Journal of Magnetics

  • 제14권1호
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  • Pages.11-14
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  • 2009
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  • 1226-1750(pISSN)
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  • 2233-6656(eISSN)
한국자기학회 (The Korean Magnetics Society)
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Comparison of Tunneling Characteristics in the MTJs of CoFeB/MgO/CoFeB with Lower and Higher Tunneling Magnetoresistance

  • Choi, G.M. (Center for Spintronics Research, KIST) ;
  • Shin, K.H. (Center for Spintronics Research, KIST) ;
  • Seo, S.A. (Semiconductor Device Lab, Samsung Advanced Institute of Tecnology) ;
  • Lim, W.C. (Department of Materials Science & Engineering, KAIST) ;
  • Lee, T.D. (Department of Materials Science & Engineering, KAIST)
  • 발행 : 2009.03.31
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초록

We investigated the I-V curves and differential tunneling conductance of two, CoFeB/MgO/CoFeB-based, magnetic tunnel junctions (MTJs): one with a low tunneling magnetoresistance (TMR; 22%) and the other with a high TMR (352%). This huge TMR difference was achieved by different MgO sputter conditions rather than by different annealing or deposition temperature. In addition to the TMR difference, the junction resistances were much higher in the low-TMR MTJ than in the high-TMR MTJ. The low-TMR MTJ showed a clear parabolic behavior in the dI/dV-V curve. This high resistance and parabolic behavior were well explained by the Simmons' simple barrier model. However, the tunneling properties of the high-TMR MTJ could not be explained by this model. The characteristic tunneling properties of the high-TMR MTJ were a relatively low junction resistance, a linear relation in the I-V curve, and conduction dips in the differential tunneling conductance. We explained these features by applying the coherent tunneling model.

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참고문헌

  1. J. G. Simmons, J. Appl. Phys. 34, 1793 (1963). https://doi.org/10.1063/1.1702682
  2. W. H. Butler, X.-G. Zhang, T. C. Schulthess, and J. M. Maclaren, Phys. Rev. B 63, 054416 (2001). https://doi.org/10.1103/PhysRevB.63.054416
  3. J. Mathon and A. Umerski, Phys. Rev. B 63, 220403(R) (2001) https://doi.org/10.1103/PhysRevB.63.220403
  4. R. Matsumoto, S. Nishioka, M. Mizuguchi, M. Shiraishi,H. Maehara, K. Tsunekawa, D. D. Djayaprawira, N.Watanabe, Y. Otani, T. Nagahama, A. Fukushima, H. ubota, S. Yuasa, and Y. Suzuki, Solid State Comm. 143, 574 (2007). https://doi.org/10.1016/j.ssc.2007.07.001
  5. G. X. Miao, Y. J. Park, J. S. Moodera, M. Seibt, G. Eilers, and M. Munzenberg, Phys. Rev. Lett. 100, 246803 (2008). https://doi.org/10.1103/PhysRevLett.100.246803
  6. G. M. Choi, K. H. Shin, S. A. Seo, S. O. Kim, W. C. Lim, and T. D. Lee, Proceedings for publication in IEEE Transactions on Magnetics as a contributed paper in Asian magnetic Conference, 10 December, 2008, Busan, South Korea, Abstract BA-05.
  7. J. Y. Bae, W. C. Lim, H. J. Kim, D. J. Kim, K. W. Kim, T. W. Kim, and T. D. Lee, J. Magnetics 11, 25 (2006). https://doi.org/10.4283/JMAG.2006.11.1.025
  8. J. C. Read, P. G. Mather, and R. A. Buhrman, Appl. Phys. Lett. 90 132503 (2007). https://doi.org/10.1063/1.2717091
  9. A. Gibson, R. Haydock, and J. P. LaFemina, Phys. Rev. B 50, 2582 (1994). https://doi.org/10.1103/PhysRevB.50.2582
  10. T. Nagahama and J. S. Moodera, J. Magnetics 11, 170 (2006) https://doi.org/10.4283/JMAG.2006.11.4.170
  11. G.-X. Miao, K. B. Chetry, A. Gupta, W. H. Butler, K. Tsunekawa, D. Djayaprawira, and G. Xiao, J. Appl. Phys.99, 08T305 (2006). https://doi.org/10.1063/1.2162047
  12. R. Matsumoto, Y. Hamada, M. Mizuguchi, M. Shiraishi, H. Maehara, K. Tsunekawa, D. D. Djayaprawira, N. Watanabe, Y. Kurosaki, T. Nagahama, A. Fukushima, H. Kubota, S. Yuasa, and Y. Suzuki, Solid State Comm. 136, 611 (2005). https://doi.org/10.1016/j.ssc.2005.08.032
  13. Y. Jang, C. Nam, K.-S. Lee, B. K. Cho, Y. J. Cho, K.-S. Kim, and K. W. Kim, Appl. Phys. Lett. 91, 102104 (2007) https://doi.org/10.1063/1.2779915
  14. S. Yuasa, A. Fukushima, H. Kubota, Y. Suzuki, and K. Ando, Appl. Phys. Lett. 89, 042505 (2006). https://doi.org/10.1063/1.2236268
  15. X.-G. Zhang and W. H. Butler, Phys. Rev. B 70, 172407(2004). https://doi.org/10.1103/PhysRevB.70.172407