Highly nitrogen-doped carbon nanotube ͑CN x NT, x = 12 at. %͒ was synthesized by the pyrolysis of acetonitrile on Co-Mo catalysts. The electronic structures and chemical bondings of CN x NT were studied using various spectroscopic techniques: Raman, photoelectron and x-ray absorption spectroscopies. The ultrafast pump-probe measurements of CN x NT exhibited a larger third-order susceptibility ͑3͒ , a relaxation time of 2 = 1 ps and improved saturable absorption, as compared with undoped multiple-walled carbon nanotubes, which indicate that N-doping can improve all-optical switching properties of carbon nanotubes.

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The effect of the magnetic field on the magnetic properties of NiFe/Cu composite wires electroplated under a longitudinal magnetic controlling field is presented. Composite wire samples of 20-μm-diameter Cu electroplated with a layer of Permalloy™ (Ni80Fe20) under the influence of a longitudinal magnetic field of intensities ranging from 0 to 400 Oe were produced, and the microstructure and magnetic properties were measured. The results showed that the longitudinal magnetic field in the composite wire plating makes the packing of the crystals in the plated layer more orderly, and thus increases the uniformity and magnetic softness of the plated material. It also shifts the magnetic anisotropy of the plated layer from circumferential to longitudinal, and increases the critical frequency of the plated composite wire in magnetoimpedance effect testing, at which the magnetoimpedance ratio reaches the maximum.

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Nanotechnology V 1505Optimization of High-Yield Biological Synthesis of Single-Crystalline Gold Nanoplates. -Single-crystalline Au nanoplates are prepared by reducing aqueous HAuCl4 solutions with the extract of Sargassum sp. (brown seaweed) at room temperature with yields as high as 80-90%. The samples are characterized by UV/VIS spectroscopy, XRD, AFM, and TEM. By simply varying the initial reactant concentrations, the size of the Au nanoplates can be controlled between 200 and 800 nm. -(LIU, B.; XIE, J.; LEE*, J. Y.; TING, Y. P.; CHEN, J. P.; J.