NABLA FRACTIONAL EXTENDED LORENTZ OSCILLATOR AND ITS STABILITY

2020 ◽  
Vol 23 (2) ◽  
pp. 151-163
Author(s):  
A. George Maria Selvam ◽  
D. Vignesh
Keyword(s):  
Lorentz Oscillator

Atomic Layer Deposition of Ruthenium Films on Hydrogen terminated Silicon

2009 ◽  
Vol 1156 ◽  
Author(s):  
Sun Kyung Park ◽  
K. Roodenko ◽  
Yves J. Chabal ◽  
L. Wielunski ◽  
R. Kanjolia ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Atomic Layer ◽  
Initial Growth ◽  
Experimental Conditions ◽  
Metallic Component ◽  
Broadband Absorption ◽  
Lorentz Oscillator ◽  
Layer Deposition ◽  
Drude Term ◽  
Number Of Cycles

AbstractAtomic Layer deposition of thin Ruthenium films has been studied using a newly synthesized precursor (Cyclopentadienyl ethylruthenium dicarbonyl) and O2 as reactant gases. Under our experimental conditions, the film comprises both Ru and RuO2. The initial growth is dominated by Ru metal. As the number of cycles is increased, RuO2 appears. From infrared broadband absorption measurements, the transition from isolated, nucleated film to a continuous, conducting film (characterized by Drude absorption) can be determined. Optical simulations based on an effective-medium approach are implemented to simulate the in-situ broadband infrared absorption. A Lorentz oscillator model is developed, together with a Drude term for the metallic component, to describe optical properties of Ru/RuO2 growth.

Interband Optical Properties of the Microcrystalline Component within the Damage Layer of Be+ - Implanted GaAs

1988 ◽  
Vol 128 ◽  
Author(s):  
G. F. Feng ◽  
R. Zallen
Keyword(s):  
Optical Properties ◽  
Size Effects ◽  
Finite Size ◽  
Bulk Crystal ◽  
Interband Absorption ◽  
Finite Size Effects ◽  
Damage Layer ◽  
Lorentz Oscillator ◽  
Fine Grain ◽  
Short Time

ABSTRACTThe damage layer in unannealed Be+-implanted GaAs samples (45-keV Be+ ions, 1013 to 5 × 1014 ions/cm2) consists of a fine-grain mixture of amorphous GaAs and GaAs microcrystals, with the characteristic microcrystal size L of the microcrystalline component decreasing with increasing fluence. We have carried out reflectivity measurements on these samples for photon energies from 2.0 to 5.6 eV, in the electronic interband regime. Using Lorentz oscillator analysis and the effective medium approximation, we have extracted the dielectric function of the microcrystalline component (μ-GaAs) within the damage layer. The optical properties of μ-GaAs deviate appreciably from those of the bulk crystal near the interband absorption peaks. The linevidths of these peaks are found to increase over the bulk-crystal value by an amount proportional to (l/L), the increase being about 0.2 eV when L =100 Å. These finite-size effects can be understood in terms of a lifetime reduction caused by the short time it takes for electrons to reach the microcrystal boundaries.

Characterization of Polycrystalline Silicon Multilayers with thin Nitride/Oxide Films Using Spectroscopic Ellipsometry

1993 ◽  
Vol 324 ◽  
Author(s):  
L.M. Asinovsky
Keyword(s):  
Spectroscopic Ellipsometry ◽  
Polycrystalline Silicon ◽  
Chemical Vapor ◽  
Strongly Correlated ◽  
Si Substrate ◽  
Lorentz Oscillator ◽  
Pressure Chemical ◽  
Complete Recrystallization ◽  
Nitride Oxide

AbstractSpectroscopic ellipsometry has been used to characterize oxide/poly-Si/oxide with thin nitride/oxide layer. Films were deposited on Si substrate using low-pressure chemical vapor deposition (LPCVD) techniques. The measurements were taken at angles of incidence of 65 and 70 degrees in the wavelength range from 300 to 800 nm. The analysis of the data using effective medium and two-dimensional Lorentz oscillator approximations identified complete recrystallization of the poly-Si after annealing and and its transformation to µ c-Si. Three wafers taken at the sequential stages of the manufacturing process were studied. Although parameters of the thin nitride/oxide layers are strongly correlated, reasonable estimates of the thicknesses were found. The resuilts were consistent with the measured Auger electron spectroscopy (AES) profiles.

Infrared reflectance spectroscopy of MgAl2O4 nanoparticles substituted by K+ ions

2018 ◽  
Vol 32 (06) ◽  
pp. 1850067 ◽  
Author(s):  
Javed Ahmad ◽  
M. Qadeer Awan ◽  
Roomana Yasmin ◽  
Maria Sabir ◽  
Shafiq Anwar ◽  
...  
Keyword(s):  
Room Temperature ◽  
Longitudinal Optical ◽  
Reflectance Spectroscopy ◽  
Optical Parameters ◽  
Frequency Range ◽  
Phonon Modes ◽  
Metallic Behavior ◽  
Lorentz Oscillator ◽  
Reflectivity Spectra ◽  
Ftir Spectrometer

The infrared reflectivity spectra for potassium-doped polycrystalline magnesium aluminates Mg[Formula: see text]K[Formula: see text]Al2O4 (x=0, 0.25, 0.50, 0.75, 1) are measured in the frequency range between 10–15, 500 cm[Formula: see text] using FTIR spectrometer at room-temperature. Four optical phonon modes are observed in measured spectra, which are fitted by Lorentz oscillator model for semiconducting behavior and Lorentz–Drude model for metallic behavior. Moreover, optical parameters are also determined for these modes which may attribute to spinel structure for samples Mg[Formula: see text]K[Formula: see text]Al2O4, their reflectivity spectra shows a typical semiconducting nature. To study ionicity and effect of polarization, Born and Szigeti effective charges are calculated from longitudinal optical and transverse optical (LO–TO) splitting of modes for all samples. Optical bandgap has been estimated through optical conductivity ([Formula: see text]([Formula: see text])) and found to be x dependent.

