  
Optical Properties ◽  
Cerium Oxide ◽  
Ceo2 Nanoparticles

Performance and Emission Analysis of Compression Ignition Engine With Neem Methyl Ester Mixed With Cerium Oxide (CeO2) Nanoparticles

2020 ◽  
Vol 142 (8) ◽  
Author(s):  
Mayank Kapoor ◽  
Narendra Kumar ◽  
Ajay Singh Verma ◽  
Gaurav Gautam ◽  
Aditya Kumar Padap
Keyword(s):  
Methyl Ester ◽  
Cerium Oxide ◽  
Desirability Function ◽  
Engine Performance ◽  
Ceo2 Nanoparticles ◽  
Performance Characteristics ◽  
Compression Ignition Engine ◽  
Emission Analysis ◽  
Performance And Emission ◽  
Harmful Emissions

Abstract This paper depicts Box-Behnken design (BBD) approach to optimize the performance and emission characteristics of adjustable compression ratio, single- cylinder diesel engine with nanoparticle-blended biofuel. Cerium oxide (CeO2) nanoparticles and diethyl ether (DEE) are mixed with neem methyl ester (NME) in corresponding ratios as per BBD experimental plan. Engine performance characteristics brake thermal efficiency (BTE), brake-specific fuel consumption (BSFC), and NOx, CO, HC, and CO2 emissions have been analyzed. To study the influence of input parameters, quadratic models are developed on each output response using analysis of variance (ANOVA). Desirability function approach has been used to optimize the performance of multi-response parameters. The results revealed that nanoparticles mixed blends of NME and DEE enhances the performance characteristics and reduce the harmful emissions.

Spectroscopic Ellipsometry Analysis of InGaN/GaN and AlGaN/GaN Heterostructures Using a Parametric Dielectric Function Model

1999 ◽  
Vol 595 ◽  
Author(s):  
J. Wagner ◽  
A. Ramakrishnan ◽  
H. Obloh ◽  
M. Kunzer ◽  
K. Köhler ◽  
...  
Keyword(s):  
Band Gap ◽  
Dielectric Function ◽  
Spectroscopic Ellipsometry ◽  
Composition Dependence ◽  
Band Gap Energy ◽  
Function Model ◽  
Gap Energy ◽  
The Individual ◽  
Gap Data

AbstractSpectroscopic ellipsometry (SE) has been used for the characterization of AlGaN/GaN and InGaN/GaN heterostructures. The resulting pseudodielectric function spectra were analyzed using a multilayer approach, describing the dielectric functions of the individual layers by a parametric oscillator model. From this analysis, the dielectric function spectra of GaN, AlxGa1−xN (x≤0.16), and In0.13Ga0.87N were deduced. Further, the dependence of the AlxGa1−xN band gap energy on the Al mole fraction was derived and compared with photoluminescence data recorded on the same material. The SE band gap data are compatible with a bowing parameter close to 1 eV for the composition dependence of the AlxGa1−xN gap energy. Finally, the parametric dielectric functions have been used to model the pseudodielectric function spectrum of a complete GaN/AlGaN/InGaN LED structure.

Near-Field Radiation Calculated With an Improved Dielectric Function Model for Doped Silicon

2008 ◽  
Author(s):  
S. Basu ◽  
B. J. Lee ◽  
Z. M. Zhang
Keyword(s):  
Energy Transfer ◽  
Dielectric Function ◽  
Near Field ◽  
Silicon Surfaces ◽  
Function Model ◽  
Fluctuation Dissipation ◽  
Doped Silicon ◽  
Energy Conversion Systems ◽  
Field Radiation ◽  
Vacuum Gap

This paper describes a theoretical investigation of near-field radiative heat transfer between doped silicon surfaces separated by a vacuum gap. Using an improved dielectric function model for heavily doped silicon, along with fluctuation-dissipation theorem, and dyadic Green’s function, the present authors calculated the energy transfer between the doped silicon surfaces near room temperature. The effects of doping level, polarization, and width of the vacuum gap on the overall radiative transfer were investigated. It was observed that increase in the doping concentration of the emitter does not necessarily enhance the energy transfer in the near field. The energy-streamline method was used to model the lateral shift of the energy pathway, which is the trace of the Poynting vectors in the vacuum gap. The analysis performed in this study may facilitate the understanding of near-field radiation for applications such as thermal management in nanoelectronics, energy conversion systems, and nanothermal manufacturing.

On the microstructure, chemistry, and dielectric function of BaTiO3 MOCVD thin films

1994 ◽  
Vol 9 (2) ◽  
pp. 426-430 ◽  
Author(s):  
V.P. Dravid ◽  
H. Zhang ◽  
L.A. Wills ◽  
B.W. Wessels
Keyword(s):  
Thin Films ◽  
Electron Diffraction ◽  
Dielectric Function ◽  
Lattice Strain ◽  
Chemical Vapor ◽  
Convergent Beam Electron Diffraction ◽  
Organic Chemical ◽  
Beam Electron ◽  
Spatially Resolved ◽  
Convergent Beam

Thin films of BaTiO3 deposited on (100)LaAlO3 substrate by metal-organic chemical vapor deposition (MOCVD) are investigated using several electron-optical techniques. Combined high resolution transmission electron microscopy (HRTEM), electron energy loss spectrometry (EELS), and convergent beam electron diffraction (CBED) indicate a substantial influence of lattice strain on the structural and optical characteristics of BaTiO3 films. Spatially resolved EELS and CBED studies indicate that the substrate influence persists up to about 40 nm away from the interface. The changes in the dielectric function of the films, as inferred from spatially resolved EELS, appear to correlate well with internal lattice strain in the films as deduced from convergent beam electron diffraction (CBED).

scholarly journals Физико-химические свойства и антиоксидантная активность наночастиц оксида церия, стабилизированных мальтодекстрином

2021 ◽  
Vol 63 (12) ◽  
pp. 2020
Author(s):  
С.А. Маслова ◽  
И.Н. Бажукова ◽  
А.В. Мышкина ◽  
Е.О. Бакшеев ◽  
М.О. Пронина ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Surface Structure ◽  
Cerium Oxide ◽  
Hydroxyl Radicals ◽  
Ceo2 Nanoparticles ◽  
Cerium Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
Structure And Properties ◽  
Peroxidase Enzymes

The study on physicochemical properties of maltodextrin-coated cerium oxide nanoparticles was carried out. The surface structure and properties of CeO2 nanoparticles were investigated. The ability of CeO2 nanoparticles to perform the functions of catalase and peroxidase enzymes, as well as to inactivate hydroxyl radicals was shown.

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