海刺猬状微纳结构钴镍化合物的合成与表征(英文)

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。

Synthesis and Characterization of Co-Ni Compound with Urchinlike Micro/Nano Structure

Particles with urchinlike micro/nano structure were synthesized by a facile homogeneous co-precipitation process via the direct reaction between cobalt salt, nickel salt and urea. By varying the reaction temperature, concentration of reactant and reactant ratio, the obtained precursors are well-defined urchinlike particles with many thorns radially grown on the surface. After subsequent heat treatment of the corresponding precursors in oxidation and reduction atmosphere, respectively, the final products with different morphologies were characterized by FE-SEM, TEM, XRD and VSM. The heat-treated products with good ferrimagnetism fairly maintain the morphology of their corresponding precursors in oxidation atmosphere. A possible mechanism for the growth of this urchinlike architecture is proposed. It is worth noting that in reduction atmosphere, the particles grow into porous micro/nanospheres and exhibit preferable ferrimagnetism.