SurfaceScience21 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 103: Poster Session VIII: Surface reactions II
O 103.6: Poster
Donnerstag, 4. März 2021, 13:30–15:30, P
Production of oxidized C60 on carbonaceous substrates — •Georgios Pantazidis1, Andrew Cassidy1, John David Thrower1, and Liv Hornekaer1,2 — 1Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C, Denmark — 2Interdisciplinary Nanoscience Center (iNANO), Aarhus University, 8000 Aarhus C, Denmark
In this poster, data characterising the production of C60 oxides on a graphitic surface, in conditions that mimic interstellar environments, are presented. Experiments were performed in an ultra-high vacuum chamber with a base pressure of 5×10−10 mbar. Thin films of C60 were prepared by in situ dosing on a highly oriented pyrolytic graphite (HOPG) substrate. Oxygen atoms were produced via thermal cracking through a hot capillary which is heated to ca. 1850 K. Surface science techniques like temperature programmed desorption (TPD), scanning tunnelling microscopy (STM) and X-ray photoelectron spectroscopy (XPS), were used for the experimental investigation. Findings suggest that C60Ox are formed, with oxygen atoms chemisorbing on the C60 molecule, forming ether and epoxide functional groups. Upon thermal annealing, the C60Ox fragment into CyOz and species like CO and CO2, which lead to the formation of thermally stable remnants on top of the HOPG, creating a porous carbonaceous substrate (m-HOPG). When the C60Ox were produced on the m-HOPG substrate, the reactivity towards oxygen atoms was higher and, apart from ether and epoxide groups, carbonyl groups were also present, suggesting a more complex chemistry, aided by the porous substrate.