Pulsed Cathodic Arc Deposition Research Articles

Cathodic arc deposited tetrahedral amorphous carbon as thin film contact pressure sensing material

Tetrahedral amorphous carbon (ta-C) film was deposited using the filtered pulsed cathodic arc deposition method. The ta-C structures deposited on high velocity oxygen fuel thermally sprayed steel beam substrates were investigated for piezoresistive properties under direct contact pressing. A load of up to 1.4 GPa was applied with point contact, with no detrimental influence on the material. The linear response for the strain applied homogeneously on the whole film surface and on the local portion of the film surface under a cylindrical contact was observed. A high gauge factor of the measured system of 305 was measured, showing the potential of the material as a good candidate for sensing applications on direct contact measurement devices.

Comparative Study of Zirconium Nitride Multilayer Coatings: Crystallinity, In Vitro Oxidation Behaviour and Tribological Properties Deposited via Sputtering and Arc Deposition.

This study aims to evaluate and compare the properties of a biomedical clinically established zirconium nitride (ZrN) multilayer coating prepared using two different techniques: pulsed magnetron sputtering and cathodic arc deposition. The investigation focuses on the crystalline structure, grain size, in-vitro oxidation behaviour and tribological performance of these two coating techniques. Experimental findings demonstrate that the sputter deposition process resulted in a distinct crystalline structure and smaller grain size compared to the arc deposition process. Furthermore, in vitro oxidation caused oxygen to penetrate the surface of the sputtered ZrN top layer to a depth of 700 nm compared to 280 nm in the case of the arc-deposited coating. Finally, tribological testing revealed the improved wear rate of the ZrN multilayer coating applied by sputter deposition.

Ion kinetic energy- and ion flux-dependent mechanical properties and thermal stability of (Ti,Al)N thin films

Ion-irradiation-induced changes in structure, elastic properties, and thermal stability of metastable c-(Ti,Al)N thin films synthesized by high-power pulsed magnetron sputtering (HPPMS) and cathodic arc deposition (CAD) are systematically investigated by experiments and density functional theory (DFT) simulations. While films deposited by HPPMS show a random orientation at ion kinetic energies (Ek)>105 eV, an evolution towards (111) orientation is observed in CAD films for Ek>144 eV. The measured ion energy flux at the growing film surface is 3.3 times larger for CAD compared to HPPMS. Hence, it is inferred that formation of the strong (111) texture in CAD films is caused by the ion flux- and ion energy-induced strain energy minimization in defective c-(Ti,Al)N. The ion energy-dependent elastic modulus can be rationalized by considering the ion energy- and orientation-dependent formation of point defects from DFT predictions: The balancing effects of bombardment-induced Frenkel defects formation and the concurrent evolution of compressive intrinsic stress result in the apparent independence of the elastic modulus from Ek for HPPMS films without preferential orientation. However, an ion energy-dependent elastic modulus reduction of ∼18% for the CAD films can be understood by considering the 34% higher Frenkel pair concentration formed at Ek=182 eV upon irradiation of the experimentally observed (111)-oriented (Ti,Al)N in comparison to the (200)-configuration at similar Ek. Moreover, the effect of Frenkel pair concentration on the thermal stability of metastable c-(Ti,Al)N is investigated by differential scanning calorimetry: Ion-irradiation-induced increase in Frenkel pairs concentration retards the wurtzite formation temperature by up to 206 °C.

Tribological Properties of Ti-Doped Diamond-Like Carbon Coatings Under Boundary Lubrication With ZDDP

Abstract Diamond-like carbon (DLC) coatings containing 0.7%, 5.8%, and 23.3% Ti were deposited via pulsed cathodic arc deposition and magnetron sputtering on AISI 316L stainless steel substrates. The varied Ti content was controlled by setting Ti target current at 3, 5, and 7A. The composition, microstructure, mechanical, and tribological properties of Ti-doped DLC (Ti-DLC) coatings were investigated using X-ray photoelectron spectroscopy, Raman spectroscopy, nanoindentation, and ball-on-disc tribometer. The results show that TiC formed when Ti content in the coating was higher than 5.8 at% and the ID/IG ratios increased gradually with the increasing Ti content. Ti-DLC with 0.7 at% Ti had the highest H/E and H3/E2 ratios and exhibited optimal tribological properties under lubrication, especially when zinc dialkyldithio-phosphate (ZDDP) was contained in the oil. Furthermore, ZDDP tribofilms played an important role in wear reduction by protecting the rubbing surfaces against the adhesion and suppressing the tribo-induced graphitization of DLC coatings.

