The first results of the deposition of coatings from accelerated ions of fluorinated fullerene C60(CF3)12 are presented. The coatings are formed at room temperature on Si substrates from a beam of singly charged C_60(CF_3)_12^ + ions with an energy of 5 keV, as well as from an ion beam that also contains doubly charged C_60(CF_3)_12^2 + ions and a certain amount of ionized fragments of molecules. The properties and structure of coatings obtained from accelerated ions of fluorinated fullerene are compared with the properties and structure of coatings obtained from accelerated fullerene C60 ions under the same conditions. According to X-ray photoelectron spectroscopy (XPS), fluorinated fullerene coatings contain about 4

From accelerated C60 ions at temperatures of 200 and 300°C hard wear-resistant carbon coatings were deposited. It has been established that the mechanical properties of the coatings are determined by the substrate temperature (Ts) and the energy composition of the beam. The hardness of coatings deposited from C_60^ + ions with an energy of 7 keV exceeds 50 GPa and is practically independent of Ts. The presence of C_60^2 + and C_60^3 + with an energy of 14 and 21 keV, respectively, in the beam leads to a result that is not typical for carbon coatings—the hardness increases by more than 1.3 times with an increase in Ts from 200 to 300°C (from 31.6 to 41.6 GPa). In this case, according to Raman spectroscopy data, the size of graphite nanocrystals in the coating increases with temperature up to almost 2 nm. Coatings obtained under conditions of irradiation with C_60^2 + and C_60^3 + ions are characterized by minimal wear (1.5 × 10–8 mm3/(N m), Ts = 200°C) and minimal friction coefficient (μ = 0.05 for Ts = 300°C). We attribute the unusual dependence of hardness on Ts and the improvement in the tribological properties of coatings to the formation of a composite structure based on a diamond-like matrix and graphite nanocrystals in this Ts range.

Among others, carbon-based coatings are of extreme interest thanks to the wonderful ability of carbon to form a wide variety of C-C atom bondings that give the unique possibility to tailor the properties of a growing blanket layer. Fullerene C-60 ions/molecules of different energy are very powerful tools to obtain carbon-based coatings on various surfaces. Substrate temperature and C-60 ion energy play a crucial role in the processes that take place during irradiation. Varying them one can tune the coating structure from amorphous to nanocomposite consisting of an amorphous diamond-like matrix filled with graphite nanoflakes. Carbon atom bonding-type can also be tuned. The friction coefficient and wear resistance of grown nanocomposite carbon coatings are close to the record values. Corrosion tests show that the coating protects the underlying substrate well in both oxidising and reducing atmospheres. The high conductivity of some films makes them suitable for use as proton exchange membrane bipolar plates in fuel cell applications. Developed nanocomposite coatings can also be used in biomedical applications (implant coating, friction pairs in artificial joints, etc.).

The paper reports on carbon coatings deposited by accelerated C-60 ion beam irradiation onto the VT1-0 titanium alloy surface at different substrate temperatures, considering potential applications in fuel-cell bipolar plates. We identified the temperature range for forming a conductive carbon nanocomposite coating (CNC) at different accelerating voltages (U-a). The obtained CNC consists of graphite nanocrystals embedded in an amorphous diamond-like matrix. The nanocomposite containing similar to 40% of sp(3) bonds is formed at T-s = 300-400 degrees C under U-a = 6 kV. The increase in accelerating voltage to 8 kV reduces the temperature of the nanocomposite formation to T-s = 200 degrees C. Interface contact resistance (ICR) of a CNC coated titanium plate decreases to 2.6 +/- 0.7 mOhm & sdot;cm(2) at a sealing pressure of 1.5 MPa, which is close to carbon paper - graphite contact resistance. This low ICR value persists after prolonged corrosion tests. Tribological studies established high wear resistance and high adhesion of CNC to titanium substrate, showing potential for stable operation of coated bipolar plates in mobile applications. CNC allows to overcome the limitation of corrosion-caused ICR increase, which makes CNC-coated titanium a promising candidate to substitute gold-coated stainless steel as a raw material for bipolar plates of proton-exchange membrane fuel cells.

The regularities of superhard carbon nanocomposite (CNCs) growth on a titanium substrate using accelerated C60 ion beam are investigated. Substrate temperature Ts and ion energy E are the main parameters varied during film growth. The formation of CNC coatings with a specific electrical resistance below 1 Ω × m is observed at a substrate temperature Ts above 300 ºC and ion energies from 5 to 8 keV. CNC coatings obtained at Ts in the range of 300–400 ºC consist of graphite crystals with a size of 1–2 nm enclosed in a diamond-like matrix. The sp2/sp3 bond ratio weakly depends on Ts in this temperature range and slightly decreases with ion energy increase (from 0.33 to 0.26 at 5–8 keV). Diamond-like coating grows on a substrate at Ts lower than 300 ºC by 5 and 7 keV ions. At an ion energy of 8 keV and above sputtering of the substrate was found. In all cases a TiC layer is formed at the substrate-coating interface due to the ion-beam mixing. Formation of this interlayer provides good adhesion of the coating to the substrate. The CNC coating on Ti exhibits high corrosion resistance and good protective properties. Thus, composite carbon films could be used as a conductive electrode in various chemical and bio applications.

