Long-wavelength optical phonons and mode behavior of Pb1−xSrxSe thin films

2003 ◽  
Vol 93 (11) ◽  
pp. 9053-9057 ◽  
Author(s):  
J. Chen ◽  
W. Z. Shen
Keyword(s):  
Thin Films ◽  
Optical Phonons ◽  
Long Wavelength ◽  
Mode Behavior

Long‐wavelength infrared characteristics of multifunctional microfibrous thin films of Parylene C

2019 ◽  
Vol 61 (9) ◽  
pp. 2206-2209
Author(s):  
C. Chandraprakash ◽  
Vijayakumar C. Venugopal ◽  
Akhlesh Lakhtakia ◽  
Osama O. Awadelkarim
Keyword(s):  
Thin Films ◽  
Parylene C ◽  
Long Wavelength ◽  
Long Wavelength Infrared

Long wavelength optical phonons in mixed crystals

1971 ◽  
Vol 20 (85) ◽  
pp. 359-404 ◽  
Author(s):  
I.F. Chang ◽  
S.S. Mitra
Keyword(s):  
Mixed Crystals ◽  
Optical Phonons ◽  
Long Wavelength

THE REFLECTIVITY OF THE MIXED CRYSTAL AB1-xCx

2010 ◽  
Vol 24 (27) ◽  
pp. 5337-5343
Author(s):  
XIAOYAN ZHANG ◽  
JINGFENG WANG ◽  
GUOLIANG FAN
Keyword(s):  
Mixed Crystal ◽  
Random Element ◽  
Mixed Crystals ◽  
Phonon Interaction ◽  
Long Wavelength ◽  
Electron Phonon Interaction ◽  
The Third ◽  
Optical Character ◽  
Mode Behavior ◽  
The One

The properties of long wavelength optical phonons in mixed crystals AB 1-x C x is discussed by a model similar to Modified Random Element Isodisplacement (MREI). Using this method we investigate the frequencies, the dielectric functions, and the reflectivity of several mixed crystals. It is found that this model can be applied to the one-mode behavior, the two-mode behavior, and that of the third category. So the model provides a possible way to understand the optical character of the ternary mixed crystal. Based on it, we can discuss other problems similar to electron–phonon interaction and so on.

Long-wavelength optical phonons inZn1−xMnxSe

1989 ◽  
Vol 39 (2) ◽  
pp. 1207-1211 ◽  
Author(s):  
W. Lu ◽  
P. L. Liu ◽  
G. L. Shi ◽  
S. C. Shen ◽  
W. Giriat
Keyword(s):  
Optical Phonons ◽  
Long Wavelength

Anisotropy of long-wavelength optical phonons in GaAs/AlAs superlattices

JETP Letters ◽  
2014 ◽  
Vol 99 (7) ◽  
pp. 396-399 ◽  
Author(s):  
V. A. Volodin ◽  
M. P. Sinyukov
Keyword(s):  
Optical Phonons ◽  
Long Wavelength

Monte Carlo Study of Phonon Heat Conduction in Silicon Thin Films Including Contributions of Optical Phonons

2010 ◽  
Vol 132 (5) ◽  
Author(s):  
Arpit Mittal ◽  
Sandip Mazumder
Keyword(s):  
Thin Films ◽  
Thermal Conductivity ◽  
Monte Carlo ◽  
Heat Conduction ◽  
Phonon Scattering ◽  
Computational Domain ◽  
Optical Phonons ◽  
Phonon Modes ◽  
Silicon Thin Film ◽  
Silicon Thin Films

