Diamond Like Carbon Research Papers (original) (raw)

2025, Journal of Applied Physics

In this study, we show and discuss the results of the interaction of living CHO (Chinese Hamster Ovary) cells, in terms of adhesion and growth on glass, SU-8 (epoxi photoresist), PDMS (polydimethylsiloxane), and DLC (hydrogen free diamond-like carbon) surfaces. Glass, SU-8, and DLC but not PDMS showed to be good surfaces for cell growth. DLC surfaces were treated by oxygen plasma (DLC-O) and sulfur hexafluoride plasma (DLC-F). After 24 h of cell culture, the number of cells on DLC-O was higher than on DLC-F surface. SU-8 with silver implanted, creating nanoparticles 12 nm below the surface, increased significantly the number of cells per unit area. V

2025, Diamond and Related Materials

High strength steel (HSS) is widely used for automobile reinforcement parts and the quantity required is rapidly grown. However, the strength and hardness of the steel are relatively high, its formability is very low and adhesion to tool material can be easily found under forming operation. This paper aimed to evaluate the anti-adhesion performance of commercial nitride and DLC films coated on cold work tool steel against HSS in forming operation. The friction coefficient and wear rate of the non-coated ball (SKD11; hardness 60± 2 HRC), balls coated with TiN-PVD, TiCN-PVD, AlTiN-PVD, Nitride + CrN and DLC have been evaluated in sliding contact against SPFH 590 (JIS) disk. The scratch and nano-indentation tests were done on each type of coated tools to characterize the adhesive strength between the film and the substrate, and the hardness and the elastic modulus, respectively. The anti-adhesion performance of various films coated tool in metal stamping process was also investigated by performing U-bending experiment. The cold roll carbon steel; SPCC (JIS) was also used to compare a material transfer problem to the case of using HSS (JIS: SPFH590). As the results, for HSS sheet, the adhesion of workpiece material on a non-coated die surface was detected after 49 strokes whereas adhesion could not be found in case of stamping SPCC sheet up to 500 strokes. The TiCN, AlTiN, and Nitride + CrN films showed good anti-adhesion performance when forming HSS, while the TiN and DLC films did not provide the satisfied results.

2025, Progress in Solid State Chemistry

2025

Anodizing is an electrolytic passivation process used to increase the thickness of the natural oxide layer on the surface of metal parts. Aluminum is ideally suited to anodizing, although other nonferrous metals, such as tantalum and titanium, can also be anodized. Titanium is used as a biocompatible material in human implants due to its excellent corrosion and wears resistance. Stable, continuous, highly adherent, and protective oxide films can be developed on titanium using various acid or alkaline baths. Anodizing of titanium generates a spectrum of different color without use of dyes. This spectrum of color dependent on the thickness of the oxide, interference of light reflecting off the oxide surface and reflecting off the underlying metal surface. The anodized film of Titanium is mainly consists of TiO2 or mixtures of TiO2 & Ti2O3 etc. In the present work, Pure Titanium plate has been anodized using bath of KOH at different voltage ranges. The anodized film is characterized by...

2025

2025, Analytical Chemistry

2025, Tribology International

Punching and blanking processes are characterized by severe tribological conditions due to the creation of virgin surfaces, which are highly prone to develop pick-up of workpiece material on the punch surface. Hazardous forming lubricants are, therefore, commonly used in punching and blanking processes for avoidance of wear induced process deviations such as diminished surface quality, reduced dimensional accuracy and reduced tool life. The present study characterizes the function and performance of lubricants used for punching and blanking operations for assessment of the tribological lubricant properties necessary for adaption of environmentally friendly lubricant alternatives. Analysis of the tribochemical properties of the studied lubricants indicate that an applicable temperature range and a high load bearing capacity are central lubricant properties necessary for ensuring sufficient lubricating ability for punching and blanking operations.

2025, Nanomaterials

This study aimed to develop hydrogenated amorphous carbon thin films with embedded metallic nanoparticles (a-C:H:Me) of controlled size and concentration. Towards this end, a novel hybrid deposition system is presented that uses a combination of Plasma Enhanced Chemical Vapor Deposition (PECVD) and Physical Vapor Deposition (PVD) technologies. The a-C:H matrix was deposited through the acceleration of carbon ions generated through a radio-frequency (RF) plasma source by cracking methane, whereas metallic nanoparticles were generated and deposited using terminated gas condensation (TGC) technology. The resulting material was a hydrogenated amorphous carbon film with controlled physical properties and evenly dispersed metallic nanoparticles (here Ag or Ti). The physical, chemical, morphological and mechanical characteristics of the films were investigated through X-ray reflectivity (XRR), Raman spectroscopy, Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Transmission Electron Microscopy (TEM) and nanoscratch testing. The resulting amorphous carbon metal nanocomposite films (a-C:H:Ag and a-C:H:Ti) exhibited enhanced nanoscratch resistance (up to +50%) and low values of friction coefficient (<0.05), properties desirable for protective coatings and/or solid lubricant applications. The ability to form nanocomposite structures with tunable coating performance by potentially controlling the carbon bonding, hydrogen content, and the type/size/percent of metallic nanoparticles opens new avenues for a broad range of applications in which mechanical, physical, biological and/or combinatorial properties are required.

