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arXiv · 1209.4368

Revealing the spin and symmetry properties of the buried Co2MnSi/MgO interface by low energy spin-resolved photoemission

Roman Fetzer·Marcel Lösch·Yusuke Ohdaira·Hiroshi Naganuma·Mikihiko Oogane·Yasuo Ando·Tomoyuki Taira·Tetsuya Uemura·Masafumi Yamamoto·Martin Aeschlimann·Mirko Cinchetti
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Abstract

We present a novel approach to study the spin and symmetry electronic properties of buried interfaces using low-energy spin-resolved photoemission spectroscopy. We show that this method is sensitive to interfaces buried below more than 20ML (~4nm) MgO, providing a powerful tool for the non-destructive characterization of spintronics interfaces. As a demonstration, we apply this technique to characterize the Co2MnSi/MgO interface, a fundamental building block of state-of-the-art magnetic tunnel junctions based on Heusler compounds. We find that a surface state with {\Delta}1 symmetry and minority spin character dominating the electronic structure of the bare Co2MnSi(100) surface is quenched at the Co2MnSi(100)/MgO interface. As a result, the interface spin-dependent electronic structure resembles the theoretically expected Co2MnSi bulk band structure, with majority spin electronic states of both {\Delta}1 and {\Delta}5 symmetry. Furthermore we find an additional thermally-induced contribution in the minority channel, mirroring the {\Delta}1/{\Delta}5 asymmetry of the majority channel.

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Roman Fetzer, Marcel Lösch, Yusuke Ohdaira, Hiroshi Naganuma, Mikihiko Oogane, Yasuo Ando, Tomoyuki Taira, Tetsuya Uemura, Masafumi Yamamoto, Martin Aeschlimann, Mirko Cinchetti. 2012-09-19. Revealing the spin and symmetry properties of the buried Co2MnSi/MgO interface by low energy spin-resolved photoemission. https://arxiv.org/abs/1209.4368

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