Mechanical Properties of Laser Processed Diamond-Like Carbon Films

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.

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

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.629.25 ◽

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.

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Properties Oftetrahedralamorphous Carbon Films Deposited By the Filtered Cathodicarc Method

MRS Proceedings ◽

10.1557/proc-750-y5.16 ◽

2002 ◽

Vol 750 ◽

Author(s):

Naruhisa Nagata ◽

Kazuhiro Kusakawa ◽

Akiyasu Kumagai ◽

Hideaki Matsuyama

Keyword(s):

Mechanical Properties ◽

Amorphous Carbon ◽

Pyrolytic Graphite ◽

High Hardness ◽

Magnetic Film ◽

Carbon Films ◽

Substrate Bias ◽

Substrate Bias Voltage ◽

Tetrahedral Amorphous Carbon ◽

Bond Ratio

ABSTRACTFirst, we studied the relation between the sp3 bond ratio and the hardness of 100-nm-thick tetrahedral amorphous carbon (ta-C) films deposited by a Filtered Cathodic Arc (FCA) system at different substrate bias voltages. For comparison, sputtered amorphous carbon (a-C) films and Highly Oriented Pyrolytic Graphite (HOPG) were also analyzed. According to the results, ta-C film deposited at a -70 volt substrate bias voltage had high hardness and high sp3 bond ratio of up to 88 GPa and 85%, respectively, whereas those of sputtered a-C were 29 GPa and 28%. Furthermore, we found that the hardness of carbon films, including sputtered a-C and HOPG, increased with increasing sp3 bond ratio. Based on this relation, the chemical bond structures of carbon films are considered to be closely related to their mechanical properties. Secondly, we investigated the relation between sp3 bond ratio and ta-C film thickness, over the range from 1 to 10 nm. The measurements showed that a 2-nm-thick initial layer grown on the surface of CoCrPt magnetic film had low sp3 bond ratios. It is suggested that this reduction in sp3 bond ratio in the initially grown layer seriously degrades the film's performance as a hard disk media overcoat. Further efforts to improve ta-C film processing will be required to improve its mechanical properties.

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Mechanical Properties and Surface Morphology of Diamond-Like Carbon Films with SiNx Interlayer

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.723.515 ◽

2015 ◽

Vol 723 ◽

pp. 515-519

Author(s):

Qing Yun Chen ◽

Kai Min Shih ◽

Man Yi Duan ◽

Lie Lin Wang

Keyword(s):

Mechanical Properties ◽

Surface Morphology ◽

Indentation Test ◽

Deposition Process ◽

Industrial Applications ◽

Carbon Films ◽

Diamond Like Carbon ◽

Dc Magnetron Sputtering ◽

Force Microscopy ◽

Atomic Force

Diamond-like carbon (DLC) film has remarkable physical, mechanical, biomedical and tribological properties that make it attractive material for numerous industrial applications needs of advanced mechanical systems. In this study, deposition process of DLC films on Si (100) are performed by direct-current (DC) magnetron sputtering method. The effects of interlayer on the compositions, structures and mechanical properties of DLC films are studied. The scanning electron microscopy (SEM) and atomic force microscopy (AFM) studies reveal the creation of high uniform surface morphology and low roughness DLC films with SiNxinterlayer. For comparison, DLC films with different interlayers are also grown. The Raman spectra are analyzed in order to characterize the film compositions. Indentation test was performed to value the mechanical properties of DLC films. Raman, SEM, and AFM analyses are correlated with the mechanical properties of the DLC films.

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Laser Ablation Deposition of Diamond-Like Carbon Films

MRS Proceedings ◽

10.1557/proc-285-557 ◽

1992 ◽

Vol 285 ◽

Cited By ~ 9

Author(s):

S. Leppävuori ◽

J. Levoska ◽

J. Vaara ◽

O. Kusmartseva

Keyword(s):

