Substitutional carbon in Si1−yCy alloys as measured with infrared absorption and Raman spectroscopy

1997 ◽  
Vol 82 (9) ◽  
pp. 4246-4252 ◽  
Author(s):  
M. Meléndez-Lira ◽  
J. Menéndez ◽  
K. M. Kramer ◽  
M. O. Thompson ◽  
N. Cave ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Infrared Absorption

scholarly journals Clinical applications of infrared and Raman spectroscopy: state of play and future challenges

The Analyst ◽  
2018 ◽  
Vol 143 (8) ◽  
pp. 1735-1757 ◽  
Author(s):  
Matthew J. Baker ◽  
Hugh J. Byrne ◽  
John Chalmers ◽  
Peter Gardner ◽  
Royston Goodacre ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Infrared Absorption ◽  
State Of The Art ◽  
Clinical Applications ◽  
The State ◽  
Infrared And Raman Spectroscopy ◽  
Future Challenges

This review examines the state-of-the-art of clinical applications of infrared absorption and Raman spectroscopy, outstanding challenges, and progress towards translation.

Quasi-Freestanding Graphene on SiC(0001)

2010 ◽  
Vol 645-648 ◽  
pp. 629-632 ◽  
Author(s):  
Florian Speck ◽  
Markus Ostler ◽  
Jonas Röhrl ◽  
Johannes Jobst ◽  
Daniel Waldmann ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Hall Effect ◽  
Carrier Concentration ◽  
Absorption Spectroscopy ◽  
Infrared Absorption ◽  
Photoelectron Spectroscopy ◽  
Short Range ◽  
Infrared Absorption Spectroscopy ◽  
Hall Effect Measurements ◽  
Comprehensive Study

We report on a comprehensive study of the properties of quasi-freestanding monolayer and bilayer graphene produced by conversion of the (6√3×6√3)R30° reconstruction into graphene via intercalation of hydrogen. The conversion is confirmed by photoelectron spectroscopy and Raman spectroscopy. By using infrared absorption spectroscopy we show that the underlying SiC(0001) surface is terminated by hydrogen in the form of Si-H bonds. Using Hall effect measurements we have determined the carrier concentration and type as well as the mobility which lies well above 1000 cm2/Vs despite a significant amount of short range scatterers detected by Raman spectroscopy.

Formation of silicate structures in Cu-containing silica xerogels

2000 ◽  
Vol 15 (12) ◽  
pp. 2875-2880 ◽  
Author(s):  
F. Ruiz ◽  
J. R. Martínez ◽  
J. González-Hernández
Keyword(s):  
Thermal Stability ◽  
Raman Spectroscopy ◽  
Infrared Absorption ◽  
Sol Gel ◽  
Heat Treatments ◽  
Thermal Treatments ◽  
Chemical Formula ◽  
Silica Xerogels ◽  
Weight Composition ◽  
Oxide Particles

Using infrared absorption and Raman spectroscopy, the structure of SiO2 sol-gel samples containing copper were analyzed as a function of air heat treatments. The weight composition of the samples was 70(SiO2)–30(CuO) and the thermal treatments were carried out in air at various temperatures in the range of 100–600 °C. It was found that the Cu might be incorporated into the SiO2 matrix at least in two ways: forming oxide particles and forming metasilicatelike structures. The copper metasilicate found had the chemical formula, Cu6 [Si6O18] · 6H2O, which is known as dioptase with a thermal stability at temperatures up to 600 °C.

scholarly journals Surface Enhanced Infrared Absorption Studies of SiO2–TiO2–Ag Nanofibers: Effect of Silver Electrodeposition Time on the Amplification of Signals

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 563
Author(s):  
Blanca Selenis Cabello-Ribota ◽  
Rurik Farías ◽  
Simón Yobanny Reyes-López
Keyword(s):  
Raman Spectroscopy ◽  
Infrared Spectroscopy ◽  
New Media ◽  
Infrared Absorption ◽  
Indium Tin Oxide ◽  
Amplification Factor ◽  
Sol Gel ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Surface Enhanced

Surface Enhanced on Infrared Absorption (SEIRAS) and Raman Spectroscopy (SERS) are nondestructive analytic techniques used to detect low concentrations and recognize the fingerprints of molecules. The recognition of the absorption from samples by conventional infrared spectroscopy (IR) via Attenuated Total Reflection (ATR) is difficult for molecules with a low signal strength. However, developed structures with SERS and SEIRAS effect present problems such as high cost, low stability, and low compatibility. Research into new media to obtain greater amplification is largely based on the creation of nanoscale structures with symmetrical arrangements and reproducible distances, resulting in aggregates of nanoparticles that help generate hot spots which are active for amplification. The sol-gel and electrospinning method for the obtention of ceramics provides an alternative means by which to produce said substrates. Fibers of nanometric scale provide an increase of surface area which allows more contact to occur with analytes. Consequently, in this study, a silica-titania-silver nanostructured support that amplifies signal intensity for Raman and infrared spectroscopy was developed. The silica-titania support was developed by sol-gel and electrospinning techniques, and the as spun fibers were treated at 800 °C. Then, the ceramic fibrous membrane was placed on conductive indium tin oxide plastic to be doped with silver using an electroplating technique, varying the silver nitrate concentration (5, 10 and 20 mM), as well as electrodeposition times (1, 2, 5 and 10 min), with a constant voltage (1 V). Twelve different supports were obtained that showed amplification. The enhancement of infrared signals from pyridine and crystal violet molecules adsorbed on silica-titania-silver (SiO2–TiO2–Ag) nanofibers was studied in situ by Attenuated Total Reflection-Fourier Transformed Infrared Spectroscopy (ATR-FTIR). The highest amplification was obtained by the support doped at 10 min in a 10 mM concentration, with an amplification factor of 2.74 in the band localized at 3301 cm−1. In Raman spectroscopy, the highest amplification factor was 27.03, on the support doped for 5 min at a concentration of 5 mM.

X-ray diffraction and vibrational-spectroscopy study of the structure of La2Ti2O7

1989 ◽  
Vol 4 (6) ◽  
pp. 1525-1528 ◽  
Author(s):  
U. Balachandran ◽  
N. G. Eror
Keyword(s):  
Raman Spectroscopy ◽  
Infrared Absorption ◽  
Vibrational Spectra ◽  
Room Temperature ◽  
Inversion Symmetry ◽  
Spectroscopy Study ◽  
Monoclinic Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bond Strengths

The compound La2Ti2O7 was prepared by a liquid mix technique and examined at room temperature by x-ray diffraction, infrared absorption, and Raman spectroscopy. The examinations confirm and supplement the earlier observation by x-ray diffraction that La2Ti2O7 crystallizes in the monoclinic structure without an inversion symmetry. The energy-shifts (cm−1) that were observed in the vibrational spectra may be explained by a sixfold coordination for the titanium and a ninefold coordination for the lanthanum in the structure. This type of coordination satisfies Pauling's electrostatic valence rule regarding the electrostatic bond strengths at the shared anions.

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