Abstract The Monte Carlo method has found prolific use in the solution of the Boltzmann transport equation for phonons for the prediction of nonequilibrium heat conduction in crystalline thin films. This paper contributes to the state-of-the-art by performing a systematic study of the role of the various phonon modes on thermal conductivity predictions, in particular, optical phonons. A procedure to calculate three-phonon scattering time-scales with the inclusion of optical phonons is described and implemented. The roles of various phonon modes are assessed. It is found that transverse acoustic (TA) phonons are the primary carriers of energy at low temperatures. At high temperatures (T>200 K), longitudinal acoustic (LA) phonons carry more energy than TA phonons. When optical phonons are included, there is a significant change in the amount of energy carried by various phonons modes, especially at room temperature, where optical modes are found to carry about 25% of the energy at steady state in silicon thin films. Most importantly, it is found that inclusion of optical phonons results in better match with experimental observations for silicon thin-film thermal conductivity. The inclusion of optical phonons is found to decrease the thermal conductivity at intermediate temperatures (50–200 K) and to increase it at high temperature (>200 K), especially when the film is thin. The effect of number of stochastic samples, the dimensionality of the computational domain (two-dimensional versus three-dimensional), and the lateral (in-plane) dimension of the film on the statistical accuracy and computational efficiency is systematically studied and elucidated for all temperatures.

Non-isodisplacement of P atoms in long-wavelength optical phonons in In1–xGaxP

1979 ◽  
Vol 91 (1) ◽  
pp. 155-165 ◽  
Author(s):  
E. Jahne ◽  
W. Pilz ◽  
M. Giehler ◽  
L. Hildisch
Keyword(s):  
Optical Phonons ◽  
Long Wavelength

Investigations of PbxSr1-xTiO3 Thin Films and Ceramics for Microelectronic Applications

2004 ◽  
Vol 811 ◽  
Author(s):  
M. Jain ◽  
Yu.I. Yuzyuk ◽  
R.S. Katiyar ◽  
Y. Somiya ◽  
A.S. Bhalla ◽  
...  
Keyword(s):  
Thin Films ◽  
Phase Transition ◽  
Room Temperature ◽  
Sol Gel ◽  
Solid State Reaction Method ◽  
Phase Shifters ◽  
Conventional Solid State Reaction ◽  
Mode Behavior ◽  
Dielectric Devices ◽  
Pst System

ABSTRACTWe have investigated electrical and optical properties of the lead strontium titanate {(PbxSr1-x)TiO3 or PST} ceramic and dielectric properties of the thin films of PST at low and high frequencies. (PbxSr1-x)TiO3 compositions with × ≤ 0.4 are paraelectric at room temperature and exhibit ferroelectric phase transition below room temperature. Only one phase transition in the PST system (compared to three in BaxSr1-xTiO3) was recorded. The studies indicated that PST has potential for tunable microwave devices in the paraelectric phase. In the present studies, Pb0.3Sr0.7TiO3 (PST30) ceramic was prepared by the conventional solid-state reaction method and thin films of PST were prepared by sol-gel technique. Structural, microstructural, dielectric, and Raman measurements were performed on these samples. Sharp phase transition was observed in case of the ceramic by dielectric and Raman measurements at 283 K. Raman measurements revealed well-pronounced soft-mode behavior below the Curie temperature in PST ceramic. The thin film of PST deposited on lanthanum aluminate substrate was highly (100) oriented and showed dielectric maxima at ∼280 K, which was close to that in case of the bulk. Eight element coupled micro-strip phase shifters (CMPS) was fabricated on the PST film and tested in the frequency range of 15-17 GHz. The average figure of merit of 49 °/dB for PST30 film in the Ku band at 533 kV/cm suggests the potentiality of these films for high frequency tunable dielectric devices.

Optical Phonons in Cubic AlxGa1-xM Approached by the Modified Random Element Isodisplacement Model

1998 ◽  
Vol 12 (11) ◽  
pp. 443-449 ◽  
Author(s):  
Ming S. Liu ◽  
L. A. Bursill ◽  
S. Prawer
Keyword(s):  
Nearest Neighbor ◽  
Phonon Frequency ◽  
Random Element ◽  
Transverse Optical ◽  
Optical Phonons ◽  
Mode Behavior

The behavior of longitudinal and transverse optical phonons in cubic Al x Ga 1-x N are derived theoretically as a function of the concentration x(0≤x≤1). The calculation is based on a Modified Random Element Isodisplacement model which considers the interactions from the nearest neighbor and second neighbor atoms. We find one-mode behavior in Al x Ga 1-x N where the phonon frequency in general varies continuously and approximately linearly with x.

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