2025, ACS Nano

We demonstrate ink-jet printing as a viable method for large area fabrication of graphene devices. We produce a graphene-based ink by liquid phase exfoliation of graphite in N-Methylpyrrolidone. We use it to print thin-film transistors, with mobilities up to∼95cm 2 V -1 s -1 , as well as transparent and conductive patterns, with∼80% transmittance and∼30kΩ/ sheet resistance. This paves the way to all-printed, flexible and transparent graphene devices on arbitrary substrates.

2025

The study of cam-tappet tribochemistry is on the rise due to the need for a better understanding of how nanoscopic tribofilms reduce friction (improved engine efficiency) and wear (durability) in internal combustion engine. Environmental legislation on exhaust gas emissions have further stimulated research on the use of less phosphorus and sulphur containing additives because phosphorus clogs the catalytic converters in an engine exhaust system. Current tests evaluate the resultant surface films formed on the contact by the additive package which has made understanding of the test conditions crucial due to the increased complexity of tribochemistry. Diamond Like Carbon (DLC) surface coatings are also receiving significant attention even though their interaction with conventional lubricants additives is still unclear. A vast majority of published studies look at these systems under steady-state conditions whereas, dynamic conditions are predominant. In this work, a newly modified ‘SL...

2025

In this study, the tribological properties of steel, Mn-phosphate, Si doped (S1s), and hydrogenated tetrahedral amorphous carbon (ta-C:H) diamond like carbon (DLC) coatings were investigated in a pin on reciprocating plate tribometer and single cam test rig. S1s and taC-H DLC coating architectures were obtained with plasma assisted chemical vapor deposition technique with hardness 20 ± 4 GPa and 35 ± 7 GPa respectively. All materials had a centre-line average surface roughness (Ra) of 0.02-0.03 µm except for the Mn(PO3)2 which had Ra of 0.30 µm. The S1s showed severe delamination after tests on the reciprocating tribometer while spots of wear flakes were observed in the bench test. Both single cam rig and reciprocating tests have shown similar wear and friction results which can be used to rank materials, surface coatings and lubricants for optimum performance of valve train components.

2025, Japanese Journal of Applied Physics

The tribological characteristics of perfluoropolyether (PFPE) and heat-treated PFPE lubricant films deposited on magnetic thin diamond-like carbon (DLC) film-coated disks by dip coating were studied using lateral modulation frictional force microscopy (LM-FFM). The topography and microstructural properties of the DLC film disk before PFPE lubricant dip coating were investigated by transmission electron microscopy (TEM) and atomic force microscopy (AFM) in the dynamic force modulation (DFM) and frictional force modulation (FFM) modes. The TEM and AFM images show valleys and fine spaces formed between grain boundaries. It is possible that free lubricants reserved in these valleys and spaces during dip coating replenished the surface as a result of tip sliding. In wear tests, the friction properties of the PFPE-DLC disk without heat curing were improved due to the supply of lubricant.

2025, IEEE Transactions on Plasma Science

This paper discusses the potential use of the hydrogen atomic line emission at 656.3 nm (H ) as an effective in-situ sensor for a closed-loop control system to improve the reproducibility of reactive sputter deposition of nano-structured, metal-containing, hydrogenated, diamond-like carbon (Me:DLC:H) coatings. The paper includes experimental results showing a good correlation between H emission in the process plasma and the formation of metal-carbide, an important component of these coatings. The first attempts at actual feedback-control of the process showed that this sensor can be effective, at least over the stage of the deposition when mostly carbides are formed in the coating. A spectrally resolved analysis of the H emission for the various stages of the deposition have shown that the emission profile is dominated by a "hot" component ( 10-20 eV), which can be attributed to dissociative excitation of molecular hydrogen (H 2 ). The molecular hydrogen is understood to evolve from the coating as a result of carbon incorporation from the reactive gas (C 2 H 2 ) and is particularly sensitive to metal carbide formation in the film, when most of the hydrogen is released from the surface in molecular form.

2025, Journal of Applied Physics

The secondary electron emission yield of fullerene, graphite, and diamondlike carbon after low-energy N2+ ion bombardment was studied for antimultipactor applications. Nitrogen incorporation into the carbon thin films decreases their secondary emission yield, contrary to the hydrogen or oxygen effect. Carbon nitride surface textured to a nanometric scale had the property of hindering secondary electron emission. Valence bands obtained from photoemission spectroscopy using synchrotron radiation were correlated with secondary electron emission measurements. Multipactor threshold power for carbon nitride was 7.5kW.

