Synthesis, magnetic and microwave absorption properties of extremely Ni-C core-shell nanoparticles
KUANG Daitao1, WEN Xiang2, LIANG Bingbing1, HOU Lizhen2, MA Songshan1, WANG Shiliang1
1. School of Physics and Electronics, Central South University, Changsha 410081, China; 2. School of Physics and Information Science, Hunan Normal University, Changsha 410081, China
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 microwave- absorbing materials.
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2018, Vol. 23 
