Temperature dependent, non-ohmic magnetoresistance in doped perovskite manganate trilayer junctions
- IBM T. J. Watson Research Center, Yorktown Heights, New York 10598 (United States)
We report spin-dependent perpendicular transport in the magnetic trilayer junction structure La{sub 0.67}Sr{sub 0.33}MnO{sub 3}/SrTiO{sub 3}/La{sub 0.67}Sr{sub 0.33}MnO{sub 3}. Large (factor of 5) changes of magnetoresistance induced by a field of {approximately}200 Oe are observed at 4.2 K. Junction I{endash}V characteristics at low temperatures are consistent with a metal{endash}insulator{endash}metal tunneling process with a large spin-polarization factor of 0.81 for the conduction electrons. Above 100 K, a variable range-hopping conduction shunts out the magnetoresistance contribution. This second conduction channel comes from the impurity states within SrTiO{sub 3} barrier and therefore is not an intrinsic limit to the magnetoresistance performance of the device at high temperatures. {copyright} {ital 1997 American Institute of Physics.}
- OSTI ID:
- 526491
- Journal Information:
- Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 13 Vol. 70; ISSN APPLAB; ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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