ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
Temperature and coverage dependent studies of p-aminobenzoic acid on a Cu(110) single crystal surface show a novel sequence of periodic structures linked to successive removal of hydrogen from the adsorbed species, as shown by LEED, STM, HREELS, and TPD. At room temperature, flat-lying molecules with a primitive unit cell of (3×4) periodicity with glide plane along the 〈001〉 direction are observed. Annealing this surface to 464 K causes partial desorption of H2 and a variation of the intensity in HREELS of various bands and formation of a (5 −22 4) periodicity. STM images suggest the formation of dimers, as a result of the dehydrogenation. On annealing to higher temperatures (510 K), further dehydrogenation forms (6 −51 2) structure. Finally, at 540 K, a (4 −31 2) periodicity is revealed in which all species correspond to dehydrogenated dimers. Through this sequence, all species retain a flat-lying orientation on the surface. © 2002 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.1426379
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