| Autor: |
Davis, A. H., MacLaren, J. M. |
| Předmět: |
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| Zdroj: |
Journal of Applied Physics; 5/15/2002 Part 1, 2 & 3, Vol. 91 Issue 10, p7023, 3p, 5 Graphs |
| Abstrakt: |
Theoretical treatment of spin dependent tunneling is used to reveal how asymmetry in the bias dependence of the tunneling magnetoresistance ratio (TMR) arises. The tunneling states in the two ferromagnetic electrodes are taken from the results of ab initio electronic structure calculations. We show that differences between the electronic structure of the electrodes at the two interfaces and/or an asymmetric barrier can cause an asymmetric TMR. Most dramatically, we treat the case of nominally identical electrodes but with different crystalline structures, specifically a Co junction where one electrode is hexagonal-close-packed Co and the other is face-centered-cubic (fcc) Co. In this case we correlate a feature common to both the experiment and the calculations with a specific feature found in the calculated band structure of fcc Co, suggesting the band structure is at the root of the asymmetry. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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