DEPARTMENT OF PHYSICS
UNIVERISTY OF CALIFORNIA SAN DIEGO
9500 GILMAN DRIVE
LA JOLLA CA 92093-0354
Website: Sinha Group
239, Special Topics: X-Ray and Neutron Scattering
2A, Introductory Mechanics
research is concerned with studying the structure and dynamics
of Condensed Matter using the techniques of X-Ray and Neutron
Scattering. Neutrons and X-Rays from Synchrotron Radiation
sources are powerful tools to study matter with at length scales
ranging from the nanoscopic to the mesoscopic. We have ongoing
programs in both hard and soft Condensed Matter.
in the hard Condensed Matter area includes novel magnetic and superconducting
materials, in particular magnetic films and multilayers, Giant Magnetoresistance
(GMR) devices and Exchange Biased systems, artificially nanostructured
magnetic materials such as magnetic dot and hole arrays, the so-called
Colossal Magnetoresistance (CMR) compounds, and High-Temperature
Superconductors. We study properties such as their magnetic and
chemical structure, the existence of polarons and other types of
combined lattice/electronic effects, such as charge density waves
or orbital ordering. We also study phonons in these materials, and
in the case of the thin film systems, how the structural and
magnetic disorder at interfaces (e.g. roughness) affects their magnetic
and transport properties.
soft condensed Matter area, our research is concerned with
molecular liquid films, polymer films and interfaces in polymeric
systems, which are very relevant at the molecular level, to properties
such as adhesion, lubrication and coatings. We use X-Rays and
Neutrons to study the fluctuations on the surfaces of polymer
films to determine how interactions with the substrate affect
these surfaces, and in particular how such fluctuations freeze
out as the glassy state is approached. There is indirect
evidence that the properties of liquids in confinement differ
remarkably from those of the bulk liquid. We study how the structure
and dynamics of liquids and polymers when they are confined between
surfaces a few molecular diameters apart are changed from those
of the same liquids in the bulk.
joining the Physics Faculty at UCSD recently, I am in the process
of setting up a laboratory at UCSD for preparing and characterizing
samples which will include an x-ray machine,light-scattering and
other equipment. The advanced characterization of these samples
will however be done at Neutron Scattering Facilities, such as
that at Los Alamos National Laboratory in New Mexico, or Synchrotron
X-Ray Scattering Facilities such as the Advanced light Source
(ALS) at Berkeley or the Advanced Photon Source (APS) at Argonne
National Laboratory near Chicago, Illinois. Visits to these facilities
to do experiments typically last 1 week to 10 days. Often experiments
are done collaboratively with other groups (at UCSD and elsewhere)
on samples of interest prepared by them but which can be
uniquely studied using our techniques.
taught several introductory graduate level courses in Neutron
and X-Ray scattering. To download my course notes, you can look
and click on National Neutron and
Publications ( Soft Condensed Matter)
S.K.Sinha, K.G.Huang and B.M.Ocko, X-ray Scattering study of Capillary
Wave Fluctuations at a Liquid Surface, Phys. Rev. Lett. 66, 628
O.H.Seeck, J.-P. Schlomka, W.Press, J.Wang, S.K. Sinha, Z.Li,
M.Rafailovich, and J.
Evidence for Capillary Waves on Dewetted Polymer Film Surfaces:
A Combined X-ray and Atomic Force Microscopy Study, Phys. Rev.
Lett. 81, 2731 (1998)
M. Tolan, T. Hohr, D. Kharas, S. Qu, J. Sokolov, M.H. Rafailovich,
H. Lorenz, J.P. Kotthaus, J. Wang, S. K. Sinha and A. Gibaud, Polymer
Thin films on Patterned Si Surfaces, Macromolecules 31, 1915, (1998).
