Regensburg 2007 – scientific programme
Parts | Days | Selection | Search | Downloads | Help
MA: Fachverband Magnetismus
MA 23: Micro- and Nanostructured Magnetic Materials I
MA 23.10: Talk
Thursday, March 29, 2007, 12:30–12:45, H22
Ordering phenomena in focused ion beam structured Co/Pt multilayers. — Markus Becherer1, •Gyorgy Csaba2, Rainer Emling1, Lili Ji3, Wolfgang Porod3, Paolo Lugli2, and Doris Schmitt-Landsiedel1 — 1Lehrstuhl für Technische Elektronik, TU München — 2Lehrstuhl für Nanoelektronik, TU München — 3Center for Nanoscience and Technology, University of Notre Dame, USA
Computation by field-coupled nanomagnetic dots is a novel computational paradigm on the nanoscale. In the so-called ’magnetic quantum cellular automata’, information is represented by the orientation of nanomagnetic dots and the signal is propagated by their magnetic interactions.
We investigate the feasibility of ion-beam patterned Co/Pt multilayers as a possible realization of magnetic field-coupling. We sputtered 40 bilayers of Co/Pt in an rf-magnetron system and employed SQUID measurements to characterize perpendicular anisotropy. The films are patterned with a 50 keV Ga+ focused ion beam (FIB) into ’checkerboards’ of (200x200)nm2 dot-size. They are demagnetized and in a remanent state mapped by a magnetic force microscope (MFM).
The arrays of 48x48-dots show antiferromagnetic ordering that extends to hundreds of dots without frustration. This indicates strong interdot coupling and small switching field variations from dot to dot, showing that these multilayers are indeed a promising implementation possibility for field-coupling. We will present the first experimental results about strongly coupled dots and will outline the design of logic gates based on them.