ICMCTF2009 Session DP: Symposium D Poster Session

Thursday, April 30, 2009 5:00 PM in Room Town & Country

Thursday Afternoon

Time Period ThP Sessions | Topic D Sessions | Time Periods | Topics | ICMCTF2009 Schedule

DP-1 Silver-Carbon Nanoparticles Produced by High-Current Pulsed Arc
F. Maya, M. Miki-Yoshida (Centro de Investigación en Materiales Avanzados (CIMAV), México); S. Muhl, O. Peña (Universidad Nacional Autónoma de México)

Great interest has been focused on Ag-Carbon material systems due to the possibility of obtaining Ag nanoparticles encapsulated by crystalline or amorphous carbon. Silver exhibits excellent thermal and electrical conductivity and has been extensively used in catalysis, electronics, photonics, photography, biological labeling, and surface-enhanced Raman scattering. Composite nanostructures using nanoscale silver as the core have been prepared by many research groups. For example, Ag/C nanocables and Ag/C nanoparticles have been synthesized in the presence of PVP; silver/cross-linked poly (vinyl alcohol) coaxial nanocables have also been prepared. In this work we have used a High-Current Pulsed electric arc in Argon between 3.3mm graphite and 1.5mm silver electrodes to produce silver-carbon nanoparticles at different gas pressures. These nanoparticles were analyzed by TEM, SEM, Optical absorption and XRD. Firstly, we measured the relation between the deposition rate and pressure and found that the deposition rate increased when the pressure decrease. The XRD analysis showed that the silver is crystalline; to confirm this the nanoparticles were analyzed by TEM. The Electron Diffraction again showed that the silver part of the nanoparticle is crystalline. Furthermore, it was established that the particles consisted of a crystalline silver nucleus coated with amorphous carbon. The size of the particles varied from ~150nm to less than 5nm depending on the gas pressure (800-100 Torr). Additionally, small quantities of cristalline graphite and amorphous carbon were found in the produced deposits. By EDS we studied the composition and structure of the deposits as a function of the gas pressure, as well as, the duration of the arc.

Finally, the analysis of the optical absorption spectra showed that the nanoparticles are not spheres but rather spheroids (an ellipsoid with two equal axes). Both, the aspect ratios ε (the ratio of the largest to the smallest axes) and the equivalent radii rV(radius of a sphere having the same volume) are dependant on the gas pressure. This is interesting since by changing the aspect ratios, it is possible to tune the frequency of the surface plasmon resonance (SPR). This SPR tunability makes these nanoparticles potentially interesting for many optical and optoelectronic applications.

