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.

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.

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.

Pseudobinary Pr12xTbx(Fe0.6Co0.4)2 (0<x<0.4) cubic Laves single phases have been synthesized by melt spinning and subsequent annealing. Their structure, magnetic properties and stability have been investigated. The composition, at which the anisotropy of Pr12xTbx(Fe0.6Co0.4)2 is compensated, is close to x50.1. The spontaneous magnetostrictions l111 of Pr0.9Tb0.1(Fe0.6Co0.4)2 and Pr0.8Tb0.2(Fe0.6Co0.4)2 are larger than 150031026 and 190031026, respectively. Pr12xTbx(Fe0.6Co0.4)2 (0.1<x<0.4) ribbon-based materials with 3% epoxy resin combine high magnetostriction with significant magnetic coercivity. Pr0.9Tb0.1(Fe0.6Co0.4)2 is a promising magnetostrictive material.

We have succeeded in synthesizing PrFe11V12xTix (x50.2-1) compound and their nitrides with the ThMn12-type structure. The phase formation and magnetic properties have been investigated by x-ray diffraction, differential thermometric analysis, and magnetic measurement. The stable temperature range of the 1-12 phase for PrFe11V12xTix alloys has been determined as a function of Ti content. PrFe11V compounds with the ThMn12-type structure do not exist and PrFe11Ti compounds with the TnMn12-type structure are obtained by annealing in a narrow temperature range between 1303 and 1383 K. Furthermore, 1-12 phase with the ThMn12-type structure can be obtained at lower temperature and wider temperature range with decreasing Ti content x (0.2<x<1). PrFe11V12xTixNy with x50.2-1 has a Tc of about 730-785K, Ba larger than 8 T and Ms in the range 144-148 emu/g. These intrinsic magnetic properties are highly favorable for permanent magnet applications. As a preliminary, an intrinsic coercivity of 5.4 kOe is obtained for PrFe11V0.5Ti0.5Ny at room temperature by using mechanical alloying technique.