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Electron Energy‐Loss Near‐Edge Structure Studies of a Cu/(11‐20)α‐Al 2 O 3 Interface
Author(s) -
Scheu C.,
Stein W.,
Rühle M.
Publication year - 2000
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/1521-3951(200011)222:1<199::aid-pssb199>3.0.co;2-2
Subject(s) - monolayer , intermetallic , materials science , electronic structure , chemical bond , enhanced data rates for gsm evolution , crystallography , electron , electron energy loss spectroscopy , atomic physics , molecular physics , chemistry , transmission electron microscopy , computational chemistry , nanotechnology , alloy , metallurgy , physics , telecommunications , organic chemistry , computer science , quantum mechanics
Electron energy‐loss near‐edge structure (ELNES) studies were employed to determine the bonding mechanisms and electronic structure of a Cu/(11‐20) α ‐Al 2 O 3 interface prepared by molecular beam epitaxy. The existence of an interfacial ELNES component at the Al‐L 2,3 edge reveals that the Al atoms participate in the bonding and change their local coordination compared to bulk Al 2 O 3 . At the interfacial O‐K ELNES some pre‐edge intensity appears, indicating the presence of deep‐level O‐2p states hybridised with Cu‐3d and/or Al‐3p states. The interfacial Cu‐L 2,3 ELNES shows a chemical shift of the edge onset to higher energy‐loss values and the existence of unoccupied Cu‐3d states. The shape and edge onset are similar to the Cu‐L 2,3 edge measured in an intermetallic CuAl 2 compound. Image simulations of the experimental high‐resolution transmission electron microscopic images were carried out assuming Cu–Al bonds at the Cu/(11‐20)Al 2 O 3 interface as found by the ELNES studies. The derived structural model for the atomistic arrangement at the interface contains a mixed monolayer of Cu and Al atoms that exhibits a projected bonding distance of (0.15 ± 0.02) nm to the first O‐layer of the Al 2 O 3 substrate.