arXiv subjects

F. Terki

Publications and source records attributed to F. Terki.

5 recordsLinked to original sources

arXiv2007

GaAs:Mn nanowires grown by molecular beam epitaxy of (Ga,Mn)As at MnAs segregation conditions

GaAs:Mn nanowires were obtained on GaAs(001) and GaAs(111)B substrates by molecular beam epitaxial growth of (Ga,Mn)As at conditions leading to MnAs phase separation. Their density is proportional to the density of catalyzing MnAs nanoislands, which can be controlled by the Mn flux and/or the substrate temperature. Being rooted in the ferromagnetic semiconductor (Ga,Mn)As, the nanowires combine one-dimensional properties with the magnetic properties of (Ga,Mn)As and provide natural, self assembled structures for nanospintronics.

cond-mat.mtrl-sci↗

arXiv2006

High ferromagnetic phase transition temperatures in GaMnAs layers annealed under arsenic capping

Thin GaMnAs layers grown by molecular beam epitaxy were subjected to low-temperature post growth annealing, with an amorphous arsenic capping layer deposited on the GaMnAs surface directly after the epitaxial growth. It is shown that the presence of arsenic capping at the GaMnAs surface significantly shortens the post-growth annealing times and facilitates a complete out-diffusion of Mn interstitials from GaMnAs volume.

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↗

arXiv2001

Calcium Rubidium Nitrate: Mode-Coupling $β$ Scaling without Factorization

The fast dynamics of viscous calcium rubidium nitrate is investigated by depolarized light scattering, neutron scattering and dielectric loss. Fast $β$ relaxation evolves as in calcium potassium nitrate. The dynamic susceptibilities can be described by the asymptotic scaling law of mode-coupling theory with a shape parameter $λ= 0.79$; the temperature dependence of the amplitudes extrapolates to $T_c\simeq 378$ K. However, the frequencies of the minima of the three different spectroscopies never coincide, in conflict with the factorization prediction, indicating that the true asymptotic regime is unreachable.

cond-mat.soft↗