In order to increase efficiency of metal-supported solid oxide fuel cells (SOFCs) and electrolysis cells (SOECs) and to lower their fabrication and operation temperatures, development of novel methods for the functional layers deposition is of primary importance. In this work, the composite anodes of metal-supported solid oxide cells (MS-SOCs), made of Ni and 10 mol.% scandia and 1 mol.% yttria co-stabilized zirconia (10Sc1YSZ), were deposited by the aerosol deposition (AD) onto high relief porous metal substrates. This step was followed by magnetron sputtering (MSP) of thin 8 mol.% yttria-stabilized zirconia (8YSZ) solid electrolyte. Vacuum co-sintering of the half-cells at 1100 degrees C resulted in the formation of well-bonded nanostructured anodes and gas-tight electrolyte membranes. The area-specific ohmic resistance of the half-cell in dry hydrogen was 0.23 Ohm.cm(2) at 577 degrees C.

The carbon films formed by accelerated C60 ion deposition are investigated by transmission electron microscopy and X-ray photoelectron spectroscopy. It is demonstrated that amorphous carbon films are formed at an ion-beam energy of 7 keV and a temperature of the substrate of 100–200°C. Substrate temperature increase to 300°C results in the formation of nanocomposite films consisting of graphite nanocrystals embedded in an amorphous carbon matrix. The presence of double- and triple-charged C60 ions with an energy of 14 and 21 keV respectively in the beam results in a decrease in the temperature of formation of the nanocomposite to 200°C. As the result of analysis of the data collected from various sample depths by X-ray photoelectron spectroscopy and Auger-electron spectroscopy, it is found that the sp3/sp2 ratio in the surface layers is higher than in the sample bulk, both in the case of a monoenergetic 7 keV beam, and in the presence of multicharged high-energy ions in the beam. If high-energy ions are present in the beam, then the sp3/sp2 ratio is higher and depends, in a complex way, on the temperature of deposition. The maximum amount of sp3 bonds in the surface layers is found at a temperature of deposition of 350°C and is equal to 88%. The water drop contact angle for this film is 96°, which is similar to the contact angle of the diamond surface.

One of the main limiting factors determining an increase in the specific power and efficiency of solid oxide fuel cells (SOFCs) is the development of deposition technique for thin-film gas-tight electrolytes. Hence, the development of inexpensive and scalable technologies to form thin-film electrolytes is the key direction of SOFC improvement. Despite existence of well-developed techniques, such as chemical vapor/solution deposition (CVD/CSD), electrochemical deposition (ED), thermal spray (TS), physical vapor deposition (PVD), all of them have a trend in rising deposition temperatures or establishing high vacuum that causes an increase in cost. The aerosol deposition (AD) also known as vacuum kinetic spraying (VKS) is a technique for deposition of thin and thick, gas-tight and porous layers. The deposition occurs due to the impact of high-energy particles to substrate and their consequent fragmentation and consolidation, this phenomenon is called room temperature impact consolidation (RTIC). The AD method is distinguished by the ability to lower the formation temperatures of a gas-tight electrolyte layer down to room temperatures by using a high-energy aerosol jet under conditions of low vacuum (1 – 1000 Pa) and room temperature. In addition, the method is characterized by low equipment cost and easy scaling. The possibility to deposit gas-tight films and films with controlled porosity in a wild range of thickness makes it possible to create all functional SOFCs layers without intermediate sintering steps. In the present work, the aerosol deposition technique was used to deposit thin-film electrolytes for anode-supported SOFCs. Two types of anode-supported SOFCs were manufactured. Type-1: thin-film electrolyte with the composition 8 mol.% yttria-stabilized zirconia (8YSZ) deposited on a bilayered anode substrate (current-collecting and functional sublayers) using the AD method followed by the screen-printing of a composite cathode with the composition of (La0.8Sr0.2)0.95MnO3-δ (LSM) and zirconia co-stabilized with 10 mol.% of scandia and 1 mol.% of yttria (10Sc1YSZ). Type-2: bilayered thin electrolyte made of 8YSZ and 10 mol% gadolinia doped ceria (GDC) protective layer deposited on a bilayered anode substrate using the AD method, followed by the screen printing of an active cathode with the composition of (La0.80Sr0.20)0.95CoO3–δ (LSC). The high quality of electrolyte layers of both types of SOFCs was confirmed by scanning electron microscopy, as well as electrochemical measurements, including the measurements of current-voltage characteristics and impedance spectroscopy. At 800 °C the anode-supported cells with humidified hydrogen as a fuel, and air as an oxidant demonstrated the open-circuit voltage of more than 1.04 V for both types of SOFCs, as well as specific power of more than 420 mW/cm2 and 780 mW/cm2 for type-1 and type-2 of SOFCs, respectively. Based on the studies carried out, further steps were determined to improve the electrochemical parameters of the cells, as well as to scale up to deposition on substrates with an area of 100x100 mm2. This work was carried out with financial support from the Russian Scientific Foundation, grant no. 17-79-30071. Figure 1