DP-2 Optical and Electron Field Emission Properties of Silver Doped Diamond Like Carbon Films Deposited by RF Reactive Sputtering Technique
Sk.F. Ahmed, M.W. Moon, K.R. Lee (Korea Institute of Science and Technology, Korea)
Diamond-like carbon (DLC) film has been extensively studied due to their remarkable properties and potential applications. The ratio of sp2/sp3 carbon atoms is one of the most important factors determining the quality of the DLC films, which can be changed by incorporating different elements into DLC matrix. Various attempts have been made to dope DLC films with different elements such as boron, phosphorus, nitrogen, sulfur, silicon and tin etc. and the doping effects of these elements have been extensively investigated. Among them silver incorporated diamond like carbon (Ag:DLC) has been an interesting research field of diamond-like carbon owing to its potential for solving some of the major drawbacks of pure DLC films. Ag incorporation in the DLC films reduce surface free energy and residual internal stress without sacrificing the hardness, increase hydrophobic properties and improve hemocompatibility and antibacterial properties for biological applica tion. In this work we have reported the effect of silver incorporation on the optical and electron field emission properties of DLC films deposited by the RF reactive sputtering technique. The chemical binding energy and the compositions of the films were investigated by X-ray photoelectron spectroscopy (XPS) studies. Optical transparency and optical band gap decreased with the silver incorporation to the DLC film. Optical band gap calculated from transmittance spectra decreased from 2.55 to 1.95 eV with a variation of Ag concentration from 0 to 12.5 at. %. The field emission measurements showed that the threshold field and effective emission barrier were reduced by silver doping and the emission current strongly depends on the silver doping percentage. The threshold field was found to decrease from 6.8 to 2.6 V/µm with a variation of Ag atomic % from 0 to 12.5. The field enhancement factor was calculated and we have explained the emission mechanism.
DP-3 Temperature Programmed Desorption and Spectroscopic Studies of Surface Functionalized Nanodiamond Particles Prepared for Bio-Applications
S.-J. Cai, Y.-C. Chiu (National Dong Hwa University, Taiwan); V. Yeh, C.P. Chen (Natioanl Dong Hwa University, Taiwan); C.-L. Cheng (National Dong Hwa University, Taiwan)
Nanometer-sized diamond (ND) has been identified to be a promising and bio compatible nanoparticle for bio applications. It can be easily conjugated with interested bio molecules; and the functionality of the conjugated bio molecules can be preserved. Despite various methods have been proposed for surface functionalization, there have been limited studies on the functionalized nanodiamond surfaces. In this study, we employed both spectroscopic (IR and Raman) and surface (Temperature Programmed Desorption, TPD) methods to investigate the surface properties of surface functionalized nanodiamonds. The creation of molecular functional groups on nanodiamond surface was achieved chemically on ND of various sizes (5-500 nm in diameter). In the first case, strong acid treatment methods create ND-COOH functionalized ND surfaces; the second case, ND-(CH2O)n are created on the nanodiamonds’ surface chemically for further conjugation with bio molecules. The surface fu nctional groups are characterized with the above mentioned methods. Various chemical bonding serves as marker to confirm the formation of the functional groups. The surface C=O stretching frequency was studied in the ND-COOH system. This frequency is ~1820 cm-1 for particle size ~500 nm, and down shifts to 1725 cm-1 with decreasing particle size to 5 nm as a result of hydrogen bonds formation between the COOH groups in the particles surface; and the C=O stretching is strongly size- and temperature-dependent. Desorption of water molecules by TPD experiment confirm the formation of hydrogen bonds. The observed red-shift on the C=O stretching for 100 nm diameter nanodiamond from 1816 cm-1 to 1804 cm-1 when temperature increased from room temperature to 600°C was attributed to water desorption. We also developed method to characterize the functionalized ND-(CH2O)n using infrared spectroscopic methods. The temperature desorp tion experiments confirmed the covalent bonging of the designed functional group on nanodiamond surfaces. This work provides understanding of nanodiamond surface and the spectroscopic properties of the functionalized nanodiamond surfaces.
DP-4 Preparation and Evaluation of the Porous Graphite/Carbon Composites for Lithium-ion Battery with High Rate Charging
M.L. Lee (National Tsing Hua University, Taiwan); J.M. Chen (Industrial Technology Research Institute, Taiwan); J.-W. Yeh, H.-C. Shih (National Tsing Hua University, Taiwan)

The electric vehicle (EV) is believed to be one of the most important industries in this century, and the lithium ion polymer battery should be the main choice because of its performance. Since high rate charging of lithium-ion battery is the major problem of this electric device. Recently, graphite material has popularly taken the place of commercial meso-carbon micro-beads (MCMB) in the anode material of the lithium-ion polymer batteries. The study utilized the spray dry technique to manufacture the porous graphite/carbon and by controlling the vaporizing of solvent in different rates to synthesize varied structures of the porous graphite/carbon composites for lithium-ion polymer batteries with high rate charging. The composite graphite performs significantly batter than MCMB in surface area e.g., the MCMB is ~4 BET (m2/g) and that of the porous graphite/carbon composite is ~40 BET (m2/g). SEM shows the morphology of porous graphite/carbon composites a nd that some other tests are done for checking the electrochemical properties of those graphite/carbon materials. The porous structure of the graphite material contributes to the diffusion of the lithium-ion while charging and discharging in a battery. By increasing the efficiency of high rate charging and discharging, the porous graphite/carbon material is popularly used in lithium ion polymer batteries for the electric vehicle or high power electric devices.

1J.Li,X.Wang, Q.Huang, S.Gamboa, P.J.Sebastian, J.Power Source 158(2006)784

2C.Lin, B.N.Popov, H.J.Ploehn, J.Electrochem, Soc, 149(2002)167.

