| 磁场对超细镍粉的磁性能及电磁屏蔽性能的影响 |
| Effect of External Magnetic Field on Magnetic Properties and Electromagnetic Shielding Performance of Ultrafine Nickel Particles |
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| 摘要: 分别在水和乙二醇溶液中，于搅拌条件下采用液相还原法制备超细镍粉，研究反应过程中外加磁场对产物形貌及性能的影响。结果表明，水中得到的产品为刺球状颗粒，外加磁场对产物的形貌影响不大；乙二醇中得到类球形颗粒，加磁场后得到短链状结构。外加磁场使超细镍粉的饱和磁化强度值降低而矫顽力值升高。将水体系中得到的超细镍粉作为导电填料制备电磁屏蔽涂料，结果发现外加磁场条件下得到的超细镍粉/树脂复合涂料在130 MHz～1.5 GHz频段内具有更好的电磁屏蔽性能。 |
| 关键词: 超细镍粉 外加磁场 磁性能 电磁屏蔽性能 |
| 基金项目: |
| Abstract: Bulk quantity of ultrafine Ni particles was synthesized under stirring condition with or without an external magnetic field in distilled water and ethylene glycol(EG), respectively. The products were analyzed by XRD, SEM, TEM and Vibrating Sample Magnetometer (VSM). All products were characterized to be pure crystalline nickel with a face-centered cubic(fcc) structure. In water, the products are spiky-sphere particles, the length of the spikies could be 300 nm while the average diameter of the spheres is ～400 nm, and in addition, the external magnetic field has little effect on the morphologies. When the solvent is EG, the products are quasi-sphere particles and the diameter is ～400 nm and when an external magnetic field is applied, the products are short chain ones. As to the magnetic properties, when compared to those of the products obtained from EG, the ultrafine nickel particles obtained from distilled water exhibit higher saturation magnetization(Ms) values and lower coercivity(Hc) values. When an external magnetic field is applied, Ms values are decreased while Ms values are increased no matter what solvent is used. The above results mean that under stirring condition, both the external magnetic filed and the solvent have an effect on the growth process of the nickel nanocrystals and thus affect the morphologies and the magnetic properties of the products. Composites filled with ultrafine nickel particles obtained from distilled water were fabricated to evaluate the electromagnetic interference shielding performance. The results show that at 130 MHz～1.5 GHz, the shielding performance of the composites filled with nickel particles obtained in presence of an external magntic field is better than that of the composites filled with nickel particles obtained in absence of an external magntic field. |
| Keywords: ultrafine Ni particles external magnetic field magnetic properties electromagnetic shielding effectiveness |
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| 龚春红,田俊涛,吴志申,张治军.磁场对超细镍粉的磁性能及电磁屏蔽性能的影响[J].无机化学学报,2008,24(6):964-970. |
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