Spin excitations of a model itinerant ferromagnetic film: Spin waves, Stoner excitations, and spin-polarized electron-energy-loss spectroscopy

Journal Article · Tue Feb 01 04:00:00 EST 1994 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.49.3880· OSTI ID:5223265

Gokhale, M P; Mills, D L ^[1]

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1. Department of Physics, University of California, Irvine, California 92717 (United States)

We discuss the spin excitations of a simple model of an ultrathin ferromagnetic film, in which the magnetic moment bearing electrons are itinerant in character. The one-band Hubbard model, treated in mean-field theory, forms the basis of the discussion. The spin excitations are treated by means of the random-phase approximation. We find spin-wave modes of standing wave character, and a spectrum of Stoner excitations influenced strongly by size effects. While the dispersion relations of the standing spin-wave modes appear as expected from a localized-spin model, there are substantive differences between the itinerant- and localized-spin cases. An example is the number of spin-wave modes evident in the appropriate spectral density functions, for each wave vector. We use a previously developed formalism of spin-polarized electron-energy-loss scattering (SPEELS) to compute SPEELS spectra for our model film. In addition to a broad feature with origin in Stoner excitations, we find clear and relatively intense spin-wave loss peaks.

• DOE Contract Number: FG03-84ER45083
• OSTI ID: 5223265
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 49:6; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

665000* -- Physics of Condensed Matter-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ENERGY-LEVEL TRANSITIONS
EXCITATION
FERROMAGNETIC MATERIALS
FILMS
FUNCTIONS
MAGNETIC MATERIALS
MATERIALS
RANDOM PHASE APPROXIMATION
SPECTRAL DENSITY
SPECTRAL FUNCTIONS
SPIN WAVES
THIN FILMS