DP-5 Wetting Behavior of a Droplet on Dual Rough Surfaces Coated with Hydrophobic and Hydrophilic DLC Films
T. Cha, J.W. Yi, M.W. Moon (Korea Institute of Science and Technology, Korea); H.Y. Kim (Seoul National University, Korea); K.R. Lee (Korea Institute of Science and Technology, Korea)

Solid surface wettability could be controlled by a chemical treatment of the material surfaces or modification of the surface topology. The chemical treatment of material surfaces causes to change the surface energy, affecting the wetting behavior like contact angle between a water droplet and material surfaces. Furthermore the increase of the surface roughness due to the presence of the micro- or nano-texture amplifies the hydrophobicity or even hydrophilicity of the materials. Here we investigated the effect of dual roughness and chemical composition on both extreme wettabilities of superhydrophobic and superhydrophilic natures. We used the dual rough structures, imitated from the morphologies of lotus leaves by combining the micro- and nano-sacle structures1 chosen hydrophobic DLC films (HMDSO - hexamethlydisiloxane) and hydrophilic oxygen treatment for extreme wettabilities. On the superhydrophobic surfaces, we observed the high static contact angle and l ow contact angle hysteresis. We then performed the systematic experiment that a water droplet on the surfaces was evaporated slowly and we have monitored the variation in contact angle of the droplet and the transition from Cassie-Baxter state to Wenzel state in high pressure. On the other hand, we observed the static contact angle and spreading velocity of a water droplet on superhydrophilic surfaces. Finally, switchable behaviors of wettabilities between superhydrophobic and superhydrophilic natures were demonstrated with repeat of HMDSO coatings and O2 plasma treatment and various wetting pattern applications were valid by using reversible wetting characteristics.

1K. Bewilogua, K. H. Oh, K.-R. Lee, Chem. Phys. Lett. 436 (2007) 199.

DP-6 Structure-Property Relationships of Galvanic Nickel Coatings Codeposited with nanoDiamond particles
O. Shenderova (International Technology Center); D.L. Schulz, R.A. Sailer (North Datota State University); G.E. McGuire, W. Mecouch (International Technology Center)

Galvanic nickel coatings have been in use for decades and have many desirable properties including wear and corrosion resistance and relative ease of application. Recently, work has been performed to enhance the tribological properties of nickel-based coatings by incorporation of diamond nanoparticles as a wear-resistant component of this functional coating.1 In this previous study, detonation nanodiamonds (DNDs) with primary particle size 5nm produced by detonation of carbon-containing explosives were used. The polydispersed DNDs with average aggregate size ~150nm were then employed as a hard filler in nickel electroplated films giving Ni-DND composite coatings. It was found that the presence of the DNDs significantly affected the properties of the coatings in an intriguing fashion. Toward that end, Ni-DND coatings exhibited improved microhardness and wear resistance when compared to Ni-only control coatings but the latter showed better erosion resistance.1 In another series of experiments2 it was revealed that the type of the steel substrate, its roughness and conditions of electroplating (current density, substrate purification, Ni adhesion layer formation) significantly influence the microhardness and tribological properties of the galvanic coatings. These observations warrant a better understanding of the structure of the Ni-DND coatings and the effect on various mechanical properties. The work presented in this paper relates to an investigation of the structure/tribological properties of Ni-DND composite coatings. Characterization data to be discussed includes wear rates, hardness profiles and composite structure as measured by pin-on-disk, nanoindentation and high resolution SEM test methods.

super 1@I. Petrov, P. Detkov, A. Drovosekov, M.S. Ivanov, T. Tyler, O. Shenderova, N.P. Voznecova, Y.P. Toporova, D. Schulz, Diamond & Related Materials 15 (2006) 2035–2038.

