The depth-resolved x-ray magnetic circular dichroism (XMCD) technique was applied to observe the interfacial and inner magnetic moments in CoFe/MgO and Co 2MnSi(CMS)/MgO. The magnetic moments of the real interface region (two monolayers from the interface) and the inner layers were separately analyzed using the XMCD sum rules. The observed interfacial moments of Co at the CMS/MgO interface show a remarkable reduction from that in the inner layers compared with the CoFe/MgO structure, suggesting small exchange stiffness in the CMS at the MgO interface. The weak exchange stiffness of Co is a possible reason for the large temperature dependence of tunnel magnetoresistance in CMS-based magnetic tunnel junctions.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2012 May 18|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics