Studies of heteroepitaxial growth of Fe/MgO/Fe3O4 multilayer on MgO (100) substrates for fabrication of magnetic tunnel junctions

The growth and interface roughness correlation in heteroepitaxial Fe/MgO/Fe3O4 junctions were investigated. The evidence of the correlation of layer interface roughness was found for the thickness of the MgO layer thinner than 0.95 nm but not for the MgO layer thicker than 2 nm. The change in the interface roughness correlation for the junction structure is thought to result from a change in the growth mode of the MgO layer. Our results suggest that the correlation of interface roughness may take a role on the thickness dependence of MgO insulating layer on the electrical properties of tunneling junctions.