Oleksiy V Penkov

Oleksiy V Penkov
Zhejiang University | ZJU · Zhejiang University/University of Illinois at Urbana-Champaign Institute

PhD

About

107
Publications
31,621
Reads
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1,378
Citations
Introduction
My research interests cover several areas of physics, materials science, and mechanical engineering, such as nano-layered coatings, tribology, and surface engineering. In particular, I work on the design of nano-structured periodical multilayer coatings which found application in the various fields of science and engineering, from X-ray optics to bio-industry. We demonstrated that strategic stacking of the nanometer-thick layers was beneficial for tailoring multiple properties and performance improvement.
Additional affiliations
March 2021 - present
University of Illinois, Urbana-Champaign
Position
  • Professor (Associate)
November 2019 - present
Zhejiang University
Position
  • Professor (Associate)
September 2013 - August 2019
Yonsei University
Position
  • Lecturer
Education
September 2000 - November 2006
September 1994 - February 2000
National Technical University "Kharkiv Polytechnic Institute"
Field of study
  • Physics of metals and semicondactors

Publications

Publications (107)
Article
Wear is an important phenomenon that affects the efficiency and life of all moving machines. In this regard, extensive efforts have been devoted to achieve the lowest possible wear in sliding systems. With the advent of novel materials in recent years, technology is moving towards realization of zero wear. Here, we report on the development of new...
Article
Functional nanocomposite coatings comprised of periodically stacked nanolayers of diamond-like carbon (DLC) and amorphous silicon were developed for biomedical applications. The periodical nanocomposite structure provided high surface durability while silicon aided in reducing the residual stress. The structural, mechanical, tribological, and biome...
Article
Ion-beam irradiation of diamond-like carbon (DLC) by He ions was studied. Molecular dynamics simulation was performed to understand the effects of irradiation on the nano-topography and chemical state of the coatings and determine the optimal irradiation conditions. Then, the experiment was conducted to validate the results of the simulation and co...
Article
Full-text available
The synthesis and structural analysis of Mo/B periodical multilayer X-ray mirrors (PMMs) for beyond extreme ultraviolet (BEUV) optics was performed. The PMMs were deposited by a combination of pulsed DC and radio frequency (RF) magnetron sputtering. The structure was analyzed by high-resolution transmission electron microscopy, X-ray photoelectron...
Article
Full-text available
The reliability and durability of devices that operate in vacuum and are subjected to wear are critical issues. The concerns rise at the macroscale wherein the contact area is large, yet the contact stress is in the GPa range. This paper reports on the design and fabrication of a coating comprising nitridized molybdenum disulfide (MoSN) supported b...
Article
Nanoscale wear can severely limit the performance of tips used in atomic force microscopy, especially in contact and lateral mode operations. Hence, we investigated the mechanical and tribological properties of...
Patent
Full-text available
Provided is a transparent structure having improved wear resistance and flexibility, and a structure according to the present invention is a nanolayered structure in which a nitride nanofilm of one or more elements selected from metals and metalloids; and a boron nitride nanofilm are alternately layered.
Article
Full-text available
We report a scalable and cost-effective fabrication approach for constructing bio-inspired micro/nanostructured surfaces. It involves silicon microstructure etching using a deep reactive ion etch (DRIE) method, nanowires deposition via glancing angle deposition (GLAD) process, and fluorocarbon thin film deposition. Compared with the smooth, microst...
Article
A silicon/diamond-like carbon (Si/DLC) multilayer nanocomposite coating (MNC) was applied to the Ti–29Nb–13Ta‒4.6Zr (TNTZ) alloy to improve its wear resistance and durability. The Si/DLC MNC on the TNTZ alloy demonstrated an extremely low wear rate of 6.2 × 10⁻¹⁰ mm³N⁻¹mm⁻¹. Moreover, the wear track depth after one million wear cycles was found to...