Laser Ablation ◽

Laser Beam ◽

Power Density ◽

Pyrolytic Graphite ◽

Deposition Process ◽

Carbon Films ◽

Fused Silica ◽

Optical Measurements ◽

Diamond Like Carbon ◽

X Ray Diffraction

ABSTRACTDiamond-like carbon (DLC) thin films were prepared by laser ablation deposition. The deposition process was carried out in a vacuum chamber at a base pressure of about 10−5 mbar using the focused beam from either an Nd:YAG laser or an XeCl excimer laser and a pyrolytic graphite target. The peak power density of the laser beam was about 108 W/cm2, and 1010 W/cm2. respectively. The effect of varying power density of the laser beam also was examined. The films were deposited on fused silica and silicon single crystal substrates between room temperature and 600 °C with and without hydrogen addition. The properties of the films were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), micro-Raman and Fourier transform infrared (FTIR) spectrometry, electrical conductivity and optical measurements. The best films were insulating (σ<10−6 Ω−1 cm−1), hard, partly transparent (optical gap 1.3 − 2.2 eV) and smooth without any particulates on the surface.

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Nanostructured Diamond-Like Carbon Films Grown by Off-Axis Pulsed Laser Deposition

Journal of Nanomaterials ◽

10.1155/2015/731306 ◽

2015 ◽

Vol 2015 ◽

pp. 1-6 ◽

Cited By ~ 3

Author(s):

Seong Shan Yap ◽

Chen Hon Nee ◽

Seong Ling Yap ◽

Teck Yong Tou

Keyword(s):

Pyrolytic Graphite ◽

Pulsed Laser ◽

Maximum Size ◽

Carbon Films ◽

Diamond Like Carbon ◽

Oblique Angle Deposition ◽

Ion Energy ◽

Graphite Deposition ◽

Axis Position ◽

Effective Angle

Nanostructured diamond-like carbon (DLC) films instead of the ultrasmooth film were obtained by pulsed laser ablation of pyrolytic graphite. Deposition was performed at room temperature in vacuum with substrates placed at off-axis position. The configuration utilized high density plasma plume arriving at low effective angle for the formation of nanostructured DLC. Nanostructures with maximum size of 50 nm were deposited as compared to the ultrasmooth DLC films obtained in a conventional deposition. The Raman spectra of the films confirmed that the films were diamond-like/amorphous in nature. Although grown at an angle, ion energy of >35 eV was obtained at the off-axis position. This was proposed to be responsible for subplantation growth of sp3hybridized carbon. The condensation of energetic clusters and oblique angle deposition correspondingly gave rise to the formation of nanostructured DLC in this study.

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Pulsed laser deposition of amorphous diamond-like carbon films with ArF (193 nm) excimer laser

Journal of Materials Research ◽

10.1557/jmr.1993.2265 ◽

1993 ◽

Vol 8 (9) ◽

pp. 2265-2272 ◽

Cited By ~ 95

Author(s):

Fulin Xiong ◽

Y.Y. Wang ◽

V. Leppert ◽

R.P.H. Chang

Keyword(s):

Pulsed Laser ◽

Deposition Process ◽

Carbon Films ◽

Laser Wavelength ◽

Diamond Like Carbon ◽

Excellent Thermal Stability ◽

Bonding Structure ◽

Optical And Mechanical Properties ◽

193 Nm ◽

Tetrahedral Bonding

We have deposited hydrogen-free diamond-like amorphous carbon films by ArF (193 nm) pulsed laser ablation of graphite. The deposition process is performed with a laser power density of only 5 × 108 W/cm2 at room temperature without any auxiliary energy source incorporation. The resulting films possess remarkable physical, optical, and mechanical properties that are close to those of diamond and distinct from the graphite target used. The films have a mechanical hardness up to 38 GPa, an optical energy band gap of 2.6 eV, and excellent thermal stability. Analysis of electron energy loss spectroscopy reveals the domination of diamond-type tetrahedral bonding structure in the films with the sp3 bond fraction over 95%. Compared with other reported results of pulsed-laser-deposited diamond-like carbon films, our experimental results confirm that the laser wavelength or photon energy plays a crucial role in controlling the properties of the pulsed-laser-deposited diamond-like carbon films.

