Magnetic microstructure of candidates for epitaxial dual Heusler magnetic tunnel junctions

Abstract

Heusler alloys are considered as interesting ferromagnetic electrode materials for magnetic tunnel junctions, because of their high spin polarization. We therefore investigated the micromagnetic properties in a prototypical thin film system comprising two different Heusler phases Co2MnSi (CMS) and Co2FeSi (CFS) separated by a MgO barrier. The magnetic microstructure was investigated by x-ray photoemission microscopy (XPEEM). We find a strong influence of the Heusler phase formation process on the magnetic domain patterns. SiO2/V/CMS/MgO/CFS and SiO2/V/CFS/MgO/CMS trilayer structures exhibit a strikingly different magnetic behavior, which is due to pinhole coupling through the MgO barrier and a strong thickness dependence of the magnetic ordering in Co2MnSi.

Two-magnon scattering by domain wall induced coupling in Co2MnGe/Au/Py layer systems

“…It is known that structurally disordered magnetic Heusler films exhibit micro‐magnetic ripples, which can be attributed to a strong variation of the local magnetocrystalline anisotropy within the sample . In Fig.…”