从磁参数（饱和磁化强度，磁晶各向异性场）温度稳定性出发，对六角铁氧体RAM的温度稳定性进行了讨论；通过对M、W型六角铁氧体在温度t=18～100℃，频率。f=8～12GHz时吸收率R（R～f）的温度稳定性和材料起始磁导率“随温度的变化曲线（μ～t）的测试，得到单轴六角铁氧体材料R～f的温度稳定性优于平面六角铁氧体材料，并且和材料的μ～t变化规律吻合较好的结果。

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。

In this paper, nanocrystalline FeNi alloy powders with different particle size were prepared by two-step mechanical alloying (MA), the first step of the processes is FeNi nanocrystalline alloying and the second step modifies particle size. As-milled powders were randomly dispersed in paraffin at a weight ratio of 5:1 for microwave complex permeability test and comparision in the frequency range of 0.5-18 GHz. It is observed and discussed that microwave complex permeability is prominently affected by FeNi microstructure and particle size. In this work, Fe0.85Ni0.15 nanocrystalline powders exhibit high value of complex permeability in 1-10 GHz, and the sample with particle size of 2.34mm possesses the maximum value as m0 6.32 at 1.81GHz, m00 3.45 at 4.09 GHz. This value may be useful for thin-thickness and wide-band microwave absorber.