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Author Bapna, Mukund ♦ Piotrowski, Stephan K. ♦ Oberdick, Samuel D. ♦ Majetich, Sara A. ♦ Li, Mingen ♦ Chien, C. -L.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS ♦ ATOMIC FORCE MICROSCOPY ♦ LAYERS ♦ MAGNESIUM OXIDES ♦ MAGNETIC FIELDS ♦ MAGNETORESISTANCE ♦ NUCLEATION ♦ SIMULATION ♦ TUNNEL EFFECT
Abstract Perpendicular CoFeB/MgO/CoFeB magnetic tunnel junctions with diameters under 100 nm are investigated by conductive atomic force microscopy. Minor loops of the tunnel magnetoresistance as a function of applied magnetic field reveal the hysteresis of the soft layer and an offset due to the magnetostatic field of the hard layer. Within the hysteretic region, telegraph noise is observed in the tunnel current. Simulations show that in this range, the net magnetic field in the soft layer is spatially inhomogeneous, and that antiparallel to parallel switching tends to start near the edge, while parallel to antiparallel reversal favors nucleation in the interior of the soft layer. As the diameter of the tunnel junction is decreased, the average magnitude of the magnetostatic field increases, but the spatial inhomogeneity across the soft layer is reduced.
ISSN 00036951
Educational Use Research
Learning Resource Type Article
Publisher Date 2016-01-11
Publisher Place United States
Journal Applied Physics Letters
Volume Number 108
Issue Number 2


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