Interfacial stiffening of Cu, Ni, and Ag thin films on the Ru(0001) surface

Journal Article · Wed Aug 15 00:00:00 EDT 1990 · Physical Review, B: Condensed Matter; (USA)

DOI:https://doi.org/10.1103/PhysRevB.42.2792· OSTI ID:6523373

O'Neill, D G; Houston, J E ^[1]

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1. Sandia National Laboratories, Albuquerque, NM (USA)

We have studied the vibrational behavior of overlayer films of Cu, Ni, and Ag grown on the Ru(0001) surface as a function of film thickness. Specifically, we have measured the thermal mean-square vibrational amplitude, through a Debye-Waller analysis of low-energy electron diffraction, for films having thicknesses ranging between 1 and 10 monolayers. The analysis indicates that the strong interfacial interaction, which gives rise to a pseudomorphic structure for 1 monolayer Cu and Ni films, also results in a reduction in the overlayer vibrational amplitude (i.e., the films are stiffened by the interaction). In addition, we find that this interfacial stiffening is long ranged and requires overlayer-film thicknesses in excess of about 10 monolayers to heal to bulklike values. In contrast, Ag is found not to grow pseudomorphically at the 1-monolayer level, and the vibrational behavior shows a lesser degree of stiffening and a much more rapid healing to bulklike values. These findings are discussed in terms of the instrumental aspects of the Debye-Waller analysis, and in terms of the {ital I}-{ital V} character of the diffraction process, and are contrasted with similar studies of the structural and electronic properties of film growth for these overlayer systems.

• DOE Contract Number: AC04-76DP00789
• OSTI ID: 6523373
• Journal Information: Physical Review, B: Condensed Matter; (USA), Journal Name: Physical Review, B: Condensed Matter; (USA) Vol. 42:5; ISSN 0163-1829; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
ALKALI METALS
COATINGS
COHERENT SCATTERING
COPPER
CRYSTAL FACES
CRYSTAL GROWTH
DEBYE-WALLER FACTOR
DIFFRACTION
ELECTRON DIFFRACTION
ELEMENTS
ENERGY LEVELS
EXCITED STATES
FILMS
LATTICE VIBRATIONS
LAYERS
METALS
NICKEL
RUBIDIUM
SCATTERING
SILVER
THIN FILMS
TRANSITION ELEMENTS
VIBRATIONAL STATES