Polyethylene: graphene—a magnetic tunable metacomposite.

Metacomposites are an interesting field of research. This research is regarding tunable magnetic metacomposite formed using graphene and polyethylene (PE). Dielectric measurements show that as the concentration of graphene was increased in PE–graphene nanocomposites, the separation between graphene sheets decreased and negative dielectric constant was observed at low frequencies while high dielectric constant was observed at high frequencies of the applied field. The switching frequency could be controlled by changing the graphene concentrations. Small angle neutron scattering (SANS) analysis showed that the graphene assembled as fractals in the nanocomposites. As more graphene was incorporated into the nanocomposites, the fractals gave rise to percolation. We propose that the fractals are the building blocks for percolation phenomenon in the PE–graphene nanocomposites. Also, we observed ferromagnetism in the PE–graphene nanocomposites till 30% graphene. At 40% graphene the nanocomposite becomes a diamagnet. We attribute this to the topological defects induced in graphene by PE. Theses PE–graphene magnetic meta composites can have potential applications in battery technology. [ABSTRACT FROM AUTHOR]