raman spectroscopy presentation
DESCRIPTION
Generally about Raman and analysis of few results of my research.TRANSCRIPT
RAMAN SPECTROSC
OPY
by Gabriela Tubon U.
PhD student of Physics
department – ITM -CNR
Advisors: • L. Caputi• A. Tavolaro
Outlets
Introduction
Description
Sample Studi
Results and Confront
Conclusions
Introduction
IR and Raman are the most common vibrational spectroscopies for assessing
molecular motion and fingerprinting species, it should be noted however, that it is
typical that only one of the vibrational techniques (FTIR or Raman) is used in long term
studies with the choice based on the level of detail that is provided for the specific
material of interest.
Raman spectroscopy is a spectroscopic technique based on inelastic scattering of
monochromatic light, usually from a laser source, is an invaluable tool for quality
control, and for comparing samples used by different research groups.
Definition
The laser light interacts with molecular vibrations, phonons or other excitations in
the system, resulting in the energy of the laser photons being shifted up or down.
The shift in energy gives information about the vibrational modes in the system.
A Raman system typically
consists of four major
components:
1. Excitation source (Laser).
2. Sample illumination
system and light collection
optics.
3. Wavelength selector
(Filter or
Spectrophotometer).
4. Detector (Photodiode
array, CCD or PMT).
Definition
Sample Study
Sample Study
Sample Study
Sample Study
Sample Study
Sample Study
Sample Study
a) Graphene obtained via micromechanical cleavage.b) Precursor graphite
Sample Study
RESULTS AND CONFRONT
RESULTS AND CONFRONT
0 500 1000 1500 2000 2500 3000 3500 4000 4500 50000
500
1000
1500
2000
2500In
ten
sity
(a
.u.)
Raman Shift (cm-1)
CLC2
1333,71 cm-1
1571,42 cm-1
2713,14 cm-1
3241,14 cm-1
D peak
G peak
2D peak
2D' peak1617,14 cm-1D' peak
2451,42 cm-12931,42 cm-1 4286,85 cm-1
RESULTS AND CONFRONT
1500 2000 2500 30000
5000
10000
15000
Inte
nsi
ty (
a.u
.)
Raman Shift (cm-1)
CLC1
1571,79 cm-1
G peak
2712,10 cm-1
2D peak
1612,65 cm-1D' peak
2449,54 cm-1
RESULTS AND CONFRONT
0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000100
150
200
250
300
350
400
450
500
550
600
650
700In
ten
sity
(a
.u.)
Raman Shift (cm-1)
LC1
1344cm-1
D peak
1578 cm-1
G peak
2683 cm-12876,57 cm-12D peak
Unidentified
RESULTS AND CONFRONT
0 500 1000 1500 2000 2500 3000 3500 4000 4500 50000
50
100
150
Inte
nsi
ty (
a.u
.)
Raman Shift (cm-1)
LC2
1324,57 cm-1
2864 cm-1
D peak
1578,28 cm-1
G peak
2698,28 cm-1
2D peak
Unidentified
Conclusions
o The raman spectroscopy is fundamental in our research for understand as compositions of materials change with the different chemical treatments , in fact, this help us to predict if the new method is suitable .
o In this first proves is important the parameters to take to do the spectroscopy, like a frequency (513 nm), incident power (~ 4 to ~0,04mW), even the room ambient for avoid the light scattering noise.
o Is important prove in the same conditions the sample result for the next measurements, is preferable do the measurements in suspensions or solutions.
Thank for your
attention.
Imagination is more important that Knowledge.Knowledge is limited; imagination encircles the world…..
RAMAN SPECTROSC
OPY