Graphene devices require electric contacts with metals, particularly with gold. Scanning tunneling spectroscopy studies of electron local density of states performed on mono-, bi-, and trigraphene layer deposited on metallic $\text{Au}/\text{Cr}/{\text{SiO}}_2/\text{Si}$ substrate shows that gold substrate causes the Fermi level shift downwards which means that holes are donated by metal substrate to graphene which becomes $p$ -type doped. These experimental results are in good accordance with recently published density function theory calculations.

Microplastics (MPs) have even been detected in remote environments, including high-latitude regions, where human activities are restricted or strongly limited. We investigated the surface water of the bays of the Barents Sea and the freshwater lakes that are located close to and several kilometers from a year-round resident field station in the remote tundra region of the Kola Peninsula. The microplastics’ presence in aquatic environments in this region has not been indicated yet. Microplastics were detected in all samples collected from the Barents Sea (<4800 items·m⁻³) and the lakes (<3900 items·m⁻³). Fibers made from polyethylene terephthalate (PET)—the most common thermoplastic polymer of the polyester family—and semi-synthetic cellulosic rayon were the most dominant. This indicated that the source of fiber contamination may come from protective clothes, ropes, ship equipment, and fishing nets. Small microplastics can spread through current and atmospheric transport. The Norwegian Current is likely responsible for the lack of correlations found between MP contamination and the distance from the field station between the studied bays of the Barents Sea. On the contrary, a significant correlation with human presence was observed in the concentration of microfibers in the water of the tundra lakes. The number of MP fibers decreased with an increase in the distance from the field station. This is the first study, to the best of our knowledge, that reports such a correlation in a remote region. We also discuss implications for animals. Our results show that even the most isolated ecosystems are not free from microplastic pollution.

The first-order orthorhombic–rhombohedral phase transition of La_1−x Sr _x Ga_1−y Mn _y O₃ (LSGMn) crystals is studied by Raman spectroscopy. An increase in Mn content causes significant changes in Raman spectra, especially in the high-wavenumber spectral range. The Raman spectrum of La_1−x Sr _x Ga_1−y Mn _y O₃ compound with x = y = 0.02 is dominated by MnO₆ internal vibrations. Moreover, a change in the spectrum of this crystal is observed when the 785-nm excitation line is used. Essential reduction in the number of Raman modes during the phase transition is experimentally observed. The temperature of the phase transition decreases with increasing Sr and Mn contents, at the rate of about 20 K/at%.