Using electron beam evaporation, thin films of various compositions (Al, Co, Ge, SiO2) were obtained on inclined Si(001) substrates. It was found that at angles of incidence of the evaporated material on the substrate of more than 70° (sliding deposition), arrays of free-standing inclined nanocolumns with lateral dimensions from 10 to 100 nm and an aspect ratio (length/transverse dimension) of at least 10 were formed on the substrate. When substrate rotation was switched on during film growth, an array of nanospirals twisted in one direction was formed. Such films are chiral metamaterials and show pronounced optical activity. Simulation of film growth processes under oblique angle deposition conditions using the Monte Carlo method showed good qualitative agreement with the experimental data. It was found that the observed processes of nanostructuring during oblique angle deposition are based on universal mechanisms of competition between growing crystalline grains under conditions of neighbor shading. This makes it possible to obtain nanostructured films of various materials with the required functional characteristics under such conditions.

Chiral thin film structures based on arrays of cobalt nanohelices obtained by oblique angle deposition were experimentally studied. It was shown that, in the conditions of electron-beam evaporation on rotating inclined substrate, arrays of nanohelices wound in the same direction are formed. By varying substrate rotation speed, it is possible to change geometrical sizes of those helixes (helix pitch, helix radius). The thus obtained chiral metasurface demonstrates pronounced asymmetry of optical characteristics at the reflection of right and left circular polarized light.

In the manufacture of the porous anodic aluminum oxide (PAAO) matrix, its quality and structural perfection primarily depend on both the grade of the aluminum alloy of the substrate and the quality of the surface. For the manufacture of PAAO, aluminum foil of high-purity aluminum with a content of 99.999% is mainly used. The technological scheme for obtaining highly organized porous aluminum oxide includes preliminary preparation of the foil surface of A9 alloy with an aluminum content of 99.91% by electrolytic plasma and electrochemical polishing methods in this work. Processing made it possible to obtain a surface with roughness parameters Ra = 0.008-0.038 microns. PAAO samples were obtained by double electrochemical anodizing of the prepared foil in 0.5 M oxalic acid, at a voltage of 60 V and a temperature of 25 degrees C and examined by scanning electron microscopy.

This paper focuses on the investigation of magnetic properties of Ni nanowire arrays synthesized using Al2O3 porous template. Porous alumina samples were obtained by double electrochemical anodizing of the prepared foil in 0.5 M oxalic acid, at a voltage of 60 V and a temperature of 25°C and examined by scanning electron microscopy. The pore diameter distribution maximums is about 85 nm. Nanowires were electrodeposited in a 2-electrode electrochemical cell into prepared matrices in a galvanostatic mode. Studies of the surface of porous membranes and the geometry of nanowires were carried out using scanning electron microscope. Investigation of the magnetic properties of Ni nanowires arrays were performed using vibrating magnetometer. Aspect ratio of Ni nanowires is about 250.

MD simulations have been performed to investigate the interface mixing in the low energy (5-10 eV) deposition of Ag on Cu(001). The statistics of single Ag atom impacts on the Cu(001) surface was studied. Interface mixing initiated by atom impacts on the substrate was found to increase with growth of atom arrival energy and temperature of substrate. It has been shown that the probability of exchange is increased in the vicinity of bridge position between two binding sites. Normal incidence was shown to yield maximum of intermixing. Finally the formulae for concentration profile of impurity atoms in the film has been derived.

Thin Co films on inclined Si(001) substrates were obtained by electron-beam evaporation. It has been established that at angles of incidence of the evaporated material on the substrate of more than 80 o (oblique angle deposition), arrays of free-standing Co nanocolumns with a cross section of 25 nm and an aspect ratio (length/transverse size) of at least 15 are formed on the substrate surface. In this case, the magnetic easy axis of the film is oriented along the axis of the nanocolumns, which leads to the appearance of a normal component of the magnetization vector to the film surface. When the substrate rotation is turned on, an array of nanospirals is formed. With a fast rotation of the substrate (30 rpm), the magnetic easy axis approaches the normal to the film surface. At a slow substrate rotation (0.6 pm), an array of nanocoils is formed, imparting pronounced chiral properties to the film. Keywords: nanostructuring, thin films, oblique angle deposition, chiral structures.

Thin Co films on inclined Si(001) substrates were obtained by electron-beam evaporation. It has been established that at angles of incidence of the evaporated material on the substrate of more than 80° (oblique angle deposition), arrays of free-standing Co nanocolumns with a cross section of 25 nm and an aspect ratio (length/transverse size) of at least 15 are formed on the substrate surface. In this case, the magnetic easy axis of the film is oriented along the axis of the nanocolumns, which leads to the appearance of a normal component of the magnetization vector to the film surface. When the substrate rotation is turned on, an array of nanospirals is formed. With a fast rotation of the substrate (30 rpm), the magnetic easy axis approaches the normal to the film surface. At a slow substrate rotation (0.6 pm), an array of nanocoils is formed, imparting pronounced chiral properties to the film.

Nanocolumnar Co thin films growth by oblique angle deposition on Si substrate is experimentally studied. Formation of regular arrays of vertical Co nanocolumns has been observed at incidence angles more than 80 degrees with rotation of substrate. Such films might be perspective material for applications as a magnetic recording media for next generations of hard disks.

