scholarly journals Особенности спектров оптического поглощения интерметаллических соединений GdFe-=SUB=-2-=/SUB=- и LuFe-=SUB=-2-=/SUB=-

2019 ◽  
Vol 126 (4) ◽  
pp. 432
Author(s):  
Ю.В. Князев ◽  
Ю.И. Кузьмин
Keyword(s):  
Optical Properties ◽  
Spectral Range ◽  
Optical Conductivity ◽  
Electronic States ◽  
Light Quantum ◽  
Absorption Region ◽  
Ellipsometric Method

AbstractThe optical properties of binary GdFe_2 and LuFe_2 compounds are studied by the ellipsometric method in the 0.22–17 μm spectral range. A number of spectral and electronic characteristics are determined. The experimental dependences of optical conductivity in the light quantum absorption region are interpreted based on previously published calculations of electronic states densities.

POLARIZATION PROPERTIES OF SYNCHROTRON RADIATION IN THE STUDY OF ANISOTROPIC INSULATING CRYSTALS

2002 ◽  
Vol 09 (01) ◽  
pp. 469-472
Author(s):  
V. N. KOLOBANOV ◽  
I. A. KAMENSKIKH ◽  
V. V. MIKHAILIN ◽  
I. N. SHPINKOV ◽  
D. A. SPASSKY ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Optical Properties ◽  
Energy Transfer ◽  
Synchrotron Radiation ◽  
Valence Band ◽  
Conduction Band ◽  
Electronic States ◽  
Absorption Region ◽  
New Information ◽  
Fundamental Absorption Region

The optical properties of a wide series of the tungstates with the scheelite and wolframite crystal structure at the threshold of the fundamental absorption region were studied. New information about the influence of the electronic states forming the bottom of the conduction band and the top of the valence band on the formation of emission centers and mechanisms of energy transfer to these centers was obtained.

scholarly journals Оптические свойства соединений YFe-=SUB=-2-=/SUB=- и TbFe-=SUB=-2-=/SUB=-

2020 ◽  
Vol 62 (7) ◽  
pp. 1004
Author(s):  
Ю.В. Князев ◽  
Ю.И. Кузьмин
Keyword(s):  
Optical Properties ◽  
Spectral Characteristic ◽  
Wavelength Range ◽  
Optical Conductivity ◽  
Light Absorption ◽  
Electronic States ◽  
Electron Transitions ◽  
Quantum Electron ◽  
Interband Light Absorption ◽  
Conductivity Spectra

Ellipsometric investigation of the optical properties of YFe2 and TbFe2 intermetalic compounds have been carried out in wavelength range of 0.22 –15 μm. A number of electronic and spectral characteristic was determined. Nature of interband light absorption in these materials is discussed on base of comparative analyses of experimental and theoretical optical conductivity spectra. Experimental optical conductivities of the compounds are shown to conform qualitatively to spectra calculated from densities of electronic states in the region of quantum electron transitions.

scholarly journals Электронная структура и оптические спектры соединений GdFeAl и GdFeSi

2021 ◽  
Vol 63 (6) ◽  
pp. 700
Author(s):  
Ю.В. Князев ◽  
А.В. Лукоянов ◽  
Ю.И. Кузьмин ◽  
А.Г. Кучин ◽  
С.П. Платонов
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
Comparative Analysis ◽  
Optical Conductivity ◽  
Electronic States ◽  
Wavelength Interval ◽  
Correlation Effects ◽  
Calculated Density ◽  
Density Of Electronic States ◽  
Conductivity Spectra

Results of investigations of electronic structure and optical properties of GdFeAl and GdFeSi compounds are presented. Spin-plarized density of states and interband optical conductivity spectra were calculated in frame of DFT+U technique with a correction for strong correlation effects in 4f shell of Gd. Optical properties were measured by ellipsometric technique in wavelength interval of 0.22 – 16 μm. Nature of quantum light absorption is discussed on the base of comparative analysis of experimental and calculated spectra. It is shown that main features of frequency dependencies of the optical conductivity are interpret qualitatively by the calculated density of electronic states.