2025, Analytical Sciences

The structure of 3 nm and 15 nm diamond-like carbon films, grown on Si(001) by filtered cathodic arc, was studied by angle-resolved X-ray photoelectron spectroscopy (ARXPS) and transmission electron microscopy (TEM). The ARXPS data was deconvolved by employing simultaneous-fitting, which allowed for a clear deconvolution of the Si 2p and C 1s spectra into their different chemical contributions. An analysis of the take-off angle dependence of the peak intensities allowed for an independent identification of the physical origin of the chemical species. It was shown that the C 1s peak at 283.3 eV and the Si 2p peak at 99.6 eV correspond to SiC, and that the C/Si interface of the 3 nm film consists of a stoichiometric ~1 nm SiC layer. To quantify the sp 3 -sp 2 ratio it was necessary to take into account not only their associated C 1s XPS-peak intensities, but also their take-off angle dependence. The thickness of the films obtained through ARXPS closely agrees with cross-sectional TEM images.

2025, Diamond and Related Materials

Diamond-like carbon films containing up to 23.1 at. % of fluorine (DLC-F), were deposited onto silicon substrates by low-frequency, pulsed DC, plasma-activated, chemical vapour deposition (PACVD). The influence of fluorine on plasma current density, deposition rate, composition, bonding structure, surface energy, hardness, stress and biocompatibility were investigated and correlated with the fluorine content. X-ray photoelectron spectroscopy (XPS) analysis revealed the presence C-C, C-CF and C-F for F-DLC films with low fluorine concentration (1.5-12.1 at. %), however for films with higher fluorine content (23.0 at. %) an additional peak due to CF 2 bonding was detected. The addition of fluorine into the DLC film resulted in lower stress and hardness values. The reduction in these values was attributed to the substitution of strong C=C by weaker C-F bonds which induces a decrease in hardness. Ion scattering spectrometery (ISS) measurements revealed the presence of fluorine atoms in the outmost layer of the F-DLC films and there was no evidence of surface oxygen contamination. The water contact angle was found to increases with increasing fluorine content and has been attributed to the change of the bonding nature in the films, in particularly increasing CF and CF 2 bonds. Biocompatibility tests performed using MG-63 osteoblast-like cell cultures indicated homogeneous and optimal tissue integration for both the DLC and the F-DLC surfaces. This pulsed-PACVD technique has been shown to produce biocompatible DLC and F-DLC coatings with potential for large area applications.

2025, HAL (Le Centre pour la Communication Scientifique Directe)

Acoustelectric devices have been used now for several decades to stabilize oscillators, to filter radio-frequency signals or to allow for physical and even chemical detection and measurements. Among all the structures that have been developed in that purpose, one has been revealing particularly interesting for the development of high quality factor resonator on an extended range of frequency. It is based on the generation of high overtones in bulk acoustic wave resonant structure and therefore are currently called HBARs. These devices may be fabricated along various approaches but they always consist of a thin (or thinned) piezoelectric layer deposited or bonded onto a high quality single crystal material. The spectral response of this kind of device exhibit a periodic comb of peaks modulated by the transducer response, yielding resonances on a very large spectrum with various characteristics and properties. We present here the basic principles of such devices, their remarkable properties, the technologies required to manufacture them and the various applications they can be applied for. A focus is particularly dedicated to oscillator stabilization and to the development of wireless sensors.

2025, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control

2025

The textured surface with superhydrophobic nature was explored for an anti-biofouling template. Hierarchical structures composed of the nano-scale wrinkle covering on micro-scale polymer pillar patterns were fabricated by combining the deposition of a thin coating layer of biocompatible diamond-like carbon (DLC) and the replica molding of poly-(dimethylsiloxane) (PDMS) micro-pillars. The as-prepared surfaces were shown to have extreme hydrophobicity (static contact angle¤ ¤160� � ) owing to low surface energy (24.2 mN/ m) and dual-roughness structures of the DLC coating. It was explored that the hierarchical surfaces showed poor adhesion of the Calf Pulmonary Artery Endothelial (CPAE) cells for cultures of 7 days suggesting that the 3-dimensional (3-D) patterned superhydrophobic DLC coating exhibits excellent anti-biofouling properties against non-specific cell adhesion. In particular, the reduced filopodia extension during cell growth was caused by disconnected focal adhesions on the pillar pattern. This limited cell adhesion could prevent undesired growth and proliferation of biological species on the surface of biomedical devices such as stents, implants or even injection syringes.

