The optical constants of natural and artificial cuprite by an ellipsometric method

1978 ◽  
Vol 42 (324) ◽  
pp. 505-508 ◽  
Author(s):  
E. F. I. Roberts ◽  
P. Rastall
Keyword(s):  
Optical Constants ◽  
Cupric Oxide ◽  
Pure Copper ◽  
Surface Oxidation ◽  
Dielectric Constants ◽  
Refractive Indices ◽  
Optical Parameters ◽  
Total Oxidation ◽  
Oxidation Method ◽  
Ellipsometric Method

SummaryEllipsometric measurements in the spectral range 250–850 nm have been made on polished single crystals of natural cuprite from Namibia and of artificial cuprite grown by a total-oxidation method from pure copper. Derived values of the refractive indices, absorption coefficients, normal reflectances, and the complex dielectric constants for the two materials are all closely similar, suggesting that the stoichiometry and purity are essentially the same. Values of the absorption coefficient at the red end of the spectrum are inconsistent with the observed transparency of the crystals, and are compatible with a 10 nm surface oxidation film of cupric oxide. This study is part of a wider survey of the effects of doping and stoichiometry on the optical parameters of cuprite.

scholarly journals Optical Parameters of Atomically Heterogeneous Systems Created by Plasma Based Low Energy Ion Beams: Wavelength Dependence and Effective Medium Model

2021 ◽  
Vol 9 ◽  
Author(s):  
Krishn Pal Singh ◽  
Sudeep Bhattacharjee
Keyword(s):  
Optical Conductivity ◽  
Optical Constants ◽  
Ion Beam ◽  
Incident Light ◽  
Input Parameter ◽  
Ion Beams ◽  
Skin Depth ◽  
Dielectric Constants ◽  
Low Energy ◽  
Optical Parameters

The article presents the irradiation effects of low energy (∼0.5 keV) inert gaseous Argon ion beams on optical constants [real (n) and imaginary (k) parts of the refractive index], dielectric constants, skin depth, and optical conductivity of copper (Cu), silver (Ag), and aluminum (Al) metallic thin films (MTF). The optical constants of pristine MTF are obtained by employing the universal Kramers-Kronig (KK) technique. The reflectivity of pristine MTF measured using UV-VIS-NIR spectrophotometry is used as an input parameter in the KK technique to determine the optical constants as a function of energy [or wavelength (λ)] of incident light ranging between ∼1–4.96 eV (or 250–1,200 nm). For the irradiated MTF, the optical constants including the skin depth (δ = λ/2πk), optical conductivity (σ = nkc/λ), and dielectric constants (ϵ1 = n2 − k2 and ϵ2 = 2nk) with varying ion fluence have been investigated by implementing the Maxwell-Garnett (MG) approximation, used to determine the effective dielectric constants of a random mixture of two different mediums. Additionally, n and k obtained from MG approximation have been compared with those obtained using the pseudo- Brewster angle technique for four different laser wavelengths (405, 532, 632.8 and 670 nm) and are found to be in good agreement with each other. It is observed that the optical constants and optical conductivity of the MTF decrease with increase in ion beam fluence, while the skin depth increases. Besides the optical constants, the behavior of skin depth, dielectric constants, and optical conductivity of the irradiated MTF with varying fluence are discussed in this article.

Refractive indices, electronic polarizabilities and dielectric constants of alkali halides

1992 ◽  
Vol 33 (5) ◽  
pp. 389-393 ◽  
Author(s):  
R.R. Reddy ◽  
S. Anjaneyulu ◽  
T.V.R. Rao
Keyword(s):  
Alkali Halides ◽  
Dielectric Constants ◽  
Refractive Indices

Study of optical parameters of two fluorinated isothiocyanato nematic liquid crystals exhibiting high birefringence

2014 ◽  
Vol 22 (1) ◽  
Author(s):  
T. Devi ◽  
B. Choudhury ◽  
A. Bhattacharjee ◽  
R. Dabrowski
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Laser Beam ◽  
Order Parameter ◽  
Refractive Indices ◽  
Optical Parameters ◽  
Optical Studies ◽  
High Birefringence ◽  
Two Samples ◽  
Direct Extrapolation

