Large electromagnetic wave absorbing bandwidth of composites containing Fe3O4 nano ribbons

High operation frequency and large absorbing bandwidth are often required for electromagnetic noise suppression. Magnetic materials with strong anisotropy field (shape anisotropy or magnetocrystalline anisotropy), for instance FeCo nano plates, are needed to increase the operation frequency into the gigahertz (GHz) zone to solve the stringent problem of electromagnetic interference among the modern electronic devices. Traditional absorbers with magnetic inclusions suffer a narrow absorbing bandwidth due to the fact that only natural resonance losses can be exploited. In order to increase the absorbing bandwidth, other sources of high-frequency magnetic losses are demanded. Recently, it was reported that the exchange coupling between magnetic nanostructures can give rise to multi resonance phenomena. In this contribution, the magnetic losses arising from the multi resonances in nano ribbons will be investigated.