Tribological Properties of DLC Film Prepared by C^+ Ion Beam-assisted Deposition (IBAD)

C^+ ion beam-assisted deposition was utilized to prepare deposit diamond-like carbon(DLC) film. With the help of a series of experiments such as Raman spectroscopy, FT-IR spectroscopy, AFM and nano-indentation, the DLC film has been recognized as hydrogenated DLC film and its tribological properties have been evaluated. The ball-on-disc testing results show that the hardness and the tribological properties of the DLC film produced by C^+ ion beam-assisted deposition are improved significantly. DLC film produced by C^+ ion beam-assisted deposition is positive to have a prosperous tribological application in the near future.

The Effects of Annealing and Discharging on the Characteristics of MgO Thin Films Prepared by Ion Beam-Assisted Deposition as a Protective Layer of AC-PDP

This study investigated the effects of annealing and discharging on the characteristicsof MgO thin films prepared by ion beam-assisted deposition as a protective layer of AC-PDP.Byan annealing process at a temperature of 450℃ for more than three hours,the crystallinity ofthe deposited MgO films was improved,but the surface of the(200)-oriented MgO thin filmsin the vicinity of the discharge electrodes,especially on the inner sides of the electrodes,wassubjected to crack formation.The failure mechanism of the(200)-oriented MgO films was dueto the compressive stress of MgO films plus the additional compressive stress induced by thedifferences in the coefficient of thermal expansion between the electrode and the dielectric layer.In the discharging process,all MgO films were eroded unevenly,and the serious erosion occurrednear the edges of the discharge electrodes.ATM(atomic force microscopy)images show that theeroded surface of the(200)-oriented MgO thin film is smoother than that of the(111)-oriented film.Also,the(200)-oriented MgO thin film shows an improved ability to resist ion erosion comparedto the(111)-oriented film.

Structure and properties of carbon nitrogen films synthesized by ion beam-assisted deposition

β-C3N4 compound is a new hard material predicted by Liu and Cohen with theoretical calculation and so far it has not been found out in nature. In was assumed that the β-C3N4 compound would adopt the known crystal structure of β-Si3N4, which constructed a network of CN4 tetrahedra linked at the corners by threefold coordinate N atoms. Thus, the atomic coordination of β-C3N4 is sp3 hybrids on the C atoms and sp2 hybrids on the N atoms. Based on the theoretical analysis and modeling calculation, it

A New hcp Phase Formed in the Ni-Nb System during Ion-beam-assisted Deposition

The NisoNb2o films were prepared by ion beam assisted deposition (IBAD)with various Ar+ ion energies. A phase evolution of fcc→amorphous→Ni+Nb→Ni+hcp was observed with the increasing of ion beam energy from 2 kev to 8 keV. When bombarded by Ar+ ions of 8 kev during deposition, a new crystalline phase with hcp structure was obtained, of which the lattice parameters are α=0.286 nm and c=0.483 nm, different from those of the similar A3B-type hcp phase previously reported. The experimental results were discussed in terms of thermodynamics and restricted kinetic conditions in the far-from-equilibrium process of IBAD. The formation of hcp phase may also be related to the valence electron effect.

Atomic-scale engineering of advanced catalytic and energy materials via atomic layer deposition for eco-friendly vehicles

Zero-emission eco-friendly vehicles with partly or fully electric powertrains have exhibited rapidly increased demand for reducing the emissions of air pollutants and improving the energy efficiency. Advanced catalytic and energy materials are essential as the significant portions in the key technologies of eco-friendly vehicles, such as the exhaust emission control system,power lithium ion battery and hydrogen fuel cell. Precise synthesis and surface modification of the functional materials and electrodes are required to satisfy the efficient surface and interface catalysis, as well as rapid electron/ion transport. Atomic layer deposition(ALD), an atomic and close-to-atomic scale manufacturing method, shows unique characteristics of precise thickness control, uniformity and conformality for film deposition, which has emerged as an important technique to design and engineer advanced catalytic and energy materials. This review has summarized recent process of ALD on the controllable preparation and modification of metal and oxide catalysts, as well as lithium ion battery and fuel cell electrodes. The enhanced catalytic and electrochemical performances are discussed with the unique nanostructures prepared by ALD. Recent works on ALD reactors for mass production are highlighted. The challenges involved in the research and development of ALD on the future practical applications are presented, including precursor and deposition process investigation, practical device performance evaluation, large-scale and efficient production, etc.

