Ferromagnetism with T(c)>350 K is observed in the diluted magnetic semiconductor Ni(2+):ZnO synthesized from solution. Whereas colloidal Ni(2+):ZnO nanocrystals are paramagnetic, their aggregation gives rise to robust ferromagnetism. The appearance of ferromagnetism is attributed to the increase in domain volumes and the generation of lattice defects upon aggregation. The unusual temperature de...

Magnetic anisotropy and magnetization reversal phenomena are studied in Ga12xMnxAs films grown on GaAs~001!. From the azimuthal dependence of the magneto-optical Kerr rotation and magnetic linear dichroism, the in-plane ^100& directions are unambiguously assigned as axes of easy magnetization. The values of the cubic and uniaxial anisotropies are determined. Magnetization reversal proceeds by n...

This paper shows the scattering mechanism at diluted magneticsemiconductors. The doped magnetic atom produces a scattering potential due to becoupled of itinerant carrier spin of host material with magnetic momentum of the dopedmagnetic atom. Formulas of scattering event were rewritten by the plane waveexpansion and then the electron mobility of DMS was calculated. Calculations showKondo effect...

We review pitfalls in recent efforts to make a conventional semiconductor, namely ZnO, ferromagnetic by means of doping with transition metal ions. Since the solubility of those elements is rather low, formation of secondary phases and the creation of defects upon low temperature processing can lead to unwanted magnetic effects. Among others, ion implantation is a method of doping, which is hig...

We demonstrate spin-dependent tunneling features of electronic transport in diluted magnetic semiconductor/semiconductor hybrid systems. It is shown that the geometrical asymmetry of the multilayer heterostructure results in the asymmetry of the spin polarization on the external electric field. The degree of the asymmetry can be changed by adjusting the structural configuration and the magnitud...

These informal lecture notes describe the progress in semiconductor spintronics in a historic perspective as well as in a comparison to achievements of spintronics of ferromagnetic metals. After outlining motivations behind spintronic research, selected results of investigations on three groups of materials are presented. These include non-magnetic semiconductors, hybrid structures involving se...

We discuss the anomalous Hall effect in a two-dimensional electron gas subject to a spatially varying magnetization. This topological Hall effect does not require any spin-orbit coupling and arises solely from Berry phase acquired by an electron moving in a smoothly varying magnetization. We propose an experiment with a structure containing 2D electrons or holes of diluted magnetic semiconducto...