2025

Tribological behaviors of the hard film on soft substrate system were explored using the hard thin film of diamond-like carbon (DLC) coated the soft polymer of polydimethysiloxane (PDMS). A DLC film with the Young's modulus of 100 GPa was coated on PDMS substrate with Young's modulus of 10 MPa using plasma enhanced chemical vapor deposition (PECVD) technique. The deposition time was varied from 10 sec to 10 min, resulting in nanoscale roughness of wrinkle patterns with the thickness of 20 nm to 510 nm, respectively, at a bias voltage of 400 Vb, working pressure 10 mTorr. Nanoscale wrinkle patterns with 20-100 nm in width and 10-30 nm height were formed on DLC coating due to the residual stress in compression and difference in Young's modulus.

2025, Thin Solid Films

The mechanical stability of diamond-like carbon (DLC) films coated on nitinol vascular stents was investigated under cyclic loading condition by employing a stent crimping system. DLC films were coated on the vascular stent of a three dimensional structure by using a hybrid ion beam system with rotating jig. The cracking or delamination of the DLC coating occurred dominantly near the hinge connecting the V-shaped segments of the stent where the maximum strain was induced by a cyclic loading of contraction and extension. However the failures were significantly suppressed as the amorphous Si (a-Si) buffer layer thickness increased. Interfacial adhesion strength was estimated from the spalled crack size in the DLC coating for various values of the a-Si buffer layer thickness.

2025, Thin Solid Films

Diamond-like carbon DLC has been a candidate for various applications due to its excellent tribological and mechanical properties. However, poor adhesion on tool steels limits its applications over a wide range. In the present work, we investigated the effect of W and W᎐C intermediate layers on the adhesion of DLC films to AISI D2 tool steels. The intermediate layers were deposited by dc magnetron sputtering and the DLC films were deposited on the various intermediate layers by rf-PACVD. Adhesion of the DLC film was significantly improved by introducing W and W᎐C intermediate layers. The adhesion was strongly dependent on the thickness of W layer and the CH fraction in the sputtering gas during the intermediate layer deposition. TEM 4 cross section revealed that, in addition to the chemical compatibility between carbon and the intermediate layer materials, the microstructure of the intermediate layer is also important to improve the adhesion. Columnar grains of the intermediate layers and structural continuity between the W and W᎐C mixed layers were the significant factors affecting the adhesion of DLC films.

2025, Surface and Coatings Technology

Micromachined Si tips have been considered as a strong candidate for cold cathode materials. However, as-prepared Si tips showed unstable emission behavior, presumably due to native oxide, chemical reaction with residual gases or changes in tip geometry during operation. In order to stabilize the emission behavior, diamond-like carbon (DLC ) films were deposited on the Si tips by DC magnetron sputtering of high purity graphite. We focused on the stability of the emission behavior by repeating the I-V measurement with anode voltages ranging from 100 to 2500 V. With increasing number of I-V measurements, the onset electric field decreased in both as-prepared and DLC-coated Si tips. However, the emission current of as-prepared Si tips decreased with increasing number of I-V measurements and eventually could not be observed after 10 measurements. On the other hand, DLC-coated tips exhibited improved emission behavior by repeating the I-V measurement. These results showed that the DLC coating can prevent the Si tips from oxidation or from being contaminated, which stabilized the field emission behavior. Furthermore, the DLC coating seems to reduce the effect of the changes in tip apex morphology by reducing the sharpness of the tip apex.

2025, Surface and Coatings Technology

The residual stress and atomic bond structure of Si-incorporated diamond-like carbon films were investigated by the molecular dynamics simulation using Tersoff interatomic potential. The effect of Si incorporation into amorphous carbon matrix was analyzed for the various Si concentrations ranging from 0 to 2.1 at.%. The present simulation revealed that the incorporation of a small amount of Si significantly reduced the residual compressive stress: when the Si content was 0.54 at.%, the minimal compressive stress of 1.4 GPa was observed. Structural analysis using the radial distribution function and the bond angle distribution indicated that the compressive stress reduction resulted from the relaxation of highly distorted bond angles less than 109.5°.

2025, Surface and Coatings Technology

We investigated the effect of plastic deformation of diamond-like carbon (DLC) coated stainless steel on the corrosion resistance in the simulated body fluid environment. We deposited the DLC film on 304 stainless steel specimens by radio frequency plasma assisted chemical vapor deposition(R.F.-PACVD) method, followed by a tensile test to apply plastic stain on the coated specimen. Corrosion behavior in the simulated body fluid environment was studied by a potentiodynamic polarization test. As the tensile deformation progressed, the cracks of the film were observed in the perpendicular direction to the tensile axis. Further deformation increase both of the cracks and the spallations. Estimated porosity and corrosion current density increased and thus the protective efficiency decreased at the strain of 2 %. In spite of the degradation, the anticorrosion properties were significantly improved comparing to the uncoated stainless steel. However, significant increase in porosity and corrosion current density was observed at the strain of 4 %.

