Ultrathin epitaxial Fe films on vicinal GaAs(001): A study by spin-resolved photoelectron spectroscopy

Abstract

Thin epitaxial Fe films have been grown on vicinal GaAs(001) substrates and their remanent magnetic properties and the degree of substrate atom diffusion investigated using synchrotron-based photoelectron spectroscopy. The vicinal Fe films, though exhibiting greater As diffusion than their singular homologues, displayed better film quality both from the structural and the magnetic points of view. The spin-resolved valence spectra of the vicinal films resemble those for crystalline bulk Fe at lower film thicknesses than for singular films.

Magnetic properties of ultra thin epitaxial Fe films on GaAs(001)

“…It is also interesting to note that, the value of the magnetic asymmetry for the Fe on the vicinal substrate is about 8% higher in the temperature range studied, indicating a somewhat higher magnetisation at the same temperature. This appears to be consistent with our earlier work [12] that, in the ultrathin region, the magnetic characteristics appeared to be enhanced for Fe grown on vicinal substrates.…”

“…Whilst recognising that the magnetic behaviour of ultrathin Fe layers is als o sensitive to both GaAs substrate surface morphology [12] and surface stoichiometry [13], this Letter reports on the temperature dependent magnetic state of Fe on GaAs(001) through a study of the magnetic dichroism of the Fe 2p and 3p core level photoelectrons with linearly polarised radiation.…”

Spin-Resolved Electronic Structure of Ultrathin Epitaxial Fe Films on Vicinal and Singular GaAs(100) Substrates

“…In a preliminary combined spin-polarized secondary electron spectroscopy, photoelectron spectroscopy and LEED study (carried out on the SRS, Daresbury Laboratory) of the remanent magnetic properties of Fe on singular and vicinal (3° offset) GaAs we have shown both that the various magnetic phases formed are dependant upon the Ga to As surface composition of the substrate and that they evolve in characteristic (but not well understood) ways with Fe overlayer thickness 8 . A remarkable feature in this system, which illustrates the importance of the Fe overlayer/substrate interaction, is the magnetic anisotropy; the easy axis of the Fe films on Ga-terminated substrates is perpendicular to that for Asterminated substrates 9,10 .…”