纳米棒状钡铁氧体的制备与吸波性能

Preparation and Microwave Absorbing Properties of Nano-rod Barium Ferrite

以硝酸铁和硝酸钡为原料,采用溶胶-凝胶与自蔓延燃烧相结合的方法制备出纳米棒状钡铁氧体,采用X射线衍射仪、透射电镜与振动试样磁强计时其组成、形貌与磁性能进行了表征;将纳米棒状钡铁氧体掺入水泥基材料制成水泥基吸波材料,采用弓形反射法测其吸波性能.结果表明:纳米棒状钡铁氧体的平均粒径为40～60 nm,平均长度为100 nm,饱和磁场强度为49.87 A·m^2/kg,矫顽力为63.1 A/m;当纳米棒状钡铁氧体的掺量为1.83%(质量分数)、试样厚度为20 mm时,水泥基吸波材料在2～18 GHz频率范围内的最小反射率为-16.78 dB,反射率小于-10 dB的带宽为6 GHz.

The nano-rod of barium ferrite was made of iron nitrate and barium nitrate as raw materials by combustion method of sol-gel and self-propagation. The composition, morphology and magnetic properties of barium ferrite nano-rod were characterized by X-ray diffraction analysis, transmission electron microsco- py and vibrating sample magnetometer. The cement-based composite absorption materials of doping bari- um ferrite nano-rod was prepared, and its microwave absorbing properties were measured by reflection method. The results indicate that the average particle size and length of barium ferrite nano-rod are 40 - 60 nm and 100 nm respectively, the saturation magnetization and coercivity are 49.87 A · m2/kg and 63.1 A/ m. When the contents of barium ferrite nano-rod in cement reaches 1. 83% （by mass） and thickness of specimen is 20 mm, the least reflectivity of cement-based composite is --16.78 dB and bandwidth for --10 dB reaches 6 GHz in 2 - 18 GHz frequency range.