scholarly journals Электронные и спектральные свойства интерметаллических соединений RRhSn (R=Gd, Tb)

2018 ◽  
Vol 60 (2) ◽  
pp. 222
Author(s):  
Ю.В. Князев ◽  
А.В. Лукоянов ◽  
Ю.И. Кузьмин ◽  
S. Gupta ◽  
K.G. Suresh
Keyword(s):  
Earth Metal ◽  
Band Spectrum ◽  
Correlation Effects ◽  
Interband Transitions ◽  
Local Electron ◽  
Satisfactory Explanation ◽  
Optical Studies ◽  
Local Electron Density ◽  
Density Of Electronic States ◽  
Wide Range

AbstractThe investigations of electronic structure and optical properties of GdRhSn and TbRhSn were carried out. The calculations of band spectrum, taking into account the spin polarization, were performed in a local electron density approximation with a correction for strong correlation effects in 4f shell of rare earth metal (LSDA + U method). The optical studies were done by ellipsometry in a wide range of wavelengths, and the set of spectral and electronic characteristics was determined. It was shown that optical absorption in a region of interband transitions has a satisfactory explanation within a scope of calculations of density of electronic states carried out.

scholarly journals Электронная структура соединения DyFe-=SUB=-2-=/SUB=-Si-=SUB=-2-=/SUB=-: зонный расчет и оптические исследования

2020 ◽  
Vol 62 (3) ◽  
pp. 364
Author(s):  
Ю.В. Князев ◽  
А.В. Лукоянов ◽  
Ю.И. Кузьмин
Keyword(s):  
Optical Properties ◽  
Electron Correlation ◽  
Earth Metal ◽  
Density Approximation ◽  
Correlation Effects ◽  
Interband Transitions ◽  
Local Electron ◽  
Strong Electron ◽  
Local Electron Density ◽  
Electron Correlation Effects

Investigations of electronic structure and optical properties of DyFe2Si2 compound have been carried out. Calculations of the band structure were made with employing local electron density approximation with correction for strong electron correlation effects in the 4f-shells of rare earth metal (GGA+U method). Optical properties were studied by ellipsometric technique in wide wavelength interval. A number of spectral and electronic characteristics were determined. It is shown that the optical conductivity of the compound in interband transitions range is interpreted satisfactorily by means of the density of states calculations.

scholarly journals Towards an accurate description of perovskite ferroelectrics: exchange and correlation effects

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Simuck F. Yuk ◽  
Krishna Chaitanya Pitike ◽  
Serge M. Nakhmanson ◽  
Markus Eisenbach ◽  
Ying Wai Li ◽  
...  
Keyword(s):  
Density Functional ◽  
General Purpose ◽  
Correlation Effects ◽  
Lattice Constants ◽  
Bulk Solids ◽  
Wide Range ◽  
Exchange Enhancement ◽  
Experimental Values ◽  
Similar Accuracy ◽  
Ferroelectric Oxides

Abstract Using the van der Waals density functional with C09 exchange (vdW-DF-C09), which has been applied to describing a wide range of dispersion-bound systems, we explore the physical properties of prototypical ABO 3 bulk ferroelectric oxides. Surprisingly, vdW-DF-C09 provides a superior description of experimental values for lattice constants, polarization and bulk moduli, exhibiting similar accuracy to the modified Perdew-Burke-Erzenhoff functional which was designed specifically for bulk solids (PBEsol). The relative performance of vdW-DF-C09 is strongly linked to the form of the exchange enhancement factor which, like PBEsol, tends to behave like the gradient expansion approximation for small reduced gradients. These results suggest the general-purpose nature of the class of vdW-DF functionals, with particular consequences for predicting material functionality across dense and sparse matter regimes.

Multilayer Heterostructures with Embedded CrSi2 and β-FeSi2 Nanocrystals on Si(111) Substrate: From the Formation to Photoelectric Properties

2020 ◽  
Vol 312 ◽  
pp. 45-53
Author(s):  
Nikolay G. Galkin ◽  
Konstantin Nickolaevich Galkin ◽  
Evgeniy Y. Subbotin ◽  
Evgeniy Anatoljevich Chusovotin ◽  
Dmitrii L. Goroshko
Keyword(s):  
Contact Potential Difference ◽  
Reflection Spectra ◽  
Interband Transitions ◽  
Optical Identification ◽  
Optical Studies ◽  
Contact Potential ◽  
Photoelectric Properties ◽  
Multilayer Heterostructures ◽  
First Time

The studies are devoted to the development of the technology of multilayer incorporation of nanocrystals (NCs) of semiconductor chromium and iron disilicides with a layer density no less than 2x1010 cm-2, the establishment of the growth mechanism of heterostructures with two types of NCs, the determination of their crystalline quality and optical properties, as well as the creation and study of rectification and photoelectric properties of p-i-n diodes based on them. Morphologically smooth heterostructures with 6 embedded layers of CrSi2 nanocrystals and two types of embedded nanocrystals (with 4 layers of CrSi2 NCs and 2 layers of β-FeSi2 NCs) for optical studies and built-in silicon p-i-n diodes were grown for the first time. The possibility of optical identification of interband transitions in embedded nanocrystals in the photon energy range of 1.2 - 2.5 eV was determined from the reflection spectra and the strongest peaks in reflection from the integrated nanocrystals were determined: 2.0 eV for CrSi2 NCs and 1.75 eV for β-FeSi2 NCs. The created p-i-n diodes have a contact potential difference of 0.95 V, regardless of the type of embedded NCs. At 80 K, an absorption band (0.7 - 1.1 eV) was detected in the diodes, which was associated with carrier photo generation in the embedded CrSi2 and β-FeSi2 NCs. From the spectra of the photoresponse at 80 K, the band gap widths in the NCs were determined: 0.50 eV in CrSi2 and 0.70 eV in the superposition of the CrSi2 and β-FeSi2 NCs.

scholarly journals The Volume Filling Factor of the WIM

1997 ◽  
Vol 166 ◽  
pp. 301-304
Author(s):  
Elly M. Berkhuijsen
Keyword(s):  
Electron Density ◽  
Filling Factor ◽  
Local Electron ◽  
Volume Filling ◽  
Local Electron Density ◽  
Warm Ionized Medium

AbstractA compilation of data on the volume filling factor fv of the warm ionized medium (WIM) as a function of the local electron density ne indicates that approximately fv ∝ n−1e over 4 decades. This result is expected for a fractal ISM.

Visible-Light-Driven Multichannel Regulation of Local Electron Density to Accelerate Activation of O–H and B–H Bonds for Ammonia Borane Hydrolysis

ACS Catalysis ◽  
2020 ◽  
Vol 10 (24) ◽  
pp. 14903-14915
Author(s):  
Shengbo Zhang ◽  
Mei Li ◽  
Lisheng Li ◽  
Fabrice Dushimimana ◽  
Jiankang Zhao ◽  
...  
Keyword(s):  
Visible Light ◽  
Electron Density ◽  
Ammonia Borane ◽  
Local Electron ◽  
Local Electron Density ◽  
Visible Light Driven
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