MgO/Cu2O Superlattices: Growth of Epitaxial Two-Dimensional Nanostructures

摘要: Alternated stacking of dissimilar layers can produce novel superlattice materials with multiple functionalities. The majority such work reported in literature on epitaxial superlattices has been alternating the same space group (SG) and crystal structure (CS), whereas CS but different SG have not studied as much. We grown two well-known oxide materials, viz. cuprite (Cu2O, CS = cubic SG = Pn $$ \bar{3} $$ m) magnesium (MgO, CS = cubic, SG = Fm m). An MgO buffer layer near 650°C at film–substrate interface was found to be essential achieving reasonable long-range atomic order. Grazing-angle x-ray diffraction, reflectivity, electron diffraction analyses well transmission microscopy were used investigate abruptness, smoothness, general crystallinity individual layers. Interdiffusion between Cu2O interfacial regions places a limit 250°C growth temperature for fabrication reasonably sharp interfaces.