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Structural and Mechanical Properties of Diamond-Like Carbon Films Prepared by Pulsed Laser Deposition With Varying Laser Intensity

MRS Proceedings ◽

10.1557/proc-593-359 ◽

1999 ◽

Vol 593 ◽

Cited By ~ 10

Author(s):

M. Bonelli ◽

A. C. Ferrari ◽

A. P. Fioravanti ◽

A. Miotello ◽

P. M. Ossi

Keyword(s):

Pulsed Laser Deposition ◽

Pyrolytic Graphite ◽

Pulsed Laser ◽

Carbon Films ◽

Laser Deposition ◽

Diamond Like Carbon ◽

Adhesion Properties ◽

Uv Raman ◽

Excellent Adhesion ◽

Scratch Tests

ABSTRACTDiamond-like carbon (DLC) films have been prepared by pulsed laser deposition (PLD) (wavelength 248 nm), ablating highly oriented pyrolytic graphite (HOPG) at room temperature in a vacuum of 10−2Pa, at fluences between 0.5 and 35 Jcm−2. Films have been deposited on Si(100) with and without a SiC interlayer. Structural analysis, such as visible and UV Raman, Infrared and Electron Energy Loss (EEL) spectroscopies show that the films are hydrogen-free and undergo a transition, from mainly disordered graphitic to up to 80% tetrahedral amorphous carbon (ta-C), above a laser threshold fluence of 5 J cm−2. The measured residual stresses of as deposited ta-C films do not exceed 2 GPa. Scratch tests show excellent adhesion properties. Low friction coefficients (0.05-0.1) have been measured in ambient humidity. Nanoindentation indicates that film hardness is as high as 70 GPa

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TEM sample preparation of wear-tested room-temperature pulsed-laser-deposited thin films of MoS2 by ultramicrotomy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100151428 ◽

1993 ◽

Vol 51 ◽

pp. 1118-1119

Author(s):

Pamela F. Lloyd ◽

Scott D. Walck

Keyword(s):

Thin Films ◽

Sample Preparation ◽

Room Temperature ◽

High Vacuum ◽

Pulsed Laser ◽

Ultra High Vacuum ◽

Wear Testing ◽

Preparation Technique ◽

Cross Sectional ◽

Aerospace Applications

Pulsed laser deposition (PLD) is a novel technique for the deposition of tribological thin films. MoS2 is the archetypical solid lubricant material for aerospace applications. It provides a low coefficient of friction from cryogenic temperatures to about 350°C and can be used in ultra high vacuum environments. The TEM is ideally suited for studying the microstructural and tribo-chemical changes that occur during wear. The normal cross sectional TEM sample preparation method does not work well because the material’s lubricity causes the sandwich to separate. Walck et al. deposited MoS2 through a mesh mask which gave suitable results for as-deposited films, but the discontinuous nature of the film is unsuitable for wear-testing. To investigate wear-tested, room temperature (RT) PLD MoS2 films, the sample preparation technique of Heuer and Howitt was adapted.Two 300 run thick films were deposited on single crystal NaCl substrates. One was wear-tested on a ball-on-disk tribometer using a 30 gm load at 150 rpm for one minute, and subsequently coated with a heavy layer of evaporated gold.

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Annealing Condition Effects on the Structural Properties of FePt Nanoparticles Embedded in MgO via Pulsed Laser Deposition

Nanomaterials ◽

10.3390/nano11010131 ◽

2021 ◽

Vol 11 (1) ◽

pp. 131

Author(s):

Tingting Xiao ◽

Qi Yang ◽

Jian Yu ◽

Zhengwei Xiong ◽

Weidong Wu

Keyword(s):

Pulsed Laser Deposition ◽

Room Temperature ◽

High Vacuum ◽

Pulsed Laser ◽

Annealing Process ◽

Ultra High Vacuum ◽

Laser Deposition ◽

Fept Nanoparticles ◽

Annealing Conditions ◽

Vacuum Atmosphere

FePt nanoparticles (NPs) were embedded into a single-crystal MgO host by pulsed laser deposition (PLD). It was found that its phase, microstructures and physical properties were strongly dependent on annealing conditions. Annealing induced a remarkable morphology variation in order to decrease its total free energy. H2/Ar (95% Ar + 5% H2) significantly improved the L10 ordering of FePt NPs, making magnetic coercivity reach 37 KOe at room temperature. However, the samples annealing at H2/Ar, O2, and vacuum all showed the presence of iron oxide even with the coverage of MgO. MgO matrix could restrain the particles’ coalescence effectively but can hardly avoid the oxidation of Fe since it is extremely sensitive to oxygen under the high-temperature annealing process. This study demonstrated that it is essential to anneal FePt in a high-purity reducing or ultra-high vacuum atmosphere in order to eliminate the influence of oxygen.

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