The work represents the results of experimental and theoretical studies of the electronic, atomic structure and morphological features of mono- and multilayer nanostructures of noble metals, nickel and indium on the Si (111) 7х7, Si (110), InSe (0001) and GaSe (0001) single-crystal surfaces under their thermal deposition in high vacuum. The mechanisms of the formation of nanostructures of noble metals, nickel, and indium on the Si (111) 7х7, Si (110), InSe (0001) and GaSe (0001) single-crystal surfaces under multistage thermal deposition are studied.
Technology for the production of self-ordered hexagonal-pyramidal nanostructures of copper and gold on the Si (111) 7х7 single-crystal surface has been developed. The formation mechanisms of the hexagonal-pyramidal structures of gold and copper are determined by the behavior of the electron density at the edges of the monoatomic growth steps. Self-ordered hexagonal-pyramidal gold and copper nanostructures under vacuum thermal deposition are formed only on the Si (111) 7x7 plane, while for the Si (110) plane only monolayer hexagonal formations are observed. The surface symmetry of the single-crystal Si (111) 7x7 plane is determining in the growth mechanism of the hexagonal-pyramidal structures of copper and gold. The electronic growth mechanism satisfactorily describes the formation of hexagonal-pyramidal nanostructures of copper and gold.
An atomically flat Ag film cannot be obtained on the semiconductor surface of Si (111) 7x7 single crystal by thermal deposition under ultrahigh vacuum at the room temperature. The formation of several-layer 2D cluster formations occurs, the heating of which at several Celsius degrees leads to their stretching into an atomically even surface coating. The formation of the “carpet” effect is described by the electronic growth mechanism.
A weak interaction of monolayer coatings of Ag with a substrate is established, which, with slight heating, allows the single-crystal surface to be cleaned of metal with restoration of the Si (111) 7x7 surface. The proposed method for the long-term storage of the reconstructed Si (111) 7x7 surface can be used to protect such single-crystal surfaces from destruction.
The mechanism for ordering 0D nickel nanostructures on single-crystal silicon surfaces during vacuum thermal deposition has been established. The symmetry of the arrangement of cluster formations of 3d metals on the Si (111) 7x7 surface repeats the symmetry of the substrate. The nanotribological parameters of subsurface roughness Ra, Rq, Rzjis, Rz, Sratio for surface deposited metal nanostructures are established.
The dynamics of the transformation of the surface morphology and density of electronic states of iron-based AMA under structural relaxation conditions are studied using highvacuum probe microscopy and tunnel spectroscopy. Substantial inhomogeneities of the densities of electronic states are observed at the intercluster limits, which indicates their complex organization. In the process of heat treatment of an amorphous alloy, a greater redistribution of boron atoms occurs compared with iron and silicon atoms, which leads to an increase in the stability of the amorphous structure. The Fermi level of the studied alloys is at the local minimum of the density of electronic states, which corresponds to the Nagel-Tauke criterion on the formation of an amorphous state.
Upon transition from the room temperature to 500 °C, the density of occupied electronic states is characterized by a shift of the main peak of the iron d-band toward the Fermi level. The initial surfaces of iron-based AMAs are characterized by the presence of silicon oxide and silicon carbide; boron on the surface is in the BN compound. The concentration of silicon changes little when moving from the surface to the volume of the sample. The presence of an insignificant amount of carbon and oxygen was established in the sample volume; apparently, this fact is determined by the technological conditions for the production of alloys.
For the first time, hybrid nanostructures based on nanodispersed calcium hydroxoapatite and nanodispersed graphite were obtained. The morphological features and electronic structure of the complexes are investigated. It has been established that the modification of a composite based on nanodispersed apatite, graphite and cellulose fibers with an epoxy oligomer with a hardener has a significant effect on the set of properties of the obtained material, in particular, the conductivity of the sample appears.
