Multidielectric polarizations in the core/shell Co/graphite nanoparticles

Hybrid core/shell Co/graphite nanoparticles synthesized by an arc-discharge method exhibit an enhanced dielectric loss property in the frequency range of 2-18 GHz. Complex permittivity expressed by Debye dipolar polarization approximate show that three kinds of dielectric polarizations coexist in this hybrid system. Combined with theoretical simulation, we further clarified that the dielectric polarizations are ascribed to the high defective graphite shells, and additional interfacial polarizations arising from the special core/shell architecture.