【摘要】 采用微乳液法成功合成出以磁性铁氧体（NiFe₂O₄）为内核,以氧化硅（SiO₂）为壳层的纳米颗粒。NiFe₂O₄/SiO₂核壳结构纳米复合材料的形成过程是:将合成出的NiFe₂O₄纳米颗粒均匀分散正硅酸乙酯（TEOS）溶液中,然后对TEOS进行水解并在NiFe₂O₄纳米颗粒表面沉淀,将纳米颗粒分离出并进行后续热处理。通过XRD、IR、SEM、TEM等测试手段对纳米颗粒样品的显微组织结构进行了相应分析和观察。研究发现,纳米颗粒具有NiFe₂O₄/SiO₂核壳结构,其晶粒的平均直径大约为40 nm。采用振动样晶磁强计测试样品磁性能可发现纳米颗粒表现出典型的超顺磁性,其饱和磁化强度为12.97 emu·g^-1更多还原

【Abstract】 Nanoparticles consisting of a magnetic core of nickel ferrite（NiFe₂O₄） and a shell of silica（SiO₂） were synthesized by reverse microemulsion method.The hydrolysis and condensation of tetraethyl orthosilicate（TEOS） in the mixture led to the encapsulation of NiFe₂O₄ particles,to form NiFe₂O₄/SiO₂ core-shell nanocomposites.And the microstructure of this nanoparticles were characterized by Powder X-ray diffraction,fourier transform infrared spectroscopy,scanning electron microscopy,and transmission electron microscopy.It was found that the average size of NiFe₂O₄/SiO₂ nanoparticles was ca.40 nm.The magnetic properties were analyzed by vibration sample magnetometer and the nanoparticles exhibited paramagnetic properties with a total magnetization value of 12.97（A·m²）-kg^-1.更多还原