The nanostructural and tribological characteristics of carbon nanocomposite coatings (CNCs), deposited by accelerated C-60 ions at high temperatures, were studied. The CNCs were successfully fabricated on Ti-alloy using a flux that contained C-60 ions with 5 and 10 keV energies. Unlike the previous studies, ion mass-separator was not implemented to the deposition process. This enabled deposition of sp(2)-rich CNCs with a lower coefficient of friction (COF) at a higher deposition rate. Laser confocal microscopy, atomic force microscopy transmission electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and X-ray Auger Electron Spectroscopy were used to investigate the structure of the coatings and friction test results. A carbon nanocomposite film consisting of graphite nanocrystals enclosed in an amorphous diamond-like matrix was formed at a deposition temperature of 300-400 degrees C. Upon deposition of the CNC, a COF of similar to 0.06 was achieved, which was almost one order of magnitude lower than that of bare Ti-alloy substrate. The surface wear was reduced by 360 times. The wear mechanism was changed from abrasive wear (on bare Ti-alloy) to a burnishing smoothening of the surface roughness (on CNCs). The transfer of graphite nanocrystals from the coating to the counter surface was identified and observed to act as a solid lubricant.

Development of a reliable, easily scalable and economically feasible technology for thin-film solid electrolyte fabrication is critical for the industrial production of solid oxide fuel cells (SOFCs). In the present work, the aerosol deposition (AD) technique has been appraised for this role. The thin-film membranes of 8 mol.% yttria-stabilized zirconia (8YSZ) solid electrolyte were applied onto two-layer anode supports, with subsequent screen-printing of the composite cathodes made of (La0.8Sr0.2)(0.)95MnO3-delta (LSM) and zirconia co-stabilized with 10 mol.% scandia and 1 mol.% ceria (10Sc1CeSZ). High quality of the thin membranes produced by the aerosol deposition was confirmed by scanning electron microscopy and electrochemical measurements, including the measurements of current-voltage dependencies and impedance spectroscopy. At 850 degrees C, the anode-supported SOFCs with wet hydrogen as fuel and air as an oxidant demonstrated the open-circuit voltage above 1.04 V, whilst the power density was higher than 500 mW/cm(2). (C) 2020 Elsevier B.V. All rights reserved.

A technology for preparation of thin-film solid-state batteries based on the silver‑iodine electrochemical system by aerosol deposition in vacuum is developed. Functional layers of the battery are studied by optical and scanning electron microscopy. Voltammetric characteristics of the thus assembled battery show that its maximum discharge current exceeds 3 mA/cm 2 , which is sufficient for supplying power to the majority of medical devices.

The results of structural and optical investigations of thin carbon films deposited from the mass-separated beam of accelerated C60 ions with energy of 5 keV are presented. The substrate temperature ranged from 100°C to 400°C. It was established that change of the TS from 100°C to 400°C leads to the consecutive formation of diamond-like carbon (DLC) films with amorphous state and superhard nanocomposites consisting nanographite structures (1-2 nm) surrounded by a diamond-like amorphous matrix. For amorphous films the band gap (Eg) was in the range of 1.2 - 1.4 eV. For nanocomposite films on optical absorption spectra, there are two energy components: one with a narrow Eg = 1 eV, which is associated with three-dimensional nanocrystals of graphite, and the other - with a wide optical gap (Eg =3,45-3,55 eV) that corresponds to the diamond-like amorphous matrix of nanocomposite. According to the results of scanning tunneling microscopy (STM) and tunnel spectroscopy (TS), the size of graphite nanocrystals is about 1-2 nm and an amorphous shell around the graphite nanocrystals had a thickness of about 1.5 nm. The graphite component had n-type conductivity and an amorphous component had p-type conductivity. The electrical conductivity of such semiconductor nanocomposite was 103 S/m that to 6 orders higher compared to the DLC film in the amorphous state.

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 C60ion beam method, as a wear protective coating.

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 nanocomposite coating (CNC) deposited by using a C-60 ion beam on a Co/Cr alloy. The structure of the coatings was investigated by Raman and XPS spectroscopy. The wear resistance was assessed by using a reciprocating tribotester under the loads up to 0.4 N in both dry and wet sliding conditions. Biocompatibility of the dental implants was tested in vivo on rabbits. Biocompatibility, bioactivity and mechanical durability of the CNC deposited on a Co/Cr alloy were investigated and compared with those of bulk Co/Cr and Ti alloys. The wear resistance of the CNC was found to be 250-650 fold higher compared to the Co/Cr and Ti alloys. Also, the CNC demonstrated much better biological properties with respect to formation of new tissues and absence of negative morphological parameters such as necrosis and demineralization. Development of the CNC is expected to aid in significant improvement of lifetime and quality of implants for dental applications. (C) 2016 Elsevier Ltd. All rights reserved.

Оттиски доступны непосредственно от издателя Фотокопирование разрешено только в соответствии с лицензией 2015 ИМФ (Институт металлофизики им.Г. В. Курдюмова НАН Украины) Напечатано в Украине.