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arXiv · 1404.3523

Impurity induced enhancement of perpendicular magnetic anisotropy in Fe/MgO tunnel junctions

A. Hallal·B. Dieny·M. Chshiev
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Abstract

Using first-principles calculations, we investigated the impact of chromium (Cr) and vanadium (V) impurities on the magnetic anisotropy and spin polarization in Fe/MgO magnetic tunnel junctions. It is demonstrated using layer resolved anisotropy calculation technique, that while the impurity near the interface has a drastic effect in decreasing the perpendicular magnetic anisotropy (PMA), its position within the bulk allows maintaining high surface PMA. Moreover, the effective magnetic anisotropy has a strong tendency to go from in-plane to out-of-plane character as a function of Cr and V concentration favoring out-of-plane magnetization direction for ~1.5 nm thick Fe layers at impurity concentrations above 20 %. At the same time, spin polarization is not affected and even enhanced in most situations favoring an increase of tunnel magnetoresistance (TMR) values.

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A. Hallal, B. Dieny, M. Chshiev. 2014-04-14. Impurity induced enhancement of perpendicular magnetic anisotropy in Fe/MgO tunnel junctions. https://doi.org/10.1103/physrevb.90.064422

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