采用溶胶凝胶方法制备前驱体样品,于氩气气氛中进行烧结合成得到单相的具有六方结构Ni纳米颗粒。利用XRD、TEM、VSM等测试手段对材料的相结构、微现结构、结构稳定性及磁性进行研究。结果表明,六方Ni纳米颗粒的最佳合成温度为300℃,其热稳定温度约为350℃。随着热处理温度的升高,样品发生六方向立方结构的相转变,温度为400℃时,全部转变为立方结构相,六方Ni为铁磁性物质,其超顺磁临界尺寸不小于12nm。 Precursor samples were prepared by a sol-gel method and sintered in an argon atmosphere to obtain a single-phase Ni nanoparticle with hexagonal structure. The phase structure, microstructure, structural stability and magnetism of the materials were studied by means of XRD, TEM and VSM. The results show that the optimal synthesis temperature of hexagonal Ni nanoparticles is 300 ℃ and the thermal stability temperature is about 350 ℃. With the increase of the heat treatment temperature, the phase transition of the cubic structure in the six directions occurred. When the temperature was 400 ℃, all of the samples were transformed into the cubic phase. The hexagonal Ni was a ferromagnetic substance with a superparamagnetic critical dimension of not less than 12 nm.