Surface morphology, magnetic resonance and antistatic properties of fabric with carbon coating, modified by metal clusters

The morphology of the surface, the magnetic resonance and antistatic properties of the 07C11-KV blended fabric manufactured by Mogotex LLC with a carbon coating doped with metal clusters are studied.The coating was applied by pulsed cathodic-arc deposition in vacuum of 3.5 · 10–3 Pa. It is established that during the coatinga droplet phase is formed. The size of the drops reaches 20 – 25 microns. The result of measuring the surface resistivity on fabric 1 side / 2 side is 3.2 · 107 and 1.9 · 107 Om, respectively. On the EPR spectrum are recorded two lines. The first line is a broad spectral line with an effective g-factor of 2.27 ± 0.01 and a width of 94.4 mT. The second line is narrow spectral line with an effective g-factor of 2.04 ± 0.01 and a width of 4.3 mT. This is corresponds to carbon coating clusters.From the ratio of the signal intensities of the filled resonator and the calibration sample, it follows that the non-resonant absorption of the microwave electromagnetic field in the system is slightly attenuated.

Effect of Fluorine Incorporation on DLC Films Deposited by Pulsed Cathodic Arc Deposition on Nitrile Butadiene Rubber and Polyurethane Rubber Substrates

Diamond-like carbon (DLC) and fluorinated diamond-like carbon (F-DLC) films were deposited via pulsed cathodic arc deposition on pretreated nitrile butadiene rubber (NBR) and polyurethane (PU) rubber substrates. Both DLC and F-DLC films showed a more than 50% decrease in coefficients of friction compared to uncoated NBR and PU rubber substrates. The incorporation of fluorine was found to have little influence on the film coefficient of friction. However, a decrease in film wettability was overserved in the F-DLC films compared to the DLC films.

Effects of Polyurethane Substrate Pre-Treatment on Pulsed Cathodic Arc Deposited DLC Films

Diamond-like carbon (DLC) films were deposited by means of pulsed cathodic arc deposition on pretreated polyurethane (PU) rubber substrates. Tetrachloroethylene was chosen as a dissolution method to remove the plasticizer added in the PU substrates. Scanning electron microscopy (SEM) and Raman spectroscopy were applied to observe and characterize the surface morphologies and compositions of the deposited films, respectively. The tribological behaviours of uncoated and coated rubbers were investigated with ring-on-disc tribo experiments under dry sliding conditions. The coefficients of friction (COFs) of the coated rubbers were 40% lower than those of uncoated rubber and the COFs of different samples decreased first and then increased slightly with the increase in temperature and the time of ultrasonic treatment under dry friction. Based on the above experiments, ultrasonic treatment with tetrachloroethylene contributes to the increase in the wear resistance of DLC films deposited on PU rubbers. The most suitable temperature and time of ultrasonic treatment with tetrachloroethylene is 50 °C for 15 min.

Properties of carbon coatings obtained by pulsed high power methods of vacuum-arc and magnetron sputtering

Investigation results of the structure, mechanical, tribological and adhesion characteristics of carbon coatings obtained by two different methods: high-power impulse magnetron sputtering (HiPIMS) and pulsed cathodic arc deposition (PCAD) are presented. Coatings obtained by PCAD demonstrated higher hardness and tribological characteristics, but lower adhesion and higher internal stresses. The defectiveness of coatings deposited by both methods is almost the same

Synthesis and characterization of Zr2Al3C4 thin films

Zr2Al3C4 is an inherently nanolaminated carbide where layers of ZrC alternate with layers of Al3C2. Characterization of bulk samples has shown it has improved damage tolerance and oxidation resistance compared to its binary counterpart ZrC. Though a potential candidate for coatings applied for use in harsh environments, thin films of Zr2Al3C4 have not been reported. We have synthesized epitaxial Zr2Al3C4 thin films by pulsed cathodic arc deposition from three elemental cathodes, and have studied the effect of incident atomic flux ratio, deposition temperature, and choice of substrate on material quality. X-ray diffraction analysis showed that Zr2Al3C4 of the highest structural quality was obtained for growth on 4H–SiC(001) substrate at 800°C. Also, suppression of competing phases could be achieved on α-Al2O3(001) at elevated substrate temperatures. Very similar growth behavior to that of the well-known Mn+1AXn phases – Al supersaturation, binary carbide intergrowth and high sensitivity to choice of substrate – indicates a strong connection between the two families of materials, despite their differences in structure and in chemistry.

Microstructure, residual stress and hardness study of nanocrystalline titanium–zirconium nitride thin films

The pulsed cathodic arc deposition technique was used to synthesize titanium–zirconium nitride (TiZrN) thin films at different substrate temperatures. A microstructural analysis extracted from the X-ray powder diffraction pattern was performed to identify the dependence of crystallite size and microstrain on TS. The residual stress state was also determined with the X-ray powder diffraction pattern assuming that the material behaved isotropically based on Young׳s modulus and the Poisson coefficient. The morphological analysis used atomic force microscopy to determine the grain size evolution with substrate temperature during deposition. The nanohardness values were obtained using nanoindentation measurements. Finally, the synthesis–property relationships were obtained with the microstructural information.

