Azimuthal angle dependent dielectric function of SnS by ellipsometry

Three-fold astigmatism resembles regular astigmatism, but it has 3-fold rather than 2-fold symmetry. Its contribution to the aberration function χ(q) can be written as:where A3 is the coefficient of 3-fold astigmatism, λ is the electron wavelength, q is the spatial frequency, ϕ the azimuthal angle (ϕ = tan-1 (qy/qx)), and ϕ3 the direction of the astigmatism.Three-fold astigmatism is responsible for the “star of Mercedes” aberration figure that one obtains from intermediate lenses once their two-fold astigmatism has been corrected. Its effects have been observed when the beam is tilted in a hollow cone over a wide range of angles, and there is evidence for it in high resolution images of a small probe obtained in a field emission gun TEM/STEM instrument. It was also expected to be a major aberration in sextupole-based Cs correctors, and ways were being developed for dealing with it on Cs-corrected STEMs.

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Optical properties of the Vanadium dioxide

JOURNAL OF ADVANCES IN PHYSICS ◽

10.24297/jap.v8i2.1520 ◽

2015 ◽

Vol 8 (2) ◽

pp. 2148-2155 ◽

Cited By ~ 1

Author(s):

Abderrahim Benchaib ◽

Abdesselam Mdaa ◽

Izeddine Zorkani ◽

Anouar Jorio

Keyword(s):

Energy Efficiency ◽

Optical Properties ◽

Critical Temperature ◽

Thin Layer ◽

Dielectric Function ◽

Vanadium Dioxide ◽

Ultra Violet ◽

Index Of Refraction ◽

Practical Utility ◽

Infra Red

The vanadium dioxide is a material thermo chromium which sees its optical properties changing at the time of theÂ transition from the phase of semiconductor state â†” metal, at a critical temperature of 68Â°C. The study of the opticalÂ properties of a thin layer of VOâ‚‚ thickness 82 nm, such as the dielectric function, the index of refraction, the coefficient ofextinction, the absorptionâ€™s coefficient, the reflectivity, the transmittivity, in the photonic spectrum of energy Ï‰ located inthe interval: 0.001242 â‰¤ Ï‰ (ev) â‰¤ 6, enables us to control well its practical utility in various applications, like the intelligentpanes, the photovoltaic, paintings for increasing energy efficiency in buildings, detectors of infra-red (I.R) or ultra-violet(U.V). We will make simulations with Maple and compare our results with those of the literature

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From Semiconductor to Metal in a Flash: Observing Ultrafast Laser-Induced Phase Transformations

MRS Proceedings ◽

10.1557/proc-481-395 ◽

1997 ◽

Vol 481 ◽

Cited By ~ 3

Author(s):

J. P. Callan ◽

A. M.-T. Kim ◽

L. Huangt ◽

E. N. Glezer ◽

E. Mazur

Keyword(s):

Phase Transformations ◽

Dielectric Function ◽

Spectral Range ◽

Laser Excitation ◽

Spectroscopic Technique ◽

Ultrafast Laser ◽

Lattice Heating ◽

Fs Laser

ABSTRACTWe use a new broadband spectroscopic technique to measure ultrafast changes in the dielectric function of a material over the spectral range 1.5–3.5 eV following intense 70-fs laser excitation. The results reveal the nature of the phase transformations which occur in the material following excitation. We studied the response of GaAs and Si. For GaAs, there are three distinct regimes of behavior as the pump fluence is increased — lattice heating, lattice disordering, and a semiconductor-to-metal transition.

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Interlayer dielectric function of a type-II van der Waals semiconductor: The HfS2/PtS2 heterobilayer

Physical Review Materials ◽

10.1103/physrevmaterials.3.124002 ◽

2019 ◽

Vol 3 (12) ◽

Author(s):

Stefana Anais Colibaba ◽

Sabine Körbel ◽

Carlo Motta ◽

Fedwa El-Mellouhi ◽

Stefano Sanvito

Keyword(s):

Dielectric Function ◽

Van Der Waals ◽

Type Ii ◽

Interlayer Dielectric

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The Lindhard dielectric function

Essential Electron Transport for Device Physics ◽

10.1063/9780735421608_app7 ◽

2020 ◽

pp. 1-12

Author(s):

A. F. J. Levi

Keyword(s):

Dielectric Function

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Diffuse Sound Absorptive Properties of Parallel-Arranged Perforated Plates with Extended Tubes and Porous Materials

Materials ◽

10.3390/ma13051091 ◽

2020 ◽

Vol 13 (5) ◽

pp. 1091 ◽

Cited By ~ 1

Author(s):

Dengke Li ◽

Daoqing Chang ◽

Bilong Liu

Keyword(s):

Boundary Condition ◽

Porous Material ◽

Porous Materials ◽

Sound Absorption ◽

Azimuthal Angle ◽

Octave Band ◽

Frequency Range ◽

Absorption Coefficients ◽

Perforated Plates ◽

Absorption Performance

The diffuse sound absorption was investigated theoretically and experimentally for a periodically arranged sound absorber composed of perforated plates with extended tubes (PPETs) and porous materials. The calculation formulae related to the boundary condition are derived for the periodic absorbers, and then the equations are solved numerically. The influences of the incidence and azimuthal angle, and the period of absorber arrangement are investigated on the sound absorption. The sound-absorption coefficients are tested in a standard reverberation room for a periodic absorber composed of units of three parallel-arranged PPETs and porous material. The measured 1/3-octave band sound-absorption coefficients agree well with the theoretical prediction. Both theoretical and measured results suggest that the periodic PPET absorbers have good sound-absorption performance in the low- to mid-frequency range in diffuse field.

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