arXiv subjects

V. Stanciu

Publications and source records attributed to V. Stanciu.

5 recordsLinked to original sources

arXiv2005

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 [-110] for the as-grown samples to [110] for the annealed samples. Both cubic an uniaxial anisotropies are tightly linked to the concentration of charge carriers, the magnitude of which is controlled by the annealing process.

cond-mat.mtrl-sci↗

arXiv2005

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

The influence of annealing parameters - temperature and time - on the magnetic properties of As-capped (Ga,Mn)As epitaxial thin films have been investigated. The dependence of the transition temperature (Tc) on annealing time marks out two regions. The Tc peak behavior, characteristic of the first region, is more pronounced for thick samples, while for the second (`saturated') region the effect of the annealing time is more pronounced for thin samples. A right choice of the passivation medium, growth conditions along with optimal annealing parameters routinely yield Tc-values of ~ 150 K and above, regardless of the thickness of the epilayers.

cond-mat.mtrl-sci↗

arXiv2004

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.

cond-mat.mtrl-sci↗

arXiv2004

Post-growth annealing of GaMnAs under As capping - an alternative way to increase Tc

We demonstrate that in situ post-growth annealing of GaMnAs 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.

cond-mat.other↗

arXiv2003

Magnetic properties of GaMnAs single layers and GaInMnAs superlattices investigated at low temperature and high magnetic field

Magnetotransport properties of GaMnAs single layers and InGaMnAs/InGaAs superlattice structures were investigated at temperatures from 4 K to 300 K and magnetic fields up to 23 T to study the influence of carriers confinement through different structures. Both single layers and superlattice structures show paramagnetic-to-ferromagnetic phase transition. In GaMnAs/InGaAs superlattice beside the Curie temperature (Tc ~ 40 K), a new phase transition is observed close to 13 K.

cond-mat.mtrl-sci↗