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选用硼氢化钠(NaBH4)作为还原剂,聚乙二醇(PEG2000)作为表面活性剂,利用简单的湿化学还原工艺,在室温下制备花状自组装的FePt纳米颗粒。XRD和TEM表征显示:所制备的FePt纳米颗粒是化学无序的面心立方(fcc)结构。颗粒形貌主要由平均粒径分别为19.2和4.9nm的梭形和球形颗粒组成。这些梭形的“花瓣”和球形的“花蕊”自组装形成大小不等的花状结构。推测认为,纳米颗粒的花状自组装主要是表面活性剂集合的结果。VSM显示所制备FePt纳米颗粒的磁性能室温下为超顺磁性,饱和磁化强度Ms约为10.9(A·m2)/kg,相同条件下PVP作为表面活性剂时Ms约为0.6(A·m2)/kg,两者比较,选用PEG作为表面活性剂,Ms大约增大18倍。
The flower-like self-assembled FePt nanoparticles were prepared at room temperature using sodium borohydride (NaBH4) as the reducing agent and polyethylene glycol (PEG2000) as the surfactant using a simple wet chemical reduction process. XRD and TEM characterization showed that the prepared FePt nanoparticles were chemically disordered face-centered cubic (fcc) structures. The particle morphology consists mainly of fusiform and spherical particles with an average particle size of 19.2 and 4.9 nm, respectively. These fusiform “petals” and spherical “stamens” self-assemble into flower-like structures of varying sizes. Presumably, flower-like self-assembly of nanoparticles is primarily the result of surfactant pooling. VSM showed that the magnetic properties of the prepared FePt nanoparticles were superparamagnetic at room temperature, the saturation magnetization Ms was about 10.9 (A · m2) / kg, and the Ms was about 0.6 (A · m2) when PVP was used as a surfactant under the same conditions. / kg, comparing the two, the choice of PEG as a surfactant, Ms increased about 18 times.