Ni/Al2O3 nanocomposites were prepared by the mechanochemical synthesis method. The annealing process enlarges the grain size of both the metal Ni and insulating Al2O3 in the as-milled nanocomposite and leads to an inc...Ni/Al2O3 nanocomposites were prepared by the mechanochemical synthesis method. The annealing process enlarges the grain size of both the metal Ni and insulating Al2O3 in the as-milled nanocomposite and leads to an increase of the saturation magnetization and a decrease of the surface anisotropy. An optimal reflection loss （RL） of -23 dB is obtained in the as-milled nanocomposite at 17.8 GHz for an absorber thickness of 6.6 mm. The annealed sample exhibits a RL exceeding -20 dB in the whole Ku-band for an absorber thickness of 6.6-9.7 mm with an optimal RL of -54.7 dB at 13.2 GHz for a layer thickness of 9.3 mm. The excellent microwave-absorption properties are a consequence of a proper match of the dielectric and magnetic losses.展开更多
基金financially supported by the Dr.Research Start-up Fund of Shenyang Ligong University(No.2008,(20))
文摘Ni/Al2O3 nanocomposites were prepared by the mechanochemical synthesis method. The annealing process enlarges the grain size of both the metal Ni and insulating Al2O3 in the as-milled nanocomposite and leads to an increase of the saturation magnetization and a decrease of the surface anisotropy. An optimal reflection loss （RL） of -23 dB is obtained in the as-milled nanocomposite at 17.8 GHz for an absorber thickness of 6.6 mm. The annealed sample exhibits a RL exceeding -20 dB in the whole Ku-band for an absorber thickness of 6.6-9.7 mm with an optimal RL of -54.7 dB at 13.2 GHz for a layer thickness of 9.3 mm. The excellent microwave-absorption properties are a consequence of a proper match of the dielectric and magnetic losses.
