We report a single step facile synthesis of highly water dispersible functionalized graphene nanosheets by plant extract-induced deoxygenation of graphite oxide (GO). The results of various characterizations reveal that the properties of such plant extract-converted graphene nanosheets (PCGN) are comparable to chemically converted graphene nanosheets (CCG). These results open a green route to the emerging graphene-based technologies.

Thin films of (0.5%, 1%) Nb:SrTiO3 dilutely doped with (2at.%) magnetic transition elements (Cr, Co, Fe, Mn) are examined for ferromagnetism. X-ray diffraction, Rutherford backscattering ion channeling, scanning transmission electron microscopy Z-contrast imaging, and electron energy loss spectroscopy techniques establish high crystalline quality of the films with no impurity phase(s) and highly uniform dopant distribution. Although the film conductivity improves dramatically by Nb doping, no ferromagnetism is found in any of our samples over the temperature range of 365 down to 5K. This is contrasted to the case of ferromagnetism reported in cobalt doped (La,Sr)TiO3.

Epitaxial thin films of optimally doped, underdoped, and Zn-doped $\mathrm{Y}{\mathrm{Ba}}_2{\mathrm{Cu}}_3{\mathrm{O}}_{7-\delta }$ (YBCO) were grown on single crystal (001) $\mathrm{Nb}:\mathrm{Sr}\mathrm{Ti}{\mathrm{O}}_3$ substrates by pulsed laser deposition (PLD) and the electrical properties of the corresponding interface junctions were examined. The growth conditions were optimized in each case to get the appropriate crystalline quality of the films as well as the desired normal state and superconducting properties. The films or heterointerfaces were characterized by x-ray diffraction, Rutherford backscattering (RBS) ion channeling spectrometry in normal and oxygen resonance modes, magnetic susceptibility, four probe in-plane resistivity, and the temperature dependent current-voltage $\left(I\text{−}V\right)$ characteristics. Nonlinear $I\text{−}V$ curves (forward and reverse) were obtained in all the cases, revealing some characteristic differences and interesting temperature evolution. These data, when analyzed within the framework of a standard description of transport across the metal-semiconductor (Schottky) interface, suggest lateral intrinsic nanoscale electrical inhomogeneity in the system. Also as compared to the case of optimally doped YBCO a small but definitive lowering of the effective Schottky barrier height ${\Phi }_{\mathrm{B}}$ is observed for junctions based on oxygen underdoped and Zn-doped YBCO.