Magnetically controlled crystallographic properties of graphite sheets with self-assembled periodic arrays of magnetoelectric nanoparticles

Abstract This paper presents an experimental study in which 30-nm CoFe2O4–BaTiO3 core-shell magnetoelectric nanostructures (MENs) were embedded into graphite sheets to enable external control of intrinsic properties such as the intercalation process. The embedded nanoparticles were self-assembled into a honeycomb pattern with a characteristic period on the order of 200 nm, as confirmed through energy-dispersive spectroscopy (EDS) by scanning electron microscopy (SEM) as well as through atomic and magnetic force microscopy (AFM and MFM). Integration of the nanoparticles into the graphite structure was also confirmed through Fourier transform infrared (FT-IR) imaging and X-Ray diffraction (XRD) analysis. XRD measurements indicate crystallographic changes in the response to application of a 500-Oe magnetic field. M-H measurements by vibrating sample magnetometer (VSM) showed the coercivity of the nanoparticles on the order of 250 Oe.