scholarly journals Visible and Deep-Ultraviolet Raman Spectroscopy as a Tool for Investigation of Structural Changes and Redistribution of Carbon in Ni-Based Ohmic Contacts on Silicon Carbide

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Paweł Borowicz ◽  
Adrian Kuchuk ◽  
Zbigniew Adamus ◽  
Michał Borysiewicz ◽  
Marek Ekielski ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Raman Spectroscopy ◽  
Structural Changes ◽  
Layer Structure ◽  
Carbon Layer ◽  
Raman Shift ◽  
Range Analysis ◽  
Silicide Layer ◽  
Deep Ultraviolet ◽  
Nickel Silicon

Three samples of 4H polytype of silicon carbide (4H-SiC) covered with the following sequence of layers: carbon/nickel/silicon/nickel/silicon were investigated with micro-Raman spectroscopy. Different thermal treatments of each sample result in differences of carbon layer structure and migration of carbon atoms thorough silicide layer. Two ranges of Raman shift were investigated. The first one is placed between 1000 cm−1 and 2000 cm−1. The main carbon bands D and G are observed in this range. Analysis of the positions of these bands and their intensity ratio enables one to determine the graphitization degree of carbon layer. Additional information about the changes of the carbon layer structure was derived from analysis of 2D band placed around 2700 cm−1. Application of deep ultraviolet excitation delivered information about the structure of carbon layer formed on the free surface of silicides and the distribution of the carbon inside the silicide layer.

scholarly journals Structure of Carbonic Layer in Ohmic Contacts: Comparison of Silicon Carbide/Carbon and Carbon/Silicide Interfaces

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Paweł Borowicz ◽  
Adrian Kuchuk ◽  
Zbigniew Adamus ◽  
Michał Borysiewicz ◽  
Marek Ekielski ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Raman Spectroscopy ◽  
Thermal Treatment ◽  
Ohmic Contacts ◽  
Carbon Film ◽  
Graphene Layers ◽  
Three Samples ◽  
Nickel Silicon

The structure of carbonic layer in three samples composed of 4H polytype of silicon carbide and the following sequence of layers: carbon/nickel/silicon/nickel/silicon was investigated with Raman spectroscopy. Different thermal treatment of the samples led to differences in the structure of carbonic layer. Raman measurements were performed with visible excitation focused on two interfaces: silicon carbide/carbon and carbon/silicide. The results showed differences in the structure across carbon film although its thickness corresponds to 8/10 graphene layers.

Correlation of Stress in Silicon Carbide Crystal and Frequency Shift in Micro-Raman Spectroscopy

2014 ◽  
Vol 1693 ◽  
Author(s):  
N. Sugiyama ◽  
M. Yamada ◽  
Y. Urakami ◽  
M. Kobayashi ◽  
T. Masuda ◽  
...  
Keyword(s):  
Residual Stress ◽  
Silicon Carbide ◽  
Raman Spectroscopy ◽  
Frequency Shift ◽  
Uniaxial Stress ◽  
Bending Test ◽  
Raman Shift ◽  
Micro Raman Spectroscopy ◽  
Four Point Bending

ABSTRACTThe correlation of stress in Silicon Carbide (SiC) crystal and frequency shift in micro- Raman spectroscopy was determined by an experimental method. We applied uniaxial stress to 4H- and 6H-SiC single crystal square bar specimen shaped with (0001) and (11-20) faces by four point bending test, under measuring the frequency shift in micro-Raman spectroscopy. The results revealed that the linearity coefficients between stress and Raman shift were -1.96 cm-1/GPa for FTO(2/4)E2 on 4H-SiC (0001) face, -2.08 cm-1/GPa for FTO(2/4)E2 on 4H-SiC (11-20) face and -2.70 cm-1/GPa for FTO(2/6)E2 on 6H-SiC (0001) face. Determination of these coefficients has made it possible to evaluate the residual stress in SiC crystal quantitatively by micro-Raman spectroscopy. We evaluated the residual stress in SiC substrate that was grown in our laboratory by utilizing the results obtained in this study. The result of estimation indicated that the SiC substrate with a diameter of 6 inch remained residual stress as low as ±15 MPa.

scholarly journals Structural and Technological Approach to Reveal the Role of the Lipid Phase in the Formation of Soy Emulsion Gels with Chia Oil

Gels ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 48
Author(s):  
Ana M. Herrero ◽  
Claudia Ruiz-Capillas
Keyword(s):  
Raman Spectroscopy ◽  
Structural Properties ◽  
Structural Changes ◽  
Protein Secondary Structure ◽  
Lipid Phase ◽  
Α Helix ◽  
Β Sheet ◽  
Shed Light ◽  
Chia Oil

