Defect mediated magnetism in Pr/TiO₂- reduced graphene oxide nanocomposites

Synthesis and characterization of Pr/TiO2 nanoparticles with its reduced graphene oxide nanocomposites by solgel and hydrothermal reaction and its magnetic properties is presented. X ray Diffraction and Raman analysis confirms the anatase phase structure in both nanoparticles and composites with Pr doping hindering the crystallite growth. Field Emission Scanning Electron Microscope and High Resolution Transmission Electron Microscope analysis confirm unambiguously the attachment of TiO2 spherical nanoparticles onto the graphene sheets forming an intimate interfacial contact between the particle and sheets enabling electron charge transfers. Difference in surface areas and surface energies give rise to variable emission intensity of the samples. Pr/TiO2 nanocomposites exhibit an increased bandgap values than their nanoparticles. Both Photoluminescence and Electron Paramagnetic Resonance spectroscopy confirm an increase in defect structure with increase of Pr doping. Magnetization studies show weak ferromagnetic ordering for pure TiO2 nanoparticles. The soft magnetic behaviour of the synthesised materials is useful in fabricating memory based devices.