Alexandr G. Domantovsky

Synergistic Effect of Superhydrophobicity and Oxidized Layers on Corrosion Resistance of Aluminum Alloy Surface Textured by Nanosecond Laser Treatment

We report a new efficient method for fabricating a superhydrophobic oxidized surface of aluminum alloys with enhanced resistance to pitting corrosion in sodium chloride solutions. The developed coatings are considered very prospective materials for the automotive industry, shipbuilding, aviation, construction, and medicine. The method is based on nanosecond laser treatment of the surface followed by chemisorption of a hydrophobic agent to achieve the superhydrophobic state of the alloy surface. We have shown that the surface texturing used to fabricate multimodal roughness of the surface may be simultaneously used for modifying the physicochemical properties of the thick surface layer of the substrate itself. Electrochemical and wetting experiments demonstrated that the superhydrophobic state of the metal surface inhibits corrosion processes in chloride solutions for a few days. However, during long-term contact of a superhydrophobic coating with a solution, the wetted area of the coating is subjected to corrosion processes due to the formation of defects. In contrast, the combination of an oxide layer with good barrier properties and the superhydrophobic state of the coating provides remarkable corrosion resistance. The mechanisms for enhancing corrosion protective properties are discussed.

Selective removal of atoms as a new method for fabrication of nanoscale patterned media

The method of selective removal of atoms is proposed for purposeful efficient modification of a solid atomic composition under exposure to an accelerated ion beam of a certain energy. Such modification can dramatically change the physical properties of a thin material layer. This method could be used to create directly the needed spatial modulation of atomic composition and physical properties of a material, i.e. to produce a nanoscale patterned media for various applications (magnetic storage media, GaAs Schottky diodes and field effect transistors, optical structures, nanoscale biochips, and many others).

Selective Removal of Atoms as a New Method for Manufacturing of Nanostructures for Various Applications

The paper demonstrates a possibility for effective modification of the thin-film material’ chemical composition, structure and physical properties as result of selective removal of atoms by the certain energy ion beam. One of the most promising results of this effect consists in developing the new technology for 3D micro-and nano-structures production for various applications.

Formation of conductive structures in insulate layers by selective removal of atoms technique

The structure and electric properties of initial oxides and metals (Bi, Ag, Cu, Ni, Co, Mo and W) produced by Selective Removal of oxygen Atoms technique (SRA) were studied. It was found a correspondence of electrical conductivity of SRA metals and pure sputtered metals films. At the same time, low resistance of some oxides, for instance CuO, will initiate big leakage currents inside the layer. Among the investigated materials special attention will be paid to SRA Bi, Mo and W because of the high values of contact resistance and puncture potential with initial oxides. It is shown the adaptability of Selective Removal of Atoms technique for formation of conductive insulated structures in layers for new micro and nano-electronic devices.

Application of laser micro- and nanotexturing for the fabrication of superhydrophobic corrosion-resistant coatings on aluminum

A new efficient method for the fabrication of corrosion-resistant composite superhydrophobic coatings on aluminum and its alloys is presented. The laser micro- and nanotexturing of the surface combined with the deposition of a hydrophobic agent makes it possible to obtain superhydrophobic coatings with unique properties on aluminum materials. The complex studies by electrochemical methods and wettability analysis showed that the proposed type of coatings is characterized by very high resistance to corrosion, including pitting resistance, and by the durability of the superhydrophobic state upon prolonged contact with aqueous chloride-containing media.

Synthesis of wear-resistant superhydrophobic coatings via laser micro- and nanotexturing

We describe a method for texturing the metal surface in order to impart it a multimodal roughness necessary to meet the requirements for achieving the superhydrophobic state of the surface. This technique is based on micro- and nanotexturing of the surface via nanosecond laser treatment, and it can easily be automated and scaled up to process metal parts with a large area and a complicated surface profile. The experimental testing under model cavitation and abrasive loads reveals the high mechanical durability of superhydrophobic coatings, unlike their conventional counterparts. The basic factors that ensure improved exploitation performance of the developed coatings are defined and briefly discussed.

Electromagnetic Radiation of Micro and Nanomagnetic Structures with Magnetic Reversal

By means of the selective removal of atoms from the cobalt oxide under ion beam irradiation, micro and nanopatterned magnetic Co structures have been produced consisting of pseudo-single domain “bits” with different coercivity. With the magnetization reversal of those structures, electromagnetic radiation pulses arise whose characteristics have been investigated in detail. It was experimentally revealed about the huge increasing of the radiation intensity (up to ≈100 times) because of the synergetic effects depending on bit coercivities (varying with their shape anisotropy) and the distance between bits. In addition, there have been discovered the strong influence of the soft magnetic underlayer (of 50 nm thickness) on the process of magnetization reversal. Peculiar properties of the magnetic structure with and without the soft magnetic underlayer have been studied by magnetic force microscopy.

Submicron metal patterns of arbitrary geometry fabricated by means of selective removal of oxygen atoms from molybdenum oxide

The possibility of manufacturing metal patterns with submicron linear elements on a silicon substrate by means of the selective removal of oxygen atoms from metal oxide is demonstrated for the first time. Structures of 0.35-μm-wide molybdenum stripes with a thickness of 20 nm have been obtained using 3-keV proton irradiation of a molybdenum oxide film on a silicon substrate via an electron-beam resist mask, followed by removal of the resist and the non-reduced oxide regions. The proposed method can be used for the fabrication of submicron metal patterns of arbitrary geometry on various substrates.