scholarly journals Tide level in time and frequency domains at Dili port: Characteristic feature of a Lorentz oscillator

2021 ◽  
Vol 2 (1) ◽  
pp. 41-48
Author(s):  
Abelito Filipe Belo ◽  
Kenji Sasa ◽  
Jose Madeira Marques ◽  
Koichi Shimakawa
Keyword(s):  
Characteristic Feature ◽  
Lorentz Oscillator ◽  
Frequency Domains ◽  
Tide Level ◽  
Time And Frequency Domains

scholarly journals Эллипсометрическое исследование тонкопленочных структур аморфного гидрогенизированного углерода и наночастиц золота

2019 ◽  
Vol 127 (11) ◽  
pp. 846 ◽  
Author(s):  
В.А. Толмачев ◽  
Д.П. Щербинин ◽  
Е.А. Коншина
Keyword(s):  
Gold Film ◽  
Layer Structure ◽  
Hybrid Structure ◽  
Spectral Features ◽  
Spectral Ellipsometry ◽  
Lorentz Oscillator ◽  
Nanoparticle Layer ◽  
Before And After ◽  
Spectrophotometric Data ◽  
Amorphous Hydrogenated Carbon

In this work, the optical constant films of amorphous hydrogenated carbon (a-C: H) and a hybrid structure based on it with a granulated gold film before and after their annealing at 300 °C were studied by spectral ellipsometry. The dispersions n (λ) and k (λ) of the a-C:H film were established using the Cauchy approximation and its thickness. The spectral features of the Au plasmon nanoparticle layer deposited on the a-C:H surface were modeled as an effective medium and a Lorentz oscillator. The parameters of the films and their thickness were determined by fitting the calculated spectra to the ellipsometric spectra  (λ) and  (λ). The obtained data were used to determine the parameters of the Lorentz oscillator in the model of a-C:H / Au two-layer structure. As a result of the a-C:H / Au structure annealing, the intensity of the maxima in the spectra n and k increased, their position shifted to the blue region, and the half-width of the bands decreased. The observed changes in the ellipsometric spectra are completely consistent with the spectrophotometric data of this structure.

scholarly journals Insight into Structural and Optical Properties of Pristine and Sr2+ Doped La2NiMnO6

2021 ◽  
Vol 58 (2) ◽  
pp. 59-71
Author(s):  
Javed Ahmad ◽  
Shoaib Hassan ◽  
Jamshaid Alam Khan ◽  
Umair Nissar ◽  
Hammad Abbas
Keyword(s):  
Sol Gel ◽  
Average Crystallite Size ◽  
Tangent Loss ◽  
Double Perovskites ◽  
Phonon Modes ◽  
Lorentz Oscillator ◽  
Reflectivity Spectra ◽  
Gel Technique ◽  
A Site ◽  
Insight Into

Double perovskites oxide (DPO) multiferroics La2-xSrxNiMnO6(x=0.0, 0.1, 0.2, 0.4, 0.6) are synthesized by sol-gel technique. The structural, optical and electrical (both DC and AC) properties of La2-xSrxNiMnO6 have been investigated by XRD and FTIR spectroscopy and two-probe resistivity and dielectric measurements as a function of temperature, respectively. The effect of doping of Strontium at A-site in double perovskites is discussed. XRD has revealed the formation of monoclinic structure of La2-xSrxNiMnO6 with space group P21 / n for x=0.0 and P21 for x=0.1, 0.2, 0.4, 0.6. The average crystallite size has been calculated to be in the range 31 to 46 nm as determined by Debye Scherrer equation. Infrared active optical phonons observed from reflectivity spectra have been analysed fitting the theoretical oscillators using Lorentz oscillator model. We have observed several well-resolved phonon modes in La2-xSrxNiMnO6 with increasing dopant concentration. Activation energy calculated using Arrhenius Plot is in the range of 0.31 to 0.18 eV, confirming the semiconducting nature of all samples. The dielectric constant and tangent loss as a function of temperature and frequency are also discussed for these multiferroics.

Spectroscopic Ellipsometric Characterization of Low Temperature GaAs

1995 ◽  
Vol 378 ◽  
Author(s):  
X. Gao ◽  
P. G. Snyder ◽  
P. W. Yu ◽  
Y. Q. Zhang ◽  
Z. F. Peng
Keyword(s):  
Low Temperature ◽  
Red Shift ◽  
Strain Effect ◽  
Lorentz Oscillator ◽  
Ellipsometric Characterization ◽  
C 30 ◽  
Low Temperature Gaas ◽  
Low Temperature Grown Gaas ◽  
Lt Gaas

AbstractPseudodielectric functions of low temperature grown GaAs (LT GaAs) measured by spectroscopic ellipsometry are presented. The spectral range includes the El (2.92eV) and El+ΔAl (3.13eV) critical point structure of GaAs. A Lorentz-oscillator model was used to fit the dielectric function of LT GaAs for samples with nominal growth temperatures (Tg) varying from 200°C to 580°C. For Tg of 200°C, 30% and 19% broadenings and −0.01 leV and −0.007eV red shifts were found for the El and El+Δl structures respectively, compared with normal GaAs. The red shift can be explained in terms of a strain effect in the LT layer. In annealed LT GaAs the broadening decreased significantly and no red shift was found.

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