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D2 Physics www.spinelectronics.deD2 Physics www.spinelectronics.de
Simulation of GMR in granular C@Conanoparticles in agarose
P.Hainke, D.Kappe, A.Hütten
D2 Physics www.spinelectronics.de
The Giant Magnetoresistance (GMR) effect
• Electrical resistance dependentson switching on and off an outermagnetic field
• Spin dependent
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Spin channel currents
• Spin channel currents act like in aparallel circuit
• Therefore they can be described byvariegating the conductivity of theparticles
R↑= High resistance R↓= Low resitance
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GMR in granular gels
• Many different sizes of the magneticparticles
• No high ordered structure
But:• Particle chains in antiferromagnetic
order to the next neighbour
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Use of the Java API
Why Java?
• Automation of generatingmany particles
• Fast and flexible variationof space and size distribution
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Flexible geometry
Particles are variable inspace and size distribution
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Magnetic field via electric conductivity
Parametric sweep for the 3 conductivitiesdepending on the magnetic field
a) High and b) low conductivity in a magnetic fieldin contrast to c) the alternating conductivity withoutfield
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Results for a single chain
Can short chains show the effects of thein fact much longer chains?
Yes!Because the GMR in converges very fast
So no need of simulation of many elements
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Other geometries
Triangle 3 chains
Triangle 6 chains
Rhombus 4 chains
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Comparison
All geometries show similar curves
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Conclusion
• Flexible and fast generation of many elements, variable in size andspace distribution
• For simulation just short chains needed, because ΔR converges fast
• All geometries show similar curves
Simulation of variations in particle size and disordered spacedistribution
Thank you for your interest!
