Magnon-assisted inelastic excitation spectra of a ferromagnetic tunnel junction

Y. Ando, J. Murai, H. Kubota, T. Miyazaki

Research output: Contribution to journalConference articlepeer-review

42 Citations (Scopus)

Abstract

Inelastic-electron-tunneling spectroscopy (IETS) has been applied to investigate the spin dependent tunneling process for a Ta(50 Å)/Fe20Ni80(60 Å)/IrMn(300 Å)/Co(60 Å)/Al(13 Å)-oxide/ Co(40 Å)/Fe20Ni80(200 Å) spin-valve-type tunnel junction. IET spectra for both parallel and antiparallel magnetization configurations of ferromagnetic electrodes showed a strong peak at 12 mV. The subtraction spectrum defined by the difference between the spectra of both the configurations was calculated. Spin-independent inelastic excitation processes are not affected by an external magnetic field, and thus, the subtraction spectrum indicates the inelastic modes induced only by the magnetic origin. It showed a strong peak at 12 and 20 mV for the positively and negatively biased direction of the bottom electrode, respectively. The tendency of the tunneling magnetoresistance ratio to decrease with bias voltage agreed with the shape of the subtraction spectrum. By assuming the surface magnon excitation, we obtained the distributions of the correlation length and the Curie temperature for both ferromagnetic electrode surfaces faced on the insulator.

Original languageEnglish
Pages (from-to)5209-5211
Number of pages3
JournalJournal of Applied Physics
Volume87
Issue number9 II
DOIs
Publication statusPublished - 2000 May
Event44th Annual Conference on Magnetism and Magnetic Materials - San Jose, CA, United States
Duration: 1999 Nov 151999 Nov 18

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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