Victor Stanciu

Postgrowth annealing of (Ga,Mn) As under As capping: An alternative way to increase TC

In situ postgrowth annealing of (Ga,Mn)As layers under As capping is adequate for achieving high Curie temperatures (TC) in a similar way as ex situ annealing in air or in N2 atmosphere practiced earlier. Thus, the first efforts give an increase of TC from 68 to 145 K after 2 h annealing at 180 °C. These data, in combination with lattice parameter determinations and photoemission results, show that the As capping acts as an efficient sink for diffusing Mn interstitials.

Influence of annealing parameters on the ferromagnetic properties of optimally passivated (Ga,Mn)As epilayers

Influence of annealing parameters on the ferromagnetic properties of optimally passivated (Ga,Mn)As epilayers

Structural and magnetic properties of Al2O3/Ni81Fe19 thin films: from superparamagnetic nanoparticles to ferromagnetic multilayers

Structural and magnetic properties of Al2O3/Ni81Fe19 thin films: from superparamagnetic nanoparticles ferromagnetic multilayers

Photoemission studies of the annealing-induced modifications of Ga0.95Mn0.05As

Using angle resolved photoemission we have investigated annealing-induced changes in Ga1-xMnxAs with x=0.05. We find that the position of the Fermi energy is a function of annealing time and temperature. It is also established that the Curie temperature is strongly correlated to the separation between the Fermi level and the valence band maximum. Valence band photoemission shows that the Mn3d spectrum is modified by the annealing treatments.

Influence of interface mixing on the magnetic properties of BCC Fe0.82Ni0.18/V (0 0 1) superlattices

Influence of interface mixing on the magnetic properties of BCC Fe0.82Ni0.18/V (0 0 1) superlattices

Annealing-induced changes of the magnetic anisotropy of (Ga,Mn)As epilayers

The dependence of the magnetic anisotropy of As-capped (Ga,Mn)As epilayers on the annealing parameters—temperature and time—has been investigated. A uniaxial magnetic anisotropy is evidenced, whose orientation with respect to the crystallographic axes changes upon annealing from [1 ¯10] for the as-grown samples to [110] for the annealed samples. Both cubic and uniaxial anisotropies are tightly linked to the magnetic transition temperature, and hence, to the concentration of charge carriers, the magnitude of which is controlled by the annealing process.

Comment on "Mn Interstitial Diffusion in (Ga,Mn)As"

The magnetic and transport properties of (GaMn)As are known to be influenced by postgrowth annealing, and it is generally accepted that these modifications are due to outdiffusion of Mn interstitials. We show that the annealing-induced modifications are strongly accelerated if the treatment is carried out under As capping. This means that the modification rate is not limited by the diffusion process, but rather by the surface trapping of the diffusing species.