Narrow Results

The theoretical calculations indicate that the metal-doped boron nitride (BN) sheets are potential materials to store the hydrogen and tune the bandgap. It is all known that the BN sheet is a nonmagnetic wide-bandgap semiconductor. Using density function theory (DFT), the lattice parameters of Cr-doped BN sheets are optimized, which are still kept on two-dimensional (2D) planar geometry, and the bandgap and ${\mathrm{\text{H}}}_2$ storage are studied. The simulation results show that the ${\mathrm{\text{H}}}_2$ molecule can be easily absorbed by Cr-doped N in BN sheet. As the adsorption energy was greatly decreasing with the increasing number of Cr-doped N, B had an affinity for adsorption of ${\mathrm{\text{H}}}_2$. With the increase of Cr doping, the bandgap of Cr-doped BN sheet is decreasing. The bandgap decreases from 4.705 eV to 0.08 eV. So Cr-doped BN sheet is a promising material in storing ${\mathrm{\text{H}}}_2$ and tuning the bandgap.

The results of the investigation of two-layer Fe/Cr systems using the magneto-optical Kerr effect (MOKE) are presented in this paper. The samples were obtained by thermal evaporation in a vacuum with a thickness of individual layers from 2 nm to 50 nm. It was found that the presence of the Cr layer significantly affects the values of the coercivity and the Kerr angle. At a substrate temperature of 450 K, the value of the coercivity is almost half that of the same sample obtained at room temperature of the substrate. In addition, the influence of the order of deposition of layers, as well as the effect of a thin gold protective layer on the parameters measured by the Kerr method, is shown. These studies have shown that the MOKE can be used as an additional method for studying the composition of multilayer systems, granular alloys and spin-valve systems, using specific software methods.