TITLE

Inverse magnetoresistance in chromium-dioxide-based magnetic tunnel junctions

AUTHOR(S)
Gupta, A.; Li, X. W.; Xiao, Gang
PUB. DATE
March 2001
SOURCE
Applied Physics Letters;3/26/2001, Vol. 78 Issue 13, p1894
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Magnetic tunnel junctions have been fabricated using half-metallic chromium-dioxide (CrO[sub 2]) epitaxial film with a Co counterelectrode. The native insulating layer formed on the surface of CrO[sub 2] after air exposure is used as the tunneling barrier. These junctions exhibit nonlinear current-voltage characteristics, and the changes in junction resistance with applied field correspond to the coercivities of the two magnetic layers. The maximum observed magnetoresistance (MR) is about 8% at 4.2 K and has a negative sign, i.e., the resistance of the junction with parallel alignment of the electrodes is higher than with antiparallel alignment. This is opposite of what is normally observed with transition-metal electrodes and an Al[sub 2]O[sub 3] barrier. Possible reasons for the inverse MR are discussed based on previous results on manganite/Co junctions. © 2001 American Institute of Physics.
ACCESSION #
4711168

 

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