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Sivaraj Ramaseshan

Sivaraj Ramaseshan, Indian physicist (Calcutta 10 December 1923 – Bangalore 29 December 2003)
 
Relative of Nobel prize winners being nephew of physicist C.V. Raman and cousin of astrophysicist Subramanyan Chandrasekhar
 
Performed studies on optics, magnetooptics, solid state physics and crystallography
 
Authored 178 papers
 
With K. Venkatesanm & N.V. Mani proposed a novel method for determining the phase angles without ambiguity in non-centro-symmetric crystals that formed the basis of the Multiple Anomalous Dispersion (MAD) in 1957
 
First to solve the structure of centrosymmetric crystals
 
Established the multiwave anomalous x-ray scattering method for the determination of phases of reflection
 
Proposed the use of anomalous neutron scattering for resolving very large structures
 
Showed theoretically that anomalous scattering of neutrons can yield information on the polarization vectors of lattice waves and described detailed experimental procedures for their determination in centro- and non-centrosymmetric crystals
 
Recognized the possibility of using anomalous scattering of x-rays coupled with multiple wavelength method to obtain the structure of amorphous or liquid binary systems  
 
Showed that the resistivity anomaly in liquid caesium is due to anomalous electron scattering during the Fermi 6s-5d electron collapse
 
Formulated and verified laws governing cleavages in crystals
 
Discovered icosahedral coordination in ionic solids
 
Developed new techniques for low-temperature crystallography
 
Predicted pressure-induced optical activity
 
Predicted and verified the existence of pressure-induced liquid crystallinity
 
Determined the critical point in solid-solid isostructural transformation of SmS

Developed instrumentation for high and low temperature x-ray crystallography
 
 

LINKS

http://www.ias.ac.in/academy/ramasesan_pop.html  

nal-ir.nal.res.in/4884/1/valluri.pdf