S. I. Protsenko

Diffusion processes in nanoscale two-layer film systems based on Fe and Cu or Fe and Cr

The results of investigations of diffusion processes (condensation-stimulated diffusion (CSD) and thermal diffusion (TD)) in nanoscale Fe/Cu and Fe/Cr Fe/Cutwo-layer film systems by means of Auger electron spectroscopy (AES) are presented. It is established that the effective CSD coefficient is about two orders of magnitude higher than the analogous TD coefficient, which is explained by grain boundary diffusion saturation as early as at the top layer condensation stage.

Conductivity of single-crystal and polycrystalline bilayer metal films under the conditions of interdiffusion

The electrical conductivity of a bilayer film with a single-crystal or polycrystalline structure is theoretically investigated under the conditions of metal interdiffusion at an arbitrary ratio between the thickness of layers and the mean free path of electrons in the layers. It is shown that analysis of the changes in the electrical conductivity of the bilayer film due to diffusion annealing allows one to elucidate the nature of the processes of bulk and grain-boundary diffusion, to determine the effective depth of penetration of impurity atoms into the bulk and grain boundaries of the sample, and to obtain information on the bulk and grain-boundary diffusion coefficient.

Micro and nano robotics

The paper presents two techniques for controlling of micro/nano robots. The first one uses so called visual servoing techniques, where the robot tip position is measured with a camera. The position of the robot tip is extracted from the live video picture, so on-line position feedback control can be established. The experimental results of 2 DOF micro robot neural network controller with resolution of 500 nm is presented. The second presented experiment will show research results of 5 DOF nano robot cell with a gripper with resolution of 62 nm. The so called adaptive bang-bang position controller will be presented. The position of each linear axis is measured by a magnetic incremental encoder. The presentation focuses to the experimental results achieved by so called interface for prevention of collision in the nano world. We use a haptic device to get filling of a touch in the nano world.

Morphological and magnetic analysis of Fe nanostructures on W(110) by using scanning tunneling microscopy and Lorentz microscopy

We investigated morphological features and magnetic properties of epitaxial Fe nanostructures (films, stripes and nanoparticles) on a W(110) surface with monoatomic steps preferentially along the direction. The nanostructures were prepared in ultra-high vacuum by using electron-beam evaporation and subsequent annealing at different temperatures. Scanning tunneling microscopy measurements in-situ revealed elongated Fe nanostructures with aspect ratios of up to . The observable shape and orientation (along or perpendicular to the monoatomic steps of the substrate) of the nanostructures depended substantially on the preparation parameters. By capping the system with 7 monolayers of Pt, the magnetic properties of selected Fe nanostructures could be analyzed ex-situ using Lorentz microscopy revealing diversified results. Depending on the size and shape, different magnetization structures, such as single domain, two domains and vortex, were observed. A precise intensity profile analysis demonstrated that the magnetic field values of different magnetic structures are close to each other and equal 2.4 T.

Transmission electron microscopy investigation of oxidation of (110)NiAl single crystal with wedge-shaped profile

Low energy electron diffraction (LEED), high resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray (EDX), and electron energy loss spectroscopy (EELS) investigations of oxidation processes in (110)NiAl single crystal of wedge like shape, i.e., on the samples areas of different thickness, were carried out. It was found that in the result of several cycles of ion etching, annealing and oxidation the upper layer of (110)NiAl is enriched with Ni. With the increase of Ni concentration from 50 to 100 at. %, the stoichiometry of the near surface area changes and the new phases of Ni3Al and Ni with Al doping are formed one after another. Up to Ni content of 75 at. % the defects concentration in the near-surface area increases and above 75 at. % it drops again. This leads to the change in orientation and azimuth direction of aluminum oxide (alumina). By varying the conditions of γ-Al2O3 epitaxial growth on (110)NiAl with (100), (110), and (111) orientations, we found that this oxide can be grown with different azimuthal directions, for example [440](111)γ-Al2O3 ∥ [002](110)NiAl and [440](111)γ-Al2O3 ∥ [022](110)NiAl.