Magnesium phosphate glasses co-doped with Er3+/Nd3+ concentration were prepared using melt quenching technique and thermal annealing process was proposed to control any defects found in the glass samples. The physical and optical properties of the samples were investigated. The amorphous nature of the samples were confirmed using X-ray diffraction pattern. It shows that all samples are in amorphous state. The optical band gaps and Urbach energies were obtained from the optical absorption spectra. The studyshows that the optical band gap energy,Eopt isincreasingas the Nd2O3 content increased. Meanwhile, Urbach energies, ΔE decreased due to increase of Nd2O3 content. The results obtained from this study shows that the optical band gap, Eopt and the Urbach energy, ΔE are intherange of 3.95 –3.98 eV and 0.367 –0.437 eV respectively.

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A new carbon material viz. graphene has been attracted an increasing research interest owing to its unique electrical and mechanical properties that is useful for the various device applications. The synthesis of graphene from graphene oxide usually involves harmful chemical reducing agents that are toxic and undesirable to human and the environment. By avoiding the use of toxic and environmentally harmful reductants, we report a green approach to effectively reduce graphene oxide to graphene in glucose solution at room temperature. Graphite oxide was synthesized from graphite powder using modified Hummers’ method. Graphite oxide then further exfoliated to graphene oxide by using ultrasonic irradiation. The mild reduction of graphene oxide is carried out by mixing graphene oxide solution with glucose. The reduction time is varied with 15, 30, 45 and 60 minutes. TEM images provide clear evidence for the formation of few layer graphene. Characterization of theresulting glucose reduced graphene oxide by FTIR indicates the partial removal of oxygen-containing functional groups from the surface of graphene oxide and formation of graphene with defects.

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