▎ 摘　　要

We fabricate hybrid magnetoactive materials (hMAMs) based on cotton fibers, silicone oil, carbonyl iron and graphene nanoplatelets (nGr) at various mass concentrations Phi(nGr). The obtained materials are used as dielectric materials for manufacturing plane electrical capacitors. The equivalent electrical capacitanceCpand resistanceRpare measured in an electric field of medium frequencyf, without and respectively with a magnetic field of magnetic flux density B in the range from 0.1 T up to 0.5 T. The results are used to extract the components epsilon(r)' and epsilon(r)'' of the complex relative permittivity epsilon(r)*, and to reveal the magnitude of the induced magnetoelectric couplings k(x) and magnetodielectric effectsMDE. It is shown that epsilon(r)', epsilon(r)'', k(x) and MDE are significantly influenced by f, B and Phi(nGr). We describe the underlying physical mechanisms in the framework of dipolar approximation and using elements of dielectric theory. The tunable magnetoelectric and magnetodielectric properties of hMAMs are useful for manufacturing electrical devices for electromagnetic shielding of living organisms.