Atomic and electronic structure of Fe films grown on Pd l brace 001 r brace

Journal Article · Fri Feb 15 04:00:00 EST 1991 · Physical Review, B: Condensed Matter; (USA)

DOI:https://doi.org/10.1103/PhysRevB.43.3959· OSTI ID:5736539

Quinn, J; Li, Y S; Li, H; Tian, D; Jona, F ^[1]; Marcus, P M ^[2]

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1. College of Engineering and Applied Science, State University of New York, Stony Brook, New York 11794 (US)
2. IBM Research Center, P.O. Box 218, Yorktown Heights, New York 10598 (USA)

The atomic and electronic structure of Fe films grown on Pd{l brace}001{r brace} is investigated by means of low-energy electron diffraction and angle-resolved photoemission spectroscopy (ARPES). The films grow pseudomorphically, probably by way of nucleation and growth of flat islands, which ultimately coalesce to form continuous Fe{l brace}001{r brace} films. The structure of these continuous films, if grown at slow rates (of the order of 0.1 A/min), is body-centered tetragonal and is shown to be a distortion from the stable bcc structure of Fe: the in-plane lattice constant is 2.75 A, as dictated by the Pd{l brace}001{r brace} substrate, and the bulk interlayer spacing is 1.50--1.53 A. In 10--12-layer films the first interlayer spacing is expanded by 3.6% above bulk, but with increasing thickness that spacing contracts progressively to about 6.3% below the bulk value in 40--50-layer films. Films as thick as 60--70 layers can be grown pseudomorphically at slow rates despite the large misfit (4.2%) between bcc Fe{l brace}001{r brace} and fcc Pd{l brace}001{r brace}. ARPES data indicate that these films are electronically indistinguishable from bulk bcc Fe. Thick (about 200-layer) films grown at fast rates are essentially bcc, with in-plane lattice constants of 2.87 A, but with slightly expanded (3%) interlayer spacing, attributed to the presence of carbon impurities.

• DOE Contract Number: FG02-86ER45239
• OSTI ID: 5736539
• Journal Information: Physical Review, B: Condensed Matter; (USA), Journal Name: Physical Review, B: Condensed Matter; (USA) Vol. 43:5; ISSN 0163-1829; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
COHERENT SCATTERING
CRYSTAL FACES
CRYSTAL STRUCTURE
DIFFRACTION
ELECTRON DIFFRACTION
ELECTRON SPECTROSCOPY
ELECTRONIC STRUCTURE
ELEMENTS
EPITAXY
FILMS
IRON
LATTICE PARAMETERS
METALS
PALLADIUM
PHOTOELECTRON SPECTROSCOPY
PLATINUM METALS
SCATTERING
SPECTROSCOPY
SUBSTRATES
TRANSITION ELEMENTS