Resonant Spin-Dependent Tunneling in Spin-Valve Junctions in the Presence of Paramagnetic Impurities

Details Resonant Spin-Dependent Tunneling in Spin-Valve Junctions in the Presence of Paramagnetic Impurities Resonant Spin-Dependent Tunneling in Spin-Valve Junctions in the Presence of Paramagnetic Impurities

2000-04-12

arxiv.org/abs/cond-mat/0004198v2

Phys. Rev. B, 63, 064429 (2001)

Physics

Condensed Matter

Materials Science

20 pages, 6 figures, submitted to Phys.Rev.B

Scientific paper

10.1103/PhysRevB.63.064429

The tunnel magnetoresistance (TMR) of F/O/F magnetic junctions, (F's are ferromagnetic layers and O is an oxide spacer) in the presence of magnetic impurities within the barrier, is investigated. We assume that magnetic couplings exist both between the spin of impurity and the bulk magnetization of the neighboring magnetic electrode, and between the spin of impurity and the spin of tunneling electron. Consequently, the resonance levels of the system formed by a tunneling electron and a paramagnetic impurity with spin S=1, are a sextet. As a result the resonant tunneling depends on the direction of the tunneling electron spin. At low temperatures and zero bias voltage the TMR of the considered system may be larger than TMR of the same structure without paramagnetic impurities. It is calculated that an increase in temperature leads to a decrease in the TMR amplitude due to excitation of spin-flip processes resulting in mixing of spin up and down channels. It is also shown that asymmetry in the location of the impurities within the barrier can lead to asymmetry in $I(V)$ characteristics of impurity assisted current and two mechanisms responsible for the origin of this effect are established. The first one is due to the excitation of spin-flip processes at low voltages and the second one arises from the shift of resonant levels inside the insulator layer under high applied voltages.

Affiliated with

Also associated with

No associations

Rating

Resonant Spin-Dependent Tunneling in Spin-Valve Junctions in the Presence of Paramagnetic Impurities does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Resonant Spin-Dependent Tunneling in Spin-Valve Junctions in the Presence of Paramagnetic Impurities, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Resonant Spin-Dependent Tunneling in Spin-Valve Junctions in the Presence of Paramagnetic Impurities will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-201786