The atomic ordering of Co2MnSi (CMS) full-Heusler film and the interface structure of CMS/MgO/CMS magnetic tunnel junctions (MTJs) were investigated by high-angle annular dark-field scanning transmission electron microscopy (HAADF STEM). We observed the atomic ordering of L21 and B2 structures of CMS from the atomic number (Z) contrast STEM images. We also confirmed that the interface structure consists of the layer next to the Co layer terminating in the CMS to MgO layer from the layer periodicity along the  direction, however, site-disorder exists between two atomic layers at the termination of CMS, including locally L21-ordered MnSi terminated structure.
ASJC Scopus subject areas
- Physics and Astronomy(all)