Resonant tunneling magnetoresistance in antiferromagnetically coupled Fe-based structures with multilayered Si/Ge spacers

R. R. Gareev, M. Weides, R. Schreiber, U. Poppe
2006 Applied Physics Letters  
We report on the experimental evidence of the tunneling magnetoresistance ͑TMR͒ effect near 3% and its inversion in strongly antiferromagnetically coupled Fe͑001͒/͓͑Si͑0.2 nm͒/ Ge͑0.2 nm͔͒ * 5͒ / Fe epitaxial structures with diffused interfaces. We explain the inversion of TMR with biasing voltage by resonant tunneling across impurity states with weak spin split ⌬E ϳ 10 meV and spin-dependent filtering in the spacer layer. The resonant tunneling is manifested in spin-dependent resonances close
more » ... t resonances close to zero biasing voltages related to antiferromagnetic coupling across impurity states.
doi:10.1063/1.2198812 fatcat:sexfc5cxvjgs7jis3kmh5pf3jq