30～1000MHz铁氧体吸收瓦（尺寸为100mm×100mm×厚度）在电磁兼容（EMC）领域具有广泛的应用。本文采用氧化物工艺制备NiCuZn尖晶石铁氧体，测试并分析了用Cu2+取代Ni2+及CO2+掺杂对材料复磁导率的影响。在900℃/2h预烧。1150℃/2h烧结。得到NiCuZn铁氧体相对复磁导率（μ=μ1，-jμ）μ1>110，μ>200（频率f=30MHz），通过对试材料优化设计。当铁氧体吸收瓦厚度d=5.5mm，在30～1000MHz，反射率R<-12dB。在f=50～800MHz。R<-15dB。

Z-type hexaferrite (Ba3(Co0.4Zn0.6)2Fe23.4O41) withBST(Ba 0.5Sr0.5TiO3) additive was prepared by conventional solidstate reaction method. We have investigated the effects of BST additive on the complex permeability, permittivity and microwave absorption in the range of 1 MHz-1 GHz. The results from XRD and SEM indicate that as the amount of BST increases, the major phase changes to Z-phase, simultaneously M-phase and perovskite phase appear, and grain size increases. When the weight percent of BST additive in Z-type hexaferrite varied from 0% to 1.5%, the BST additive not only improved complex permeability and complex permittivity, but also provided broadband reflectivity characteristics. Meanwhile the minimum reflection point shifts to lower frequency with increase of BST content.

The evolutions of microstructure of Fe0.85Ni0.15 products, which were prepared by mechanical alloying (MA) with and without process control agent (PCA), were studied using X-ray diffraction and scanning electron microscopy respectively. After MA without PCA (dry method) for 30h, Fe0.85Ni0.15 nanocrystalline alloy powders with bcc-Fe(Ni) phase were obtained; however, powders milled with PCA (wet method) from 20 to 90h, were unalloyed Fe-Ni mixtures with balanced morphology. It seems that dry method works efficiently in nanocrystalline alloying while wet method postpones MA but functionally fines the morphology of materials. Finally, the results were discussed considering the MA kinetics.