Raman analysis of the E1 and A1 quasi-longitudinal optical and quasi-transverse optical modes in wurtzite AlN

1999 ◽  
Vol 85 (7) ◽  
pp. 3535-3539 ◽  
Author(s):  
Leah Bergman ◽  
Mitra Dutta ◽  
Cengiz Balkas ◽  
Robert F. Davis ◽  
James A. Christman ◽  
...  
Keyword(s):  
Longitudinal Optical ◽  
Transverse Optical ◽  
Raman Analysis ◽  
Optical Modes

Longitudinal optical and transverse optical modes of (Ca, Sr) F2 films grown on Si(111)

1993 ◽  
Vol 223 (1) ◽  
pp. 143-145 ◽  
Author(s):  
W.Q. Zheng ◽  
T. López-Ríos ◽  
C. Fontaine ◽  
A. Munoz-Yague ◽  
C. Julien
Keyword(s):  
Longitudinal Optical ◽  
Transverse Optical ◽  
Optical Modes

Long-wavelength lattice vibrations of Ag3In5Se9 and Ag3In5Te9 single crystals — An inversion of LO- and TO-mode frequencies

2016 ◽  
Vol 30 (18) ◽  
pp. 1650229 ◽  
Author(s):  
Nizami Mamed Gasanly
Keyword(s):  
Refractive Index ◽  
Single Crystals ◽  
Longitudinal Optical ◽  
Absorption Index ◽  
Energy Losses ◽  
Optical Parameters ◽  
Lattice Vibrations ◽  
Frequency Range ◽  
Long Wavelength ◽  
Optical Modes

Infrared (IR) reflectivities are registered in the frequency range of 50–2000 cm[Formula: see text] for Ag3In5Se9 and Ag3In5Te9 single crystals grown by Bridgman method. Three infrared-active modes are detected in spectra. The optical parameters, real and imaginary parts of the dielectric function, the function of energy losses, refractive index, absorption index and absorption coefficient were calculated from reflectivity experiments. The frequencies of transverse and longitudinal optical modes (TO and LO modes) and oscillator strength were also determined. The bands detected in infrared spectra were tentatively attributed to various vibration types (valence and valence-deformation). The inversion of LO- and TO-mode frequencies of the sandwiched pair was observed for studied crystals.

Spin-phonon relaxation due to transverse optical modes

Physica ◽  
1967 ◽  
Vol 34 (3) ◽  
pp. 387-397 ◽  
Author(s):  
N. Kumar ◽  
K.P. Sinha
Keyword(s):  
Transverse Optical ◽  
Optical Modes

Transverse Optical Modes of a RF Excited Ar-Xe Laser: Experiment and Theory

2005 ◽  
Author(s):  
N.N. Elkin ◽  
I.V. Kochetov ◽  
A.P. Napartovich ◽  
V.N. Troshchieva ◽  
F.J. Blok ◽  
...  
Keyword(s):  
Transverse Optical ◽  
Optical Modes ◽  
Laser Experiment

scholarly journals On the dynamics of polarons in the strong-coupling limit

2017 ◽  
Vol 29 (10) ◽  
pp. 1750030 ◽  
Author(s):  
Marcel Griesemer
Keyword(s):  
Strong Coupling ◽  
Longitudinal Optical ◽  
Strong Coupling Limit ◽  
Poisson System ◽  
Phonon Modes ◽  
Polar Crystal ◽  
Effective Dynamics ◽  
Optical Modes ◽  
Non Local ◽  
With Memory

The polaron model of H. Fröhlich describes an electron coupled to the quantized longitudinal optical modes of a polar crystal. In the strong-coupling limit, one expects that the phonon modes may be treated classically, which leads to a coupled Schrödinger–Poisson system with memory. For the effective dynamics of the electron, this amounts to a nonlinear and non-local Schrödinger equation. We use the Dirac–Frenkel variational principle to derive the Schrödinger–Poisson system from the Fröhlich model and we present new results on the accuracy of their solutions for describing the motion of Fröhlich polarons in the strong-coupling limit. Our main result extends to [Formula: see text]-polaron systems.

scholarly journals Structural and optical study of alternating layers of In and GaAs prepared by magnetron sputtering

2019 ◽  
Vol 24 (3) ◽  
pp. 523-542 ◽  
Author(s):  
Santiago Torres-Jaramillo ◽  
Camilo Pulzara-Mora ◽  
Roberto Bernal-Correa ◽  
Miguel Venegas de la Cerda ◽  
Salvador Gallardo-Hernández ◽  
...  
Keyword(s):  
Magnetron Sputtering ◽  
Low Cost ◽  
Longitudinal Mode ◽  
Longitudinal Optical ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mode Behavior ◽  
Optical Modes ◽  
High Concentrations ◽  
Secondary Ion

Currently, the obtention of nano-structures based on III-V materials is expensive. This calls for novel and inexpensive nanostructure manufacturing approaches. In this work we report on the manufacture of a nanostructures consisting of alternating layers of In and GaAs on a silicon substrate by magnetron sputtering. Furthermore, we characterized the produced nanostructures using secondary ion mass spectroscopy (SIMS), X-ray diffraction analysis, and Raman spectroscopy. SIMS revealed variation in the concentration of In atoms across In/GaAs/In interphases, and X-ray diffraction revealed planes corresponding to phases associated with GaAs and InAs due to In interfacial diffusion across GaAs layers. Finally, in order to study the composition and crystalquality of the manufactured nanostaructures, Raman spectra were taken using laser excitation lines of 452 nm, 532 nm, and 562 nm at different points across the nanostructures.This allowed to determine the transverse and longitudinal optical modes of GaAs and InAs,characteristic of a two-mode behavior. An acoustic longitudinal vibrational mode LA(Γ) of GaAs and an acoustic longitudinal mode activated by disorder (DALA) were observed. These resulted from the substitution of Ga atoms for In atoms in high concentrations due to the generation of Ga(VGa) and/or Arsenic(VAs) vacancies.This set of analyses show that magnetron sputtering can be aviable and relatively low-cost technique to obtain this type of semiconductors.

Crystallographic Structure of 8H- and 10H-SiC Analyzed by Raman Spectroscopy and Diffraction Methods

2014 ◽  
Vol 778-780 ◽  
pp. 479-482
Author(s):  
Tomoaki Hatayama ◽  
Ryota Hori ◽  
Hiroshi Yano ◽  
Takashi Fuyuki
Keyword(s):  
Raman Spectroscopy ◽  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Transverse Optical ◽  
Crystallographic Structure ◽  
Laue Diffraction ◽  
Transmission Electron ◽  
Optical Modes ◽  
Crystallographic Structures

Crystallographic structures of 8H-and 10H-SiC crystals were analyzed by the Raman spectroscopy and diffraction methods. Two and four transverse-optical modes for 8H-and 10H-SiC were observed, and their values were different from those of 4H-and 6H-SiC. Crystallinity for the wide and narrow areas of these crystals was analyzed by the Laue diffraction and the transmission electron microscope, respectively. Based on these results, the stacking sequences of these polytype were discussed.

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