Temperature dependence of Raman-active mode frequencies and linewidths in TlGaSe2 layered crystals

2005 ◽  
Vol 40 (3) ◽  
pp. 264-270 ◽  
Author(s):  
N. S. Yuksek ◽  
N. M. Gasanly
Keyword(s):  
Temperature Dependence ◽  
Raman Active Mode ◽  
Active Mode ◽  
Layered Crystals

Vibrational dynamic of the Raman-active mode in barium nitrate crystal

1995 ◽  
Vol 20 (23) ◽  
pp. 2378 ◽  
Author(s):  
P. G. Zverev ◽  
T. T. Basiev ◽  
W. Jia ◽  
H. Liu
Keyword(s):  
Barium Nitrate ◽  
Raman Active Mode ◽  
Active Mode

Application of a Novel Linear/Exponential Hybrid Force Field Scaling Scheme to the Longitudinal Raman Active Mode of Polyyne

2007 ◽  
Vol 111 (12) ◽  
pp. 2434-2441 ◽  
Author(s):  
Shujiang Yang ◽  
Miklos Kertesz ◽  
Viktor Zólyomi ◽  
Jenő Kürti
Keyword(s):  
Force Field ◽  
Raman Active Mode ◽  
Active Mode

Measurement of Thermal Conductivities of Bi2Te3 and Sb2Te3 Nano-Powders at Extreme Temperature and Strain

2020 ◽  
Author(s):  
Chenxin Xu ◽  
Brandon Wang ◽  
Emily Sneddon ◽  
Gianna Marcovecchio ◽  
Greg Ota ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Conductivity ◽  
Extreme Temperature ◽  
Peak Position ◽  
Raman Active Mode ◽  
Thermal Measurement ◽  
Active Mode ◽  
Conductivity Of Thin Films ◽  
First Time ◽  
Refined Version

Abstract The Raman optothermal technique has been the most successful method for measurement of thermal conductivity of two dimensional (2D) materials, and was used to measure the thin films for the first time in this work. In this technique, a laser is focused at the center of a thin film and used to measure the peak position of a Raman-active mode. As the laser power is increased, the sample is heated which enables red-shift Raman mode due to thermal softening. Another comparison experiment is conducted by placing the samples on a heating platform and monitor the change of Raman-active mode peak position shift. Combining these two sections of experiments provide us the thermal modeling can then be used to extract the thermal conductivity from the measured shift rate. We have used a refined version of the optothermal Raman technique to study thermal conductivity of thin films of Bi2Te3 and Sb2Te3, at extreme temperatures and mechanical strains. It is the first thermal measurement on these two materials by Raman optothermal technique. This work also addresses several important issues in the measurement of thermal conductivity of thin films using Raman spectroscopy.

scholarly journals Temperature dependence of the first-order Raman scattering in GaS layered crystals

2000 ◽  
Vol 116 (3) ◽  
pp. 147-151 ◽  
Author(s):  
N.M. Gasanly ◽  
A. Aydınlı ◽  
H. Özkan ◽  
C. Kocabaş
Keyword(s):  
Raman Scattering ◽  
Temperature Dependence ◽  
First Order ◽  
Layered Crystals

Temperature Dependence of the Critical Electron Dose for Fatty Acid Monolayers

1982 ◽  
Vol 40 ◽  
pp. 78-79
Author(s):  
Kenneth H. Downing ◽  
Robert M. Glaeser
Keyword(s):  
Electron Beam ◽  
Fatty Acid ◽  
Inelastic Scattering ◽  
Temperature Dependence ◽  
Structural Damage ◽  
Direct Result ◽  
Second Step ◽  
Strong Temperature Dependence ◽  
Electron Dose ◽  
Covalent Bonds

The structural damage of molecules irradiated by electrons is generally considered to occur in two steps. The direct result of inelastic scattering events is the disruption of covalent bonds. Following changes in bond structure, movement of the constituent atoms produces permanent distortions of the molecules. Since at least the second step should show a strong temperature dependence, it was to be expected that cooling a specimen should extend its lifetime in the electron beam. This result has been found in a large number of experiments, but the degree to which cooling the specimen enhances its resistance to radiation damage has been found to vary widely with specimen types.

Temperature Dependence of Magnetic Domains and Wall Structures

1972 ◽  
Vol 30 ◽  
pp. 496-497
Author(s):  
Sonoko Tsukahara ◽  
Tadami Taoka ◽  
Hisao Nishizawa
Keyword(s):  
Temperature Dependence ◽  
Domain Walls ◽  
Magnetic Domain ◽  
Iron Film ◽  
Objective Lens ◽  
Lorentz Microscopy ◽  
Domain Structures ◽  
Wall Structures ◽  
Crystal Films ◽  
Metallurgical Structure

The high voltage Lorentz microscopy was successfully used to observe changes with temperature; of domain structures and metallurgical structures in an iron film set on the hot stage combined with a goniometer. The microscope used was the JEM-1000 EM which was operated with the objective lens current cut off to eliminate the magnetic field in the specimen position. Single crystal films with an (001) plane were prepared by the epitaxial growth of evaporated iron on a cleaved (001) plane of a rocksalt substrate. They had a uniform thickness from 1000 to 7000 Å.The figure shows the temperature dependence of magnetic domain structure with its corresponding deflection pattern and metallurgical structure observed in a 4500 Å iron film. In general, with increase of temperature, the straight domain walls decrease in their width (at 400°C), curve in an iregular shape (600°C) and then vanish (790°C). The ripple structures with cross-tie walls are observed below the Curie temperature.

Mosaic Mapping: A Means of Tiling Images to Shorten Acquisition Speed for Lower - Magnification SEM Images and Wavelength Dispersive Spectrometers (WDS) X-Ray Maps

1996 ◽  
Vol 54 ◽  
pp. 438-439
Author(s):  
J.D. Geller ◽  
C.R. Herrington
Keyword(s):  
Limiting Factors ◽  
X Rays ◽  
Angular Range ◽  
Acceptance Angle ◽  
Sem Images ◽  
Worst Case ◽  
X Ray ◽  
Focusing Distance ◽  
Layered Crystals ◽  
Working Distance

The minimum magnification for which an image can be acquired is determined by the design and implementation of the electron optical column and the scanning and display electronics. It is also a function of the working distance and, possibly, the accelerating voltage. For secondary and backscattered electron images there are usually no other limiting factors. However, for x-ray maps there are further considerations. The energy-dispersive x-ray spectrometers (EDS) have a much larger solid angle of detection that for WDS. They also do not suffer from Bragg’s Law focusing effects which limit the angular range and focusing distance from the diffracting crystal. In practical terms EDS maps can be acquired at the lowest magnification of the SEM, assuming the collimator does not cutoff the x-ray signal. For WDS the focusing properties of the crystal limits the angular range of acceptance of the incident x-radiation. The range is dependent upon the 2d spacing of the crystal, with the acceptance angle increasing with 2d spacing. The natural line width of the x-ray also plays a role. For the metal layered crystals used to diffract soft x-rays, such as Be - O, the minimum magnification is approximately 100X. In the worst case, for the LEF crystal which diffracts Ti - Zn, ˜1000X is the minimum.

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