in this work we report synthesis and magnetic characterization of cobalt doped zno nanoparticles (with different percent of doped cobalt oxide). synthesis of the materials was carried out at room temperature by polyacrylamide-gel method, using zink sulfate and cobalt nitrate as source materials, acrylamide as monomer and n,n-methylene bisacrylamide as a lattice reagent. characterization of the ...

Ballistic spin polarized transport through diluted magnetic semiconductor single and double barrier structures is investigated theoretically using a two-component model. The tunneling magnetoresistance ~TMR! of the system exhibits oscillating behavior when the magnetic field is varied. An interesting beat pattern in the TMR and spin polarization is found for different nonmagnetic semiconductor/...

The magnetic and magneto-optical properties of a Cr-doped II-VI semiconductor ZnTe were investigated. Magnetic circular dichroism measurements showed a strong interaction between the sp carriers and localized d spins, indicating that Zn(1-x)Cr(x)Te is a diluted magnetic semiconductor. The Curie temperature of the film with x=0.20 was estimated to be 300+/-10 K, which is the highest value ever r...

Deposition of 0.5 monolayer of Mn by molecular beam epitaxy on the surface of a Ge(0 0 1) substrate, and annealing, allowed the fabrication of a cluster-free Ge(Mn) diluted solution. Electronic spin resonance (ESR) was used to study the magnetic properties of this solution. These measurements, combined with secondary ion mass spectrometry, atomic force microscopy, and Auger electron spectroscop...

We present a theory of carrier-induced ferromagnetism in diluted magnetic semiconductors ( III1-xMnxV) which allows for arbitrary itinerant-carrier spin polarization and dynamic correlations. Both ingredients are essential in identifying the system's elementary excitations and describing their properties. We find a branch of collective modes, in addition to the spin waves and Stoner continuum w...