2R.A. Sailer, O.Shenderova, D.L. Schulz, W.Mecoach, G.McGuire, in preparation

DP-7 Metal-Containing Diamond Like Carbon (DLC:Me) and AlN (AlN:Me) Metallo-Dielectric Nanocomposites
G.M. Matenoglou, H. Zoumbos (University of Ioannina, Greece); A. Lotsari (Aristotle University of Thessaloniki, Greece); Ch.E. Lekka, D.F. Anagnostopoulos (University of Ioannina, Greece); Ph. Komninou (Aristotle University of Thessaloniki, Greece); G.A. Evangelakis, P. Patsalas (University of Ioannina, Greece)
Pulsed Laser Deposition (PLD) from sectored targets is a versatile technique, which is able of growing nanocomposite films. Of special importance are nanocomposites consisting of a nitride or a carbonaceous dielectric matrix incorporating metal nanoparticles, which are promising materials for various applications in mechanical protection, electronics and plasmonics. In this work we study the structure of PLD-grown, metal-containing diamond like carbon DLC:Me (Me=Ag,Cu,Ti,Zr,W,Mo) and AlN:Me composites (Me=Ag,Cu,Au) vs. various parameters, such as the metal content, nanoparticle size and distribution and the working pressure. The films have the form of a dielectric matrix (DLC or AlN) incorporating metal nanoclusters of 3-10 nm diameter. The density of the a-C and AlN matrices are studied by means of X-Ray and Neutron Reflectivity (XRR/NR). The composition of the films and the crystal structure of the inclusions have been determined by in-situ auger electron spectroscopy and high-resolution transmission electron microscopy, respectively. The optical properties of the films have been determined by optical reflectance spectroscopy. We show that the incorporation of the metal nanoparticles may severely alter the structure and properties of the matrix and a simple rule of mixture does not apply. Thus, we investigate the interactions at the matrix-nanoparticle interface using ab-initio calculations. Finally we demonstrate the tailoring of the optical properties of DLC:Me and AlN:Me nanocomposite films by varying the metal nanoparticles' size and content.
DP-9 Effect of Oxygen Plasma Treatment on Bonding States for Columnar Structured a-CNx Thin Films Prepared by a Reactive Sputtering
M. Aono, S. Kikuchi, N. Kitazawa, Y. Watanabe (National Defense Academy, Japan)
Amorphous carbon nitride (a-CNx) thin films were deposited on silicon single crystal substrates by rf-reactive sputtering method using a graphite target, and after deposition the films were exposed to oxygen plasma so as to be modified on their surface. Effect of oxygen plasma treatment on bonding structures of the film surface has been studied. A substrate temperature was varied from room temperature (RT) to 853 K. Oxygen gas of about 16 Pa was discharged by rf-power and oxygen plasma was generated. Plasma treatment time was kept at 30 sec. The chemical bonding states and film composition were analyzed by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT-IR). The films thickness was calculated from images of scanning electron microscopy (SEM) and ellipsometer. XPS study has revealed the films have NO2 and NO3 bonding structures when the films are deposited with a deposition temperature over 673 K. After exposure to oxygen plasma, carbon in the film surface was etched selectively and this phenomenon was observed in all the films. However, NO3 bonding state was remarkably increased after oxygen plasma treatment for the films deposited at high deposition temperature.
DP-10 DLC Coated Spinal Disks with Predictable Long Term Adhesion
R. Hauert, C.V. Falub (Empa, Switzerland); G. Thorwarth (Swiss Federal Institute for Materials Testing and Research (EMPA)); B. Weisse, U. Müller (Empa, Switzerland); M. Parlinska-Wojtan (Swiss Federal Institute for Materials Testing and Research (EMPA)); C. Voisard (Synthes GmbH, Switzerland); M. Tobler (IonBond AG, Switzerland)
In spinal disk replacement, articulating implants increasingly contribute to restore full spine flexibil-ity. Release of wear debris has been observed with all commercially available metal-on-polyethylene and metal-on-metal implants. Theoretically, over a long term, this may increase the risk of allergic reactions, hypersensitivity, or failure of the device. In view of their extremely low wear, application of Diamond Like Carbon (DLC) coatings to medical implants seems feasible. Yet, the body environment has shown to cause unpredictable DLC layer delaminations, so far barring an adoption for the MedTech field. The key to this problem rests in the design of an interface layer stable in-vivo, which is the aim of this presentation. Interface reaction layers between DLC and CoCrMo implant materials have been analyzed by XPS depth profiling. The presence of an about 6 nanometer thick reactive interface layer consisting of cobalt-, chrome- and molybdenum- carbides formed at the beginning of deposition could be shown. We will show that the interface reaction layer determines the adhesion lifetime of the coating, which, in the case of DLC on CoCrMo, can be predicted. Wear and friction tests have been performed on a newly developed simulator using calf serum as a lubricant. As long as layer adhesion is guaranteed, a wear mass reduction by a factor of 20 is observed with respect to the uncoated implants, whereas no change in the coefficient of friction by the DLC coating was observed.
DP-11 Structural and Optical Properties of Ultrananocrystalline Diamond / InGaAs/GaAs Quantum Dot Structures
C. Popov, A. Gushterov, L. Lingys, C. Sippel, J.P. Reithmaier (University of Kassel, Germany)
The combination of the unique properties of ultrananocrystalline diamond (UNCD) films and of semiconductor quantum dot (QD) structures could significantly improve the performance of different electronic and optoelectronic devices, where e.g. good thermal management and advanced mechanical parameters are required. In the current work quantum dot InGaAs/GaAs heterostructures have been grown by molecular beam epitaxy (MBE) with different densities between 1.6 x 1010 cm-2 and 1.6 x 1011 cm-2 controlled by the deposition temperature. These structures were overgrown with UNCD by microwave plasma chemical vapor deposition (MWCVD) using methane/nitrogen mixtures. Scanning electron microscopy (SEM) reveals that without ultrasonic pretreatment the diamond nucleation density on QD structures is low and only separate islands of UNCD are deposited, while after pretreatment thin closed films are formed. From the cross-section SEM images a growth rate of ca. 3 nm/min is estimated which is very close to that on silicon at the same deposition conditions. The UNCD coatings exhibit a morphology consisting of two types of structures as shown by atomic force microscopy (AFM). The first one includes nodules with diameters between 180 and 350 nm varying with the density of the underlying QDs; the second is formed by a kind of granular substructure of these nodules with diameters of about 40 nm for all QD densities. The optical properties were investigated by photoluminescence (PL) spectroscopy before and after the deposition of UNCD. The PL signals of QD structures overgrown with UNCD remain almost unchanged with respect to the peak positions and widths, revealing that the UNCD/QD structures retain the optical properties of uncoated InGaAs/GaAs quantum dots.
DP-13 Deposition of Amorphous Carbon-Silver Composites
O. Garcia-Zarco, Z. Montiel, S.E. Rodil (Universidad Nacional Autónoma de México); M. Camacho-López (Universidad Autónoma del Estado de México)

