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Focused ion beam structured Co/Pt multilayers for field-coupled magnetic computing

Published online by Cambridge University Press:  21 March 2011

Markus Becherer ,
Gyorgy Csaba ,
Rainer Emling ,
Lili Ji ,
Wolfgang Porod ,
Paolo Lugli  and
Doris Schmitt-Landsiedel
Markus Becherer
Affiliation:
Institute for Technical Electronics, Technical University Munich, Theresienstrasse 90, Munich, 80333, Germany
Gyorgy Csaba
Affiliation:
Institute for Nanoelectronics, Technical University Munich, Theresienstrasse 90, Munich, 80333, Germany
Rainer Emling
Affiliation:
Institute for Technical Electronics, Technical University Munich, Theresienstrasse 90, Munich, 80333, Germany
Lili Ji
Affiliation:
Department of Electrical Engineering, Center for Nanoscience and Technology, University of Notre Dame, 203 Cushing Hall, Notre Dame, IN, 46556
Wolfgang Porod
Affiliation:
Department of Electrical Engineering, Center for Nanoscience and Technology, University of Notre Dame, 203 Cushing Hall, Notre Dame, IN, 46556
Paolo Lugli
Affiliation:
Institute for Nanoelectronics, Technical University Munich, Theresienstrasse 90, Munich, 80333, Germany
Doris Schmitt-Landsiedel
Affiliation:
Institute for Technical Electronics, Technical University Munich, Theresienstrasse 90, Munich, 80333, Germany
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Abstract

We fabricated and patterned magnetic dots from Co/Pt multilayers and optimized the structure for strong inter-dot magnetic coupling. SQUID measurements show strong perpendicular anisotropy with characteristic sheared hysteresis loops. The films are fabricated by RF-magnetron sputtering and then patterned with a 50 keV Ga+ focused ion beam (FIB) tool. This keeps surface roughness low and feature sizes in the hundred-nanometer-regime are achievable by a single processing step. Simulations with the well established SRIM (Stopping and Range of Ions in Matter) code give an estimation of the beam diameter and help to estimate the FIB patterning potential. In order to show antiferromagnetic ordering large 48×48 dot arrays of (200×200) nm2 single domain dots were fabricated. The samples were demagnetized and scanned by magnetic force microscopy (MFM) in the remanent state. The demagnetized checkerboard patterns show no frustration over hundreds of dots. The fabricated single domain magnets are prospective building blocks for field-coupled magnetic logic devices.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 998: Symposium J – Nanoscale Magnetics and Device Applications , 2007 , 998-J06-07
Copyright
Copyright © Materials Research Society 2007

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References

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