Article

Scanning tunneling microscopy observations of single-crystal Fe∕ MgO∕ Fe magnetic tunnel junctions

Department of Materials Engineering Science, Graduate School of Engineering Science, Core Research for Evolutional Science and Technology (CREST), Osaka University, 560-8531, Toyonaka, Osaka, Japan
Journal of Applied Physics (Impact Factor: 2.19). 04/2006; 99(8). DOI: 10.1063/1.2170069

ABSTRACT Scanning tunneling microscopy observations of a single-crystal Fe001 / MgO001 /Fe001 magnetic tunnel junction which shows a large tunnel magnetoresistance effect were performed. Step-and-terrace structures of an epitaxial MgO barrier layer, which are very similar to surfaces of a bottom Fe underlayer, were observed. This indicates that the MgO terraces were grown flatly on each terrace of the Fe electrode. It is supposed that these atomically flat terraces enable a coherent tunneling of electrons through magnetic tunnel junctions. © 2006 American Institute of Physics.

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