Composites of Amorphous carbon films and silver were deposited by co-sputtering, where the target (10 cm diameter) was of pure graphite with small inclusion of pure silver (less than 1 cm2). The films were deposited under different power, from 40 to 250 W, and different target-substrate distances. The substrate was earthed and rotating in order to obtain an uniform distribution of the silver content (less than 10 at%). The addition of the Ag piece into the target increased the deposition rate of the carbon films, which could be related to the higher sputter yield of the silver, but there seem to be also a contribution from a larger emission of secondary electrons from the Ag that enhances the plasma and therefore the sputtering process becomes more efficient.

Scanning electron micrographs acquired using backscattered electrons showed that the silver was segregated from the carbon matrix, forming nanoparticles or larger clusters as the power was in-creased. The X-ray diffraction pattern showed that silver was crystalline and the carbon matrix remains amorphous, although for certain conditions a peak attributed to fullerene-like structures was obtained. Ellipsometric spectroscopy was used to determine the variation in the optical properties as the silver con-tent and distribution was changed; at low power conditions, the Plasmon resonance of the Ag nanoparti-cles dominates the spectra. Finally, we used Raman spectroscopy to understand the bonding characteristics of the carbon-silver composites, finding that there are variations in the D/G ratio, which can be correlated to the observed structure and X-ray diffraction results.

DP-14 Enhancement of Deposition Rate and Droplet Reduction in T-Shape Filtered Arc Deposition System for DLC Preparation
M. Kamiya, T. Yanagita, H. Tanoue, S. Oke, Y. Suda, H. Takikawa (Toyohashi University of Technology, Japan); M. Taki, Y. Hasegawa (Onward Ceramic Coating Co., Ltd., Japan); T. Ishikawa (Hitachi Tool Engineering, Ltd., Japan); H. Yasui (Industrial Research Institute of Ishikawa, Japan)

T-shape filtered arc deposition system (T-FAD) is powerful tool as a physical vapor deposition (PVD) system for preparing various kinds of diamond-like carbon (DLC) films with high quality, especially hydrogen-free hard DLC, named tetrahedral amorphous carbon (ta-C). Most of macro-particles (droplets) emitted from the graphite cathode are removed from the cathodic arc plasma when the plasma beam passes thorough the T corner of the filter duct. However, further droplet reduction is required.

In the present study, in order to increase the deposition rate and decrease the number of droplets on the film, the electric field was applied in the T-shape droplet-filter duct. The ion current in front of the substrate, deposition rate, and number of droplets on prepared DLC film were measured as a function of the electric field strength. As a result, the ion current had a maximum at the electric field generated by applying the same voltage as the filtered carbon-arc-pl asma potential. The deposition rate increased by approximately 10%, and thus the number of droplets was reduced by same level. Similar experiment was carried out for carbon-argon mixture plasma.

