The charge transfer effect at the graphene/transition metal interface has been studied extensively during the last few years; however, the experimental results are very poor. In the present work, a Co atom capped with porphyrin is attached on the graphene surface to realize the induced magnetic properties arising due to the charge transfer effect at the interface. Ferromagnetic ordering with fairly large coercivity (516 Oe) is observed as a result of this induced magnetism in graphene due to the presence of a transition metal atom on the graphene surface. Temperature dependent magnetotransport has also been investigated to understand the effect of spin-orbit coupling arising due to the electric field generated at the interface as a result of this charge transfer effect.

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Nickel oxide nanoparticles of diameter ∼21 nm were prepared by a sol–gel method using the triblock copolymer poly(ethylene glycol)- b -(propylene glycol)- b -(ethylene glycol). X-ray photoelectron spectroscopy analysis showed the presence of Ni 2+ and Ni 3+ ions in the material. The electrical conductivity of this material was due to small polaron hopping between Ni 2+ and Ni 3+ sites. The magnetization shown by these nanoparticles was much higher than that reported in the literature. This is ascribed to the presence of Ni 3+ ions with uncompensated spin moments. Spin-glass behavior was exhibited by the material at 10.7 K. The electrochemical characterization of electrodes comprising of these NiO nanoparticles using cyclic voltammetric measurements showed a specific capacitance value of 810 F/g, the highest reported for this material. These materials will thus form one of the useful multifunctional systems.