Ni-SiO_2纳米复合材料的制备及磁学性质

Preparation and Magnetic Properties of Ni-SiO_2 Nanocomposites

以正硅酸乙酯和硝酸镍为原料,利用溶胶-凝胶法制备了纳米NiO-SiO2复合体,再通过氢气还原得到Ni-SiO2纳米复合材料。利用X射线衍射(XRD)确定了样品的相组成,利用透射电子显微镜(TEM)观察了样品的微观结构,利用振动样品磁强计测定了样品的磁性能。研究了成分和焙烧温度对纳米复合颗粒微观结构和性能的影响。研究发现,所形成的纳米颗粒是以Ni为核心,外面包裹着非晶态SiO2层的核壳结构。随着硅含量的增加,包裹层变厚,随着焙烧温度升高颗粒直径增大。讨论了制备条件和SiO2含量对材料的微观形貌和磁学性能的影响。

Using Ni（NO3）2 and TEOS as nickel and silica sources, NiO-SiO2 nanocomposites were prepared by sol-gel method, Ni-SiO2 nanocomposites were obtained by reducing NiO-SiO2. The phase structure, microstructure and magnetic properties of the particles was determined and measured by X-ray diffraction （XRD）, transmission electron microscopy （TEM） and vibrating samples magnetometer （VSM）, respectively, As the content of the silicon increases, the thickness of silica shells increases. It was found that the particle size increases as the temperature increases. The influences of Ni content and preparation conditions on the magnetic properties and microstructures were discussed.