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    COLLOQUIUM OF THE LABORATORY FOR COMPUTER DESIGN OF MATERIALS
        Institute for Computational Sciences and Informatics
	                      CSI 898-Sec 001  
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                MAGNETIC PROPERTIES OF NANOMATERIALS

                         Robert D. Shull

                    Magnetic Materials Group
           National Institute of Standards and Technology
                     Gaithersburg, Maryland


Nanocrystalline materials can possess bulk properties quite different
from those commonly associated with conventional large-grained
materials.  Nanocomposites, a subset of nanocrystalline materials, in
addition have been found to possess magnetic properties which are
similar to, but different from, the properties of the individual
constituents.  When at least one of the constituents possesses a
permanent magnetic moment, the magnetization statics and dynamics
of the nanocomposite can be very different from that of the magnetic
species in bulk form.  New magnetic phenomena, unusual property
combinations, and both enhanced and diminished magnetic property
values are just some of the changes observed in magnetic
nanocomposites from conventional magnetic materials.  In addition,
the sensitivity of these magnetic properties to composition and
morphology allows the class of magnetic nanocomposites to serve as
a laboratory for the atomic engineering of materials with specific
magnetic characteristics.  Here, a description will be presented of
some of the exciting magnetic applications envisioned for these
materials along with methods used in our laboratory for making
them.  Particular attention will be devoted to the use of magnetic
nanocomposites for cooling, an application pioneered at NIST.  The
origin of the "Giant Magnetocaloric Effect" in magnetic
nanocomposites will be reviewed together with data showing the
effect in a variety of materials.  This effect forms the basis for
magnetic refrigerators, historically an efficient low temperature and
high magnetic field process.  Magnetic nanocomposites offer a very
attractive new method for potentially circumventing these historical
limitations.

	               Monday , October 27 1997
                                 4:30 pm
                        Room 206, Science & Tech. I

Refreshments will be served.
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(http://www.csi.gmu.edu/lcdm/seminar/schedule.html)