scholarly journals Электронная структура и оптические свойства соединения FeAl-=SUB=-2-=/SUB=-

2020 ◽  
Vol 62 (1) ◽  
pp. 85
Author(s):  
Ю.В. Князев ◽  
А.В. Лукоянов ◽  
Ю.И. Кузьмин
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
Intermetallic Compound ◽  
Optical Conductivity ◽  
Magnetic Moments ◽  
Electronic States ◽  
Spectral Interval ◽  
Calculated Density ◽  
Density Of Electronic States ◽  
Spin Polarized

Electronic structure and optical properties of the FeAl2 intermetallic compound are investigated. Spin-polarized calculations of the electronic structure were carried out, magnetic moments of the atoms were determined. Optical properties of the compound were measured by ellipsometric technique in spectral interval 0.22 – 15 μm. It is shown that the experimental optical conductivity is satisfactory interpreted on the base of the calculated density of electronic states.

scholarly journals Valence Band Mixing in GaAs/AlGaAs Quantum Wells Adjacent to Self-Assembled InAlAs Antidots

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Takuya Kawazu
Keyword(s):  
Optical Properties ◽  
Quantum Wells ◽  
Valence Band ◽  
Energy Barrier ◽  
Heavy Hole ◽  
Electronic States ◽  
Light Hole ◽  
Photoluminescence Excitation ◽  
Band Mixing ◽  
Valence Band Mixing

Optical properties of GaAs/AlGaAs quantum wells (QWs) in the vicinity of InAlAs quantum dots (QDs) were studied and compared with a theoretical model to clarify how the QD strain affects the electronic states in the nearby QW. In0.4Al0.6As QDs are embedded at the top of the QWs; the QD layer acts as a source of strain as well as an energy barrier. Photoluminescence excitation (PLE) measurements showed that the QD formation leads to the increase in the ratio Ie-lh/Ie-hh of the PLE intensities for the light hole (lh) and the heavy hole (hh), indicating the presence of the valence band mixing. We also theoretically calculated the hh-lh mixing in the QW due to the nearby QD strain and evaluated the PLE ratio Ie-lh/Ie-hh.

Optical properties of selected native and coagulated human brain tissues in vitro in the visible and near infrared spectral range

2002 ◽  
Vol 47 (12) ◽  
pp. 2059-2073 ◽  
Author(s):  
A N Yaroslavsky ◽  
P C Schulze ◽  
I V Yaroslavsky ◽  
R Schober ◽  
F Ulrich ◽  
...  
Keyword(s):  
Optical Properties ◽  
Human Brain ◽  
Spectral Range ◽  
Near Infrared ◽  
Infrared Spectral Range ◽  
Infrared Spectral ◽  
Brain Tissues

scholarly journals Aerosol direct radiative forcing during Sahara dust intrusions in the Central Mediterranean

2010 ◽  
Vol 10 (8) ◽  
pp. 20673-20727
Author(s):  
M. R. Perrone ◽  
A. Bergamo ◽  
V. Bellantone
Keyword(s):  
Optical Properties ◽  
Radiative Transfer ◽  
Spectral Range ◽  
Mediterranean Basin ◽  
Transfer Model ◽  
Clear Sky ◽  
Fine Mode ◽  
The Mediterranean ◽  
The Mediterranean Basin ◽  
Sahara Dust

