2008 NOV 17 - (VerticalNews.com) -- According to a study from Jena, Germany, "In this paper, we present an overview of recent progress made in understanding of the spin-torque induced magnetization dynamics in nanodevices using mesoscopic micromagnetic simulations. In the first part, we perform a detailed quantitative comparison between numerical modelling and experimental data obtained on nanopillar devices."

  "Here we show that although many qualitative features of the observed dynamics can be satisfactorily explained by full-scale micromagnetic models, our understanding of nanopillar experiments is still far from being complete. This manifests itself not only in the incorrect current dependence of the simulated microwave power, but also in the systematic discrepancy between measured and simulated oscillation frequencies; the latter should be considered as an especially alarming signal. We proceed with the numerical analysis of the point contact experiments. These systems demonstrate a much more complicated magnetization dynamics (compared with nanopillars). Numerical simulations reveal that such rich behaviour is due to the formation of several kinds of strongly non-linear oscillation modes. Simulations not only confirm the analytically predicted existence of a so-called non-linear 'bullet', but also predict a much more complicated non-linear mode governed by creation and annihilation of at least two vortex-anti vortex pairs," wrote D.V. Berkov and colleagues ...read more

  2008 NOV 17 - (VerticalNews.com) -- According to a study from Netherlands, "Carbon nanofibres (CNFs) and tungsten oxide (W18O49) nanowires have been incorporated into a continuous flow type microplasma reactor to increase the reactivity and efficiency of the barrier discharge at atmospheric pressure. CNFs and tungsten oxide nanowires were characterized by high-resolution scanning electron microscopy, transmission electron microscopy and nanodiffraction methods. ...read more

  2008 NOV 17 - (VerticalNews.com) -- "The polyethylene glycol (PEG) modified gold nanoparticle complex was synthesized by a one-solution synchrotron x-ray irradiation method. The impact on the structure and morphology of the gold nanoparticles of process parameters such as the PEG molecular weight, the PEG/gold molar ratio and the x-ray dosage were investigated," investigators in Taipei, Taiwan report.

  "The size of PEG modified gold particles was found to decrease with increasing PEG addition and x-ray dosage. With the capability to monitor the absorption spectra in situ during the fast synthesis process, this opens the way to accurate control of the size and distribution. PEG chains with an intermediate length (MW6000) were found optimal for size control and colloidal stability in biologically relevant media," wrote C.H. Wang and colleagues ...read more