MICROSTRUCTURES OF CO CR BILAYER FILMS EPITAXIALLY GROWN ON MGO SINGLE-CRYSTAL SUBSTRATES/

Microstructures of Co/Cr bilayer films epitaxially grown on MgO (100) and (110) single-crystal substrates have been studied by high-resoluti on transmission electron microscopy. The bicrystalline Co layer formed on the MgO (100) substrate contains a number of (0001) stacking fault s. The single-crystal Co layer formed on the MgO (110) substrate consi sts of slightly misoriented subgrains, grown on (211)-oriented Cr doma ins. Dislocations and lattice strain are observed at the Cr/MgO (110) interface. The misorientations and the defects are thought to be intro duced to accommodate the large lattice mismatch of about -16% in the M gO [$($) over bar$$ 110] direction at the Cr/MgO (110) interface.