Major Ions in Atmospheric Deposition in Lake Kivu Basin

This study investigated the major ion composition and sources in wet and dry deposition samples collected over 15 months (December 2017 to February 2019) at four stations representing four different land use/cover types on the western side of Lake Kivu basin in D.R. Congo. The samples were collected every 13 days for dry deposition and two to three times per month for wet deposition. Samples were analyzed for major ionic components (Cl-, NO-3, SO2-4, Na+, K+, NH+4, Ca2+, CO2-3, HCO-3 and Mg2+). Electrical conductivity and pH were analyzed immediately in the field while major ion measurements were in the laboratory. Results showed the pH of both the dry and the wet depositions were higher than what would have been expected based on equilibration with atmospheric CO2 (pH > 5.6) at all four sites, with conductivity less than 50 μS/cm. The neutralization process in dry and wet atmospheric deposition is due to Ca2+, NH+4, HCO-3 and CO2-3. The anion: cation ratio in dry deposition was close to 1 for Iko and Bukavu, and it was greater than 1.0 (1.1 - 1.2) for Lwiro and Goma in wet deposition. The dominant anions in wet deposition were SO2-4 and NO-3, found around the rural area near cement factory and the urban area near active volcanoes, respectively. The most abundant cation was Na+ followed by K+. The enrichment factors and correlation analysis suggest that the main sources of Ca2+, Na+ and Mg2+ were disintegration of soil processes, aeolian suspension of soil and volcanic ash, biomass burning and the cement/lime factory around the Lake Kivu basin.

Fabrication of long-length ion beam-assisted deposited MgO templates for YBCO-coated conductors

The biaxially textured ion beam-assisted deposited(IBAD)-MgO templates were successfully prepared on polycrystalline Hastelloy metal substrate with reel-to-reel system for YB2Cu3O7-d(YBCO)-coated conductors.By the solution deposition planarization technique,amorphous Y2O3films were coated on untreated Hastelloy substrate as the bed layer to obtain smooth,dense,and crack-free surface for subsequent IBAD-MgO deposition.The 50 m long IBAD-MgO and homo-epitaxial(epi)-MgO buffer layers deposited on Y2O3films exhibit excellent crystallographic consistency along the scope with full width half maximum(FWHM)values of(110)DU and(200)Dx in the range of 5.5°–6.0°and3.0°–3.5°,respectively.To match the lattice constant of YBCO material,LaMnO3cap layer was fabricated on IBAD-MgO templates by radio frequency(rf)magnetron sputtering with the FWHM values of in-plane and out-ofplane of 6.8°and 3.7°,respectively,indicating excellent biaxial texture.

Mo SILTCIDE SYNTHISIS BY DUAL ION BEAM DEPOSITION

Mo suicides Mo5 Si3 with high quality were prepared using ion beam deposition equipment with two Filter Metal Vacuum Arc Deposition (FMEVAD). When the number of alternant deposition times was 198, total thickness of the coating is 40nm. The coatings with droplet free can be readily obtained, so the surface is smooth. TEM observation shows that Mo and Si alternant deposition coating is compact structure. The fine Mo suicide grains densely distributed in the coating. The coating adherence on silicon is excellent.

Regulating Zn Deposition via an Artificial Solid–Electrolyte Interface with Aligned Dipoles for Long Life Zn Anode

Aqueous zinc ion batteries show prospects for next-generation renewable energy storage devices.However,the practical applications have been limited by the issues derived from Zn anode.As one of serious problems,Zn dendrite growth caused from the uncontrollable Zn deposition is unfavorable.Herein,with the aim to regulate Zn deposition,an artificial solid–electrolyte interface is subtly engineered with a perovskite type material,BaTiO3,which can be polarized,and its polarization could be switched under the external electric field.Resulting from the aligned dipole in BaTiO3 layer,zinc ions could move in order during cycling process.Regulated Zn migration at the anode/electrolyte interface contributes to the even Zn stripping/plating and confined Zn dendrite growth.As a result,the reversible Zn plating/stripping processes for over 2000 h have been achieved at 1 mA cm^(−2) with capacity of 1 mAh cm−2.Furthermore,this anode endowing the electric dipoles shows enhanced cycling stability for aqueous Zn-MnO2 batteries.The battery can deliver nearly 100%Coulombic efficiency at 2 Ag^(−1) after 300 cycles.

