三种金属离子掺杂对纳米镍锌铁氧体吸波性能的影响

Influence of Doping with Metal Ions Co^(2+), Mn^(2+) and Cu^(2+) on Absorbability of Nano Ni-Zn Ferrite

应用水热法将Co^(2+)、Mn^(2+)和Cu^(2+)掺杂到纳米镍锌铁氧体粉末中,使用XRD、TEM和VNA等手段对其进行表征和分析,研究了掺杂不同金属离子对样品的粒度、形貌、电磁损耗性能以及吸收性能的影响。采用水热法制备纳米钴镍锌铁氧体纯相,以提高Co^(2+)的含量。结果表明:掺杂后纳米镍锌铁氧体颗粒的结构由球形转变为不规则四边形,平均粒径增加到35~60 mn。掺杂Co^(2+)后,晶格常数由0.8352增加到0.8404。掺杂Co^(2+)改变了反射率与频率的关系曲线中吸收峰的位置,增大了吸收器的带宽,提高了材料的低频吸波性能。Mn^(2+)的掺杂比例影响晶格常数的大小,但是纳米晶粒容易团聚,并且没有提高电磁损耗吸波性能反而降低。掺杂Cu^(2+)仍然出现团聚,当掺杂量为0.15(原子分数)时吸波性能较为优异。

Powder of nano Ni-Zn ferrite was doped with Co^2＋, Mn^2＋ and Cu^2＋ respectively with hydrothermal method, which then was characterized by means of XRD, TEM, and VNA in terms of the doping effect on the particle size, morphology, and electromagnetic wave absorption performance of the doped powders. Meanwhile, plain nanometer Co-Ni-Zn ferrite was also prepared by hydrothermal method for varying Co2＋content. Results show that after doping, the particle morphology changed from spherical one to irregular quadrilateral one with the average particle size 35-60 nm. The lattice constant also increases from 0.8404 to 0.8352 nm for Co^2＋ doping. The Co^2＋ doping can change the position of the absorption peaks, increase the bandwidth of the absorber, and improve the performance of the materials in GHz low frequencies. The doping ratio of Mn2＋can affect the lattice constant of the nano Ni-Zn ferrite, but nano particles are easy to agglomerate, thus Mn^2＋ doping exhibited negative effect on the absorbance performance. For the doping of Cu^2＋ , particles are still apt to agglomerate, however, with a dopant dose of0.15 Cu2＋（atomic fraction）, the absorbing performance of nano Ni-Zn ferrite powder became better.