2025, Sensors and Actuators A: Physical

A new capacitive displacement sensor is designed and fabricated for measurement of a large displacement with very high accuracy. This sensor is a kind of linear encoder with an array of micro electrodes made by micromachining processes. The two patterned electrodes on the sensor substrates are assembled facing each other after being coated with thin dielectric film. Due to the thin dielectric film, it is highly sensitive to displacement but minimizes expected misalignments such as a tilting error. The sensor fabricated as a sample has a grating of electrodes with a width of 100µm, which is coated with a Diamond-Like Carbon(DLC) film 0.8 µm thick. The proposed sensor was tested to conclude that its resolution is 9.07 nanometers for the measuring range of 15 millimeters and that the linearity error is expected to be less than 0.02% throughout the measurable range.

2025, Journal of Oral Rehabilitation

summary The aim of this study was to quantify the extent of abutment screw loosening and thus understand the role of frictional and wear factors in abutment screw loosening by using a cyclic loading device to compare Diamond Like Carbon (DLC)‐coated and non‐coated implants. The properties of DLC films, including hardness, wear resistance, chemical stability, and biocompatibility, are similar to those of real diamond materials. In this study, a 1‐μm thick DLC film served to protect and lubricate a layer of commercially‐pure titanium affixed to the top of a dental implant (external hexagon‐shaped implant). A cyclic loading force was then applied to the top of the prosthetic portion of the implants in order to determine the difference in looseness of the titanium abutment screw between ten DLC‐coated implants and ten non‐coated implants. The abutment screw loosening tests were performed with 100 N of force at a frequency of 20 Hz. Data indicate that implants with a DLC coating are mor...

2025, Journal of Bioactive and Compatible Polymers

The surfaces of Nitinol (TiNi), a popular metal alloy for arterial stents were thin-coated with diamond-like carbon (DLC) and then grafted with poly(ethylene glycol) (PEG) to increase biocompatibility. The TiNi control, DLC-coated TiNi (TiNi—DLC), and the PEG-grafted TiNi—DLC (TiNi—DLC—PEG) surface characteristics and biocompatibility were evaluated. The hydrophilicity of the TiNi—DLC—PEG significantly increased and the amount of both oxygen and nitrogen on the TiNi—DLC—PEG also increased compared to the TiNi control and TiNi—DLC due to the grafted PEG. The ratio between albumin and fibrinogen was higher on the PEG-grafted surface than the other surfaces when tested with human blood components; the platelet adhesion decreased the most on the TiNi—DLC—PEG surface, indicating improved blood compatibility. For in vivo tests using a rat model, the samples that were implanted for 6 weeks formed fibrous tissue; the tissue layer was much thinner on the PEG-grafted sample than the other two...

2025, Diamond and Related Materials

Diamond-like carbon (DLC) films deposited on Si(100) wafer by r.f.-plasma assisted chemical vapor deposition were friction tested by ball-on-disk type tribometer in various test environments. The friction tests were performed in an ambient air of relative humidity ranging from 0 to 90% or dry oxygen environment. We focused on the tribochemical reactions by analyzing the chemical composition, chemical bond structure and agglomerated shape of the debris. High and unstable frictional behavior was observed in both humid air and dry oxygen environment. In these environments, Auger spectrum analysis showed that the debris contained large amount of Fe. Significant incorporation of Fe in the debris resulted from the wear of the steel ball, which might be enhanced by the surface oxidation of the ball. However, a very low frictional coefficient was observed against the sapphire ball even in dry oxygen environment. These results show that the increased frictional coefficient of the DLC film is closely related with the increased Fe concentration in the debris. Hence, the humidity dependence of the frictional coefficient is not an inherent tribological property of DLC film but results from the surface reaction of the steel ball with humid environment. Two possible reasons for the Fe rich debris to affect the frictional behavior were suggested.

2025, Diamond and Related Materials

DLC coating can be used for vascular stents to prevent the stainless steel substrate from eluting Ni and Cr by plastic deformation and corrosion environment. The stress corrosion cracking (SCC) of Si-diamond-like carbon (Si-DLC) coated on 316L stainless steel was studied in a simulated body environment of a deaerated 0.89 wt.% NaCl electrolyte at 37 °C. This paper investigated the effect of Si-DLC coating on the SCC of 316L SS by slow-strain-rate test (SSRT), constant load test (CLT), and electrochemical impedance spectroscopy (EIS). The EIS data were monitored for the elastic and plastic regions under CLT to determine the electrochemical behavior of the passive film during SCC phenomena. The Si-DLC coated steel exhibited more ductility than uncoated steel and less susceptibility to SCC in this environment. According to X-ray photoelectron spectroscopy (XPS) analysis, the film repassivation occurs due to the presence of the silicon oxide layer on the Si-DLC film surface.