Article
The effect of annealing temperature on the structure and mechanical properties of Ti41Zr39Ni20 coatings was examined. Coatings were deposited on stainless-steel substrates via magnetron sputtering and then annealed in a vacuum under temperatures from 200 to 850°C. Evaluation of structure and mechanical properties under annealing was performed using...
Article
Full-text available
Notwithstanding the success of nanolayered coatings in the reduction of wear at nano-/microscales, the improvement of the wear resistance at the macroscale remains an issue. Moreover, the effects of nanointerfaces in nanolayered coatings on their macrotribological properties are not understood well. This paper reports on the engineering of nanointe...
Article
Full-text available
The development of microelectronics is always driven by reducing transistor size and increasing integration, from the initial micron-scale to the current few nanometers. The photolithog-raphy technique for manufacturing the transistor needs to reduce the wavelength of the optical wave, from ultraviolet to the extreme ultraviolet radiation. One appr...
Preprint
Full-text available
The development of microelectronics is always driven by reducing transistor size and increasing integration, from the initial micron-scale to the current few nanometers. The photolithog-raphy technique for manufacturing the transistor needs to reduce the wavelength of the optical wave, from ultraviolet, deep, to the existing extreme ultraviolet lig...
Article
The nanostructural and tribological characteristics of carbon nanocomposite coatings (CNCs), deposited by accelerated C60 ions at high temperatures, were studied. The CNCs were successfully fabricated on Ti-alloy using a flux that contained C60 ions with 5 and 10 keV energies. Unlike the previous studies, ion mass-separator was not implemented to t...
Poster
Full-text available
In the computer industry, continuous efforts have been made to increase the operating frequency and decrease the power consumption of microprocessors. One approach toward achieving this is the use of extreme ultraviolet (EUV) radiation and beyond extreme ultraviolet (BEUV) radiation, which requires the use of advanced reflective optical devices lik...
Article
Graphene is considered as a promising material for reducing friction and wear, owing to its structural features. The tribological properties of graphene depend on several factors, including thickness, fabrication process and substrate properties. However, the effect of substrate on the tribological behaviors of graphene films are not well known. Pr...
Article
Full-text available
The exfoliation of graphene has opened a new frontier in material science with a focus on 2D materials. The unique thermal, physical and chemical properties of these materials have made them one of the choicest candidates in novel mechanical and nano-electronic devices. Notably, 2D materials such as graphene, MoS2, WS2, h-BN and black phosphorus ha...
Preprint
Full-text available
The exfoliation of graphene has opened a new frontier in material science with a focus on 2D materials. The unique thermal, physical and chemical properties of these materials have made them one of the choicest candidates in novel mechanical and nano-electronic devices. Notably, 2D materials such as graphene, MoS2, WS2, h-BN, and Black Phosphorus h...
Patent
Full-text available
Provided is a transparent structure having improved wear resistance and flexibility, and a structure according to the present invention is a nanolayered structure in which a nitride nanofilm of one or more elements selected from metals and metalloids; and a boron nitride nanofilm are alternately layered.
Preprint
The structure of Mo/B periodical multilayer coatings for beyond extreme ultraviolet (BEUV) optics was investigated. The coatings were deposited by a combination of Pulse DC/RF magnetron sputtering and investigated by HRTEM, XPS, and grazing incidence X-ray reflectometry. It was shown that the formation of thin interlayers occurred at Mo/B interface...
Article
Full-text available
X-Ray Calc is a fast and convenient tool for the simulation of X-ray reflectivity (XRR). The software was developed with the aim of simplification and acceleration of the XRR simulation through a user-friendly interface and optimized computation core. X-Ray Calc implements the recursive approach of calculation of XRR based on Fresnel equations and...
Article
This paper introduces a highly durable functional multilayer coating (FMCs) with outstanding mechanical properties using comprehensive design principles. Architecting the layers with degrees of freedom in structure and thickness is the core idea to design WC/DLC FMC. This concept seeks to combine advantages of superior properties of single-layer me...
