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Dr. D. Victor Suvisesha Muthu
Principal Research Scientist
Department of Physics,
Indian Institute of Science,
Bangalore 560012, INDIA.
email: victor@physics.iisc.ernet.in
phone: 91-80-2293-2857,   
fax: 91-80-2360-2602


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Academic Background:

M.Sc. (Physics) - 1985 Madurai Kamaraj University, Madurai
M.Tech. (Laser Technology) - 1990 Indian Institute of Technology, Kanpur
Ph.D. (Physics)- 2000 Indian Institute of Science, Bangalore

Post-doctoral fellow :  May 2000 -  August 2001 Department of Physics, University of Missouri, Kansas City, U.S.A.
Visiting Scientist : May 2006 - September 2006 
Department of Physics, University of Missouri, Kansas City, U.S.A.
Sabbatical : December 2007 - October 2008
Department of Physics, University of Missouri, Kansas City, U.S.A.

Research Interest
  


Raman Spectroscopy




Raman Scattering


            Raman scattering is a powerful probe for characterization and to unravel basic science behind many novel phenomena in physics. It is a contactless method
with high spatial 
resolution (~ 1 micron). It is very  sensitive to external and internal perturbations like strain, electric fields, temperature and pressure. We study
systems under low temperature
( up to 4 K ) and at high pressure ( up to 30 GPa). We have studied many interesting systems like carbon and boron nitride
nanotubes, pyrochlores, topological insulators,
iron pnictide superconductors using Raman spectroscopy. Most of these studies were carried out in collaboration
with Prof. A.K. Sood’s group.

High Pressure Physics

         High pressure research involves studying the effects of extremely high pressures on materials. To attain pressures of approximately 300,000 to 400,000 atmospheres, 
a device known as the diamond anvil cell is used.
A small amount of sample material (typically ~ 100 micron in size) is placed between the tips of two gem quality diamonds
which are mounted in the diamond anvil cell. The diamonds are then pushed together. Due to the small areas (typically ~ 10
-7 m2), only nominal forces are needed to achieve
high pressures. We use a number techniques ( Raman scattering and x-ray diffraction ) to study the materials under pressure.





Facilities


1)     
Single monochromator based Raman Spectrometer:

 

We have built a micro Raman spectrometer in the lab based on a single monochromator.  It uses a single grating 0.5 m monochromator (Jobin Yvon iHR550 model)
to disperse the light and a notch filter to reject the laser line. The sample is excited with 532 nm laser line using an air cooled diode pumped solid state laser (DPSS).
A 50 X objective is used to focus the laser beam (spot size ~ 3 µm) and also to collect the scattered light. The scattered light from the sample is detected with a back
illuminated CCD. It is a very simple system but the through put is very high so that experiments under ultra high pressure can be carried out.





2)     
 Diamond anvil cells for high pressure Raman measurements:

 

We have a Mao-Bell type diamond anvil cell which contains two gem quality diamonds facing each other with a flat face of 600 micron. Samples will be placed
 and squeezed in between the diamonds and  pressures up to 30 GPa (3,00,000 atm) can be achieved.

Ruby