Optical Properties of CaNb2O6 Single Crystals Grown by OFZ*

CaNb2O6 single crystals with an orthorhombic columbite structure are grown via an optical floating zone (OFZ) method. The as-grown crystals are colorless and free of low-angle grain boundaries and inclusions. They are transparent (up to 62%) in the visible to the infrared region (400–1000 nm) and have a low absorption coefficient (α = 1.56). The bandgap is determined as a direct transition and Eg = 4.28 eV. The wavelength-dependent refractive index and extinction coefficient of the CaNb2O6 crystals are derived from the obtained T and α spectra. Their photoluminescence spectra exhibit a strong and broad emission band centered at 465 nm.

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Broadband spectroscopy of astrophysical ice analogues

Astronomy and Astrophysics ◽

10.1051/0004-6361/201935619 ◽

2019 ◽

Vol 629 ◽

pp. A112 ◽

Cited By ~ 8

Author(s):

B. M. Giuliano ◽

A. A. Gavdush ◽

B. Müller ◽

K. I. Zaytsev ◽

T. Grassi ◽

...

Keyword(s):

Refractive Index ◽

Optical Properties ◽

Time Domain ◽

Complex Refractive Index ◽

Far Infrared ◽

Infrared Region ◽

Thz Radiation ◽

The Real ◽

Thz Range ◽

The Time Domain

Context. Reliable, directly measured optical properties of astrophysical ice analogues in the infrared and terahertz (THz) range are missing from the literature. These parameters are of great importance to model the dust continuum radiative transfer in dense and cold regions, where thick ice mantles are present, and are necessary for the interpretation of future observations planned in the far-infrared region. Aims. Coherent THz radiation allows for direct measurement of the complex dielectric function (refractive index) of astrophysically relevant ice species in the THz range. Methods. We recorded the time-domain waveforms and the frequency-domain spectra of reference samples of CO ice, deposited at a temperature of 28.5 K and annealed to 33 K at different thicknesses. We developed a new algorithm to reconstruct the real and imaginary parts of the refractive index from the time-domain THz data. Results. The complex refractive index in the wavelength range 1 mm–150 μm (0.3–2.0 THz) was determined for the studied ice samples, and this index was compared with available data found in the literature. Conclusions. The developed algorithm of reconstructing the real and imaginary parts of the refractive index from the time-domain THz data enables us, for the first time, to determine the optical properties of astrophysical ice analogues without using the Kramers–Kronig relations. The obtained data provide a benchmark to interpret the observational data from current ground-based facilities as well as future space telescope missions, and we used these data to estimate the opacities of the dust grains in presence of CO ice mantles.

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Floating zone growth and optical properties of nickel tantalum oxide single crystals

Materials Research Bulletin ◽

10.1016/0025-5408(94)90071-x ◽

1994 ◽

Vol 29 (4) ◽

pp. 385-391 ◽

Cited By ~ 2

Author(s):

Kazuto Ando ◽

Mikio Higuchi ◽

Junichi Takahashi ◽

Kohei Kodaira

Keyword(s):

Optical Properties ◽

Single Crystals ◽

Tantalum Oxide ◽

Floating Zone ◽

Zone Growth

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Study the Effect of Heat Treatment and Pressure on some the Optical Properties of the Pure PVA Nano Polymer

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.900.16 ◽

2021 ◽

Vol 900 ◽

pp. 16-25

Author(s):

Tabarak Mohammed Awad ◽

May A.S. Mohammed

Keyword(s):

Heat Treatment ◽

Dielectric Constant ◽

Refractive Index ◽

Optical Properties ◽

Absorption Coefficient ◽

Polyvinyl Alcohol ◽

Complex Dielectric Constant ◽

Different Temperatures ◽

German Origin ◽

Increasing Temperature

In this study, some optical properties were studied of the pure vinyl polyvinyl alcohol (PVA) nanopolymer (German origin). Under the influence of different temperatures and pressures of PVA. Where 25 samples were prepared for the purpose of conducting the research. Which studied the study of these samples was done by recording the absorbance and transmittance spectra of the wavelengths (200-900) nm. From them, absorbance, transmittance, reflectivity, absorption coefficient, refractive index, extinction coefficient, complex dielectric constant were calculated. At different temperatures (25,40, 80, 120, 160)°C. And with different pressures within the range (7.5,8,8.5,9,9.5) MPa. The results are that the permeability of the polymer (PVA) at different temperatures for each pressure decreases with increasing temperature, and that all other calculated optical properties increase with increasing temperature.

