Cu interactions with α-Al2O3(0001): effects of surface hydroxyl groups versus dehydroxylation by Ar-ion sputtering

Autor:	D. R. Jennison, K Shepherd, C. Niu, J. Tong, D Martini, Alexander Bogicevic, Jeffry A. Kelber
Rok vydání:	2000
Předmět:	Annealing (metallurgy) Analytical chemistry Surfaces and Interfaces Sputter deposition Condensed Matter Physics Surfaces Coatings and Films Ion chemistry.chemical_compound Adsorption chemistry X-ray photoelectron spectroscopy Chemisorption Sputtering Materials Chemistry Aluminium oxide
Zdroj:	Surface Science. 465:163-176
ISSN:	0039-6028
DOI:	10.1016/s0039-6028(00)00728-7
Popis:	XPS studies and first principles calculations compare Cu adsorption on heavily hydroxylated sapphire (0001) with a dehydroxylated surface produced by Ar{sup +} sputtering followed by annealing in O{sub 2}. Annealing a cleaned sapphire sample with an O{sub 2} partial pressure of {approximately}5 x 10{sup {minus}6} Torr removes most contaminants, but leaves a surface with {approximately}0.4ML carbon and {approximately}0.4ML OH. Subsequent light (6 min.) Ar ion sputtering at 1 KeV reduces the carbon to undetectable levels but does not dehydroxylate the surface. Further sputtering at higher Ar ion excitation energies (>2 KeV) partially dehydroxylates the surface, while 5 KeV Ar ion sputtering creates oxygen vacancies in the surface region. Further annealing in O{sub 2} repairs the oxygen vacancies in the top layers but those beneath the surface remain. Deposition of Cu on the hydroxylated surface at 300 K results in a maximum Cu(I) coverage of {approximately}0.35 ML, in agreement with theoretical predictions.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::b858f38d39aeb20db090f0cb9107b4b6 https://doi.org/10.1016/s0039-6028(00)00728-7 Zobrazit plný text záznamu Full Text from ScienceDirect