Fluctuation Microscopy Studies of Amorphous Diamond-Like Carbon Films

2000 ◽  
Vol 6 (S2) ◽  
pp. 432-433
Author(s):  
X. Chen ◽  
J. M. Gibson ◽  
J. Sullivan
Keyword(s):  
Electronic Devices ◽  
High Hardness ◽  
Carbon Films ◽  
Optical Coatings ◽  
Diamond Like Carbon ◽  
Electron Loss ◽  
Negative Electron Affinity ◽  
Chemical Inertness ◽  
Potential Applications ◽  
Key Questions

Hydrogen-free amorphous diamond-like carbon films have stimulated great interest because of their useful properties, such as high hardness, chemical inertness, thermal stability, wide optical gap, and negative electron affinity[l]. Consequently, they may have various potential applications in mechanical and optical coatings, MEMS systems, chemical sensors and electronic devices. Amorphous diamond-like carbon films often contains significant amounts of four-fold or sp3 bonded carbon, in contrast to amorphous carbon films prepared by evaporation or sputtering which consist mostly of three-fold or sp2 bonded carbon. The ratio and the structure configurations of these three-fold and four-fold carbon atoms certainly decide the properties of these amorphous diamond-carbon films. Although the ratio of three-fold and four-fold carbon has been studied with Raman spectroscopy and electron-loss-energy spectroscopy, very little has been understood regarding key questions such as how the three-fold and the four-fold carbon atoms are integrated in the film, and what structures those three-fold carbon atoms take.

Precision Coating of ta-C Films on Quartz Surfaces

2020 ◽  
Author(s):  
Kotaro Kawai ◽  
Yuki Hirata ◽  
Hiroki Akasaka ◽  
Naoto Ohtake
Keyword(s):  
Cutting Tools ◽  
Three Dimensional ◽  
High Hardness ◽  
Carbon Films ◽  
Vacuum Arc ◽  
High Wear Resistance ◽  
Chemical Inertness ◽  
Filtered Cathodic Vacuum Arc ◽  
Surface Morphologies

Abstract Diamond-like carbon (DLC) films have excellent properties such as high hardness, low friction coefficient, high wear resistance, chemical inertness and so on. Because DLC film is considered as an effective coating material to improve their surface properties, this films are used in various applications such as parts for automobiles engines, hard disk surfaces, cutting tools and dies, and so on. DLC films consist of a mixture of sp2 bonded carbon atoms and sp3 bonded carbon atoms. Among them, ta-C film is known as the hardest and strongest film since it mainly consists of sp3 bonded carbon atoms. One of deposition methods to form ta-C is Filtered Cathodic Vacuum Arc (FCVA). The characteristic of this method is that it is possible to remove the droplets and form a high-quality film.. However, even though lots of mechanical components which require ta-C coating have three-dimensionally shapes, it is difficult to coat ta-C film three dimensionally by using FCVA process. At present, researches on 3D deposition of amorphous carbon films on three dimensional components is still insufficient, and investigation reports on the deposition mechanism and characterization of the deposited films are even more limited. In this study, we tried to deposit films on 3D components by the FCVA method and evaluated the microstructure and surface morphologies of films. Although films were coated successfully in the entire surfaces, different properties were showed depending on the location of components. These properties were investigated by Raman spectroscopy and laser microscope.

Structural Stability of Si-O-a-C:H/Si-a-C:H Layered Systems

1996 ◽  
Vol 434 ◽  
Author(s):  
U. Müller ◽  
R. Hauert
Keyword(s):  
Structural Changes ◽  
Plasma Deposition ◽  
Temperature Stability ◽  
High Hardness ◽  
Interface Layer ◽  
Amorphous Structure ◽  
Carbon Films ◽  
Rf Plasma ◽  
Chemical Inertness ◽  
Amorphous Hydrogenated Carbon

