聚吡咯/Gd-掺杂铜锌铁氧体复合物的制备及电/磁性能

用溶胶-凝胶法和溶液原位聚合法分别制备了Gd-掺杂纳米级Zn_0.6Cu_0.4Fe_2－xGd_xO₄ (x＝0～0.10)铁氧体粉末和聚吡咯/Zn_0.6Cu_0.4Fe_1.96Gd_0.04O₄纳米复合物. 用现代分析技术表征了样品的结构、形貌和电磁性能. 结果表明Gd-掺杂铁氧体的饱和磁化强度随Gd含量的增加而增大; 复合物的电导率和饱和磁化强度与聚吡咯的含量有关, 当聚吡咯的含量从w＝50%增加到w＝80%, 复合物的电导率从0.0139增加到0.0423 S/cm, 而饱和磁化强度则从18.37减小到14.35 emu/g. 在8～18 GHz频段内, 吸收层厚度为2 mm时, PPy在16 GHz附近的反射损耗峰值为－19.68 dB, 有效带宽为6.2 GHz; 而ZCGFO的反射损耗峰值和有效带宽分别为－16.6 dB和5.16 GHz. 和PPy和ZCGFO相比, PPy/ZCGFO复合物有更低的反射损耗和更大的有效带宽, ZCGFO相对含量为20%的PPy/ZCGFO复合物的反射峰值和有效带宽分别达到－20.90 dB和14.05 GHz. 这些结果说明PPy/ZCCFO复合物适合作为电磁波吸收与屏蔽的候选材料.

Preparation and Electrical/Magnetic Properties of Polypyrrole/Cu-Zn Ferrites Doped with Gd Nanocomposites

Nanosized Zn_(0.6)Cu_(0.4)Gd_xFe_(2-x)O_4 (x=0～0.10) ferdtes doped with Gd and polypyrrole/Zn_(0.6)Cu_(0.4)Gd0.04Fe1.96O4 nanocomposites were prepared by a sol-gel method and an in situ polymerization method, respectively. The structures, morphology, conductive and magnetic properties of ferrite powders and nanocomposites were characterized by means of modem analytical techniques. The results showed that the saturation magnetization of the ferrites doped with Gd increased with increase of Gd content. The conductive and magnetic properties of composites depended on the polypyrrole content. As the polypyrrole content increased from w=50% to w= 80%, the conductivity increased from 0.0139 to 0.0423 S/cm, while the saturation magnetization decreased from 18.37 to 14.35 emu/g. The pure PPy with thickness of 2 mm showed a minimum reflection loss of -19.68 dB at 16 GHz and an available bandwidth of 6.2 GHz in the 7～18 GHz range. The minimum reflection loss value and the available bandwidth of ZCCFS_(0.04)O had only-16.6 dB and 5.16 GHz. PPy/Zn_(0.6)Cu_(0.4)Gd_xFe_(2-x)O_4 composites with w=20% Zn_(0.6)Cu_(0.4)Gd_xFe_(2-x)O_4 had the minimum reflection loss of -20.90 dB and available bandwidth was broadened to 11.30 GHz. The results show that the PPy/ZCGFO composites could be used as advancing microwave absorption and shielding materials due to their favorable microwave absorption properties.