Study of the Surface Morphology of Titanium Oxide Films Epitaxially Grown on MgO(100) by Non-contact AFM

摘要

The surface morphology of very thin titanium oxide films grown on MgO(100) was studied by use of non-contact atomic force microscopy (AFM). When Ti was deposited, in an O_2 atmosphere of 2.6 X 10~(-6) Pa, on MgO(100) maintained at 600 deg C, rectangular structures of spinel nano-crystals were observed. Solid state reactions simultaneously occur during film deposition. When the surface was heated at 900 t in an O_2 atmosphere of 2.6 X 10~(-6) Pa, a long range stripe structure was observed. The structure is related to the modulated structure characteristics of the Mg_2TiO_4(100) surface. A titanium oxide-MgO interfacial reaction proceeded by prolonged annealing. The stripe structure disappeared and atomically flat terraces with a step height of 0.2 nm were observed.