Organization of methoxysilane molecules on iron

The deposition of methoxysilane molecules from a methanolic solution on an iron substrate has been investigated uding X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). XPS has confirmed that, under the conditions employed, a thin uniform silane layer of thickness 1.7 nm is deposited. This layer displaces adventitious carbonaceous material covering the substrate. Depth profiling using ToF-SIMS has demonstrated the very complex nature of the silane deposit and has shown that the silane layer is far from ordered. Strong evidence exists to support the presence of an Fe-O-Si primary bond, profiles indicate that this layer is present as a discrete layer under an overlayer containing other silane fragments.