Filtered pulsed cathodic arc deposition of fullerene-like carbon and carbon nitride films

Carbon and carbon nitride films (CNx, 0 ≤ x ≤ 0.26) were deposited by filtered pulsed cathodic arc and were investigated using transmission electron microscopy and X-ray photoelectron spectroscopy. A “fullerene-like” (FL) structure of ordered graphitic planes, similar to that of magnetron sputtered FL-CNx films, was observed in films deposited at 175 °C and above, with N2 pressures of 0 and 0.5 mTorr. Higher substrate temperatures and significant nitrogen incorporation are required to produce similar FL structure by sputtering, which may, at least in part, be explained by the high ion charge states and ion energies characteristic of arc deposition. A gradual transition from majority sp3-hybridized films to sp2 films was observed with increasing substrate temperature. High elastic recovery, an attractive characteristic mechanical property of FL-CNx films, is evident in arc-deposited films both with and without nitrogen content, and both with and without FL structure.

Annealing effect of thermal spike in MgO thin film prepared by cathodic vacuum arc deposition

MgO films were prepared by using pulsed cathodic vacuum arc deposition technique. The substrate bias voltage was in the range of −150 to −750 V. Film structure was investigated by X-ray diffraction (XRD). The annealing effect of thermal spike produced by the impacting of energetic ions was analyzed. The calculated results showed that the lifetime of a thermal spike generated by an energetic ion with the energy of 150 eV was less than one picosecond and it was sufficient to allow Mg2+ or O2- to move one bond length to satisfy the intrinsic stress relief in the affected volume. The MgO(200) lattice spacings of the films deposited at different bias voltages were all larger than the ideal value of 2.1056 Å. As the bias amplitude increased the lattice spacing decreased, which indicated that the compressive stress in the film was partially relieved with increasing impacting ion energy. The stress relief also could be reflected from the film orientation with bias voltage. The biaxial elastic modulus for MgO(100), MgO(110) and MgO(111) planes were calculated and they were M(100) = 199 GPa, M(110) = 335 GPa and M(111) = 340 GPa, respectively. The M values indicated that the preferred orientation will be MgO(200) due to the minimum energy configuration when the lattice strain was large. It was confirmed by the XRD results in our experiments.

Carbon diffusion in alumina from carbon and Ti2AlC thin films

Carbon diffusion is observed in single crystal α-Al2 O3 substrates from carbon and Ti2AlC thin films synthesized via pulsed cathodic arc deposition. Diffusion was found to occur at substrate temperatures of 570 °C and above. The diffusion coefficient of carbon in α-Al2 O3 is estimated to be of the order 3×10-13 cm2/s for deposition temperatures in the 570–770∘C range by examining elastic recoil detection analysis (ERDA) elemental depth profiles. It is suggested that an appropriate diffusion barrier may be useful when depositing carbon containing thin films on α-Al2 O3 substrates at high temperatures.

Optical properties of amorphous carbons and their applications and perspectives in photonics

Amorphous carbon exhibits a wide variety of optical properties and, thus, offers substantial opportunities for various applications in photonics. The main optical properties, which should be taken into account for the design of new photonic devices, are the refractive index n, the fundamental gap E g and the E 04 gap. In this work, the optical properties of the various forms of amorphous carbon films grown by plasma-enhanced chemical vapor deposition, pulsed laser deposition, sputtering and vacuum cathodic arc deposition and the crucial structural and chemical factors that determine n, E g , and E 04 are reviewed. The knowledge of the optical properties of such films is exploited in order to design and implement various photonic devices such as: 1) anti-reflection (AR) coatings for various uses including photovoltaic modules, 2) interferometric sensors and indicators based on carbon-based AR layers, and 3) laser patterning of amorphous carbons and study of its photosensitivity for holographic applications.

Cathodic arc co-deposition of highly oriented hexagonal Ti and Ti 2AlC MAX phase thin films

Ti 2AlC belongs to a family of ternary nanolaminate alloys known as the MAX phases, which exhibit a unique combination of metallic and ceramic properties. Here we report pulsed cathodic arc deposition of c axis normal oriented Ti 2AlC thin films on α-Al 2O 3 (001) single crystal substrates heated to 900 °C, without an intentionally pre-deposited seed layer. Oriented hexagonal Ti is observed in some films and an in-plane epitaxial relationship between the α-Al 2O 3 (001) substrate, the hexagonal Ti and Ti 2AlC MAX phase is observed. We observe formation of the Ti 2AlC phase in all films despite variations in elemental composition. The electrical resistivity of our films was in the range 0.48–0.67 μΩ m, higher than other values found for Ti 2AlC in the literature.

