Parameters of Fundamental Optical Functions and Elementary Transition Bands for Mg2X Compounds (X = Si, Ge, Sn)

2021 ◽  
Author(s):  
V. Val. Sobolev ◽  
A. I. Kalugin ◽  
E. A. Antonov
Keyword(s):  
Optical Functions ◽  
Elementary Transition

The physical properties of ThCr2Si2-type superconductors MPd2P2 (M = Y, La): A theoretical investigation

2018 ◽  
Vol 32 (28) ◽  
pp. 1850312
Author(s):  
Md. Lokman Ali ◽  
Md. Tosaddek Hossen ◽  
Shahin Alam ◽  
Md. Sadek Hossain ◽  
Jakiul Islam ◽  
...  
Keyword(s):  
Experimental Data ◽  
Elastic Constants ◽  
Structural Data ◽  
Computer Code ◽  
Generalized Gradient ◽  
Generalized Gradient Approximation ◽  
Anisotropic Factor ◽  
Optical Functions ◽  
Debye Temperatures ◽  
Ductile Behavior

The structural stability, elastic, mechanical, optical characteristics and Debye temperature of single crystalline superconductors MPd2P2 (M = Y, La) were investigated by using the ab initio technique. We have carried out the plane wave pseudopotential within the generalized gradient approximation (GGA) implemented in the CASTEP computer code. Our investigated results of structural data are in well consistent with the previous experimental data. The bulk modulus B, shear modulus G, Young’s modulus E, Poisson’s ratio v, hardness H, and anisotropic factor A of MPd2P2 (M = Y, La) compounds were evaluated from the calculated elastic constants. The analysis of ratio B/G shows that the MPd2P2 superconductors are in ductile behavior. The Debye temperatures are also investigated from the elastic constants. Finally, the optical functions including reflectivity, absorption coefficient, loss function, conductivity, refractive index, dielectric function are calculated and analyzed.

Optical Data of Rough-Surfaced Ceramics: Infrared Specular and Diffuse Reflectance versus Spectra Simulation

1993 ◽  
Vol 47 (4) ◽  
pp. 423-429 ◽  
Author(s):  
V. Hopfe ◽  
E. H. Korte ◽  
P. Klobes ◽  
W. Grählert
Keyword(s):  
Phase Shift ◽  
Smooth Surface ◽  
Diffuse Reflectance ◽  
Optical Data ◽  
Evaluation Procedure ◽  
Alumina Ceramics ◽  
Specular Reflectance ◽  
Optical Functions ◽  
Infrared Reflection ◽  
Simple Evaluation

Infrared reflection of strongly absorbing as well as scattering samples was studied. The optical functions of sintered alumina ceramics were derived with the use of the Kramers-Kronig transformation to reconstruct the phase shift under the assumption of a semi-infinite sample with an ideal plane and, in any scale, a smooth surface. In order to validate this procedure and to optimize measuring parameters, the results were compared to their simulated counterparts. Starting from the dielectric functions of monocrystalline Al2O3, the optical response of the sample was calculated by taking into account the polycrystallinity of the bulk and the roughness of the surface; eventually the spectra of specular reflectance were simulated on this basis for different angles of incidence. It turned out that the comparably simple evaluation procedure is well suited in spite of the rough surface and is particularly reliable in the case of large angles of incidence whereby scattering is minimized. Some characteristics of this diffusely reflected component are discussed.

Optical properties of Quantum Disks: Real density matrix approach

Open Physics ◽  
2006 ◽  
Vol 4 (2) ◽  
Author(s):  
Gerard Czajkowski ◽  
Leonardo Silvestri
Keyword(s):  
Density Matrix ◽  
Guided Wave ◽  
Matrix Approach ◽  
Electron Hole ◽  
Optical Functions ◽  
Quantum Disk ◽  
All Optical ◽  
Quantum Disks ◽  
Analytical Expressions ◽  
Real Density

AbstractWe show how to compute the optical response of a Quantum Disk (QDisk) to an electromagnetic wave as a function of the incident wave polarization, in the energetic region of interband transitions. Both the TM and TE polarization in guided-wave geometry are analyzed. The method uses the microscopic calculation of Quantum Disk eigenfunctions and the macroscopic real density matrix approach to compute the effective QDisk susceptibility, taking into account the valence band structure of the QDisk material and the Coulomb interaction between the electron and the hole. Analytical expressions for the QDisk susceptibility are obtained for a certain model electron — hole potential. Using these expressions, all optical functions can be computed. Results for the absorption coefficient are computed for InAs/GaAs QDisks. Fair agreement with experiments is obtained.

The set of optical functions, transition parameters, and electronic structure of the ZnSiAs2 crystal

1996 ◽  
Vol 63 (5) ◽  
pp. 669-674
Author(s):  
S. P. Batanov ◽  
V. E. Grachev ◽  
V. V. Sobolev
Keyword(s):  
Electronic Structure ◽  
Optical Functions

Electronic and optical properties of zinc-blende GeC by first principles study

2015 ◽  
Vol 29 (20) ◽  
pp. 1550103
Author(s):  
Jinhui Zhai ◽  
Jinguang Zhai ◽  
Ajun Wan
Keyword(s):  
Optical Properties ◽  
First Principles ◽  
Density Functional ◽  
Dielectric Constants ◽  
Electronic And Optical Properties ◽  
Optical Functions ◽  
Zinc Blende ◽  
The Density Functional Theory ◽  
Valence Bands ◽  
Energy Dependent

The electronic and optical properties of zinc-blende (zb)[Formula: see text]GeC have been investigated using first principles calculations based on the density functional theory (DFT). The obtained band gap of zb–GeC is 2.30[Formula: see text]eV by means of Heyd–Scuseria–Ernzerhof (HSE) functional. We have discussed the energy-dependent optical functions including dielectric constants, refractive index, absorption, reflectivity, and energy-loss spectrum in detail. The results reveal that zb–GeC has a higher static dielectric constant compared with that of zb–SiC. The optical functions are mainly associated with the interband transitions from the occupied valence bands (VBs) Ge[Formula: see text][Formula: see text] and C[Formula: see text][Formula: see text] states to Ge[Formula: see text][Formula: see text], [Formula: see text] and C[Formula: see text][Formula: see text] states of the unoccupied conduction bands (CBs).

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