Bismuth postdosing thermal desorption mass spectroscopy: Performance and limitations

Autor:	Charles T. Campbell, Melanie E. Domagala, Markus B. Hugenschmidt
Rok vydání:	1992
Předmět:	Thermal desorption spectroscopy Analytical chemistry Thermal desorption chemistry.chemical_element Surfaces and Interfaces Condensed Matter Physics Mass spectrometry Surfaces Coatings and Films Bismuth chemistry.chemical_compound Adsorption chemistry Desorption Monolayer Methyl iodide
Zdroj:	Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films. 10:2556-2559
ISSN:	1520-8559 0734-2101
Popis:	The applications of bismuth postdosing thermal desorption mass spectroscopy (BPTDS) to the analysis of molecular and nonmolecular adsorbates on Pt(111) is briefly reviewed. In this method, about one monolayer of bismuth adatoms is vapor deposited onto a surface at 100 K containing some previously prepared adlayer. The surface is then heated while monitoring for gas phase species mass spectrometrically. All molecular adsorbates studied to date, which includes methyl iodide and hydrocarbons alone or in mixtures, are found to desorb intact and nearly quantitatively in BPTDS. Nonmolecular adsorbates such as Ha, CH3,a, and c‐C6H9,a are found to give high yields of the singly hydrogenated gas phase product at ∼200 K in BPTDS when coadsorbed with Ha. Coadsorption with Da can be used to distinguish such reactions from simple desorption. The thermodynamic driving forces which cause these results are discussed, and it is argued that BPTDS should be generally applicable to many molecular and some nonmolecular adsorb...
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::145f42d7ce05ec91f93eb1d085337727 https://doi.org/10.1116/1.578098 Zobrazit plný text záznamu