RATIONALE
Low‐energy secondary electrons are formed when energetic particles interact with matter. High‐energy electrons or ions are used to form metallic structures from adsorbed organometallic molecules like W(CO)6 on surfaces. We investigated low‐energy electron attachment to W(CO)6 in the gas phase to elucidate possible reactions during surface modification.
METHODS
Two crossed electron/molecular beam setups were utilised: (i) a high‐resolution electron monochromator combined with a quadrupole mass spectrometer which was used for the measurement of relative cross sections as a function of the electron energy, and (ii) a double focusing mass spectrometer used for measurements of metastable decays of anions.
RESULTS
The study was performed in the electron energy range between ~0 and 14 eV. W(CO)6 efficiently decomposed upon attachment of a low‐energy electron and no stable W(CO)6– anion was observed on mass spectrometric time scales. The transient negative ion formed lost instead sequentially CO ligands. The fragment anions W(CO)5–, W(CO)4–, W(CO)3–, and W(CO)2– were observed. However, no W– was detectable.
CONCLUSIONS
Dissociative electron attachment (DEA) to W(CO)6 led to strong dissociation but a complete loss of all CO ligands was not observed in DEA. Deposit contaminations might be a direct result of DEA reactions close to the irradiation spot in beam deposition techniques. Copyright © 2012 John Wiley & Sons, Ltd.