Scattering of carbon dioxide molecules from Pd(111) surfaces

• Published in: Surface science Vol. 323; no. 3; pp. 207 - 218
• Main Authors: Schlathölter, T., Heiland, W.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 20.01.1995; Amsterdam Elsevier Science; New York, NY
• Subjects: Applied sciences; Atomic, molecular, and ion beam impact and interactions with surfaces; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electron and ion emission by liquids and solids; impact phenomena; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Exact sciences and technology; Impact phenomena (including electron spectra and sputtering); Metals. Metallurgy; Physics; Surface and interface electron states; Surface states, band structure, electron density of states; Work functions; Charge exchange; Scattering; Carbon dioxide; Time-of-flight method; Palladium; Experimental study; Ion beams; Energy dependence; Adsorption; Surface reactions; Transition elements; Molecular beams; Potassium
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/0039-6028(94)00668-7

Carbon dioxide positive ions and neutral molecules are subject to different charge exchange processes when scattered off clean or potassium-covered Pd(111) surfaces under grazing incidence. The time-of-flight method is a suitable tool to investigate these processes with respect to dissociation and different charge state formation. Using projectiles with primary energies of 250 up to 1500 eV we found not only a strong energy dependence but also a sizeable influence of initial charge state and work function on the molecular survival. In particular, potassium increases the dissociation probability whereas switching from CO + 2 to CO 2 projectiles leads to the opposite effect. Furthermore, in the case of CO 2 on Pd(111) +K we found evidence for the formation of negative molecular ions, which are known to play an important role in dissociative chemisorption.