2025, Diamond and Related Materials

Frictional behaviors of wrinkle patterns on a diamond-like carbon (DLC) film coated on a soft polymer were investigated. Wrinkle patterns of the DLC layer were formed due to the large difference in elastic moduli between the DLC film and the soft polymer of polydimethylsiloxane (PDMS) as well as high residual compressive stress in the film. The roughness of wrinkled surfaces varied with the thickness of the DLC films, affecting the frictional behaviors. The coefficient of friction significantly reduced as the thickness of the DLC film increased. For lower thicknesses, slip-stick events and surface damages like fish-scales on the wear track were strongly developed. With an increase of sliding distance, a randomly oriented wrinkle pattern was getting worn on its top surfaces, resulting in an increase of the contact area as well as a coefficient of friction (COF). However, for thicker films simple wear was observed with the lower COF due to DLC nature.

2025, Applied Surface Science

With the invention of miniaturized devices like micro-electro-mechanical systems (MEMS), tribological studies at micro/nano-scale have gained importance. These studies are directed towards understanding the interactions between surfaces at micro/nano-scales, under relative motion. In MEMS devices, the critical forces, namely adhesion and friction restrict the smooth operation of the elements that are in relative motion. These miniaturized devices are traditionally made from silicon (Si), whose tribological properties are not good. In this paper, we present a short investigation of nano-and micro-tribological properties of diamond-like carbon (DLC) nano-dot surfaces. The investigation was undertaken to evaluate the potential of these surfaces for their possible application to the miniaturized devices. The tribological evaluation of the DLC nano-dot surfaces was done in comparison with bare Si (1 0 0) surfaces and DLC coated silicon surfaces. A commercial atomic force microscope (AFM) was used to measure adhesion and friction properties of the test materials at the nano-scale, whereas a custom-built micro-tribotester was used to measure their micro-friction property. Results showed that the DLC nano-dot surfaces exhibited superior tribological properties with the lowest values of adhesion force, and friction force both at the nano-and micro-scales, when compared to the bare Si (1 0 0) surfaces and DLC coated silicon surfaces. In addition, the DLC nano-dot surfaces showed no observable wear at the micro-scale, unlike the other two test materials. The superior tribological performance of the DLC nano-dot surfaces is attributed to their hydrophobic nature and the reduced area of contact projected by them.

2025

2025, Journal of Biomedical Materials Research Part A

Hydrogenated diamond-like carbon films (a-C:H DLC) were deposited on STS 304 substrates for the fabrication of vascular stents by means of the r.f. plasmaassisted chemical vapor deposition technique. This study provides reliable and quantitative data for the assessment of the effect of strain on the corrosion performance of DLC-coated systems in the simulated body fluid obtained through electrochemical techniques (potentiodynamic polarization test and electrochemical impedance spectroscopy) and surface analysis (scanning electron microscopy). The electrolyte used in this test was 0.89% NaCl solution at pH 7.4 and 378C. It was found that the corrosion resistance of the plastically deformed DLC coating was insufficient for use as a protective film in a corrosive body environment. This is due to the increase in the delamination area and degradation of the substrate's corrosion properties with increasing tensile deformation. 2007 Wiley

2025

The structure and surface morphology of diamond films grown on (100) single crystal silicon substrates by HF-CVD technique using H 2 :CH 4 (100:1 sccm) gas mixture are reported. The diamond films were characterized by scanning electron microscopy, x-ray diffraction and Raman spectroscopy. The influence of substrate pretreatment on the surface morphology and structure of the deposited diamond films have been explored. SEM micrographs of the deposited diamond film without any substrate pretreatment were found to consist of scattered diamond nuclei of about 5 µm or less in diameter having cubo-octahedral shapes which clearly exhibit (100) and (111) planes of diamond lattice which are not significantly clustered. As the pretreatment time increases to 20 minutes the diamond nuclei grow in number and clustering starts to dominate and the signals of secondary nucleation disappear. After 30 minutes pretreatment of the substrate the micrographs of the deposited films showed that the film was continuous and nicely faceted exhibiting predominant (111) surface morphology. A successful attempt has been made to incorporate boron in easy and simple way in the deposited diamond films. It was found that the presence of boron introduced cauli-flower type features to diamond crystallites on micron scale.

2025, Diamond and Related Materials

doped diamond like-carbon coatings (DLC-Si/Ag) for biomedical applications fabricated using the modified chemical vapour deposition method, Diamond & Related Materials (2016),

2025, Procedia Engineering

Fabrication procedure and refractive index (RI) sensitivity of a diamond-like carbon (DLC) nano-coated optical fiber sensing structure is presented. The overlays were deposited by Radio Frequency Plasma Assisted Chemical Vapor Deposition (RF PACVD) method on both cores of a polymer-clad silica (PCS) multimode optical fibers and oxidized silicon wafers. It is shown that thin (120 to 330 nm in thickness measured on the silicon wafers) and high refractive index (~2.14 at λ=620 nm) overlays can effectively modify optical response of the structures to variation of the external RI. By deposition of the overlay we achieved 5-times increase in the RI sensitivity of the investigated samples.