AMORPHIZATION IN Nb-M (M=Fe, Co, Ni) BINARY METAL SYSTEMS INDUCED BY ION BEAM ASSISTED DEPOSITION (IBAD)

Ion beam assisted deposition technique (IBAD) was utilized to systematically study amorphization in binary metal systems of Nb-magnetic element, i.e., Nb-M (M=Fe, Co or Ni). The glass forming range termed as Nb fraction of Nb-Fe system was about 34at.% to 56at.%, that of Nb-Co system was about 32at.% to 72at.% and that of Nb-Ni about 20at. % to 80at. %. Similar percolation patterns were found in amorphous alloy films. The fractal dimensions of the percolation patterns approach to 2, which indicates 2-D layer growth for amorphous phases. It is regarded that the assisted Ar+ ion beam during the deposition process plays important role for the 2-D layer growth. Some metastable crystalline phases were obtained in these three systems by IBAD, e.g., bcc supersaturated solid solutions in Nb-Fe and Nb-Co systems, fcc and hcp phases in Nb-Co and Nb-Ni systems. The formation and competing between the amorphous and the metastable crystalline phases were determined by both the phases’ thermodynamic states in binary metal systems and kinetics during IBAD process.

Fabrication of anatase titanium dioxide nanotubes by electroless deposition using polycarbonate for separate casting method

Titanium dioxide nanotubes(TNTs)were prepared by electroless deposition using ion track etched polycarbonate templates.The ion tracks were prepared to the desired diameter of the TNTs outer diameter.Titanium dioxide nanotubes with a diameter of minimum 80 nm having a wall thickness of minimum 10 nm can be fabricated using this method.To achieve nanotubes with thin walls and small surface roughness the tubes were generated by a several steps procedure under aqueous conditions at nearly room temperature.The presented approach will process open end nanotubes with well defined outer diameter and wall thickness.Using this method TNT arrays up to 109 tubes per cm2having a tube length up to 30μm can be produced,single tubes are also possible.The structural properties of the grown TNTs were investigated by using various analytical techniques,i.e.scanning electron microscopy(SEM),energy dispersive X-ray fluoresence spectrometer(EDX),X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD),Raman spectroscopy and Photoluminescence.

Pt Deposition on Anode Enhances the Performance of Dye-Sensitized Solar Cell with Non-Cross-Linked Gel Electrolyte

We fabricated dye-sensitized solar cells with non-cross-linked fluorinated gel electrolyte. The application of fluorinated gel to electrolyte is a challenging issue at present. The gelation of the electrolyte is of importance in order to solve the problem in the durability of the cell. We investigated, in this article, the effect of Pt deposition on the anode of the cell. The Pt was deposited by means of a DC sputtering technique. The studies showed that the deposition time strongly affected both open voltage and short-circuit current of the cell. The adaptive thickness of the Pt layer was determined to be 10 nm for the non-cross-linked fluorinated gel electrolyte cells.

Fabrication of Sn-Ni alloy film anode for Li-ion batteries by electrochemical deposition

Sn-Ni alloy films for Li-ion batteries were fabricated by electrochemical deposition with rough copper foils as current collectors.The influence of electrochemical-deposition temperature and heat treatment were also investigated.By galvanostatic cell cycling the film anodes can deliver a steady specific capacity.The morphological changes cause the differences in capacity retention. After farther heat treatment,the film anodes present a better cycle performance,with a specific capacity of 314 mA·h/g after 100 cycles.This high capacity retention can be due to its smooth,compact surface formed in the heat treatment process.

Chitosan—The Application of a Natural Polymer against Iron Hydroxide Deposition

As a consequence of mining, heavy metal ions can be exposed to the environment hence contaminate ground water and surface water amongst others. The natural polymer chitosan was proved to be an excellent adsorber material for the effective removal of iron and sulfate ions in batch as well as in column experiments. The adsorption behavior of iron ions, as well as sulfate ions was investigated by utilizing chitosan flakes as a natural adsorbent. The removal was studied using adsorbance measurements, SEM and SEM-EDX. The adsorption capacity of chitosan was determined at different times. The received adsorption capacities for iron ions were very promising with a maximum adsorption capacity of 85 mg/g and a rate of separation of 100%. The maximum adsorption capacity obtained for sulfate ions was 188.8 mg/g and a rate of 80%.

Effect of ion-beam assisted deposition on the film stresses of TiO_2 and SiO_2 and stress control

Based on Hartmann-Shack sensor technique, an online thin film stress measuring system was introduced to measure the film stresses of TiO2 and SiO2 , and comparison was made between the film stresses prepared respectively by the conventional process and the ion-beam assisted deposition. The effect of ion-beam assisted deposition on the film stresses of TiO2 and SiO2 was investigated in details, and the stress control methodologies using on-line adjustment and film doping were put forward. The results show that the film stress value of TiO2 prepared by ion-beam assisted deposition is 40 MPa lower than that prepared by conventional process, and the stress of TiO2 film changes gradually from tensile stress into compressive stress with increasing ion energy; while the film stress of SiO2 is a tensile stress under ion-beam assisted deposition because of the ion-beam sputtering effect, and the film refractive index decreases with increasing ion energy. A dynamic film stress control can be achieved through in-situ adjustment of the processing parameters based on the online film stress measuring technique, and the intrinsic stress of film can be effectively changed through film doping.