DP-15 Ashing of DLC Film by Oxygen Plasma Beam Converted from Filtered Carbon-Cathodic-Arc
H. Tanoue, M. Kamiya, S. Oke, Y. Suda, H. Takikawa (Toyohashi University of Technology, Japan); M. Taki, Y. Hasegawa (Onward Ceramic Coating Co., Ltd., Japan); T. Ishikawa (Hitachi Tool Engineering, Ltd., Japan); H. Yasui (Industrial Research Institute of Ishikawa, Japan)
Diamond-like carbon (DLC) film has a great advantage as a protective film to realize the reuse of cutting tools and press molds, since it can be removed from the workpiece by ashing treatment. RF oxygen plasma is usually used for ashing DLC film. However, RF plasma ashing has some problems; the tiny piece of film residue, mirco-arcing at edges of workpieces, difficulty of uniform ashing for workpieces with complex shape or curvature. It is better to use beam-form-plasma to solve such problems. Therefore, in the present study, oxygen plasma beam was generated by converting from the filtered cathodic carbon-arc-plasma and feasibility of the ashing of the DLC film was examined. First, the converted oxygen plasma was analyzed by optical emission spectroscopy. The hydrogen-free DLC films were prepared on superhard alloy substrate by T-shape filtered arc deposition system (T-FAD). The oxygen plasma beam was irradiated to the DLC film. The biases of uni-polar pulse (repetition frequency, 10 kHz; duty, 20%) and DC were applied to the substrate. The ashing rate of the DLC film and surface roughness of the substrate were measured at various bias conditions. Micro-Raman spectroscopy was used to confirm whether DLC film was removed.
DP-16 Characterization of High sp3 Diamond-Like Carbon Films Synthesized by Cathodic Arc Activated Deposition Process
W.-C. Lin, D.-Y. Wang (Mingdao University, Taiwan)
The diamond-like carbon (DLC) film has been widely used in the cutting and forming industries for its superb properties of high hardness, low friction coefficient, high wear resistance, and chemical inertness. In this study, an amorphous hydrogenated carbon film (a-C:H) was synthesized by using a cathodic-arc activated deposition (CAAD) process. The CAAD process consisted of a PVD stage, where a metallic and nitride transition layers were deposited, and a follow-up CVD stage, where the super-hard CrxC/DLC gradient coating was deposited. During the later CVD stage, the energetic metal plasma catalyzed the decomposition of the hydrocarbon gas (C2H2) and induced the formation of the final gradient carbon film. In order to maintain the sp3/sp2 ratio of the DLC film with specific tribological properties, the deposition parameters have to be regulated through a control mechanism. Results of this study demonstrated that the carbon bond ratio of DLC is closely related to the fl ow ratio of the reactive gas C2H2/(C2H2+N2). The formation mechanism of metal carbides and DLC during the CAAD process was analyzed by using optical emission spectroscopy, XRD, and ESCA. The tribological tests, electron microscopy, and Raman spectroscopy were employed to characterize the microstructure and carbon bond properties of DLC coatings.
DP-17 On Mechanism of Self-Arrangement of Nanosized Diamond Particles Under Sintering
O.O. Bochechka, G.S. Oleynik, A.V. Kotko (National Academy of Sciences, Ukraine)

The results of TEM investigation for formation of 50-80 nm single crystals with decahedral and icosahedral faceting produced under high pressure (4-7 GPa) and temperature (1600-2000°С) in the system of 1-7 nm diamond particles of detonation synthesis are discussed. The appearance of such crystals occurs in the absence of diffusion mass transfer and is determined by the self-arrangement process, that is, by the oriented association of the initial diamond nanoparticles. A mechanism of the self-arrangement is proposed, which includes several successive elementary stages such as i) the formation of contacts between particles along morphologically flat facet surfaces; ii) selection of contacting particles and contact planes formed due to the realization of recognition mechanism (this determines the oriented growing together and/or homoepitaxy of independent particles and so the formation of single crystals of regular habitus. The oriented interaction of diamond part icles containing surface layers of non-diamond carbon1 seems to be possible as it is known that transfer of structural information of a substance can proceed through layers of foreign substances); iii) transformation of non-diamond carbon into diamond. The mechanism of the transformation under the action of one-dimensional periodic potential arising due to the altering of layers of substances with different forbidden energy gaps is possible2. A diamond particle with a surface 5-10 Å thick layer of non-diamond carbon is, in fact, a fragment of the superlattice whose constituents differ in the forbidden gap value: it is equal to 3.5 eV for diamond (particle core) and to zero for carbon with sp2- hybridization.

