Preparation and microwave characterization of submicrometer-sized hollow nickel spheres

Abstract: The hollow structural submicrometer-sized nickel spheres were successfully fabricated by the autocatalytic reduction method. Because of the metallic and ferromagnetic behaviour of the nickel spheres, the low-density microspheres could obtain high dielectric constant and magnetic loss in microwave frequencies. The abrupt variation of the real part and the sharp peaks of the imaginary part of permittivity and permeability were observed for the micrometer-sized and nanometer-sized nickel hollow spheres. Reflection loss less than −25dB were predicted over 11GHz with a thickness of 1.5–2.0mm. [Copyright &y& Elsevier]