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THEORETICAL MODEL FOR THE CALCULATION OF OPTICAL PROPERTIES OF GOLD NANOPARTICLES

Journal of Nonlinear Optical Physics & Materials ◽

10.1142/s0218863510005297 ◽

2010 ◽

Vol 19 (03) ◽

pp. 427-436

Author(s):

A. MENDOZA-GARCÍA ◽

A. ROMERO-DEPABLOS ◽

M. A. ORTEGA ◽

J. L. PAZ ◽

L. ECHEVARRÍA

Keyword(s):

Gold Nanoparticles ◽

Refractive Index ◽

Optical Properties ◽

Theoretical Model ◽

Absorption Coefficient ◽

Molecular System ◽

Two Dimensional ◽

Box Models ◽

Solvent Environment ◽

Absorption And Dispersion

We have developed an analytical method to describe the optical properties of nanoparticles, whose results are in agreement with the observed experimental behavior according to the size of the nanoparticle under analysis. Our considerations to describe plasmonic absorption and dispersion are based on the combination of the two-level molecular system and the two-dimensional quantum box models. Employing the optical stochastic Bloch equations, we have determined the system's coherence, from which we have calculated expressions for the absorption coefficient and refractive index. The innovation of this methodology is that it allows us to take into account the solvent environment, which induce quantum effects not considered by classical treatments.

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Preparation and Studying the Optical Properties of (Sb2o3) Thin Films

Journal of University of Babylon for Pure and Applied Sciences ◽

10.29196/jubpas.v26i10.1881 ◽

2018 ◽

Vol 26 (10) ◽

pp. 249-256

Author(s):

Waleed Khalid Kadhim

Keyword(s):

Thin Films ◽

Dielectric Constant ◽

Refractive Index ◽

Optical Properties ◽

Absorption Coefficient ◽

Thermal Evaporation ◽

Glass Slide ◽

Antimony Trioxide ◽

Hot Plate ◽

Different Thickness

In this paper I present the preparation of (Sb2o3) thin films using thermal evaporation in vacuum, procedure with different thickness (100 ,150 ,200 ,and 250) nm, by using ( hot plate) from Molybdenum matter at temperature in ( 9000c) and the period of time (15mint) ,the prepared in a manner thermal evaporation in a vacuum and precipitated on glass bases, pure Antimony Trioxide (sb2o3 ) thin films with various condition have been successfully deposited by (T.E.V) on glass slide substrates. The substrates temperature of about 100oC and the vacuum of about 10-6 torr, to investigated oxidation of evaporated, measure spectra for prepared films in arrange of wavelength (250 – 1100 nm). The following optical properties have been calculated: the absorption coefficient, the forbidden (Eg) for direct and indirect transitions "absorbance, refractive index, extinction coefficient, real and imaginary parts" of the dielectric constant.

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Deposition Time induced Structural and Optical Properties of Lead Tin Sulphide Thin Films

Journal of the Nigerian Society of Physical Sciences ◽

10.46481/jnsps.2021.157 ◽

2021 ◽

pp. 455-458

Author(s):

J. Damisa ◽

J. O. Emegha ◽

I. L. Ikhioya

Keyword(s):

Thin Films ◽

Refractive Index ◽

Optical Properties ◽

Absorption Coefficient ◽

Tin Oxide ◽

Deposition Time ◽

Deposition Process ◽

Structural And Optical Properties ◽

X Ray ◽

Prepared Material

Lead tin sulphide (Pb-Sn-S) thin films (TFs) were deposited on fluorine-doped tin oxide (FTO) substrates via the electrochemical deposition process using lead (II) nitrate [Pb(NO3)2], tin (II) chloride dehydrate [SnCl2.2H2O] and thiacetamide [C2H5NS] precursors as sources of lead (Pb), tin (Sn) and sulphur (S). The solution of all the compounds was harmonized with a stirrer (magnetic) at 300k. In this study, we reported on the improvements in the properties (structural and optical) of Pb-Sn-S TFs by varying the deposition time. We observed from X-ray diffractometer (XRD) that the prepared material is polycrystalline in nature. UV-Vis measurements were done for the optical characterizations and the band gap values were seen to be increasing from 1.52 to 1.54 eV with deposition time. In addition to this, the absorption coefficient and refractive index were also estimated and discussed.