AbstractAmorphous hydrogenated carbon films are of technological interest as protection coatings due to their special properties such as high hardness, chemical inertness, electrical insulation and infrared transparency. However, some applications still suffer from the poor thermal stability and adhesion problems of these coatings. To ensure good adhesion, especially on hardened steels and non-carbide forming substrates, an extra interlayer has to be deposited first. Often a silicon containing interlayer, Si-a-C:H for example, is used for this purpose. This Si-a-C:H interface layer was deposited by rf plasma deposition from tetramethylsilane. Then a-C:H films containing Si-O with a varying silicon content were produced from a mixture of acetylene and hexamethyldisiloxane. The structural changes upon annealing of these films were investigated using Raman spectroscopy. The analysis of the development of the different peaks upon annealing temperature reveals the transition from the amorphous structure to the more graphitic-like structure. This transition temperature increases by as much as 100°C when silicon is incorporated into the DLC film. However, when Si-O is incorporated instead of only silicon the same increase in temperature stability is observed.

Effects of Copper Interlayer and Annealing on Structure and Mechanical Properties of Diamond-Like Carbon Films by Cathode Arc Evaporation

2012 ◽  
Vol 629 ◽  
pp. 25-31
Author(s):  
Bing Zhou ◽  
Xiao Hong Jiang ◽  
A.V. Rogachev ◽  
Rui Qi Shen
Keyword(s):  
Mechanical Properties ◽  
Annealing Temperature ◽  
Morphological Characteristics ◽  
High Hardness ◽  
Carbon Films ◽  
Element Distribution ◽  
Diamond Like Carbon ◽  
Bilayer Films ◽  
Cathode Arc ◽  
Cu Interlayer

Diamond-like carbon (DLC) bilayer films with Cu interlayer were prepared on silicon substrate by direct-current and pulsed cathode arc plasma technique, and annealed at various temperatures in vacuum. Structure, morphology and mechanical properties of the bilayer films were investigated by Raman spectroscopy, Auger electron spectroscopy, scanning electron microscopy and atomic force microscopy, surface profilometer and Vickers sclerometer. The results show that Cu interlayer changes the bilayer microstructure, including the thickness and element distribution of diffusion layer, the relative fraction of sp3/sp2bonding and growth model of bilayer. A simple three-layer model was used to describe the interdiffusion between Cu and C layer. Cu interlayer could be more effective against graphitization upon annealing. Morphological characteristics of the films were studied by analyzing the surface features of substrate. Cu/DLC bilayer exhibits highly dispersed nano-agglomerates with smaller size on the surface due to low surface energy of Cu interlayer. The stress and hardness of the films were affected accordingly. Cu/DLC bilayer shows a relatively high hardness at low annealing temperature but the stress almost no change. By changing Cu interlayer and annealing temperature, excellent DLC films could be designed for the protective, hard, lubricating and wear resistant coatings on mechanical, electronic and optical applications.

scholarly journals In vivo biocompatibility of diamond-like carbon films containing TiO2 nanoparticles for biomedical applications

2021 ◽  
Vol 32 (9) ◽  
Author(s):  
C. C. Wachesk ◽  
S. H. Seabra ◽  
T. A. T. Dos Santos ◽  
V. J. Trava-Airoldi ◽  
A. O. Lobo ◽  
...  
Keyword(s):  
Inflammatory Process ◽  
Antimicrobial Properties ◽  
Chemical Vapor ◽  
High Hardness ◽  
Carbon Films ◽  
High Wear Resistance ◽  
Diamond Like Carbon ◽  
Dlc Coatings ◽  
Inflammatory Reactions

