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Institut f. Physik FG Nanostrukturierte Materialien
Martin-Luther-Universitat Halle-Wittenberg
Von-Danckelmann-Platz 3, D-06120 Halle, Germany
Tel.: +49 345 55 25321
Fax.: +49 345 55 27034
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J. Liu, P. Bach, E. Girgis, C. Ruester, C. Gould, G. Schmidt, L. Molenkamp Magnetoresistive devices based on epitaxial NiMnSb layers with built-in anisotropy INTERMAG 2006 - IEEE International Magnetics Conference 4261812 (2015-02-24 09:14:21), 379
We have fabricated tunnelling magnetoresistance (TMR) devices based on an epitaxial layer of NiMnSb grown almost lattice matched on (In,Ga)As, an aluminium oxide barrier and a CoFe counter electrode. The devices show a TMR of 14% at low temperature and 8% at room temperature. The as-grown NiMnSb layer exhibits a strong uniaxial anisotropy, which leads either to a clean spin valve signal with layers that switch separately and in single steps when the field is applied along the easy axis of the material, or to a resistance which varies linearly with B-field when the field is applied along the hard axis of the Heusler layer. Giant magnetoresistance (GMR) devices have also been fabricated, using sputter deposition of a Cu interlayer onto the NiMnSb and subsequent deposition of CoFe. Devices fabricated this way exhibit a magnetoresistance of 3.5% at room temperature. Depending on the thickness of the interlayer no coupling or a strong antiferromagnetic coupling can be observed. Link |
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