Hostname: page-component-7c8c6479df-8mjnm Total loading time: 0 Render date: 2024-03-28T20:59:39.049Z Has data issue: false hasContentIssue false

How Many Fe layers Cause TMR?

Published online by Cambridge University Press:  01 February 2011

Christian Heiliger
Affiliation:
c.heiliger@physik.uni-halle.de, Martin Luther University, Department of Physics, Von-Seckendorff-Platz 1, D-06120 Halle, Halle, N/A, N/A, Germany
Peter Zahn
Affiliation:
peter.zahn@physik.uni-halle.de, Martin Luther University, Department of Physics, D-06099 Halle, N/A, N/A, Germany
Ingrid Mertig
Affiliation:
ingrid.mertig@physik.uni-halle.de, Martin Luther University, Department of Physics, D-06099 Halle, N/A, N/A, Germany
Get access

Abstract

The influence of the structural properties of the leads of planar tunnel junctions on the tunneling current is investigated by means of ab initio electronic structure calculations. In particular, a NM/Fe/MgO/Fe/NM tunnel junction with non-magnetic (NM) leads and finite Fe spacer layers between the leads and the MgO barrier is discussed. The conductance is calculated as a function of the number of Fe layers. The results show that even one iron layer next to the barrier is sufficient to obtain a high spin polarization and a high TMR ratio. This finding implies that similar results can be expected for tunnel junctions with nonmagnetic and even amorphous leads, if states of Δ1 symmetry are provided.

Type
Research Article
Copyright
Copyright © Materials Research Society 2006

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1 Yuasa, S., Nagahama, T., Fukushima, A., Suzuki, Y., and Ando, K., Nature Materials 3, 868 (2004).Google Scholar
2 Parkin, S.S.P., Kaiser, C., Panchula, A., Rice, P.M., Hughes, B., Samant, M., and Yang, S.H., Nature Materials 3 862 (2004).Google Scholar
3 Djayaprawira, D.D., Tsunekawa, K., Nagai, M., Maehara, H., Yamagata, S., Watanabe, N., Yuasa, S., Suzuki, Y., and Ando, K., Appl. Phys. Lett. 86 092502 (2005).Google Scholar
4 Meyerheim, H.L., Popescu, R., Jedrecy, N., Vedpathak, M., Sauvage-Simkin, M., Pinchaux, R., Heinrich, B., and Kirschner, J., Phys. Rev. B 65 144433 (2002).Google Scholar
5 Tusche, C., Meyerheim, H. L., Jedrecy, N., Renaud, G., Ernst, A., Henk, J., Bruno, P., and Kirschner, J., Phys. Rev. Lett. 95 176101 (2005).Google Scholar
6 Tiusan, C., Faure-Vincent, J., Bellouard, C., Hehn, M., Jouguelet, E., and Schuhl, A., Phys. Rev. Lett. 93 106602 (2004).Google Scholar
7 Zhang, C., Zhang, X.G., Krstiæ, P.S., Cheng, H.p., Butler, W.H., and MacLaren, J.M., Phys. Rev. B 69 134406 (2004).Google Scholar
8 Heiliger, C., Zahn, P., Yavorsky, B. Yu., and Mertig, I., Phys. Rev. B 72 180406 (2005).Google Scholar
9 Landauer, R., Z. Physik B 68 217 (1987).Google Scholar
10 Baranger, H.U. and Stone, A.D., Phys. Rev. B 40 8169 (1989).Google Scholar
11 Mavropoulos, Ph., Papanikolaou, N., and Dederichs, P.H., Phys. Rev. B 69 125104 (2004).Google Scholar