Book
An exhaustive reference guide on the tribology of graphene-based materials, this book starts by looking at the selection of the proper graphene-based material, then segues into topics such as choosing a deposition method, control of its structure and properties, and concludes by outlining the most effective working conditions and applications. The...
Article
Full-text available
In this study, SiNx/BN periodical nanolayered coatings (PNCs) are developed. PNCs were deposited at the room temperature on plastic and glass substrates. They demonstrate the excellent mechanical durability of inorganic materials and optical transparency and flexibility of organic ones. The 150-nm thick PNC shows optical transparency, sapphire-like...
Article
Full-text available
Material loss and plastic deformation induced by frictional interactions at moving mechanical interfaces continues to be a major issue responsible for efficiency and performance degradation of systems. Establishment of fully elastic interactions at the contact region without compromising the structural rigidity and integrity of material represents...
Article
This review paper summarizes and provides an overview of our recent studies related to two types of short-period multilayer X-ray mirrors, W/B4C and Co/C. It deals with the experimental observation of the layer intermixing effects and how they affect the X-ray mirror’s optical performance. The paper presents also some examples of using the fabricat...
Article
It was found that ultrasonic nanocrystal surface modification (UNSM) treatment performed on Ti-Nb-Ta-Zr (TNTZ) alloy surface to produce a gradient nanostructured surface layer also resulted in the nano-scale spinodal decomposition of β phase. For the first time, nano-scale spinodal decomposition of β phase induced by ultrasonic mechanical impacts w...
Presentation
Full-text available
Nanocomposite coatings based on diamond-like carbon (DLC) are developed for biomedical applications. The nanocomposite structure provides high mechanical durability and aids in enhancing the biocompatibility and reducing the residual stress in the DLC. The coatings are deposited by magnetron sputtering. The structural, mechanical, tribological, and...
Article
Full-text available
Friction and wear phenomena encountered in mechanical systems with moving components are directly related to efficiency, reliability and life of the system. Hence, minimizing and controlling these phenomena to achieve the desired system performance is crucial. Among the numerous strategies developed for reducing friction and wear, coatings have bee...
Article
A novel functional multilayer coating with periodically stacked nanolayers of amorphous carbon (a:C)/ tungsten carbide (WC) and an adhesion layer of chromium (Cr) was deposited on 304 stainless steel using a dual magnetron sputtering technique. Through process optimization, highly densified coatings with high elasticity and shear moduli, excellent...
Article
Full-text available
Extensive research efforts have been devoted to understand the complex mechanisms of wear with the aim to minimize wear in sliding systems. Improvements in the instruments used for the characterization of the wear phenomenon are required to enhance the effectiveness of research method. In this paper, we report the design of an experimental platform...
Patent
Full-text available
The present invention relates to a coating layer formed on a surface of structure in an attempt to reduce friction and abrasion among structures performing a relative motion while touching each other. More specifically, the present invention relates to a coating layer exhibiting excellent shock attenuation effects and high shearing strength, by hav...
Article
Structural evolution of the ultra-thin cobalt layers grown on amorphous carbon by DC magnetron sputtering were studied in detail by transmission electron microscopy and low-angle X-ray diffraction for a range of the cobalt thickness from 1.5 nm to 4.6 nm. It was shown that atomic structure of cobalt layers was amorphous at the layer thicknesses bel...
Presentation
Full-text available
Relationships between structure, mechanical and tribological properties of periodical nanolayer coatings were assessed. It was found that nano-scale multilayer coatings with individual layer thickness of several nanometers were able to provide high wear resistance. The results of this work are expected to lead to the development of ultra-low wear c...
Conference Paper
Full-text available
Relationships between structure, mechanical and tribological properties of periodical nanolayer coatings were assessed. It was found that nano-scale multilayer coatings with individual layer thickness of several nanometers were able to provide high wear resistance. The results of this work are expected to lead to the development of ultra-low wear c...
Article
The aim of this study was to elucidate the micro-abrasion characteristics of thin metallic coatings through in-situ visualization of the scratch formation process. Pure silver (Ag), pure copper (Cu), and Ag/Cu composite coatings with thicknesses of a few hundred nanometers were deposited on silicon substrates using a magnetron sputtering system. A...
