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采用均相沉淀法,以Co(NO_3)_2·6H_2O和Ni(NO_3)_2·6H_2O为原料,尿素作为沉淀剂,成功制备出了新型海刺猬状微/纳复合结构。通过调节反应温度,反应物浓度和物质的量的比,所获得的前驱体呈放射状纳米线构成的海刺猬结构。随后分别在氧气氛和氢气氛下对制备出的前驱体进行热处理,利用FE-SEM、TEM、XRD以及VSM等测试手段对制备出的微/纳复合结构前驱体及热处理产物进行了形貌表征、物相分析以及磁学性能表征。在氧气氛条件下处理得到的产物具有良好的亚铁磁性,并且很好地保持了前驱体的结构与形貌。结合热处理产物的分析,对该海刺猬微纳结构前驱体提出了一种可能的形成过程和机理。另外,在氢气还原条件下处理得到的产物为多孔微纳米球状结构,呈现出更为优异的亚铁磁性。
A novel hedgehog-shaped micro / nano composite structure was successfully prepared by homogeneous precipitation method with Co (NO_3) _2 · 6H_2O and Ni (NO_3) _2 · 6H_2O as raw materials and urea as the precipitating agent. By adjusting the reaction temperature, the concentration of reactants and the ratio of the amount of material, the precursors obtained are structures of sea hedgehog formed by radial nanowires. Subsequently, the prepared precursors were respectively heat-treated in oxygen atmosphere and hydrogen atmosphere. The prepared micro / nano composite structure precursors and heat-treated products were characterized by means of FE-SEM, TEM, XRD and VSM , Phase analysis and characterization of magnetic properties. The product obtained under the treatment of oxygen atmosphere has good ferrimagnetism and good structure and morphology of the precursor. Combined with the analysis of the heat-treated products, a possible formation process and mechanism of the Hedgehog micro-nano structure precursor was proposed. In addition, the products treated under the conditions of hydrogen reduction are porous micro-nano spherical structure, showing more excellent ferrimagnetism.