Abstract. The clear-sky, instantaneous Direct Radiative Effect (DRE) by all and anthropogenic particles is calculated during Sahara dust intrusions in the Mediterranean basin, to evaluate the role of anthropogenic particle's radiative effects and to obtain a better estimate of the DRE by desert dust. The clear-sky aerosol DRE is calculated by a two stream radiative transfer model in the solar (0.3–4 μm) and infrared (4–200 μm) spectral range, at the top of the atmosphere (ToA) and at the Earth's surface (sfc). Aerosol optical properties by AERONET sun-sky photometer measurements and aerosol vertical profiles by EARLINET lidar measurements, both performed at Lecce (40.33° N, 18.10° E) during Sahara dust intrusions occurred from 2003 to 2006 year, are used to perform radiative transfer simulations. Instantaneous values at 0.44 μm of the real (n) and imaginary (k) refractive index and of the of aerosol optical depth (AOD) vary within the 1.33–1.55, 0.0037–0.014, and 0.2–0.7 range, respectively during the analyzed dust outbreaks. Fine mode particles contribute from 34% to 85% to the AOD by all particles. The complex atmospheric chemistry of the Mediterranean basin that is also influenced by regional and long-range transported emissions from continental Europe and the dependence of dust optical properties on soil properties of source regions and transport pathways, are responsible for the high variability of n, k, and AOD values and of the fine mode particle contribution. Instantaneous all-wave (solar+infrared) DREs that are negative as a consequence of the cooling effect by aerosol particles, span the – (32–10) Wm−2 and the – (44–20) Wm−2 range at the ToA and surface, respectively. The instantaneous all-wave DRE by anthropogenic particles that is negative, varies within – (13–7) Wm−2 and – (18–11) Wm−2 at the ToA and surface, respectively. It represents from 41% up to 89% and from 32% up to 67% of the all-wave DRE by all particles at the ToA and surface, respectively during the analysed dust outbreaks. A linear relationship to calculate the DRE by natural particles in the solar and infrared spectral range is provided.

scholarly journals Influence of Fe2O3 Dopant on Dielectric, Optical Conductivity and Nonlinear Optical Properties of Doped ZnO-Polystyrene Composites Films

2021 ◽  
Vol 12 (1) ◽  
pp. 170-179
Keyword(s):  
Optical Properties ◽  
Optical Conductivity ◽  
Electron Mobility ◽  
Relative Permittivity ◽  
Nonlinear Optical ◽  
The Other ◽  
Filler Concentration ◽  
Casting Method ◽  
Polystyrene Nanoparticles ◽  
Doped Zno

ZnO-Polystyrene nanoparticles doped with Fe2O3 were prepared by the casting method. Both Ed and Eo were calculated. εL and N/m* increase with filler concentrations for these samples. On the other hand, both M-1, M-3, decreased with increasing filler. The filler concentrations affected on determined values of both of ε\ and ε\\. These values increase with filler, and also the same result was achieved for both σ1 and σ2, which also increases with filler. The relation between VELF and SELF was determined. χ(1) increases with increasing filler ratio. n2, χ(3), βc, were determined theoretically. The electrical susceptibility χe and relative permittivity εr increase with the increase of filler concentration as a result of increasing electron mobility.

AB INITIO CALCULATIONS OF THE MAGNETO-OPTICAL RESPONSE OF LAYERED SYSTEMS

2002 ◽  
Vol 09 (02) ◽  
pp. 1135-1142
Author(s):  
HUBERT EBERT ◽  
ALEXANDER PERLOV ◽  
TILMANN HUHNE
Keyword(s):  
Optical Properties ◽  
Band Structure ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Optical Conductivity ◽  
Atomic Layer ◽  
Magnetic Multilayer ◽  
Layered Systems ◽  
Layer System ◽  
Multilayer Systems

The concept of the layer-resolved optical conductivity [Formula: see text] applied by means of a conventional band structure method is introduced. It is demonstrated that it allows a detailed discussion of the magneto-optical properties of magnetic multilayer systems. In particular it is found that the layer-projected optical conductivity [Formula: see text] of an atomic layer is influenced by only very few neighboring layers. This property can be exploited within the Baukasten principle, which aims to predict the magneto-optical properties of a complex layer system from the properties calculated for a closely related but simpler one.

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