CORROSION BEHAVIOR OF Cu-Nb AND Ni-Nb AMORPHOUS FILMS PREPARED BY ION BEAM ASSISTED DEPOSITION

The Cu25Nb75 and Ni45Nb55 amorphous films with about 500nm thickness were prepared by ion beam assisted deposition (IBAD). Potentiodynamic polarization measurement was adopted to investigate the corrosion resistance of samples and the tests were carried out respectively in 1mol/L H2SO4 and NaOH aquatic solution. The corrosion performance of the amorphous films was compared with that of multilayered and pure Nb films. Experimental results indicated that the corrosion resistance of amorphous films was better than that of the corresponding multilayers and pure Nb films for both Ni-Nb system with negative heat of formation and Cu-Nb system with positive heat of formation.

Characterization and Electrochemical Properties of LiMn_2O_4 Thin Films Prepared by Solution Deposition

LiMn2O4 thin films were prepared by solution deposition using lithium acetate and manganese acetate as raw materials. The phase constitution and surface morphology were observed by X-ray diffraction and scanning electron microscopy. The electrochemical properties of the thin films were studied by cyclic voltammetry, charge-discharge experiments and impedance spectroscopy in 1 mol·L -1 LiPF6/EC-DMC solution using lithium metal as both the counter and reference electrodes. The films prepared by this method are of spinel phase. The lattice parameter increases with the annealing temperature and annealing time. The film annealed at 750 ℃ for 30 minutes has the highest capacity of 34.5 μAh·cm -2 ·μm -1 , and its capacity loss per cycle is 0.05% after being cycled 100 times.

Effect of cathode composition on microstructure and tribological properties of TiBN nanocomposite multilayer coating synthesized by plasma immersion ion implantation and deposition

Nanocomposite multilayer TiBN coatings were prepared on Si(100) and 9Cr18Mo substrates using TiBN composite cathode plasma immersion ion implantation and deposition technique(PIIID). Synthesis of TiBN composite cathodes was conducted by powder metallurgy technology and the content of hexagonal boron nitride(h-BN) was changed from 8% to 40%(mass fraction). The as-deposited coatings were characterized by energy dispersive spectrometer(EDS), grazing incidence X-ray diffraction(GIXRD), Fourier Transform Infrared Spectroscopy(FTIR) and high resolution transmission electron microcopy(HRTEM). EDS results show that the B content of the coatings was varied from 3.71% to 13.84%(molar fraction) when the composition of the h-BN in the composited cathodes was changed from 8 % to 40%(mass fraction). GIXRD results reveal that the TiBN coatings with a B content of 8% has the main diffraction peak of TiN(200),(220) and(311), and these peaks disappear when the B content is increased. FTIR analysis of the multilayer coatings showed the presence of h-BN in all coatings. TEM images reveal that all coatings have the characteristics of self-forming nanocomposite multilayers, where the nanocomposites are composed of face-centered cubic Ti N or h-BN nanocrystalline embedded in amorphous matrix. The tribological tests reveal that the Ti BN coatings exhibit a marked decrease of coefficient at room temperature(~0.25). The improved properties were found to be derived from the comprehensiveness of the self-forming multilayers structure and the h-BN solid lubrication effects in the coatings.

SYNTHESIS OF TiN FILM WITH ION BEAM ENHANCED DEPOSITION AND ITS PROPERTIES

The TiN films were synthesized with an alternate process of depositing titanium from a E-gunevaporation source and 40 keV N^+ bombarding onto the target.It is shown from the composi-tion analysis and structure investigations using RBS,AES,TEM,XPS and X-ray diffractionspectrum that the formed fihns are mainly composed of TiN phase with grain size of 30—40nm and without preferred orientation,the nitrogen content in the film is much less than that incase without N^+ bombarding,and an intermixed region about 40 nm thick exists between thefilm and the substrate.The films exhibt high microhardness and low friction. ZHOU Jiankun,Ion Beam Laboratory,Shanghai Institute of Metallurgy,Academia Sinica,Shanghai 200050。

PREPARATION OF B-N FILMS BY ION BEAM ASSISTED DEPOSITION

BN films,synthesized by ion beam assisted deposition,were analysed by RBS,AES,IR spectra and TEM.Formatiom of c-BN phase was shown not only by IR spectra atabsorption peak of 1100 cm-1,but also by electron diffraction pattern.The results ofAES demonstrate an effect of N+ implantation near the film surface.The deposited filmsconsist of three layers,i.e.,ion implantation layer,film layer and mixed intermediatelayer,according to the difference of concentration.The micro-Knoop hardness of the film is25—35 GPa.