メタマテリアルとしての強磁性金属ナノコンポジットの透磁率計算

摘要

We have numerically studied magnetic permeability of Ni nanocomposite films, in which the dipolar interactions between Ni particles are considered explicitly. Eddy current losses as a function of particle diameter are estimated. Moreover, numerical model of thenanocomposite is constructed according to our recent experimental results and a micromagnetic calculation is conducted. The value of permeability strongly depends on the volume fraction of Ni particles. We reveal that particle volume fraction of 0.035 is necessaryto realize negative permeability of the nanocomposites. As the randomness of particles increases, the negative value of permeability drastically shrinks. However, the region of applied field, where the permeability is negative, becomes broader. This is advantageousfor broad-band lefthanded metamaterials in microwave regions.