AbstractHybrid diamond-like carbon (DLC) with incorporated titanium dioxide (TiO2) nanoparticle coatings have low friction coefficient, high wear resistance, high hardness, biocompatibility, and high chemical stability. They could be employed to modify biomedical alloys surfaces for numerous applications in biomedical engineering. Here we investigate for the first time the in vivo inflammatory process of DLC coatings with incorporated TiO2 nanoparticles. TiO2-DLC films were grown on AISI 316 stainless-steel substrates using plasma-enhanced chemical vapor deposition. The coated substrates were implanted in CF1 mice peritoneum. The in vivo cytotoxicity and biocompatibility of the samples were analyzed from macrophage lavage. Analysis in the first weeks after implantation could be helpful to evaluate the acute cytotoxicity generated after a possible inflammatory process. The in vivo results showed no inflammatory process. A significant increase in nitric oxide production on the uncoated substrates was confirmed through cytometry, and the coated substrates demonstrated biocompatibility. The presence of TiO2 nanoparticles enhanced the wound healing activity, due to their astringent and antimicrobial properties. DLC and TiO2-DLC coatings were considered biocompatible, and the presence of TiO2 nanoparticles reduced the inflammatory reactions, increasing DLC biocompatibility.

Pulsed electrodeposition of diamond-like carbon films

1997 ◽  
Vol 12 (11) ◽  
pp. 3102-3105 ◽  
Author(s):  
Hao Wang ◽  
Ming-Rong Shen ◽  
Zhao-Yuan Ning ◽  
Chao Ye ◽  
He-Sun Zhu
Keyword(s):  
Raman Spectroscopy ◽  
Carbon Films ◽  
Methanol Solution ◽  
Breakdown Field ◽  
Diamond Like Carbon ◽  
Current Voltage ◽  
Chemical Inertness ◽  
Current Voltage Characteristics ◽  
Pulsed Electrodeposition ◽  
Hardness Values

Diamond-like carbon (DLC) films have been prepared by electrolysis of methanol solution using a pulse-modulated source. The deposition rate of the films is enhanced significantly compared to that of dc value. That the films do not contain bonded hydrogen is confirmed by infrared spectra. The structures of the films are characterized by Raman spectroscopy. These films show chemical inertness and hardness values in the range 12.5–19 GPa. Current-voltage characteristics of the films are measured, indicating that the resistivity is in the 107 Ω cm range and the breakdown field is larger than 1 MV cm−1.

Mechanical Properties of Laser Processed Diamond-Like Carbon Films

1995 ◽  
Vol 397 ◽  
Author(s):  
Ashok Kumar ◽  
R. B. Inturi ◽  
Y. Vohra ◽  
U. Ekanayake ◽  
N. Shu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Room Temperature ◽  
Pyrolytic Graphite ◽  
High Vacuum ◽  
Pulsed Laser ◽  
Chemical Properties ◽  
High Hardness ◽  
Deposition Process ◽  
Carbon Films ◽  
Diamond Like Carbon

ABSTRACTDiamond-like carbon (DLC) films have a unique combination of physical and chemical properties such as high hardness, optical transparency, low coefficient of friction and chemical inertness. A pulsed laser (248 nm) has been used to ablate a pyrolytic graphite target to deposit DLC films on Si (100) and 7059 Corning glass substrates. The deposition was carried out in high vacuum (≤ 10−6 Torr) at different temperatures ranging from room temperature to 400°C. The films were characterized by x-ray diffraction, scanning electron microscope, and Raman spectroscopie techniques. The mechanical properties (hardness and Young's modulus) of these films were characterized by nanoindentation. We have found that the films deposited at room temperature and 100°C show the characteristic features of DLC films and have the better hardness and modulus properties compared to the films fabricated at higher temperatures, which transform into amorphous carbon. Correlations of pulsed laser deposition process parameters with the properties of deposited DLC films will be discussed in this paper.

