ESR and TPD Investigations of the Adsorption of Di-tert-butyl Nitroxide on Au(111) and NiO(111). Evidence for Long-Range Interactions
✍ Scribed by U.J. Katter; T. Risse; H. Schlienz; M. Beckendorf; T. Klüner; H. Hamann; H.-J. Freund
- Publisher
- Elsevier Science
- Year
- 1997
- Tongue
- English
- Weight
- 167 KB
- Volume
- 126
- Category
- Article
- ISSN
- 1090-7807
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✦ Synopsis
Electron spin resonance and temperature-programmed desorpmolecules can be affected. In this paper we corroborate this tion spectra of thin layers of DTBN (di-tert-butyl nitroxide) adresult for the system di-tert-butyl nitroxide (DTBN)/ sorbed on Au(111) and NiO(111)/Au(111) surfaces have been Au(111) using a different experimental setup. measured. The temperature-programmed desorption data show a If, instead of a metal, an oxide is used as substrate, ESR weak chemisorption of the DTBN molecules in the monolayer on signals of molecular monolayers may well be observed. Exboth surfaces. On Au(111) as well as on NiO(111)/Au(111), the amples are DTBN, NO 2 , and self-assembled fatty acid films ESR signal from monolayer coverages is totally suppressed. This on a thin epitaxial Al 2 O 3 layer (2-4). It appears, however, suppression continues into the multilayer regime on both subthat a magnetic oxide as substrate may cause complications: strates. Disturbances of the substrate/adsorbate interface have a For the system DTBN adsorbed on an epitaxially grown strong influence on the range of the signal suppression. Possible NiO(111) film, we report here on a strong suppression effect reasons for this behavior are discussed. ᭧ 1997 Academic Press
which is surprising in view of the poor conductance of NiO. We invoke magnetic coupling to explain the phenomenon.