Monolayer Sm films on Ta and Cu substrates

• Published in: Physical review. B, Condensed matter Condensed matter, 1993-11, Vol.48 (20), p.15289-15296
• Main Authors: TAO, L, GOERING, E, HORN, S, DENBOER, M. L
• Format: Article
• Language: English
• Subjects: 360104 - Metals & Alloys- Physical Properties; Applied sciences; CHEMICAL STATE; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; COPPER; ELECTRONIC STRUCTURE; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; ELEMENTS; EMISSION; Exact sciences and technology; Impurity and defect levels; energy states of adsorbed species; INTERATOMIC FORCES; Lattice dynamics; MATERIALS SCIENCE; METALS; Metals. Metallurgy; Phonon-electron and phonon-phonon interactions; Phonons and vibrations in crystal lattices; PHOTOEMISSION; Physics; RARE EARTHS; SAMARIUM; SECONDARY EMISSION; SUBSTRATES; Surface and interface electron states; TANTALUM; TRANSITION ELEMENTS; VALENCE
• ISSN: 0163-1829; 1095-3795
• DOI: 10.1103/PhysRevB.48.15289

We have studied the electronic properties of ultrathin layers of Sm on Ta and Cu substrates using valence-band and resonant photoemission. The average formal chemical valence of Sm on Ta increases from below 2.4 at low coverage to the value measured from bulk Sm at higher coverage, while the valence of Sm on Cu is 3 at low coverage and decreases abruptly to the same value measured for Ta substrates at higher coverage. These changes in electronic properties reflect interlayer and intralayer interactions in these films, particularly the weak Sm-Ta and strong Sm-Cu interactions.