NIRT: Building Nanospintronic and Nanomagnetic Structures:

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NIRT Building Nanospintronic and Nanomagnetic
Structures Growth, Manipulation, and
Characterization at the Atomic Scale
DMR-0304314. Arthur R. Smith, Saw-Wai Hla, Nancy
Sandler, and Sergio Ulloa, Ohio University,
Athens, OH-45701.
Nanoscale magnetism is explored by spin-polarized
Scanning Tunneling Microscopy (SP-STM) on the
Mn3N2 (010) surface using a combination of
experiment and first-principles theory.
spin contrast
In the left column below, spin- polarized STM
data obtained at different positive energies is
com- pared with theory performed by NIRT
collaborators A. Dick and J. Neugebauer at the
Max-Planck- Institut für Eisenforschung GmbH.
Energy-dependence of the contrast was found to
agree perfectly between experiment and theory, as
seen at upper right in a plot of spin
contrast versus energy. The excellent
agreement shows that spin- polarized STM is THE
ideal method for obtaining spin-contrast on
surfaces with nanometer-scale resolution, and
also confirms the use of the Tersoff-Hammann
approach for spin-polarized STM. At right is a
plot of the spin-density on the atoms obtained in
a section view through the surface. Bright means
spin density up dark means spin density down.
tip
sample surface
experiment
theory
Above plot shows optimal agreement between
spin-pol- arized contrast from theory and
experiment. This interna- tional collaboration
was enabled through the NIRT grant support.
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NIRT Building Nanospintronic and Nanomagnetic
Structures Growth, Manipulation, and
Characterization at the Atomic Scale
DMR-0304314. Arthur R. Smith, Saw-Wai Hla, Nancy
Sandler, and Sergio Ulloa, Ohio University,
Athens, OH-45701.
L.G.G.V. Dias da Silva et al. Phys. Rev. Lett.
97, 096603 (2006)
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NIRT Building Nanospintronic and Nanomagnetic
Structures Growth, Manipulation, and
Characterization at the Atomic Scale
DMR-0304314. Arthur R. Smith, Saw-Wai Hla, Nancy
Sandler, and Sergio Ulloa, Ohio University,
Athens, OH-45701.
Professors Arthur R. Smith (PI-left) and Sergio
Ulloa (co-PI-right) prepare to make a team
presentation about nanoscience to Southeastern
Ohio High School science students within the
Frontiers of Science lecture series. Ulloas
portion focused on general ideas of nanoscale
science and tech- nology, while Smith focused on
the atomic scale, including atoms imaged using
STM.
The team nano presentation took place at Athens
High School in Athens, OH, home of Ohio
University. Attendance and stu- dent
participation were both high, with 200 students
in the high school auditorium observing. The
picture at right shows the high school students
looking on, as Smith shows a movie (courtesy of
NIRT co-PI Saw-Wai Hla) of the atom-by-atom
con- struction of the worlds smallest OU using
silver atoms.