M. Tolan, O.H. Seeck , S.K. Sinha, O. Bahr, M.H. Rafailovich,
and J. Sokolov, "Surfaces of Strongly Confined Polymer Thin
Films Studied by X-ray Scattering," Phys. Rev. Lett., 83,
Y.Pu, M.H.Rafailovich, J.Sokolov, O.H.Secck, S.K. Sinha, M.Tolan
and R. Kolb,
Surfaces of Free-standing Polystyrene Thin Films, Macromolecules
34, 5620, (2001)
A.K.Sood, P.V.Satyam,Y.P.Feng, X.Z.Wu,Z.H.Cai,W.B.Yun and S.K.Sinha,X-ray
Fluorescence Correlation Spectroscopy: A method for Studying Particle
Dynamics in Condensed Matter, Phys. Rev. Lett. 80, 1110 (1998).
Sinha, Small Angle Scattering from Porous Materials, Book Chapter
in Physics of Porous Media, P.Z. Wong, Ed., Academic Press, 1999).
A.Ruhm, L.B.Lurio, J.K.Basu,J.Lal, D.Lumma, S.G.J.Mochrie, and
S.K.Sinha, Surface Dynamics of Polymer Films (submitted)
H.J.Kim, D.R.Lee, D.Shu, I.Kaendler, J.K.Basu and S.K.Sinha, Observation
of Thickness Quantization in Liquid Films Confined to Molecular
Publications (Hard Condensed Matter)
Osgood, S.K. Sinha, J.W. Freeland, Y.U. Idzerda, and S.D. Bader,
"X-ray Scattering from Magnetically and Structurally Rough
Surfaces," J. Magn. Magnetic Materials, 198-199,
Nelson, G. Srajer, J.C. Lang, C.T. Venkataraman, S.K. Sinha, H.
Hashizume, N. Ishimatsu, and N. Hosoito, "Charge-Magnetic
Roughness Correlations in an Fe/Gd Multilayer," Phys. Rev.B,
60, 12 234, (1999).
The Impact of Synchrotron Radiation on Nanoscience, Appl.Surf.
Sci. 182, 176 (2001)
Stepanov and S.K. Sinha, "X-ray Resonant Reflection from
Magnetic Multilayers: Recursion Matrix Algorithm," Phys.
Rev. B , 61, 15302, (2000).
S. Rosenkranz, R. Osborn, S.K. Sinha, J.W. Lynn, J. Mesot, O.
H. Seeck, A.J. Fedro, and J.F. Mitchell, "Charge Melting
and Polaron Collapse in La1.2Sr1.8Mn2O7,"
Phys. Rev. Let 83, 4393 (1999).
S. Rosenkranz, D.N. Argyriou, L. Vasilliu-Doloc, J.W. Lynn, S.K.
Sinha, J.F. Mitchell, K.E. Gray, and S.D. Bader, "Neutron
Scattering Investigation of Magnetic Bilayer Correlations in La1.2Sn1.8Mn2O7,"
Phys. Rev. Lett. 81, 3964, (1998).
S.K.Sinha, D.Haskell, J.C.Lang, G.Srajer, D.R.Haeffner, B.W.Veal,
and H.A.Mook, X-Ray Diffraction Study of Charge Density Waves
and Oxygen Ordering in YBa2Cu3O6+x (submitted)
Sinha and R. Pynn, "Diffuse X-ray and Neutron Reflection
from Surfaces and Interfaces," in Local Structure
from Diffraction, S.J.L. Billinge and M.F. Thorpe, Eds., (Plenum
Press, New York, 1998.
E.B.Sirota, S.Garoff and H.B.Stanley, X-ray and Neutron Scattering
Rev. B 38, 2297 (1988)
"Theory of Inelastic X-ray Scattering from Condensed Matter,
J.Phys. Cond. Matter 13, 7511 (2001)
Sinha, "New Developments in the Application of Synchrotron
Radiation to Material Science," Jpn. J. Appl. Phys., 38,
St. Austin (Secy.)
Researchers in my group (past 5 years) and their current affiliations:
Ryeol Lee (Argonne National Laboratory)
Seeck (KFA, Julich, Germany)
Zhong Wu (IBM Almaden)
Zhao (Lucent Technologies)
Wang (Argonne National Laboratory)
Feng (Lucent Technologies)
Islam (Argonne National Laboratory)
Satyam (Inst. Physics, Bhubaneshwar, India).