The electrochemical exfoliation of graphite to give one-atom-thick graphene with desirable properties is a green, cost-effective method for high-yield graphene production. This paper presents the results of electrochemical exfoliation of two different graphite precursors under an applied direct current voltage of +12 V. The used characterization techniques (elemental analysis, Fourier transform infrared spectroscopy, X-ray diffraction, X-photoelectron spectroscopy, Raman spectroscopy, field emission scanning electron microscopy and atomic force microscopy) showed that the exfoliated powder is highly functionalized with a low carbon/oxygen content that is similar to graphene oxide. The exfoliated graphene sheets dispersed in N,N′-dimethylformamide were deposited on ano-discs by vacuum filtration and transferred to glass ceramic substrates. The thermal annealing of the as-deposited films at 600 °C for 30 minutes resulted in an increase in the carbon/oxygen ratio by more than 3 fold and a decrease in the sheet resistance by 25%. The lowest values for the sheet resistance of the annealed graphene thin films were in the range of 0.32 ± 0.04 to 0.84 ± 0.1 kohm sq⁻¹ depending on the graphite source that was used.

Laser-induced periodic surface structures (LIPSSs) and chemical composition changes of Ti-based nanolayered thin films (Al/Ti, Ni/Ti) after femtosecond (fs) laser pulses action were studied. Irradiation is performed using linearly polarized Ti:Sapphire fs laser pulses of 40 fs pulse duration and 800 nm wavelength. The low spatial frequency LIPSS (LSFL), oriented perpendicular to the laser polarization with periods slightly lower than the irradiation wavelength, was typically formed at elevated laser fluences. On the contrary, high spatial frequency LIPSS (HSFL) with uniform period of 155 nm, parallel to the laser light polarization, appeared at low laser fluences, as well as in the wings of the Gaussian laser beam distribution for higher used fluence. LSFL formation was associated with the material ablation process and accompanied by the intense formation of nanoparticles, especially in the Ni/Ti system. The composition changes at the surface of both multilayer systems in the LSFL area indicated the intermixing between layers and the substrate. Concentration and distribution of all constitutive elements in the irradiated area with formed HSFLs were almost unchanged.

Thin films of nichrome were deposited by d.c. sputtering of a target (80%Ni 20%Cr w.t) by Ar+ions at a working pressure of 10-1 Pa and at room temperature. The phase composition and grain size were studied by X-ray Diffraction (XRD), while the surface chemical composition was determined by Low Energy Ion Scattering (LEIS). Analysis of phase composition showed that the NiCr thin films were a solid solution of chromium in a nickel matrix with increased nickel lattice parameters. LEIS analysis showed the presence of Ni Cr and O in the first atomic layer. There is a strong suspicion that surface passivation occurred by forming Cr2O3 oxide at the surface.