In this paper electrical conductivity measurements and optical investigations takes place in AOT/ heptane/ (water or aqueous) systems. The water in oil system prepared with adding water in 50% by weight of AOT/ heptane solution.  In other systems instead of water, aqueous solutions of 1) zinc acetate and water 2) Potassium Hydroxide and water were used. In each phase, the trend of the electrica...

In this paper electrical conductivity measurements and optical investigations takes place in AOT/ heptane/ (water or aqueous) systems. The water in oil system prepared with adding water in 50% by weight of AOT/ heptane solution.  In other systems instead of water, aqueous solutions of 1) zinc acetate and water 2) Potassium Hydroxide and water were used. In each phase, the trend of the electrica...

We investigate the effect of hydrogen coverage on the optical conductivity of single-side hydrogenated graphene from first-principles calculations. To account for different degrees of uniform hydrogen coverage we calculate the complex optical conductivity for graphene supercells of various sizes, each containing a single additional hydrogen atom. We use the linearized augmented plane wave metho...

The optical conductivities of graphene layers are strongly dependent on their stacking orders. Our first-principle calculations show that, while the optical conductivities of single-layer graphene (SLG) and bilayer graphene (BLG) with Bernal stacking are almost frequency-independent in the visible region, the optical conductivity of twisted bilayer graphene (TBG) is frequency-dependent, giving ...

nanoparticles of zirconium(iv) tungstate are prepared by chemical co-precipitation method. thecharacterizations have been carried out by tg/dta, dsc, afm, xrd, ftir and uv-vis spectrum. plspectrum shows two emission bands at 350 nm and at 477 nm. the effects of frequency on the dielectricbehavior and ac electrical conductivity have been studied. the dielectric constant is found to be 119.43 at1...

We studied NbCl5 and ZnMg alloy intercalated graphite compounds using an optical spectroscopy technique. These intercalated metallic graphite samples were quite challenging to obtain optical reflectance spectra since they were not flat and quite thin. By using both a new method and an in situ gold evaporation technique we were able to obtain reliable reflectance spectra of our samples in the fa...

In this manuscript, we develop printable graphene ink through a solvent-exchange method. Printable graphene ink in ethanol and water free of any surfactant is dependent on matching the surface tension of the cross-solvent with the graphene surface energy. Percolative transport behavior is observed for films made of this printable ink. Optical conductivity is then calculated based on sheet resis...

The transient optical conductivity of freely suspended graphene was examined by femtosecond time-resolved spectroscopy using pump excitation at 400 nm and probe radiation at 800 nm. The optical conductivity (or, equivalently, absorption) changes abruptly upon excitation and subsequently relaxes to its initial value on the time scale of 1 ps. The form of the induced change in the optical conduct...

ZnO and ZnO: Mn nanocrystals synthesized via reverse micelle method. The structural properties nanocrystals were investigated by XRD and Transmission electron microscopy (TEM). The XRD results indicate that the synthesized nanocrystals had a pure wurtzite (hexagonal phase) structure. The various optical properties of these nanocrystals such as optical band gap energy, refractive index, dielectr...

We calculate the optical conductivity in a clean system of quasiparticles coupled to charge-ordering collective modes. The absorption induced by these modes may produce an anomalous frequency and temperature dependence of lowenergy optical absorption in some cuprates. However, the coupling with lattice degrees of freedom introduces a nonuniversal energy scale leading to scaling violation in low...