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.
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.
Authors: Michal Lacko; Peter Papp; Iwona B Szymańska; Edward Szłyk; Štefan Matejčík Journal: Beilstein J Nanotechnol Date: 2018-02-01 Impact factor: 3.649
Authors: Ragesh Kumar T P; Paul Weirich; Lukas Hrachowina; Marc Hanefeld; Ragnar Bjornsson; Helgi Rafn Hrodmarsson; Sven Barth; D Howard Fairbrother; Michael Huth; Oddur Ingólfsson Journal: Beilstein J Nanotechnol Date: 2018-02-14 Impact factor: 3.649
Authors: Pablo de Vera; Martina Azzolini; Gennady Sushko; Isabel Abril; Rafael Garcia-Molina; Maurizio Dapor; Ilia A Solov'yov; Andrey V Solov'yov Journal: Sci Rep Date: 2020-11-30 Impact factor: 4.379