纳米镍/炭复合材料的制备与磁性表征

Preparation and magnetic behavior of nano-Ni/C composite material

以废弱酸型聚丙烯酸系阳离子交换树脂为炭前驱体,经过与镍离子交换后,再经热解制备纳米镍粒子均匀分散于炭基体的纳米镍/炭(N i/C)复合材料。以XRD、TEM为主要分析手段研究了热解条件对纳米镍粒子在N i/C复合材料中的形貌、大小的影响。结果表明:通过热解条件可以控制N i/C复合材料中纳米镍粒子的平均粒径;热解温度的升高和热解保温时间的增加都可使N i/C中纳米镍粒径增大。磁性能测试结果表明:N i/C-500表现为超顺磁特性,而N i/C-600、N i/C-700为铁磁性;N i/C-600、N i/C-700的比剩磁化强度、矫顽力都要大于微米镍粉与块体镍,但其比饱和磁化强度要小于微米镍粉和块体镍。

A kind of Ni/C composite material, in which nano nickle particles were uniformly distributed in carbon matrix, was prepared by pyrolysis of Ni - exchanged cation exchange resin （ Ni - PAA）. The effect of pyrolytic conditions on the morphology, size of nano nickel particles in Ni/C composite material was studied by means of X -ray diffraction （XRD）, Transmission Electron Microscope （TEM）. The resuits show the particle size of nano nickel in Ni/C can be controlled by pyrolytic conditions; the particle size increases as the pyrolytic temperature and the holding time increase. Magnetic tests show that Ni/C -500 is superparamagnetic, while Ni/C -600, Ni/C -700 are ferromagnetic. The remanence and the coercivity at room temperature of Ni/C -600 and Ni/C -700 are higher than those of the corresponding micrometer nickel powders and bulk nickle, while the saturation magnetization is lower than those of micrometer nickel powders and bulk nickel.