Sulphur overlayers on the Au(110) surface: LEED and TPD study
Krasnikov, Sergey A., Hughes, GregORCID: 0000-0003-1310-8961 and Cafolla, Attilio A.
(2007)
Sulphur overlayers on the Au(110) surface: LEED and TPD study.
Surface Science, 601
(16).
pp. 3506-3511.
ISSN 0039-6028
The adsorption and desorption of sulphur on the clean reconstructed Au(1 1 0)–(1 × 2) surface has been studied by low energy electron diffraction, Auger electron spectroscopy and temperature programmed desorption. The results obtained show a complex behaviour of the S/Au(1 1 0) system during sulphur desorption at different temperatures. Two structures of the stable ordered sulphur overlayer on the Au(1 1 0) surface, p(4 × 2) and c(4 × 4), were found after annealing the S/Au(1 1 0) system at 630 K and 463 K, respectively. The corresponding sulphur coverage for these overlayers was estimated by AES signal intensity analysis of the Au NOO and S LMM Auger lines to be equal to 0.13 ML and 0.2 ML, respectively. Both sulphur structures appear after removing an excess of sulphur, which mainly desorbs at 358 K as determined from TPD spectra. Furthermore, it was not possible to produce the lower coverage p(4 × 2) sulphur structure by annealing the c(4 × 4) surface. In the case of the p(4 × 2) S overlayer on the Au(1 1 0)–(1 × 2) surface it is proposed that the sulphur is attached to “missing row” sites only. The c(4 × 4) S overlayer arises via desorption of S2 molecules that are formed on the surface due to mobility of sulphur atoms after a prolonged anneal.
Item Type:
Article (Published)
Refereed:
Yes
Uncontrolled Keywords:
Au(110); sulphur overlayers; LEED; TPD; Auger electron spectroscopy;