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The total and partial densities of electron states of layered gold structures of different symmetry with thickness from 1 to 10 monolayers are calculated within the framework of the density functional theory. As shown, the first co-ordination sphere is determinant in the formation of the fine structure and the extent of the valence bands of the monolayer gold structures. The splitting of the peaks of the TDOS curve, which leads to its finer structure, is influenced not only by the lengths of interatomic bonds, but by the mutual arrangement of atoms too. The influence of long-range interactions on the electronic structure of gold monolayers is established. For example, for the (110) plane, a change in the atomic ordering in the third co-ordination sphere as a result of the introduction of a vacancy leads to noticeable changes in the TDOS curve that indicates either a significant role of the atoms of the third co-ordination sphere, or a significant redistribution of the interaction of dorbitals of different symmetries of close neighbours. A correlation between the packing density as well as the number of neighbours in the first coordination sphere and the width of the energy bands of gold monolayers is revealed. [ABSTRACT FROM AUTHOR]

Copyright of Progress in Physics of Metals / Uspehi Fiziki Metallov is the property of G.V. Kurdyumov Institute for Metal Physics, N.A.S.U and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Nanosistemi, Nanomateriali, Nanotehnologii is the property of G.V. Kurdyumov Institute for Metal Physics, N.A.S.U and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Nanosistemi, Nanomateriali, Nanotehnologii is the property of G.V. Kurdyumov Institute for Metal Physics, N.A.S.U and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Self-assembled core-shell Ni-C nanoparticles (NPs) with nearly uniform sizes were grown on the van der Waals (0001) surfaces of GaSe layered crystals. The metal NPs encapsulated within graphite shells (Ni@C) with the sizes ranging from a few to 15 nm were produced by electron beam induced vacuum deposition from metal-carbon melts under UV-irradiation without annealing after the deposition. The samples were characterized by X-ray diffraction, atomic force microscopy, X-ray photoelectron spectroscopy, Raman spectroscopy. The van der Waals interactions between the NPs and the surface electrostatic interactions are utilized for encapsulated NPs self-assembly. The Coulomb staircases and the negative differential conductance were observed at temperatures lower than 300 K in the current-voltage ( I- V) curves of the vertical hybrid structures Au/Ni/(Ni-C)/Ni@CNCs/n-Ga2O3/p-GaSe/In consisting of ferromagnetic metal Ni, (Ni-C) nanocomposite thin film and two layers of magnetic NPs (Ni@CNCs), which were embedded in n-Ga2O3 wide-band-gap oxide. The I- V characteristics of this structure depend on orientation of the external weak (∼60 mT) magnetic field relative to the (0001) GaSe plane. Peculiarities observed in the I- V characteristics of the hybrid structures may be caused by magnetic-field-dependent phenomena of spin-dependent tunneling through the barriers, which gives rise to spin accumulation, and spin-polarized electric current interactions with magnetic NPs. [ABSTRACT FROM AUTHOR]

In this paper, we synthesize the series of Ca-HAP--carbon nanomaterials composites. We use various synthes is methods--mechanical mixing and mixing in aqueous suspension with ultrasonication (original calcium hydroxyapatite powder was synthesized by deposition method from basic aqueos solution). We utilize carbon nanotubes, fullerenes (C6-) and shungite as modifying materials. By X-ray photoelectron spectroscopy we investigate the electronic structure of samples. We also conduct the infrared spectroscopy examination of samples. We reveal that the interaction between Ca-HAP and carbon nanomaterials leads to insignificant redistribution of electron density between oxygen, phosphorus and calcium atoms. This indicates the increase of covalent component share in the overall chemical bond balance of Ca-HAP modified by carbon nanomaterials. Similarly at these modifications the PO3-4 - tetrahedra vibrations symmetry increases and the structure orders. All the obtained results demonstrate that introducing carbon nanomaterials into calcium hydroxyapatite leads to formation of molecular complexes and structure ordering. [ABSTRACT FROM AUTHOR]