Sulphur overlayers on the Au(110) surface: LEED and TPD study

SURFACE SCIENCE

卷:601

Article

Krasnikov, Sergey A. ; Hughes, Greg ; Cafolla, Attilio A.

关键词: Au(110);    sulphur overlayers;    LEED;    TPD;    auger electron spectroscopy;   

DOI  :  10.1016/j.susc.2007.06.064

来源: Elsevier

【 摘 要 】

The adsorption and desorption of sulphur on the clean reconstructed Au(110)-(1 x 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(110) system during sulphur desorption at different temperatures. Two structures of the stable ordered sulphur overlayer on the Au(1 10) surface, p(4 x 2) and c(4 x 4), were found after annealing the S/Au(1 10) system at 630 K and 463 K, respectively. The corresponding sulphur coverage for these overlayers was estimated by AES signal intensity analysis of the An 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 x 2) sulphur structure by annealing the c(4 x 4) surface. In the case of the p(4 x 2) S overlayer on the Au(110)-(1 x 2) surface it is proposed that the sulphur is attached to missing row sites only. The c(4 x 4) S overlayer arises via desorption of S-2 molecules that are formed on the surface due to mobility of sulphur atoms after a prolonged anneal. (c) 2007 Elsevier B.V. All rights reserved.

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