Nanostructured Magnetism for Super-Dense Memories Ivan K. Schuller

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Nanostructured Magnetism for Super-Dense
MemoriesIvan K. Schuller UCSDPresent
Towards 1 Tb/sq. inch

• Objective
• Stabilize magnetization of nanostructures for
  Tb/sq.inch recording applications
• Overcome the superparamagnetic limit.
• Study the stabilization effect of exchange bias
  using
• SQUID
• MOKE
• FMR, neutron scattering (collaboration)
• Implement integrated fabrication and testing of
  the nanometer-size nanodots.

• Summary
• Papers 10 published, 3 submitted
• Talks 17 Invited 16 Contributed
• Patents 2 (pending)
• Education 2 Undergraduate 2 Graduate
  students 5 Postdocs 2 Visitors
• Collaborators 38
• Jobs Academia 3, grad. school 1
• Equipment Preparation (Porous Al2O3)
  Sensitive Low T Kerr

• Potential Benefits to Air Force
• Miniaturized Memory Elements
• Terabit per sq. inch (1012/in2) recording density
• Orders of magnitude improvement in stability of
  the recorded information.
• Potential Radiation Hardness

• Results
• Fabrication of ordered magnetic nanodots arrays
  over 1cm2 area using self-assembly.
• Stabilization of nanodot magnetization.
• Size-dependent modes of magnetic reversal in
  nanostructures.

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Nanostructured Magnetism for Super-Dense Memories
Ivan K. Schuller UCSDMagnetic Nanodots
Fabrication and Characterization
increased
K. Liu, J. Nogues, C. Leighton, H. Masuda,K.
Nishio, I. V. Roshchin, and Ivan K. Schuller,
Appl. Phys. Lett. 81, 4434 (2002).

• AccomplishedIncreased squareness and enhanced
  coercivityfor Exchange Biased Dots

Developed Fabrication of regular arrays of
magnetic nanodots over 1 cm2
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Nanostructured Magnetism for Super-Dense Memories
Ivan K. Schuller UCSDVortex State
Polarized Neutron Reflectometry
Single Domain
Vortex
Simulation
Demonstrated and Studied Different Magnetic
reversal Vortex State Single Domain

• Vortex Core determined

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Nanostructured Magnetism for Super-Dense Memories
Ivan K. Schuller UCSDFuture Beyond
Terabits/Sq. Inch

• Research
• Year 1
• - Decrease size of dots
• - Improve regularity
• - Stamping
• - Changing shapes
• - Technology Transfer (Porous Alumina)
• Year 2
• - Other lithography methods (diblock copolymer)
• - New room temperature antiferromagnest (Fe
  oxides, IrMn,...)
• - Radiation Hardness of Antiferromagnets
• - Technology Transfer (New Antiferromagnets)
• Year 3
• - Use of vortex state for recording
• - Vertical recording
• - Perpendicular anisotropy ferromagnets,
  antiferromagnets
• - Radiation Hardness of Exchange Biased Memory
  Elements
• - Technology Transfer (Perpendicular Recording)

Recording
parallel
perpendicular

• Education and Extension
• Education of Undergraduates, Graduate and
  Postdoctoral Fellows
• Basic Researchers to Air Force Labs
• Applied Researchers to Industrial Labs
• Website on Novel High Density Recording
• Movie for the General Public "When Things Get
  Small"