Spin dependent photoelectron tunnelling from GaAs into magnetic Cobalt

The spin dependence of the photoelectron tunnel current from free standing GaAs films into out-of- plane magnetized Cobalt films is demonstrated. The measured spin asymmetry (A) resulting from a change in light helicity, reaches +/- 6% around zero applied tunnel bias and drops to +/- 2% at a bias of -1.6 V applied to the GaAs. This decrease is a result of the drop in the photoelectron spin polarization that results from a reduction in the GaAs surface recombination velocity. The sign of A changes with that of the Cobalt magnetization direction. In contrast, on a (nonmagnetic) Gold film A ~ 0%

Interplay between Anisotropic Strain Relaxation and Uniaxial Interface Magnetic Anisotropy in Epitaxial Fe Films on (001) GaAs

International audienc

Interface formation and structural properties of iron films on Al0.48_{0.48} In0.52_{0.52}As(001)

Using reflection high-energy electron diffraction as well as ultraviolet and X-ray photoemission spectroscopy we have investigated the growth of epitaxial Fe ultrathin films onto Al$_{0.48}$In$_{0.52}$(001)-($2\times 4$) surface. The Fe films grow in a body centered cubic (bcc) structure with epitaxial relationship Fe(001)//Al$_{0.48}$In$_{0.52}$As(001). The analysis of the photoemission data demonstrates that Fe atoms react with the Al$_{0.48}$In$_{0.52}$As substrate. In and As atoms, liberated during the first stage of the growth, tend to segregate at the films surface while reacting Al atoms are accommodated in an interfacial alloy. The Fermi level pinning position at the Fe/Al$_{0.48}$In$_{0.52}$As(001) interface, determined from the photoemission results, is found 0.76 +/- 0.08 eV below the conduction band minimum

Temperature dependence of the mechanical behaviour of a GeAsSe glass

International audienceno abstrac