Article
Diamond-like carbon coatings are increasingly used as wear-protective coatings for dental implants, artificial joints, etc. Despite their advantages, they may have several weak points such as high internal stress, poor adhesive properties or high sensitivity to ambient conditions. These weak points could be overcome in the case of a new carbon nano...
Article
Ultra-thin carbon-based nanocomposite coatings comprised of graphite nanocrystals embedded in diamond-like carbon (DLC) matrix were deposited on stainless steel substrates by the C60 ion beam method, as a wear protective coating. Increasing the C60 irradiation energy and deposition temperature led to the formation of graphite nanocrystals with a si...
Article
The effect of n-pentanol vapor phase lubrication on the wear mechanism of borosilicate glass was investigated. Glass micro-balls with a diameter of ~60 μm were slid against a silicon wafer under a normal load of 100 μN up to a sliding distance of ~210 km. It was shown that wear volume of the micro-ball could be reduced by ~18 times by using n-penta...
Article
The mechanical and tribological properties of extruded aluminum matrix composites reinforced with various weight percentages (1, 3, 5, 7, 10 wt.%) of Al13Fe4 complex metallic alloys (CMAs) were investigated. The nanocomposites were produced using conventional powder metallurgy and a hot extrusion process. The tribological behavior of the composites...
Article
AbstractThe backlight unit of a liquid crystal display (LCD) consists of a set of vertically stacked polymeric optical sheets that may experience sliding motion when subjected to vibration. In this work, the surface damage characteristics of the optical sheets were assessed by conducting sliding tests between specimens sampled from the sheets. Surf...
Conference Paper
Full-text available
Relationship between structure, mechanical and tribological properties of metal-carbon nanolayer periodical coatings were reported. It was found that even structures with thicknesses of individual layers of several nanometers were able to provide high macroscale wear resistance. FEM analysis showed that high wear resistance of the multilayer coatin...
Data
Full-text available
Wear is an important phenomenon that affects the efficiency and life of all moving machines. In this regard, extensive efforts have been devoted to achieve the lowest possible wear in sliding systems. With the advent of novel materials in recent years, technology is moving towards realization of zero wear. Here, we report on the development of new...
Article
Full-text available
Behaviors of film growth and surface during irradiation of the indium tin oxide targets (ITO, 90 % In 2 O 3 + 10 % SnO 2 ) by accelerated C 60 ion beam were investigated. The ion beam energy was in the range of 2.5–20 keV and target (substrate) temperature T S was in the range of 373–673 K. The effects of the ion energy and temperature on the sputt...
Article
Graphene oxide nanosheet (GONS) coatings were fabricated by using electrodynamic spraying process (ESP) with the aim to utilize the coatings as a solid lubricant. Well-dispersed GONSs in a mixture of EtOH/H2O solution was deposited on Si (100) substrates. The characteristics of the coatings such as surface roughness and thickness were assessed with...
Article
Full-text available
Atmospheric pressure plasma jets (APPJs) have received significant attention due to their combination of simplicity, low cost, and wide possibilities for surface treatment and modification. In this article, the latest developments in the design and applications of APPJs are reviewed. It is shown that APPJs could be successfully used in materials sc...
Article
Wear resistance and frictional behavior of InZnO thin coatings deposited on an acryl substrate using an atmospheric pressure plasma jet (APPJ) method was investigated by using a reciprocating pin-on-disk tribo-tester. The results showed that the wear and friction of the ZnOcoatings could be significantly improved by doping with indium. The wear rat...
Article
Full-text available
Formation of intermixing zones, their structure and phase composition in C/Si multilayers in as-deposited state and after annealing are studied. During deposition intermixing zones of ~0.6 m thick are formed at both silicon/carbon and carbon/silicon interfaces. The zone formed C-on-Si interlayer is denser than adjacent zone due to amorphous SiC nuc...