Related papers: Ordering effects in diluted magnetic semiconductor…
In this work a simple concept was used for a systematic search for new materials with high spin polarization. It is based on two semi-empirical models. Firstly, the Slater-Pauling rule was used for estimation of the magnetic moment. This…
Multicomponent Heusler alloys exhibit various magnetic properties arising from their diverse atomic compositions and crystal structures. Identifying the general physical principles that govern these behaviors is essential for advancing…
Alloys with a first-order magnetic transition are central to solid-state refrigeration technology, sensors and actuators, or spintronic devices. The discontinuous nature of the transition in these materials is a consequence of the coupling…
Diluted Magnetic Semiconductors (DMS) doped with a small concentration of magnetic impurities inducing ferromagnetic DMSs have attracted a lot of attention in the few last years. In particular, DMS based on III-V and II-VI semiconductors…
Doping nonmagnetic semiconductors with magnetic impurities is a feasible way to obtain diluted magnetic semiconductors (DMSs). It is generally accepted that for the most extensively studied DMS, (Ga, Mn)As, its highest Curie temperature…
Using a recently developed semi-analytical method (Self-Consistent Local RPA or SC-LRPA) we study the stability of the ferromagnetic phase in diluted magnetic systems where the exchange coupling between magnetic impurities are of RKKY form.…
We present systematic temperature-dependent resistance noise measurements on a series of ferromagnetic Ga$_{1-x}$Mn$_{x}$As epitaxial thin films covering a large parameter space in terms of the Mn content $x$ and other variations regarding…
Recent experiments on the amorphous magnetic semiconductor Gd_x Si_{1-x}, Phys. Rev. Lett. 77, 4652 (1996), ibid 83, 2266 (1999), ibid 84, 5411 (2000), ibid 85, 848 (2000), have revealed an insulator-metal transition (i-m-t), as a function…
We discuss fluctuating order in a quantum disordered phase proximate to a quantum critical point, with particular emphasis on fluctuating stripe order. Optimal strategies for extracting information concerning such local order from…
In the absence of magnetic field or spin-orbit coupling the one-parameter scaling theory predicts localization of all states in two-dimensional (2D) disordered systems, for any amount of disorder. However, a 2D metallic phase has been…
We present the studies of Sn/1-x/Cr/x/Te semimagnetic semiconductors with chemical composition x ranging from 0.004 to 0.012. The structural characterization indicates that even at low average Cr-content x < ?0.012, the aggregation into…
Magnetic materials are typically described in terms of the Heisenberg model, which provides an accurate account of thermodynamic properties when combined with first principles calculations. This approach is usually based on an energy…
Recent developments in the synthesis of new magnetic materials lead to the discovery of new quantum paramagnets. Many of these materials, such as the perovskites Ba$_{4}$LnMn$_{4}$O$_{12}$ (Ln = Sc or Nb), Ba$_{3}$Mn$_{2}$O$_{8}$, and…
We present a unified, global perspective on the magnetic properties of strongly disordered electronic systems, with special emphasis on the case where the ground state is metallic. We review the arguments for the instability of the…
In this work we investigate Ising and classical Heisenberg models for two and three dimensional lattices in presence of diluted ferromagnetic dimers. For such models the Curie temperature as a function of ratio of intra-dimer exchange…
The accurate determination of magnetic phase transitions in electronic systems is an important task of solid state theory. While numerically exact results are readily available for model systems such as the half-filled 3D Hubbard model, the…
Semiconductors are currently an active topic of study due to the endless range of applications in electronic hardware and computer engineering. In this experiment, the material properties (i.e. resistivity $\rho$, Hall coefficient $R_{H}$,…
The magnetic properties of $\alpha$-NaFeO$_2$ are studied by neutron diffraction and magnetization measurements. An ordered phase with spins aligned along the b$_hex$ axis exists at low temperatures (T < 4 K). At intermediate temperatures…
By path integral Monte Carlo simulations we study the phase diagram of two - dimensional mesoscopic clusters formed by electrons in a semiconductor quantum dot or by indirect magnetoexcitons in double quantum dots. At zero (or sufficiently…
We consider the effects of the non-local Ising-like "core spin" correlations on the order-parameter fluctuation contribution to the resistivity and thermodynamics of metals showing Ising-like order at finite temperature. We employ the…