Thickness uniformity and surface morphology of Fe, Ti, and Hf films produced by filtered pulsed cathodic arc deposition

The thickness of films produced by filtered pulsed cathodic arc deposition can typically be varied from tens of nanometers to micrometers. Because of plasma confinement in the curved duct that is frequently used to eliminate deleterious macro-particles and divergent diffusion of the plasma from the exit, the characteristics of the films are affected. In this work, the thickness uniformity across the film is investigated and the variations in the morphologies of Fe, Ti, and Hf films with different thicknesses are studied. The root-mean-square (RMS) roughness values of the Fe and Ti films with a thickness of around 350 nm are similar whereas much smoother Hf films can be obtained, suggesting that atomic diffusion plays an important role in addition to the deposition parameters.

The electronic structure of tungsten oxide thin films prepared by pulsed cathodic arcdeposition and plasma-assisted pulsed magnetron sputtering

Pulsed cathodic arc and pulsed magnetron sputteredWO3 thin films were investigated using electron microscopy. It wasfound that the cathodic arc deposited material consisted of theα-WO3 phase with a high degree of crystallinity. In contrast, the magnetron sputteredmaterial was highly disordered making it difficult to determine its phase. Electronenergy-loss spectroscopy was used to study the oxygen K edge of the films and it wasfound that the near-edge fine structures of films produced by the two depositionmethods differed. The oxygen K-edge near-edge structures for various phases ofWO3 were calculated using two different self-consistent methods. Each phase was foundto exhibit a unique oxygen K edge, which would allow different phases ofWO3 to be identified using x-ray absorption spectroscopy or electron energy-lossspectroscopy. Both calculation methods predicted an oxygen K edge for theγ-WO3 phase which compared well to previous x-ray absorption spectra. In addition,a close match was found between the oxygen K edges obtained experimentallyfrom the cathodic arc deposited material and that calculated for theα-WO3 phase.

Characterization of diamond-like carbon coatings prepared by pulsed bias cathodic vacuum arc deposition

Hydrogen free diamond-like carbon (DLC) coatings have been deposited on Si(100) and stainless steel substrates by cathodic vacuum arc plasma deposition with pulse voltage. Adherent deposits on silicon can be obtained through applying gradient Ti/TiC/DLC layers. A pulse bias of − 100 V was applied to the substrate in order to obtain a denser structure of DLC coating approximately 1 μm thick. The microstructure and hardness value of DLC films were analyzed by using X-ray photoelectron spectroscopy and nano-indenter. The experimental results show that the duty cycle strongly influenced the hardness and sp 3 content of the DLC coatings. We observed that when the duty cycle was raised from 2.5% to 12.5%, the hardness increased from 26 GPa to 49 GPa, and the sp 3 fraction of the DLC films measured by XPS increased from 39% to 50.8 % as well. But at constant duty cycle, say 12.5%, the hardness is dropped from 49 to 14 GPa in proportion to the increase of residual gas pressure from 3 × 10 − 3 Pa to 1 Pa. As the residual gas pressure increased, collisional phenomenon will decrease the energy of the ions. Ions with low energy make more graphitic carbon links and result in a low hardness value.

Properties of TiAl and TiAlN Thin Films by Pulsed Cathodic ARC

TiAl and TiAlN thin films are deposited on glassy carbon and Si substrates by the pulsed cathodic arc deposition process. In our pulsed cathodic arc system, because the spatial position of plasma on the surface of the evaporation source can be controlled by pulsed arc discharge, the thickness of the TiAl and TiAlN films can be controlled at nanometer scale. Amorphous stoichiometric Ti-Al films are synthesized from one Ti-Al alloy target at room temperature by changing the number of pulses of the arc discharge.

Optimizing the triggering mode for stable operation of a pulsed cathodic arc deposition system

In order to deposit fine structures such as nanoscale multilayers using a pulsed cathodic arc, it is necessary to ensure that the deposition per pulse is stable over a large number of pulses. We compare the deposition rate using centre and edge triggering in a pulsed cathodic arc system by determining the rate of change of thickness of a growing film. Three arc currents were used and the results indicated that the centre triggering configuration provides a constant deposition rate when compared to edge triggering. It was also observed that the highest arc current in the centre mode showed the most uniform deposition rate. The erosion profile of the cathodes for the two different triggering types were examined and used to explain the differences in terms of uniformity of erosion. We also measured the discharge voltage and found that there was an increase with increasing arc current.