Atomistic simulation with semiempirical Stillinger-Weber potential has been used to study the energetics of strain relaxation in Ge/Si(001) heteroepitaxial system. Several alternative scenarios for misfit strain relief through dislocation nucleation have been investigated. Minimal energy path for each transition trajectory has been found using combination of modified DRAG and Nudged Elastic Band methods. Our results showed that standard 90° Lomer dislocation is the most favorable (global minimum) defect for this heteroepitaxial system. Alternative more complex defects containing two shifted 60° dislocations are indeed also local minima for this system, however corresponding to higher energy states. Their appearance in experiments might be the result of growth kinetics.

Formation of regular arrays of nanorods with high aspect ratio (length to transverse size) has been found in the process of Al thin film growth at oblique angle deposition on silicon substrate by the method of electron beam evaporation. It was found that the optimal conditions for nanostructuring are realized at the inclination angle larger than 80 degrees.

The dynamics of a transverse domain wall in a narrow magnetic permalloy nanowire in an external field is studied by the method of micromagnetic simulation. It was found that in the limit of a very small nanowire width (less than 40 nm), a precession of the domain wall is observed, accompanied by a change in its chirality. It is shown that the precession frequency increases with an increase in the external field and with an increase in the damping constant and decreases with an increase in the nanowire width. This effect imposes restrictions on the possibility of reducing the width of the nanowire used to create racetrack memory.

Formation of regular arrays of nanorods with high aspect ratio (length to transverse size) has been found in the process of Al thin film growth at oblique angle deposition on silicon substrate by the method of electron beam evaporation. It was found that the optimal conditions for nanostructuring are realized at the inclination angle larger than 80 degrees.

An experimental stand for express diagnostics of multilayer spin tunnel structures has been developed. The current-in-plane tunnelling method (CIPT) requires no processing, is fast, and provides reliable data which are reflective of the deposition only. The stand is based on the four-probe method for measuring resistance at external alternating magnetic field. This technique can be applied after only a short processing route, thereby saving time and resources, and reducing the potential for damaging the junction.

The results of study of multilayer thin film structure using Rutherford Backscattering Spectroscopy (RBS) are presented. The structure 5(nm)Ta/30CuN/5Ta/3NiFe/16IrMn/2.0CoFe/0.9Ru/2.5CoFeB/2MgO/2.5CoFeB/10Ta/7Ru on SiO2 was used as a test sample. This kind of structure is using for MRAM fabrication. The RBS analysis of such samples might appear significant difficulties during measurement and interpretation of RBS spectra because of small layers thickness and overlay of peaks of elements with close masses. It was found that using different experimental conditions for RBS analysis one can obtain information about the density and thickness of each layer. The data about these parameters are presented.

Micromagnetic modeling is used to study the energetics of magnetic switching of single-layer permalloy nanowire. The energy landscape of the system is studied using Nudged Elastic Band method. Using different initial guess trajectories for NEB minimization several alternative minimal energy transition paths were found corresponding to possible scenarios of magnetic switching of the nanowire through nucleation and propagation of transverse domain walls. Dependence of energy barrier for DW nucleation on lateral sizes of the nanowire has been studied. Besides that, the effect of additional constant external bias magnetic fields (longitudinal and transverse) on nanowire switching has been explored. It has been shown that presence of rectangular shape notch on the nanowire long side leads to the appearance of local minimum on the energy profile. Thus artificially created notches can be used for DW pinning.

Micromagnetic modeling is used to study the energetics of magnetic switching of single-layer permalloy nanowire. The energy landscape of the system is studied using Nudged Elastic Band method. It has been shown that presence of rectangular shape defects on long side and inside nanowire leads to the appearance of local maxima and minima on the energy profile. Thus artificially created imperfections can be used for effective DW pinning.

Several experimental methods for controlling the quality of the multilayer film structures used for the fabrication of magnetic tunneling junctions (MTJs) are considered. A multilayer magnetoresistive structure of the following composition is deposited using magnetron sputtering on a Singulus Timaris cluster tool: Ta/CuN/Ta/NiFe/IrMn/CoFe/Ru/CoFeB/MgO/CoFeB/Ta/Ru. A layer-by-layer elemental analysis of the composition of the deposited structure is carried out by the time of flight (TOF) secondary ion mass-spectrometry on a TOF.SIMS 5 installation. A cross section of the structure is analyzed using transmission electron microscopy (TEM) (Tecnai G2 F20 U-TWIN). The crystal structure of the layers is characterized using X-ray diffraction. A comparison of the data obtained using different analytical methods lets us estimate the accuracy of the analysis and the quality of the structure intended for further MTJ fabrication.

Micromagnetic modeling is used to study the energetics of magnetic switching of a rectangular single-layer permalloy nanoisland. The potential local energy minima of this system are found in the absence of an external field. The magnetization reversal along the long axis of the island is studied at different values of a constant transverse bias field. It is found that the presence of such a bias leads to a reduction of the longitudinal switching field. The energy landscape of the system is studied using the Nudged Elastic Band (NEB) method to shed more light on the nature of the effect. It is shown that the energy barrier for longitudinal switching is reduced with the growth of the magnitude of the transverse bias. This effect may have practical applications for optimizing MRAM technology, because it helps reduce the memory cell’s switching field.