Inelastic electron tunneling spectrum from surface magnon and magnetic impurity scatterings in magnetic tunnel junctions

Journal Article · Fri Jan 01 04:00:00 EST 2010 · Physical Review B

DOI:https://doi.org/10.1103/PhysRevB.82.134436· OSTI ID:992093

Wei, H. X. ^[1]; Qin, Q. H. ^[1]; Ma, Q. L. ^[1]; Zhang, Xiaoguang ^[2]; Han, Prof. X. F. ^[1]

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1. Institute of Physics, Chinese Academy of Science
2. ORNL

Analytic expressions for contributions to the inelastic electron tunneling spectrum (IETS) from surface magnon scattering and magnetic impurity scattering are obtained. It is shown that surface magnon scattering alone does not lead to peaks in the IETS. The peaks at small bias often observed in the IETS of magnetic junctions are due to magnetic impurity scattering, in agreement with the traditional model for zero bias anomaly. These impurity resonance peaks can sometimes split due to the impurities' magnetic coupling to the electrodes. Measurements of AlO and MgO barrier junctions yield excellent agreement to the theory. The experiment further shows that the magnetic impurities in MgO barriers are strongly coupled to the electrodes but those in AlO barriers are not magnetically coupled to the electrodes.

• Research Organization: Oak Ridge National Laboratory (ORNL); Center for Nanophase Materials Sciences
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 992093
• Journal Information: Physical Review B, Journal Name: Physical Review B Journal Issue: 13 Vol. 82; ISSN 1098-0121; ISSN 1550-235X
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ELECTRODES
ELECTRONS
IMPURITIES
MAGNONS
RESONANCE
SCATTERING
TUNNELING