Adherence Study of Diamond-Like Carbon Films Deposited on X45 CrSi 9-3 Steel with a Silicon Interlayer

2014 ◽  
Vol 802 ◽  
pp. 642-647
Author(s):  
Lânia Auxiliadora Pereira ◽  
Marcelo Brison de Mattos ◽  
Evaldo José Corat ◽  
Vladimir Jesus Trava-Airoldi
Keyword(s):  
Automotive Industry ◽  
High Hardness ◽  
Carbon Films ◽  
Low Friction ◽  
Tribological Test ◽  
Mechanical And Tribological Properties ◽  
Pulsed Dc ◽  
Deposition Parameters ◽  
Chemical Inertness ◽  
Silicon Interface

The martensitic stainless steel X45CrSi93 is widely used in the automotive industry. One way to improve its properties is the deposition of high adhesiveness DLC films, which are well known for their excellent properties such as high hardness, low friction coefficient, chemical inertness, biocompatibility and excellent wear resistance. In this work, the adhesion between substrate and film was studied, by growing silicon interfaces with different deposition parameters. The technique used for growing these films was PECVD pulsed-DC. In order to obtain information of the silicon interface formation, ionic sub-implantation simulations were performed, by the software SRIM/TRIM. Raman spectroscopy was used to verify the atomic structure of the films. Scratch tribological test was performed to study adhesion. It was observed that the mechanical and tribological properties were greatly improved with the deposition of DLC films on the silicon interface. A correlation between the residual stress and adhesion of DLC films was found.

Formation of Graphene onto Atomically Flat 6H-SiC

2014 ◽  
Vol 778-780 ◽  
pp. 1158-1161 ◽  
Author(s):  
Gemma Rius ◽  
Narcis Mestres ◽  
Yayoi Tanaka ◽  
Hidetoshi Miyazaki ◽  
Osamu Eryu ◽  
...  
Keyword(s):  
Electronic Devices ◽  
High Hardness ◽  
Wide Band ◽  
Single Step ◽  
Wide Band Gap ◽  
Thermal Decomposition Process ◽  
Chemical Inertness ◽  
And Control ◽  
Atomically Flat ◽  
Selective Formation

SiC crystal is a wide band gap material of high hardness and chemical inertness. Graphene is nowadays a ubiquitous 2D material that would revolutionize many applications. Combining the characteristics of SiC and graphene higher performance and efficiency are expected, e.g. for high frequency electronic devices. The obtaining of graphene directly on SiC substrates by a single step thermal decomposition process is promising, but optimal standardized conditions are not established. We present the use of chemical-mechanical polishing (CMP) as a pre-graphene growth SiC conditioning to enable deep comprehension of the mechanisms of SiC decomposition and control towards selective formation of graphene.

Biocompatibility of Diamond-Like Carbon Coated NiTi Orthodontic Wire and Acrylic Resin Teeth

2005 ◽  
Vol 284-286 ◽  
pp. 783-786 ◽  
Author(s):  
S. Kobayashi ◽  
K. Ozeki ◽  
Y. Ohgoe ◽  
Li Gei ◽  
K.K. Hirakuri ◽  
...  
Keyword(s):  
Acrylic Resin ◽  
Carbon Films ◽  
Diamond Like Carbon ◽  
Orthodontic Wire ◽  
Nickel Release ◽  
Chemical Inertness ◽  
Coated Wire ◽  
Carbon Coated ◽  
Orthodontic Archwires ◽  
Artificial Teeth

A variety of dental devices such as orthodontics, artificial teeth are implanted in oral cavity for long term. The implant coated with protective films, which can reduce corrosion and wear, may prevent the problems described above and extend the lifetime of implants to the benefit of the patients. Diamond-like carbon films have extreme hardness, low friction coefficients, chemical inertness, and high-corrosion resistance. Moreover, these properties make the good candidates as biocompatible coatings for dental devices. In this study, DLC films using the plasma CVD method deposited on acrylic resin and orthodontic archwires have investigated to detect the Ni release from the wires and to estimate cell growth in E-MEM immersed acrylic plates. After 6 months, the concentration of the nickel release from DLC-coated wire and Non-coated wire was 150 [ppb] and 933 [ppb], respectively. Results indicated DLC films inhibit the release of these materials, and prevent degradation of these materials in the solution.

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