Coherent tunneling and giant tunneling magnetoresistance in Co2 FeAl/MgO/CoFe magnetic tunneling junctions

Physical Review B - Condensed Matter and Materials Physics

Volumn 81, Issue 14, 2010, Pages

  Wang, Wenhong ^a,b   Liu, Enke ^b   Kodzuka, Masaya ^a,c   Sukegawa, Hiroaki ^a   Wojcik, Marec ^d   Jedryka, Eva ^d   Wu, G H ^b   Inomata, Koichiro ^a   Mitani, Seiji ^a   Hono, Kazuhiro ^a,c  

^a NATIONAL INSTITUTE FOR MATERIALS SCIENCE   (Japan)

^b INSTITUTE OF PHYSICS   (China)

^c UNIVERSITY OF TSUKUBA   (Japan)

^d INSTITUTE OF PHYSICS   (Poland)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 77955205788     PISSN: 10980121     EISSN: 1550235X     Source Type: Journal    
DOI: 10.1103/PhysRevB.81.140402     Document Type: Article

References (30)

1. J. S. Moodera, L. R. Kinder, T. M. Wong, and R. Meservey, Phys. Rev. Lett. 74, 3273 (1995). 10.1103/PhysRevLett.74.3273
2. T. Miyazaki and N. Tezuka, J. Magn. Magn. Mater. 139, L231 (1995). 10.1016/0304-8853(94)01648-8
3. R. A. de Groot, F. M. Mueller, P. G. van Engen, and K. H. J. Buschow, Phys. Rev. Lett. 50, 2024 (1983). 10.1103/PhysRevLett.50.2024
4. S. Ishida, J. Phys. Soc. Jpn. 64, 2152 (1995). 10.1143/JPSJ.64.2152
5. I. Galanakis, P. H. Dederichs, and N. Papanikolaou, Phys. Rev. B 66, 174429 (2002). 10.1103/PhysRevB.66.174429
6. S. Picozzi, A. Continenza, and A. J. Freeman, Phys. Rev. B 66, 094421 (2002). 10.1103/PhysRevB.66.094421
7. S. Yuasa, Nature Mater. 3, 868 (2004). 10.1038/nmat1257
8. S. Yuasa, Appl. Phys. Lett. 89, 042505 (2006). 10.1063/1.2236268
9. S. S. P. Parkin, Nature Mater. 3, 862 (2004). 10.1038/nmat1256
10. D. Djayaprawira, Appl. Phys. Lett. 86, 092502 (2005). 10.1063/1.1871344
11. W. H. Butler, X. G. Zhang, T. C. Schulthess, and J. M. MacLaren, Phys. Rev. B 63, 054416 (2001). 10.1103/PhysRevB.63.054416
12. J. Mathon and A. Umerski, Phys. Rev. B 63, 220403 (R) (2001). 10.1103/PhysRevB.63.220403
13. K. Inomata, Jpn. J. Appl. Phys. 42, L419 (2003). 10.1143/JJAP.42.L419
14. Y. Sakuraba, Appl. Phys. Lett. 88, 192508 (2006). 10.1063/1.2202724
15. T. Ishikawa, Appl. Phys. Lett. 89, 192505 (2006). 10.1063/1.2378397
16. N. Tezuka, Appl. Phys. Lett. 89, 252508 (2006). 10.1063/1.2420793
17. T. Marukame, Appl. Phys. Lett. 90, 012508 (2007). 10.1063/1.2428412
18. W. H. Wang, Appl. Phys. Lett. 92, 221912 (2008). 10.1063/1.2940595
19. S. Tsunegi, Appl. Phys. Lett. 93, 112506 (2008). 10.1063/1.2987516
20. H. Sukegawa, W. Wang, R. Shan, T. Nakatani, K. Inomata, and K. Hono, Phys. Rev. B 79, 184418 (2009). 10.1103/PhysRevB.79.184418
21. R. Shan, H. Sukegawa, W. H. Wang, M. Kodzuka, T. Furubayashi, T. Ohkubo, S. Mitani, K. Inomata, and K. Hono, Phys. Rev. Lett. 102, 246601 (2009). 10.1103/PhysRevLett.102.246601
22. S. Mizukami, J. Appl. Phys. 105, 07D306 (2009). 10.1063/1.3067607
23. W. H. Wang, Appl. Phys. Lett. 95, 182502 (2009). 10.1063/1.3258069
24. K. Inomata, M. Wojcik, E. Jedryka, N. Ikeda, and N. Tezuka, Phys. Rev. B 77, 214425 (2008). 10.1103/PhysRevB.77.214425
25. We have measured the spin polarization (P) of the disordered B 2 CFA film by point contact Andreev reflection method and found the value of P = 0.54 at 4 K. According to Jullière's model, the TMR ratios for MTJs can be determined by the tunneling spin polarizations at E F, P 1, and P 2 of the two electrodes, i.e., TMR = 2 P 1 P 2 / (1 - P 1 P 2). Within this model, the upper limit of the TMR values expected from MTJs using a CFA electrode will be 74%, if the other electrode is CoFe with P = 0.50.
26. R. Matsumoto, Appl. Phys. Lett. 90, 252506 (2007). 10.1063/1.2750398
27. Y. Miura, K. Nagao, and M. Shirai, Phys. Rev. B 69, 144413 (2004). 10.1103/PhysRevB.69.144413
28. D. Bagayoko, A. Ziegler, and J. Callaway, Phys. Rev. B 27, 7046 (1983). 10.1103/PhysRevB.27.7046
29. J. S. Moodera, J. Nowak, and R. J. M. van de Veerdonk, Phys. Rev. Lett. 80, 2941 (1998). 10.1103/PhysRevLett.80.2941
30. See supplementary material at http://link.aps.org/supplemental/10.1103/ PhysRevB.81.140402 for a figure showing the oscillation of TMR in the CFA/MgO/CFA MTJs.