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arXiv · 0708.2092

Spin Valve Effect in Self-exchange Biased Ferromagnetic Metal/Semiconductor Bilayers

M. Zhu·M. J. Wilson·B. L. Sheu·P. Mitra·P. Schiffer·N. Samarth
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Abstract

We report magnetization and magetoresistance measurements in hybrid ferromagnetic metal/semiconductor heterostructures comprised of MnAs/(Ga,Mn)As bilayers. Our measurements show that the (metallic) MnAs and (semiconducting) (Ga,Mn)As layers are exchange coupled, re- sulting in an exchange biasing of the magnetically softer (Ga,Mn)As layer that weakens with layer thickness. Magnetoresistance measurements in the current-perpendicular-to-the-plane geometry show a spin valve effect in these self-exchange biased bilayers. Similar measurements in MnAs/p- GaAs/(Ga,Mn)As trilayers show that the exchange coupling diminishes with spatial separation between the layers.

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M. Zhu, M. J. Wilson, B. L. Sheu, P. Mitra, P. Schiffer, N. Samarth. 2007-08-15. Spin Valve Effect in Self-exchange Biased Ferromagnetic Metal/Semiconductor Bilayers. https://doi.org/10.1063/1.2806966

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