Considerable attention has been paid to emulsion gels (EGs) in recent years due to their interesting applications in food. The aim of this work is to shed light on the role played by chia oil in the technological and structural properties of EGs made from soy protein isolates (SPI) and alginate. Two systems were studied: oil-free SPI gels (SPI/G) and the corresponding SPI EGs (SPI/EG) that contain chia oil. The proximate composition, technological properties (syneresis, pH, color and texture) and structural properties using Raman spectroscopy were determined for SPI/G and SPI/EG. No noticeable (p > 0.05) syneresis was observed in either sample. The pH values were similar (p > 0.05) for SPI/G and SPI/EG, but their texture and color differed significantly depending on the presence of chia oil. SPI/EG featured significantly lower redness and more lightness and yellowness and exhibited greater puncture and gel strengths than SPI/G. Raman spectroscopy revealed significant changes in the protein secondary structure, i.e., higher (p < 0.05) α-helix and lower (p < 0.05) β-sheet, turn and unordered structures, after the incorporation of chia oil to form the corresponding SPI/EG. Apparently, there is a correlation between these structural changes and the textural modifications observed.

Study of structural changes of gluten proteins during bread dough mixing by Raman spectroscopy

2021 ◽  
Vol 358 ◽  
pp. 129916
Author(s):  
Eloïse Lancelot ◽  
Joran Fontaine ◽  
Joëlle Grua-Priol ◽  
Ali Assaf ◽  
Gérald Thouand ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Structural Changes ◽  
Bread Dough ◽  
Gluten Proteins ◽  
Dough Mixing

scholarly journals Overview of Popular Techniques of Raman Spectroscopy and Their Potential in the Study of Plant Tissues

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1537
Author(s):  
Aneta Saletnik ◽  
Bogdan Saletnik ◽  
Czesław Puchalski
Keyword(s):  
Raman Spectroscopy ◽  
Cell Walls ◽  
Structural Changes ◽  
Spatial Information ◽  
Technological Development ◽  
Analytical Techniques ◽  
High Sensitivity ◽  
Plant Tissues ◽  
Wide Range ◽  
Identification Technique

Raman spectroscopy is one of the main analytical techniques used in optical metrology. It is a vibration, marker-free technique that provides insight into the structure and composition of tissues and cells at the molecular level. Raman spectroscopy is an outstanding material identification technique. It provides spatial information of vibrations from complex biological samples which renders it a very accurate tool for the analysis of highly complex plant tissues. Raman spectra can be used as a fingerprint tool for a very wide range of compounds. Raman spectroscopy enables all the polymers that build the cell walls of plants to be tracked simultaneously; it facilitates the analysis of both the molecular composition and the molecular structure of cell walls. Due to its high sensitivity to even minute structural changes, this method is used for comparative tests. The introduction of new and improved Raman techniques by scientists as well as the constant technological development of the apparatus has resulted in an increased importance of Raman spectroscopy in the discovery and defining of tissues and the processes taking place in them.

scholarly journals Structural Changes in Doped Ge2Sb2Te5 Thin Films Studied by Raman Spectroscopy

2013 ◽  
Vol 44 ◽  
pp. 82-90 ◽  
Author(s):  
S. Kozyukhin ◽  
M. Veres ◽  
H.P. Nguyen ◽  
A. Ingram ◽  
V. Kudoyarova
Keyword(s):  
Thin Films ◽  
Raman Spectroscopy ◽  
Structural Changes

Mechanical properties of nickel silicon carbide nanocomposites

2002 ◽  
Vol 328 (1-2) ◽  
pp. 137-146 ◽  
Author(s):  
A.F. Zimmerman ◽  
G. Palumbo ◽  
K.T. Aust ◽  
U. Erb
Keyword(s):  
Mechanical Properties ◽  
Silicon Carbide ◽  
Nickel Silicon

S-Edge-rich MoxSy arrays vertically grown on carbon aerogels as superior bifunctional HER/OER electrocatalysts

Nanoscale ◽  
2019 ◽  
Vol 11 (42) ◽  
pp. 20284-20294 ◽  
Author(s):  
Yu Cheng ◽  
Pengfei Yuan ◽  
Xiaohui Xu ◽  
Sijie Guo ◽  
Kanglei Pang ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Active Sites ◽  
Structural Changes ◽  
Carbon Aerogels ◽  
Clear Identification ◽  
First Time

Operando Raman spectroscopy is used for the first time for clear identification of the intrinsic active sites, intermediates and structural changes in Mo4S16@GCA.

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