Investigation of atomic mixing during adsorption of iron film on silver substrate

The results of calculations of the energy and magnetic characteristics of the activated adsorption of a monolayer ferromagnetic iron film on the silver surface are presented. The studies were carried out using two approaches: the variational method of the spin density functional taking into account temperature effects and inhomogeneous distribution of magnetization and the ab initio one, implemented using the VASP software package. Calculations were made of the total and interfacial energies, magnetic moment and adsorption energy of the Fe / Ag system, depending on the orientation of the substrate face, the coating parameter Θ and the fraction of adatoms in the film. The strong influence of mixing and the energetic advantage of the formation of a "sandwich" system have been revealed. A continuous Fe film will not form on the close-packed Ag face, which is confirmed by experimental studies.

GeTe-Based Alloy Films Prepared by a Room Temperature Solution Process

This article describes the preparation of GeTe-based alloy films using a solution-based technique. The dissolution behavior of GeTe was initially examined by comparing the weight loss of GeTe powder in different solvents, and it was found that, unlike in the cases of n-butylamine and NH4OH, KOH fully dissolved GeTe to form an agglomerate-free solution. X-ray diffraction analysis revealed that the reaction between GeTe and KOH resulted in the formation of rhombohedral GeTe, cubic GeTe4, and hexagonal Te structures after drying. GeTe-based alloy films were then prepared by the spin coating of the GeTe-containing solutions on a silicon substrate. The surface morphology and reflectance properties of the prepared films were found to be highly dependent on the spin speed, with optimization of the spin coating parameter resulting in the deposition of a continuous and smooth film.

Исследование энергетических и магнитных свойств монослойной пленки Fe-=SUB=-x-=/SUB=-Ni-=SUB=-1-x-=/SUB=- на немагнитных металлических подложках

In the framework of the variational method of the spin density functional theory the formation of a monolayer FexNi1-x alloy film on the W, Ag and Au substrates depending on the concentration of the alloy components and coating parameter is described. The temperature effects of the mixing of adsorbate and substrate atoms and ferromagnetic ordering effects are taken into account. The adsorption energy for a close-packed face is minimal for all presented systems. A monolayer film without mixing is formed on Au and W substrate mainly for large values of the coating parameter and the concentration of iron. For the Ag substrate, the difference in the crystal structure leads to an increase in mixing and the formation of a sandwich similar structure with pushing silver atoms onto the surface. The values of the adsorption energy calculated at T = 0 K in the framework of the variational and first-principle approaches are compared. Calculations of the magnetic moments and exchange integrals for FexNi1-x bulk alloy were carried out using the spin-polarized relativistic Korring-Kohn-Rostoker method. The equilibrium lattice constants were obtained by first-principle calculations. The exchange interaction of the nearest neighbors is ferromagnetic and for heterogeneous nearest neighbors J1Ni-Fe increases with increasing nickel concentration, and for the same type neighbors J1Ni - Ni decreases. The next nearest neighbors exchange interaction is carried out only for atoms of the same type, and for iron, atoms have a ferromagnetic character, while for nickel atoms it is weak antiferromagnetic.

Multiparametric reference materials for metrological support in the area of coating parameter control

The present work analyses the state and development prospects of metrological support and standardization of in the field of measuring surface density, thickness and chemical composition of coatings. The main characteristics of the State Primary Measurement Standard GET 168-2015 and developed multiparameter reference materials are described.

The Development of Explosive Metalworking in Poland

The author coordinated the research in Poland by the collaboration with civil and military scientific and research centres. In result they elaborated detonation process of spraying coats designed and constructed stands equipped with detonative devices, they also elaborated the techniques of basic coating parameter measurement and built devices for commercial and scientific services. In the research the author's achievements within the range of explosive welding have been used. The experience of the scientific teams was very effective. It was observed that many phenomena that take place in the processes of detonative layer coating and explosive welding are the same. In order to obtain a required connection the plastic strain of the connected material surfaces has to be achieved and cumulative flows have to be formed. There are a similar range of the connecting process conditions and the mechanisms of plastic strain. The highest connection strength is obtained when an intermediate zone is formed. The zone has to be composed of the two connected materials. The intermediate layer is formed as a result of mechanical alloying of the materials due to large plastic strain. The plastic strain leads to forming meta-stable phases that have properties of pseudo solid solution, chemical compounds, intermetallic phases and fragmentation corresponding to nanomaterials and amorphous states.

Numerical Contact Analysis of Transversely Isotropic Coatings: A Cylinder Within a Circumferential Groove

The contact characteristics of transversely isotropic coatings are investigated for a cylinder within a circumferential groove using a two-dimensional finite element model. With the model, contact behavior is evaluated at more than 400 operating conditions by varying coating material, coating thickness, normal load, and cylinder/groove radii. Based on the finite element results, numerical expressions are derived for the maximum surface pressure, contact length, and approach distance as a function of a transversely isotropic coating parameter, ζ. The importance of these expressions, as related to design and the selection of materials for reducing wear in contacting surfaces, is subsequently discussed.