Temperature dependence of low-frequency optical phonons in TlInS2

2015 ◽  
Vol 12 (6) ◽  
pp. 826-829 ◽  
Author(s):  
Raul Paucar ◽  
YongGu Shim ◽  
Kazuki Wakita ◽  
Oktay Alekperov ◽  
Nazim Mamedov
Keyword(s):  
Temperature Dependence ◽  
Low Frequency ◽  
Optical Phonons

Temperature Dependence of the Air/Water Interface Revealed by Polarization Sensitive Sum-Frequency Generation Spectroscopy

2018 ◽  
Author(s):  
Daniel R. Moberg ◽  
Shelby C. Straight ◽  
Francesco Paesani
Keyword(s):  
Temperature Dependence ◽  
Low Frequency ◽  
Potential Energy Function ◽  
Md Simulations ◽  
Sum Frequency Generation ◽  
Water Molecules ◽  
Water Interface ◽  
Sum Frequency ◽  
Air Water Interface ◽  
Frequency Generation

<div> <div> <div> <p>The temperature dependence of the vibrational sum-frequency generation (vSFG) spectra of the the air/water interface is investigated using many-body molecular dynamics (MB-MD) simulations performed with the MB-pol potential energy function. The total vSFG spectra calculated for different polarization combinations are then analyzed in terms of molecular auto-correlation and cross-correlation contributions. To provide molecular-level insights into interfacial hydrogen-bonding topologies, which give rise to specific spectroscopic features, the vSFG spectra are further investigated by separating contributions associated with water molecules donating 0, 1, or 2 hydrogen bonds to neighboring water molecules. This analysis suggests that the low frequency shoulder of the free OH peak which appears at ∼3600 cm−1 is primarily due to intermolecular couplings between both singly and doubly hydrogen-bonded molecules. </p> </div> </div> </div>

Temperature dependence of the low-frequency surface impedance of metals near the extreme anomalous limit

1978 ◽  
Vol 17 (4) ◽  
pp. 1721-1737 ◽  
Author(s):  
A. Manz ◽  
J. Black ◽  
Kh. Pashaev ◽  
D. L. Mills
Keyword(s):  
Temperature Dependence ◽  
Surface Impedance ◽  
Low Frequency

Interaction of Point Defects in Ice

1978 ◽  
Vol 21 (85) ◽  
pp. 115-122
Author(s):  
J. H. Bilgram ◽  
H. Gränicher
Keyword(s):  
Experimental Data ◽  
Dielectric Properties ◽  
Temperature Dependence ◽  
Point Defects ◽  
Low Frequency ◽  
Defect Concentration ◽  
Dielectric Measurements ◽  
Long Time ◽  
Nmr Techniques ◽  
Bjerrum Defect

AbstractThe interaction of point detects in ice has been neglected for a long time. Experimental data obtained from dielectric measurements on HF-doped crystals stimulated a new evaluation of the possibility of an interaction between Bjerrum defects and ions. In a previous paper it has been shown that this leads us to assume the existence of aggregates of Bjerrum defects and ions. In this paper these aggregates and Bjerrum defects are used to explain the dielectric properties of ice, especially the temperature dependence of the product of the high and low frequency conductivity σ0σ∞.The interaction of Bjerrum defects and impurity molecules leads to a dependence of the concentration of frenkel pairs on Bjerrum-defect concentration. At HF concentrations above the native Bjerrum-defect concentration the formation of a Frenkel pair is enhanced. This leads to the fast out-diffusion which has been studied in highly doped crystals by means of NMR techniques.

Calculation of NQR v's and T1-1' s being proportional to T4 and T5 , respectively

1990 ◽  
Vol 45 (3-4) ◽  
pp. 536-540
Author(s):  
Mariusz Máckowiak ◽  
Costas Dimitropoulos
Keyword(s):  
Temperature Dependence ◽  
Relaxation Rate ◽  
Spin System ◽  
Low Frequency ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Lattice Vibrations ◽  
Spin Lattice ◽  
Simplifying Assumptions ◽  
The One

Abstract The second-order Raman phonon process for a multilevel spin system is shown to give a quadru-polar spin-lattice relaxation rate T1-1varying as T5 at very low temperatures. This relaxation rate for quadrupole spins is similar to the one discussed for a paramagnetic spin system having a multilevel ground state. The temperature dependence of T1 is discussed on the basis of some simplifying assumptions about the nature of the lattice vibrations in the Debye approximation. This type of relaxation process has been observed below 20 K in tetramethylammonium hydrogen bis-trichloroacetate for the 35Cl T1-1 . Below 20 K the NQR frequency in the same crystal reveals a T4 temperature dependence due to the induced modulations of the vibrational and librational coordinates by the low-frequency acoustic phonons.

Hypersonic Attenuation by Low-Frequency Optical Phonons in SrTiO3Crystals

1969 ◽  
Vol 188 (3) ◽  
pp. 1456-1464 ◽  
Author(s):  
R. NAVA ◽  
R. CALLAROTTI ◽  
H. CEVA ◽  
A. MARTINET
Keyword(s):  
Low Frequency ◽  
Optical Phonons

Critical Roles of High- and Low-Frequency Optical Phonons in Photodynamics of Zero-Dimensional Perovskite-like (C6H22N4Cl3)SnCl3 Crystals

2019 ◽  
Vol 10 (24) ◽  
pp. 7586-7593 ◽  
Author(s):  
Xiaoyu Liu ◽  
Wenhui Wu ◽  
Yumeng Zhang ◽  
Yuanyuan Li ◽  
Huaxin Wu ◽  
...  
Keyword(s):  
Low Frequency ◽  
Optical Phonons
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