2025, Materials Science and Engineering: B

The paper discusses optical properties and thickness of the diamond-like carbon (DLC) films deposited with Radio Frequency Plasma Assisted Chemical Vapour Deposition (RF PACVD) method onto 1 1 1 oriented silicon substrates. Measurements performed with spectroscopic ellipsometer indicated a significant influence of both self-bias voltage and deposition time on thickness and refractive index of the DLC films. It was also found that optical properties are strongly deposition time dependent. Determination of DLC film thickness with constant optical properties cannot be realized just by adjusting deposition time.

2025, Diamond and Related Materials

The paper presents diamond-like carbon (DLC) film as a coating for optical fibres with long-period gratings (LPG). The coatings were successfully obtained using the Radio Frequency Plasma Chemical Vapour Deposition (RF PCVD) method. Thin DLC coatings significantly change the properties of the LPG-based sensing elements. The sensing systems built using those elements can be very sensitive to concentration changes of various chemical solutions due to changes in their refractive index. DLC-coated LPGs can be as much as 15 times more sensitive than uncoated LPGs to variations within a specified range of the refractive index of the surrounding medium. The influence of RF PCVD process parameters on sensitivity is discussed.

2025, Diamond and Related Materials

The paper presents analyses of the optical properties and thickness of diamond-like carbon (DLC) films deposited on oxidized silicon wafers and silicon wafers with various resistivity and different crystallographic orientations. The influence of the parameters of the radio frequency plasma-assisted chemical vapor deposition (RF PACVD) process, notably the duration of the deposition process and the negative self-bias voltage of RF-powered electrode, on the optical properties and thickness of the DLC film were investigated. These properties were determined by spectroscopic ellipsometry. To the best of our knowledge, this is the first comparative analysis of these properties for various silicon and oxidized silicon substrates. Our results show that the substrate has a significant influence on both the optical properties and the thickness of the DLC film. The differences observed are highly dependent on the discussed process parameters.

2025

High stresses and complex stress fields are usually developed in thin films when they are submitted to an indentation. Studies on this subject have proved to be important for the understanding of the mechanical behavior of these films. This work was developed to study the stress fields obtained when successive indentations are conducted on coated systems. The finite element method (FEM), through the software ABAQUS, was used and axisymmetric bidimensional meshes were selected. During the indentations, a spherical indenter was considered and applied normal loads of 50 N on a system composed by a film with elastic behavior and a substrate with elastic-plastic behavior. The analyses have also considered the possibility and the effects of the propagation of circular cracks initially distributed along the film surface. The results allowed an analysis of t he propagation of the circular cracks as a function of the number of indentations carried out and the resulting stress fields.

2025, ACS Applied Materials & Interfaces

Porous diamond-like carbon (DLC) electrodes have been prepared, and their electrochemical performance was explored. For electrode preparation, a thin DLC film was deposited onto a densely packed forest of highly porous, vertically aligned multiwalled carbon nanotubes (VACNT). DLC deposition caused the tips of the carbon nanotubes to clump together to form a microstructured surface with an enlarged surface area. DLC:VACNT electrodes show fast charge transfer, which is promising for several electrochemical applications, including electroanalysis. DLC:VACNT electrodes were applied to the determination of targeted molecules such as dopamine (DA) and epinephrine (EP), which are neurotransmitters/hormones, and acetaminophen (AC), an endocrine disruptor. Using simple and low-cost techniques, such as cyclic voltammetry, analytical curves in the concentration range from 10 to 100 μmol L -1 were obtained and excellent analytical parameters achieved, including high analytical sensitivity, good response stability, and low limits of detection of 2.9, 4.5, and 2.3 μmol L -1 for DA, EP, and AC, respectively.

2025, AIChE Journal

Diamond‐like carbon films have been deposited from ternary mixtures of butadiene, hydrogen and argon in a parallel plate plasma reactor at constant pressure and power. These films have been etched in O2 and CF4/O2 plasma discharges. A new linear relationship between the composition of the deposition gas mixture and a dimensionless number (EN) defined in terms of etch and deposition rates and the bias voltage during deposition has been derived. EN is a function of the ion flux during deposition. Electron‐impact ionization processes are considered for relating the ion flux to the feed gas composition and ionization potentials. The etch and deposition rate data follow this linear relationship very well. The proportionality constant in this linear relationship varies with composition for CF4/O2 etching data. Film hardness and failure modes on silicon and glass substrates are also described.

