20 nm diameter Fe-Co nanowire arrays with different composition were fabricated by electrodeposition. A nanoporous anodized aluminium oxide film was used as the substrate. The microstructure and magnetic properties were studied by x-ray fluorescence, transmission electron microscopy, x-ray diffraction and vibrating samplemagnetometry. Both the coercivity Hc and the spontaneous magnetization Ms increase when the Co content in Fe-Co alloy increases from 0 to about 30 at.%, and then decrease with further increase in the Co content. A model called the 'chain of crystals' is developed and solved to explain the experimental results.

CoFe2O4 nanowire arrays with an average diameter of about 40 nm were prepared in porous anodic aluminum oxide (AAO) template using sol-gel process. Transmission electron microscopy (TEM) diffraction pattern and X-ray diffraction (XRD) showed that the nanowires were polycrystalline phase. Magnetic measurements showed the arrays of nanowires did not show a preferential magnetic orientation, the reason was briefly discussed. The effect of heating rate on the structure and magnetic properties of CoFe2O4 nanowire arrays was investigated. The result showed that the coercivity decreased with the increase of the heating rate.

A series of (GdxDy1-x)Co2 (0-0.55) compounds have been prepared by arc-melting method. In order to determine the phase transition order in these compounds, we have performed some magnetization measurements. Only from the plots of temperature dependence of magnetization and the low-field magnetization isotherms, it is difficult to judge the phase transition order. The low-field Arrott plot is proved to be a more reliable method to characterize the first-order transition and the second-order transition. No first-order transition is observed in (GdxDy1 x)Co2 compounds (xa0). The result is discussed in the Inoue-Shimizu like model.

A simple hydrothermal route, using cetyltrimethylammonium bromide (CTAB) as the surfactant, has been proposed for synthesizing single-crystalline spinal cobalt ferrite (CoFe2O4) nanorods. Transmission electron microscope (TEM) and scanning electron microscopy (SEM) images indicated that the final product consists of nanorods with a diameter of about 25nm andlength up to about 120 nm.Furthermore, high-resolution TEM (HRTEM) revealeda clear lattice structure of the [1 0 0] planes in the nanorods. The magnetic properties of the CoFe2O4 nanorods were characterized using vibrating sample magnetometer (VSM). The possible formation mechanism for the CTAB-assistedhyd rothermal synthesis of CoFe2O4 nanorods has been discussed.

Co-Pb nanowire arrays with an average diameter of 20nm and lengths up to several micrometers were grown in ordered anodic alumina templates using AC electrodeposition. The as-deposited samples were annealed at different temperatures. The structure and magnetic properties of Co-Pb nanowires were analyzed by X-ray diffraction and a vibrating sample magnetometer. We found that the sample annealed at 700℃ had large perpendicular coercivity Hc (as high as 2660 Oe) and high squareness (MR/Ms) (about 0.97), which was much larger than that of pure Co nanowires annealed at 700℃ (2170 Oe, 0.9). The change in coercivity and squareness associated with the microstructure was discussed.