【摘要】 以乙酰酮丙镍为原料,通过金属有机物化学气相沉积,合成超细Ni-C核-壳纳米颗粒。采用XRD、Raman光谱仪、TEM和多功能物理测试系统对合成的纳米颗粒的物相、结构和磁学性能进行表征。这种超细纳米颗粒外表包覆一层厚度1³ nm的C层,内部Ni核的平均粒径为13 nm。磁学测试表明,超细Ni-C核-壳纳米颗粒的饱和磁矩为24.5 emu/g,矫顽力为65.5 Oe,远低于直径超过20 nm的Ni-C核-壳纳米颗粒的对应值。微波吸收测试表明,超细Ni-C核-壳纳米颗粒和石蜡的混合物的最小反射损失值(RL_min)为-48.7 d B,有效带宽(BW_eff,RL≤-10dB)为7.4 GHz,是一种非常具有潜力的微波吸收材料。更多还原

【Abstract】 Ultra-small Ni-C core-shell nanoparticles were synthesized by the metal organic chemical vapor deposition(MOCVD) using Ni(acac)2 as precursor. The structure and magnetic properties of the as-synthesized nanoparticles were characterized by XRD, Raman spectroscopy, TEM and Physical Property Measurement System respectively. The Ni nanocores have an average diameter of 13 nm, and are encapsulated by C shells with the thickness of 1-3 nm. The Ni-C core-shell nanoparticles have a saturation magnetic moment of 24.5 emu/g, coercivity of 65.5 Oe which is much smaller than the corresponding values of bulk Ni and Ni-C core-shell nanoparticles which are 20 nm in diameters. In the microwave absorption tests, a low reflection loss(RL) of-48.7 dB and a large effective bandwidth(frequency range for RL≤-10 dB) of 7.4 GHz are obtained from the composites of small Ni-C core-shell nanoparticles and paraffin. This suggests that the as-synthesized ultra-small Co-C core-shell nanoparticles have a high potential as the microwaveabsorbing materials.更多还原