2025, ABM Proceedings

Quando processos de engenharia de superfícies multifuncionais que combinam fases de propósito orientadas são aplicados a substratos moles, uma combinação de alta resistência ao desgaste, suporte de alta carga e baixos coeficientes de atrito podem ser obtidos. Neste estudo, os efeitos de diferentes camadas nitretadas no comportamento tribológico de revestimento Diamond-Like-Carbon (DLC) depositado sobre aço SAE 1040 são investigados. A nitretação foi conduzida sob diferentes temperaturas e misturas de gases para criar três camadas de nitretos distintas: duas camadas de compostos com predominância de fases ε e γ' e uma camada de difusão. Todas as superfícies foram então revestidas com DLC, depositado via Plasma-Enhanced-Chemical-Vapour-Deposition (PACVD). As fases de nitreto foram analisadas utilizando difração de raios-X e a topografia da superfície foi analisada por interferometria de luz branca e microscopia eletrônica de varredura. O comportamento tribológico foi investigado utilizando esfera e plano com movimento alternado com carregamento incremental até a falha do filme DLC. Os testes tribológicos indicaram que o melhor desempenho foi alcançado por uma específica combinação de dureza, rugosidade superficial e tipo de nitreto. A melhor capacidade de mancalização entre o revestimento DLC e o substrato mole foi alcançada quando a camada de nitretos constitui-se apenas de uma camada de difusão.

2025, IEEE Electron Device Letters

This work reports on the realization and test of a compact beam-profiling system for UV and X-ray sources, based on polycrystalline CVD diamond detectors. Multistrip and pixel structures have been used for 1-D and 2-D photodetectors, respectively. A dedicated read-out electronic circuitry has been designed and used to independently sample the signal produced by each strip (or pixel), enabling a real-time beam profile reconstruction.

2025, Journal of Food Engineering

The surface properties of several modified stainless steel samples were characterized according to their chemical composition, roughness, topography and wettability. The modifications tested were SiF þ 3 and MoS 2þ 2 ion implantation; diamond-like carbon (DLC) sputtering; DLC, DLC-Si-O and SiO x plasma enhanced chemical vapor deposition (PECVD); autocatalytic Ni-P-PTFE and silica coating. X-ray photoelectron spectroscopy (XPS) and X-ray microanalysis were applied to determine the surface chemical composition. Atomic force microscopy (AFM) and stylus-type instruments were used for roughness determination, and the surface topography was imaged with AFM and scanning electron microscopy (SEM). The contact angle and surface tension were measured with the Wilhelmy plate method and the sessile drop method. For thick modified layers, only the elements of the coating were detected at the surface, whereas for thin layers the surface composition determined was that of the stainless steel substrate. The roughness of the 2R (cold rolled and annealed in a protective atmosphere) surfaces was not altered by the modification techniques (except for the Ni-P-PTFE coating), while for the 2B (cold rolled, heat treated, pickled and skinpassed) surfaces an increase in roughness was observed. The silica coating produced surfaces with consistent roughness, independent of which steel substrate was used. DLC sputtering and Ni-P-PTFE coating produced surfaces with the highest roughness. All modified surfaces revealed a similar surface topography with the exception of the Ni-P-PTFE coating, for which the coating masked the underlying steel topography. In terms of wettability, the SiO x -plasmaCVD and Ni-P-PTFE coating techniques produced the most hydrophilic and hydrophobic surfaces, respectively.

2025

Plasma-based ion implantation (PBII) allows the formation of diamond-like carbon (DLC) films with excellent tribological properties. A large number of examples from the literature are discussed in detail, and the process parameters of PBII, such as plasma-forming gas, bias voltage, pulse length, pulse repetition rate and experimental setup, are correlated with the DLC film properties, such as bonding characteristics, stress, hardmess, friction and wear behavior and corrosion protection ability. Trends in the variation of film features with the process parameters are shown, and the underlying physical processes are discussed.

2025, Coatings

Amorphous carbon films with a high hardness usually suffer from high internal stress. To deposit films with a hard top surface but reduced internal stress, a simple bilayer approach was used. Films were prepared by plasma source ion implantation, using only hydrocarbon precursors. The single layer with the highest hardness (deposited by a low direct current (DC) voltage and radio frequency (RF) generation of the plasma) has the highest internal stress with more than 3.5 GPa. By adding an interlayer with a lower hardness, the resulting stress of the bilayer film can be reduced to below 1.4 GPa while maintaining the high hardness of the top layer. By avoiding metallic interlayers or dopants within the films, the deposition process can be kept simple and cost-effective, and it is also suitable for three-dimensional samples.

2025, Coatings

The intrinsic high electrical resistivity of diamond-like carbon (DLC) films prevents their use in certain applications. The addition of metal or nitrogen during the preparation of the DLC films leads to a lower resistivity of the films, but it is usually accompanied by several disadvantages, such as a potential contamination risk for surfaces in contact with the film, a limited area that can be coated, deteriorated mechanical properties or low deposition rates of the films. To avoid these problems, DLC films have been prepared by plasma source ion implantation using aniline as a precursor gas, either in pure form or mixed with acetylene. The nitrogen from the precursor aniline is incorporated into the DLC films, leading to a reduced electrical resistivity. Film properties such as hardness, surface roughness and friction coefficient are nearly unchanged as compared to an additionally prepared reference sample, which was deposited using only pure acetylene as precursor gas.