1Aleksenskiy A.Ye., Baidakova M.V., Vul A.Ya., et al. FTT. 2000. T 42. N 8. S.1531-1534.

2Zavaritskaja T. N., Karavanskij V. A., Melnik N. N., Pudonin F. A. Pisma v JETF. 2004. T. 79. N 6.S.340-343.

DP-19 A New Globular Nanocarbon Material and Production Fire Method Therof
V.G. Suschev, V.A. Marchukov, V. Y. Dolmatov (FSUP SCTB Technolog, Russia)

A new thermal-oxidative gas-cycle (fire) production method for nanosized porous globules of high-purity carbon (GNC Globular Nanocarbon) by means of combustion of methane in special conditions using chlorine as an oxidizing agent has been developed.

A distinctive feature of this method is the combustion process organization in such a way as to almost all thermal energy of oxidation is consumed to the target process of chemical synthesis of complex carbon structures without effluent of carbonic acid gas and nonutilizable heat to the environment. The method allows to solve a problem of obtaining of uniform structural nanosized carbon particles using controlled high-speed chain chemical reactions proceeding in conditions wide of the equilibrium. General foundations being a basis of the method are guided by a theory of formation of permolecular structures in nonequilibrium systems developed by Professor Aleskovsky V.B. (St.Petersburg, Russia). The method is a way of obtaining of nanosized metal – carbon compounds.

A primary nanomaterial obtained by means of plasma synthesis represents an aggregate of uniform carbon microporous globules with the size of 20-30 nm coated with surface chlorine atoms chemically combined with carbon (nanocarbochloride - GNC-Cl). This material is a progenitor of a new class of nanocarbon products composed of a nanosized porous structural carbon core and a purposefully-formed shell containing functional groups combined with carbon atoms. Joint name of this class of products is GNC–globular nanocarbon.

After reductive and oxidative thermal treatment with hydrogen, methane, water or other special reagents one can obtain high-active forms of high-pure nanocarbon materials (GNC-A) with the characterization specific surface >1000 m2/g, the carbon content >99,5% and practically zero-ash content. GNC-A is characterized by an uniformity of primary nanoglobules of pure carbon and unique combination of high dispersivity of particles with their microporous structure.

The zero-ash content, high carbon basis purity, easiness of modification of surface structure make this new material very promising for all traditional directions of application of carbon nanoproducts. As for potential fields of application of GNC, these are analogous to the well-known ordered carbon structures such as fullerenes, nanotubes, ultradispersed diamonds. But, in comparison with them there is an advantage: after creation of industrial production GNC can be cheaper by a factor of 10 or 100 than above–listed analogues.

DP-20 New Approaches to Industrial Production of Detonation Nanodiamonds
V. Y. Dolmatov, V.A. Marchukov, M.V. Veretennikova (FSUP SCTB Technolog, Russia)

At present a modern industrial production of detonation synthesis nanodiamonds (DND) is created on the bases of FSUP «Special engineering and design bureau.

The detonation synthesis is based on the technique of explosion of TNT-RDX charge in aqueaous solution of a strong reducing agent. That allowed to redouble the yield of diamond-containing blend (DB) and DND, to decrease the content of incombustible impurities in the DB 2-3 times, to transform a main part of the incombustible impurities into a soluble form of complex salts.

The DB obtained in the form of an aqueous suspension is filtrated from coarse and fine impurities, subjected to magnetic separation and centrifugated to give a dense and readily-removed sediment. Further the moist DB is directed to the chemical purification stage where the DB is added to ~ 60% HNO3, subjected to strong dispersion, filtrated from difficult-to-remove impurities and pumped up to the system of continuous complex contour plug-flow titanium reactors. The process temperature is ~230-240°C, pressure is 8 to 10 Mpa, a stay period of reaction mass in the high temperature zone is 30-40 minutes. In this conditions the DB is purified from non-diamond carbon and incombustible impurities being as complex salt kind. As a result, a number of residuary incombustible impurities in the DND is ~0,07-0,10 wt.%. Such product can be used in any technologies of application. After chemical purification the obtained nitric-acid suspension of DND is released from nitric oxides and washed out from waste HNO3. Then the weak-acidic suspension of DND is treated with ammonia and again added to the zone of high temperature and pressure to desorb nitric oxides and HNO3 from internal pores of DND-agglomerates. The formed ammonium salts are decomposed at the high temperature. The obtained re-purified DND are washed out from an excess of ammonia and directed to a thickening stage to give 8-12 % aqueous suspension of pure DND (1st commodity form of DND as an aqueous suspension). In order to obtain a dry ultrafine granular product (2nd commodity form) the DND-suspension is directed to a spray-type drying stage.

