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 ...

The electrical resistivity values for a series of pure and doped (Co, Mn, Al) ZnO epitaxial films grown by pulsed laser deposition were measured with equipment designed for determining the direct current resistivity of high resistance samples. Room-temperature resistances ranging from 7 x 10(1) to 4 x 10(8) Omega/sq were measured on vacuum-reduced cobalt-doped ZnO, (Al,Co) co-doped ZnO, pure co...

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 ...

In this study we investigated the optical and electronic properties of cobalt doped Zinc Oxide (ZnO) nanoparticles (quantum dots) fabricated by a precipitation method. We observed significant reduction in ZnO nanoparticle diameter as we increased the percentage of cobalt. UV-VIS absorption measurement show a systematic increase in bandgap from 3.40 eV to 3.69 eV as the cobalt percentage is incr...

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 ...

Surface x-ray diffraction experiments reveal that, in cobalt-doped ZnO films two to five monolayers thick, Wurtzite-type CoO nanocrystals are coherently embedded within a hexagonal boron-nitride- (h-BN)-type ZnO matrix, supporting the model of a phase separation. First-principles calculations confirm that, in contrast with ZnO, the formation of h-BN-type CoO is unfavorable in the ultrathin film...

The electronic properties of cobalt-doped ZnO were investigated through site-selective and element-sensitive x-ray-absorption spectroscopy in the vicinity of the Co L2,3 edge, the oxygen K edge, and at the Zn L3 edge. The spectroscopic measurements of the ferromagnetic cobalt-doped ZnO films appear to have additional components in the O K edge x-ray-absorption spectrum not observed in the undop...

Spintronics aims at developing a new generation of electronic materials for consumer products based on electron spin rather than on electron charge. Its main objective is the fabrication of new devices based on semiconductor materials with magnetic behavior (so called diluted magnetic semiconductors). These devices combine the manipulation of electrons as classically known in semiconductor devi...

The hypothesis that high-Curie-temperature ferromagnetism in cobalt-doped ZnO (Co2+: ZnO) is mediated by charge carriers was tested by controlled introduction and removal of the shallow donor interstitial zinc. Using oriented epitaxial Co2+: ZnO films grown by chemical vapor deposition, kinetics measurements demonstrate a direct correlation between the oxidative quenching of ferromagnetism and ...

We review two strategies for growing ZnO nanowires from zinc salts in aqueous and organic solvents. Wire arrays with diameters in the nanoscale regime can be grown in an aqueous solution of zinc nitrate and hexamethylenetetramine. With the addition of poly(ethylenimine), the lengths of the wires have been increased to 25 mum with aspect ratios over 125. Additionally, these arrays were made vert...