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Annealing Effect on Some Optical Properties of Cr2O3 Thin Films Prepared by Spray Pyrolysis Technique

Baghdad Science Journal ◽

10.21123/bsj.8.2.561-565 ◽

2011 ◽

Vol 8 (2) ◽

pp. 561-565

Author(s):

Baghdad Science Journal

Keyword(s):

Thin Films ◽

Dielectric Constant ◽

Refractive Index ◽

Optical Properties ◽

Absorption Coefficient ◽

Spray Pyrolysis ◽

Annealing Temperature ◽

Spray Pyrolysis Technique ◽

Annealing Effect ◽

Before And After

Cr2O3 thin films have been prepared by spray pyrolysis on a glass substrate. Absorbance and transmittance spectra were recorded in the wavelength range (300-900) nm before and after annealing. The effects of annealing temperature on absorption coefficient, refractive index, extinction coefficient, real and imaginary parts of dielectric constant and optical conductivity were expected. It was found that all these parameters increase as the annealing temperature increased to 550°C.

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Optical properties of CuSe thin films - band gap determination

Science of Sintering ◽

10.2298/sos1702167p ◽

2017 ◽

Vol 49 (2) ◽

pp. 167-174 ◽

Cited By ~ 5

Author(s):

Milica Petrovic ◽

Martina Gilic ◽

Jovana Cirkovic ◽

Maja Romcevic ◽

Nebojsa Romcevic ◽

...

Keyword(s):

Thin Films ◽

Optical Properties ◽

Band Gap ◽

Room Temperature ◽

Nir Spectroscopy ◽

Copper Selenide ◽

Photoluminescence Spectra ◽

Indirect Transition ◽

Direct Transition ◽

Scanning Electron

Copper selenide thin films of three different thicknesses have been prepared by vacuum evaporation method on a glass substrate at room temperature. The optical properties of the films were investigated by UV-VIS-NIR spectroscopy and photoluminescence spectroscopy. Surface morphology was investigated by field-emission scanning electron microscopy. Copper selenide exhibits both direct and indirect transitions. The band gap for direct transition is found to be ~2.7 eV and that for indirect transition it is ~1.70 eV. Photoluminescence spectra of copper selenide thin films have also been analyzed, which show emission peaks at 530, 550, and 760 nm. The latter corresponds to indirect transition in investigated material.

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Dielectric Nano-Systems with Unique Optical Properties

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.677.36 ◽

2013 ◽

Vol 677 ◽

pp. 36-41 ◽

Cited By ~ 1

Author(s):

Yurii N. Kulchin ◽

Vladimir P. Dzyuba ◽

Valentin A. Milichko

Keyword(s):

Refractive Index ◽

Optical Properties ◽

Absorption Coefficient ◽

Radiation Intensity ◽

Optical Nonlinearity ◽

Energy Structure ◽

Optical Fields ◽

Coefficient Increase ◽

Intensity Changes ◽

Theoretical Results

The study of optical properties of Al2O3, SiO2, TiO2, and ZnO nanoparticles in weak optical fields is presented. We found that some nanoparticles have unique optical nonlinearity: The values of portions to nanoparticle refractive index and absorption coefficient increase to maxima, and then decrease to zero when the radiation intensity changes from 1 to 500 W/cm2. We estimated electron energy structures of nanoparticles and experimentally determined that such nonlinearity is directly related to peculiarities of the energy structure. We obtained a good fitting of theoretical results to the experimental ones (e.g. absorbance spectra of nanoparticles; the dependence of nanoparticle refractive index and absorption coefficient on radiation intensity).

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