DP-24 Development of Si-Doped Hydrogenated Amorphous Diamond-Like Carbon (a-C:H:Si) for Tribological Applications in Humid Environment
H.-R. Stock, B. Hilker (Stiftung Institut fuer Werkstofftechnik, Germany)
Due to their excellent tribological properties, such as low friction and high wear resistance, amorphous hydrogenated carbon (a-C:H) films are known as a solid lubricant. These a-C:H films were doped with silicon (a-C:H:Si) to expand the possible applications of the a-C:H:films. Silicon is known for reducing the internal stress and increasing the thermal stability. We also investigate the influence of different friction partners on wear and friction mechanism. For depositing the films onto polished steel discs we used dc pulsed magnetron sputtering (Cemecon CC800/9). A transition layer was created to improve adhesion by decreasing the voltage of a chromium target, using nitrogen gas flow and increase the voltage of a graphite target. The final a-C:H:Si layer were deposited by sputtering from graphite targets with silicon inserts and reactive deposition from acetylene. The resulting films have a coating thickness of 2 µm and show good adhesion. By varying different pa rameters like bias voltage and acetylene flow as well as modify the amount of silicon content in the top layer we investigate the friction coefficients in humid environment. The tribological properties were analyzed by a pin-on-disc test in water. Under an applied load of 20 N the coated samples were slid against pins of different materials. This materials were for example 100Cr6, a-C:H:Si or CrNx. The a-C:H:Si films showed low friction coefficients in water against a-C:H:Si coated 100Cr6 pins of μ = 0.06. These tribological tests illustrate the potential of Si doped a-C:H films to effectively reduce friction and wear in humid environment.
DP-25 Annealing Effect on the Structural, Mechanical and Electrical Properties of Titanium-Doped Diamond-Like Carbon Thin Films
Y.-H. Lin, H.-D. Lin, C.-K. Liu (National Tsing Hua University, Taiwan); Y.-C. Chen (National Chung Hsing University, Taiwan); Y.-S. Chang, H.-C. Shih (National Tsing Hua University, Taiwan)

Abstract Diamond-like carbon (DLC) films are a form of amorphous carbon containing a significant fraction of sp3 bonding, which are well known for their superior physical and chemical properties of high hardness, chemical inertness, optical transparency, thermal conductivity and biocompatibility.1,2 Recently, metal-doped DLC films have stimulated great interests and been widely investigated owing to their extraordinary microstructure of nanocrystalline metal carbide precipitated in the amorphous carbon matrix.3,4 In this study, titanium-doped diamond-like carbon (Ti-doped DLC) thin films with Ti compositions of 1.1 at. % were synthesized on a Si substrate by a process combining filtered cathodic vacuum arc (FCVA) and metal vacuum arc (MeVVA) system. This study discusses on the effect of annealing temperature on the microstructure, surface roughness, hardness and electrical resistivity of the resulting films. The Raman spectra reveal that the degree of graphizatio n of Ti-doped DLC thin films increases with increasing annealing temperature from 100 to 600°C. Because the degree of graphization of the thin films increases, the hardness of the thin films improved, and the electrical resistivity of the Ti-doped DLC thin films decreases from 0.038 to 0.006 Ω cm.

1A. Grill, Diamond Relat. Mater. 8 (1999) 428.

2S. Sattel, J. Robertson, H. Ehrhardt. J. Appl. Phys. 82 (1997) 4566.

3K.W. Weng, Y.C. Chen, T.N. Lin, D.Y. Wang, Thin Solid Films 515 (2006) 1053.

4W.Y. Wu, J.M. Ting, Carbon 44 (2006) 1210.

5K. Baba, R. Hatada, Surf. Coat. Technol.169 (2003) 287.

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