Fluorine-doped iron oxide nanomaterials by plasma enhanced-CVD: an XPS study

In this work, we report on a single-step Plasma Enhanced-Chemical Vapor Deposition (PE-CVD) process for the synthesis of iron(III) oxide based nanomaterials. A key feature of the adopted fabrication strategy is the use of a fluorinated Fe(II) ?-diketonate diamine precursor, enabling a homogeneous Fe2O3 in-situ doping and resulting in a tunable fluorine content as a function of deposition temperature. To this regard, a detailed study of the nature and amount of fluorine-containing moieties is strongly required in view of the process optimization. Specifically, X-ray Photoelectron Spectroscopy (XPS) analysis represents a strategic tool to evaluate the system chemical composition, and also to evidence the presence of fluorine in different chemical states, such as lattice fluorine (F-Fe) and traces of precursor residuals (CFx) at the system surface. In the present study, spectroscopic data are presented and discussed in detail for a representative Fe2O3 specimen.