Chemical vapor deposition (CVD) is a well-known technique, capable of depositing uniform thin films on topographically complex structures and large areas. Film deposition by CVD uses volatile precursor molecules containing the atoms needed for the film material. The chemical process from precursor to thin film always involves surface reactions and often also gas phase reactions. CVD processes of elemental electropositive metals, such as Al, Fe, and Ti, typically requires high deposition temperatures to overcome the thermodynamical barrier associated with reducing them from a positive valance in the precursor molecule to a zero valent state in the film. An alternative to high thermal energy is to supply the energy partly by a plasma discharge, utilizing free electrons, ions, photons, radicals and excited species to enable alternative reactions paths. We have recently presented a CVD process where we used the metallocenes ferrocene, FeCp2, cobaltocene, CoCp2, and nickelocene, NiCp2, as iron, cobalt, and nickel precursors, respectively, and utilized the free electrons in an argon (Ar) plasma as reducing agents to deposit iron, cobalt, and nickel films without external heating. We refer to the process as electron CVD (e-CVD). However, the e-CVD of iron, cobalt, and nickel films were heavily contaminated by carbon, most likely emanating from the cyclopentadienyl (C5H5, Cp) ligands. While these metals are known to form carbides and have an affinity for carbon, preventing carbon containing species from the metallocene decomposition to interact with the film surface is likely the key to reduce the carbon contamination when using metallocenes as the precursor. We envision that the carbon contamination originates from incomplete FeCp2 decomposition on the film surface, redeposition of by-products and/or from plasma volume decomposition. This is supported by our recent QCM findings where we saw a mass increase after the plasma pulse. For the e-CVD process, it is a vital step to understand the plasma chemistry of FeCp2 in order to in the future connect the plasma chemistry to the film growth. For plasma CVD processes using FeCp2 as a precursor and especially those also utilizing electrons, this paper can therefore give insight into the plasma chemistry and plasma decomposition paths for FeCp2.