AbstractOptical studies have been carried out on two fluorinated isothiocyanato nematic liquid crystal (LC) compounds 4′-butylcyclohexyl-3, 5-difluoro-4-isothiocyanatobiphenyl and 4′-pentylcyclohexyl-3, 5-difluoro-4-isothiocynatobiphenyl. Transition temperatures of the two samples were confirmed using a polarizing microscope. The two LC compounds were found to exhibit fairly high clearing temperatures. Measurements of refractive indices of the two compounds were done by using thin prism method with He-Ne laser beam of wavelength 630 nm. Birefringence of the two LC compounds was calculated from the measured refractive indices. Both the compounds are found to display fairly high values of birefringence. Validation of a modified four-parameter model, based on Vuks equation describing the temperature dependence of refractive indices of the two liquid crystals, is also presented in this paper. The model is validated by fitting the experimentally measured values of refractive indices, birefringence and average refractive indices of the two nematic LCs with the theoretical values. In this paper, the calculation of order parameters of the LCs is presented by using two methods: direct extrapolation method based solely on the birefringence data and by using modified Vuks method based on Haller’s extrapolation. As observed from the obtained results, this procedure of calculating order parameter gives very reasonable results.

SOLUTION OF THE FILM SPECTRA EQUATION

2021 ◽  
Author(s):  
E. N. Kotlikov ◽  
◽  
Yu. A. Novikova ◽  
Yu. N. Tsarev ◽  
◽  
...  
Keyword(s):  
Optical Constants ◽  
Refractive Indices ◽  
Spectrophotometric Methods

The work is analyzing the possibility of unambiguously determining the optical constants of films by spectrophotometric methods. The ambiguity of such a problem and the ways of its solution when using a spectrum section are shown. Based on the analysis performed, methods are considered for finding the optical constants of films with absorption. on the example of the film. The refractive indices of the CaY2F8 film have been determined in the range 1,3–17 μm.

Optimization of Maximum VO2 Content in Polymorphous Oxides of Vanadium

2013 ◽  
Vol 538 ◽  
pp. 113-116 ◽  
Author(s):  
S.N. Svitasheva
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Optical Constants ◽  
Ellipsometric Method

Optical properties of thin films of vanadium thermally oxidized at air were studied by ellipsometric method using wavelength of He-Ne laser. Multipart composition of these films was revealed and method of optimization of technological conditions based on dynamic of changing optical constants near 68°C was developed.

CORONENE ORGANIC FILMS: OPTICAL AND SPECTRAL CHARACTERISTICS UNDER ANNEALING TEMPERATURE INFLUENCES

2021 ◽  
pp. 2150081
Author(s):  
ERMAN ERDOGAN
Keyword(s):  
Refractive Index ◽  
Annealing Temperature ◽  
Film Growth ◽  
Low Cost ◽  
Spectral Characteristics ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Optical Bandgap ◽  
Dielectric Constants ◽  
Optical Parameters

In this study, spin coating, which is a chemical film layer thin film deposition method, was used for coronene films that were grown on Si substrates annealed at 325, 350 and 375[Formula: see text]K to examine the impacts on the optical properties of films. This method allows for easy control of the deposition parameters such as concentration, temperature and time as well as enables the film growth at low cost. Optical (UV–Vis) spectral measurements in the wavelength range from 200[Formula: see text]nm to 800[Formula: see text]nm were used to extract the bandgap information and to calculate various optical parameters of the spin-coated coronene films. The electronic transitions on the absorption of photons of suitable energy are of indirect allowed type. The corresponding optical bandgap ([Formula: see text]) was determined. Complex dielectric constants, dissipation factor, optical and electrical conductances and refractive index of coronene films were analyzed as a function of temperature. As the film annealing temperature was increased, the dielectric constants and the refractive index values increased, whereas the optical bandgap and electrical and optical conductivity values decreased.

A high-efficiency and stable cupric oxide photocathode coupled with Al surface plasmon resonance and Al2O3 self-passivation

2019 ◽  
Vol 55 (100) ◽  
pp. 15093-15096 ◽  
Author(s):  
Haiyang Xing ◽  
Lei E ◽  
Dan Zhao ◽  
Xifei Li ◽  
Mengnan Ruan ◽  
...  
Keyword(s):  
Surface Plasmon Resonance ◽  
Magnetron Sputtering ◽  
Water Splitting ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
High Efficiency ◽  
Cupric Oxide ◽  
Photoelectrochemical Water Splitting ◽  
Oxidation Method ◽  
Spontaneous Oxidation

A high-efficiency and stable CuO/Al/Al2O3 photocathode for photoelectrochemical water splitting has been successfully synthesized by a facile magnetron sputtering combined with spontaneous oxidation method.

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