WELCOME

“SOME STUDIES OF OPTICLE PROPERTIES AND RAMAN SPECTROSCOPY OF CARBON

NANOTUBES”

Dr.SHAILENDRA KUMAR SACHIDA NAND SING PROFESSOR OF PHYSICS

FOCAL THEMES

OPTICAL PROPERTIES & RAMAN SPECTROSCOPY OF CARBON NANOTUBES

CALCULATIONS OF ENERGY SEPARATION IN NANOTUBE AS A FUNCTION OF NANOTUBE DIAMETER

CHARACTERISATION OF CARBON NANOTUBES BY RAMAN SPECTROSCOPY

DIAMETER DEPENDENT RESONANCE

RAMAN SCATTERING

ANALYSIS STROKES

CHAPTER 1GENERAL INTRODUCTION

ABOUT CARBON NANOTUBES

WE HAVE PRESENTED THE GENERAL INTRODUCTION ABOUT CARBON

NANOTUBES

CHAPTER 2RELATION OF CARBON NANOTUBE WITH OTHER CARBON MATERIALS

STARTS WITH THE BONDING BETWEEN CARBON ATOMS AND ENDS WITH THE GRAPHITE INTERACTION COMPOUNDS

CHAPTER 3STUDY OF NANOTUBE GROWTH

AND CHARACTERIZATION

WE HAVESTUDIED THE GROWTH & CHARACTERIZATION

CHAPTER 4STUDY OF OPTICAL PROPERTIES OF CARBON NANOTUBES AND CALCULATIONS OF ENERGY SEPARATION AS A FUNCTION OF NANOTUBE

DIAMETER

WE HAVE STUDIED THE OPTICAL PROPERTIES OF CARBON NANOTUBES AND PRESENTED A METHOD OF CALCULATING ENERGY SEPARATION OF CARBON

NANOTUBES AS A FUNCTION OF NANOTUBE DIAMETER. WE HAVE EVALUATED THE ENERGY SEPARATION FOR METALLIC AND SEMI CONDUCTING CARBON

NANOTUBES. ON COMPARING OUR THEORITICALLY EVALUATED RESULT WITH THE EXPERIMENT, WE FIND THAT OUR RESULTS FOR BOTH THE NANOTUBES ARE

LOWER THAN THE EXPERIMENTAL DATA BUT THE TREND IS SAME FOR NANOTUBE DIAMETER 0.7<dt<3.0. THE ENERGY SEPARATION E(ev)

FOR BOTH THE NANOTUBES DECREASES WITH dt . THE VALUE IS MAXIMUM AT dt=0.7 AND LOWER AT dt=3.0

CHAPTER 5CHARACTERISATION OF CARBON

NANOTUBES BY RAMAN SPECTROSCOPY

WE HAVE PRESENTED A METHOD OF CARBON NANOTUBES BY RAMAN SPECTROSCOPY. WE

HAVE CALCULATEDTHE DIAMETER DISTRIBUTION USING EXPRESSION (5.1) AND THE RESULTS IS SHOWN IN TABLE 5T1 WITH SHIFT IN RAMAN SPECTRA. WE OBSERVED THAT G/D RATIO IS A

DIRECTMEASURE OF THE QUALITY OF THE SAMPLE.

CHAPTER 6STUDY OF DIAMETER –DEPENDENT RESONANCE RAMAN SCATTERING

ANDANALYSIS OF STOKES AND ANT STOKES LIMITS FOR METALLIC NANOTUBE

WE HAVE STUDIED THE DIAMETER DEPENDENCE RESONANCE RAMAN SCATERRING AND ANALYSED THE EXPERIMENTAL RESULTS OF STOKES AND

ANTI-STOKES LINES FOR METALLIC NANOTUBES. THE WIDTH OF THE METALLIC WINDOW IS OBSERVED IN RESONANT RAMAN EXPERIMENTS AND THROUGH THE ANALYSES OF STOKES AND ANTI-STOKES SPECTRA IT IS ALSO OBSERVED

THAT THE SPECTRA OF DENSITY OF STATES (DOS) FOR SINGLE WALL NANOTUBES (SWNTs) HAVE SOME STRONG CHIRALITY DEPENDENCE. FOR METALLIC

NANOTUBES THE DOS PEAKS ARE FOUND TO BE SPILIT IN TWO PEAKS BECAUSE OF THE TRIGONAL WARPING AFFECT,WHILE SEMI CONDUTING NANOTUBES DO

NOT SHOW ANY TYPE OF SPLITTING.

CHAPTER 7SUMMARY AND CONCLUSION

FROM THE ABOVE ANALYSIS AND DISCUSSION IN THIS THESIS, WE HAVE COME ACROSS THE FOLLOWING CONCLUSION 1) FROM RESONANCE RAMAN SACTTERING, ONE CAN PROBE

THE VARIETY OF NANOTUBE PARAMETER LIKE (a) (n,m) VALUES, DIAMETER AND CHIRALITY, (b) LASER ENERGY, (c) POLARIZATION OF LIGHT, (d) SIMPLE ORIENTATION RELATIVE TO THE POLARIZATION, (e) STOKES AND ANTI STOKES RAMAN SPECTRO etc. MICRO – RAMAN SPECTROSCOPY HAS BECOME A STANDARD TOOL FOR CHARACTERISING NANOTUBE AND NANO – MATERIALS.

2) IN SINGLE NANOTUBE SPECTROSCOPY, ALL RAMAN PEAKS COME FROM THE SAME SWNT, SO THAT THE TOTAL RAMAN SPECTRA CONTAINS A WEALTH OF INFORMATION WHICH NEEDS TO BE INTERPRETED FOR SELF CONSISTENCY

HOPE YOU ENJOYED IT …

THANK YOU. . .