中文摘要：

以FeCl_3·6H_2O（AR）、FeSO_4·7H_2O（AR）、NH_3·H_2O（AR）为原料,采用水热法制备得到纳米Fe_3O_4,采用X射线衍射仪、扫描电镜和矢量网络分析仪对其相组成、形貌与电磁性能进行了表征,将纳米四氧化三铁掺入到水泥基材料中制备水泥基吸波材料,采用弓形法测试水泥基吸波材料在8~18 GHz频段内的吸波性能。结果表明：纳米四氧化三铁的平均尺寸在80~90 nm之间;电损耗角正切tanδe和磁损耗角正切tanδm分别在0.03~0.29和0.01~0.41之间;当其掺量为10%,试样厚度为30 mm时,水泥基复合吸波材料在8~18 GHz频段范围内的吸波性能最佳,反射率小于-10 d B的频带宽为4.7 GHz。

英文摘要：

Taking FeCl_3·6H_2O,FeSO_4·7H_2O and NH_3·H_2O as the reaction raw materials,the nanometer Fe_3O_4 was successfully prepared by the hydrothermal method. The composition,morphology and electromagnetic properties of the nanometer Fe_3O_4 were characterized by X-ray diffraction analysis（ XRD）,scanning electron microscopy（ SEM） and Vector network analyzer（ VNA）.The cement-based composite absorption materials of doping nanometer Fe_3O_4 were prepared. The reflectivity of cement-based plates was measured by the Naval Research Laboratory（ NRL） testing system in the frequency ranges from 8 to 18 GHz. The experimental results show that the average particle size are 80 ~ 90 nm,the electric loss tangent and magnetic loss tangent are 0.03 ~ 0.29 and 0.01 ~ 0.41,respectively. When the contents of nanometer Fe_3O_4 in cement 10%（ by mass） and thickness of specimen is 30 mm,the reflectivity of cement-based composite is optimal and bandwidth for-10 d B reaches 4.7 GHz in8 ~ 18 GHz frequency range.