Magnetodielectric effect of Graphene-PVA Nanocomposites
  Graphene-Polyvinyl alcohol (PVA) nanocomposite films with thickness $120 \mu m$ were synthesized by solidification of PVA in a solution with dispersed graphene nanosheets. Electrical conductivity data were explained as arising due to hopping of carriers between localized states formed at the graphene-PVA interface. Dielectric permittivity data as a function of frequency indicated the occurrence of Debye-type relaxation mechanism. The nanocomposites showed a magnetodielectric effect with the dielectric constant changing by 1.8% as the magnetic field was increased to 1 Tesla. The effect was explained as arising due to Maxwell-Wagner polarization as applied to an inhomogeneous two-dimensional,two-component composite model. This type of nanocomposite may be suitable for applications involving nanogenerators. 
Sreemanta Mitra, Oindrila Mondal, Dhriti ranjan Saha, Anindya Datta,   Sourish Banerjee, Dipankar Chakravorty
cond-mat.mes-hall cond-mat.mtrl-sci