BeSt coating GmbH

Innsbruck, Austria

BeSt coating GmbH

Innsbruck, Austria
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Klauser F.,University of Innsbruck | Steinmuller-Nethl D.,BeSt coating GmbH | Kaindl R.,University of Innsbruck | Bertel E.,University of Innsbruck | Memmel N.,University of Innsbruck
Chemical Vapor Deposition | Year: 2010

Amulti-wavelength, visible-Raman study of structurally different nanocrystalline diamond (NCD) films grown by means of hotfilament (HF)CVD is presented. The Raman spectra are qualitatively and quantitatively analyzed by applying current interpretation models. It is demonstrated that specific properties of the diamond phase as well as the grain boundaries can be extracted from the Raman spectr A. Hydrogenated amorphous carbon is detected in the films grain boundaries and characterized regarding its hydrogen content, optical gap, and sp3 content. The characteristic trans-polyacetylene-like signals are observed, and the behavior of the corresponding peaks studied in detail. The results are correlated with film properties such as grain size, morphology, roughness, and refractive index, as determined by atomic force microscopy (AFM), X-ray diffraction (XRD), and ellipsometry.

Szunerits S.,Interdisciplinary Research Institute IRI | Szunerits S.,Lille University of Science and Technology | Ghodbane S.,BeSt coating GmbH | Niedziolka-Jonsson J.,Interdisciplinary Research Institute IRI | And 10 more authors.
Journal of Physical Chemistry C | Year: 2010

The paper reports on the fabrication of a localized surface plasmon resonance (LSPR) interface with nanocrystalline diamond (NCD) as overcoating. The LSPR interface is formed through thermal evaporation of a 4 nm gold film onto quartz substrates and postannealed at 800 °C. The resulting gold nanostructures (Au NSs) are further coated with nanocrystalline diamond (NCD) films produced by hot filament-assisted chemical vapor deposition (HFCVD) at 800 °C. The influence of the NCD film thickness on the wavelength at maximum absorption (λmax) was investigated by recording UV-vis transmission spectra in air. The experimentally obtained data were compared to the theoretically calculated one. The possibility to introduce chemical functions on the quartz/Au NSs/NCD interfaces was demonstrated by (i) photochemical oxidation of the NCD overcoating and subsequent reaction of the oxidized surface with perfluorodecyltrichlorosilane or (ii) chemical linking of the 4-nitrobenzene diazonium salt directly onto as-grown hydrogen-terminated NCD films. © 2010 American Chemical Society.

Klauser F.,University of Innsbruck | Ghodbane S.,BeSt coating GmbH | Boukherroub R.,Institute Of Recherche Interdisciplinaire Iri | Szunerits S.,Institute Of Recherche Interdisciplinaire Iri | And 3 more authors.
Diamond and Related Materials | Year: 2010

Various oxidation techniques (plasma-beam, sulfo-chromic acid, UV-ozone, heating in air) were applied to single-crystalline (111) and (100) diamond surfaces as well as nanocrystalline diamond (NCD) films and analyzed by X-ray photoelectron spectroscopy (XPS) with respect to oxygen content and type of carbon-oxygen groups formed upon oxidation. Due to their increased surface, NCD films show a significantly higher oxygen uptake as compared to their single-crystal counterparts. No marked differences were observed between the different oxidation techniques. For all oxidation techniques used, several carbon-oxygen groups are simultaneously present on the surface. The relative fraction of singly-oxidized carbon atoms (attributed to isolated ether or epoxy-like groups) generally decreases slightly with increasing oxygen content, but always remains the dominating species. © 2009 Elsevier B.V. All rights reserved.

Steinmueller-Nethl D.,BeSt coating GmbH | Roy M.,Defence Metallurgical Research Laboratory | Franek F.,Vienna University of Technology
International Journal of Refractory Metals and Hard Materials | Year: 2010

Diamond films are well known for their outstanding properties such as high hardness, possible low coefficient of friction, high thermal conductivity, excellent biocompatibility and electrical insulation. Diamond films with nanocrystalline grains (grain sizes between 3 and 15 nm) offer further advantages of low compressive stress, low surface roughness, and high amount of surface atoms in relation to volume leading to enhanced surface properties. In view of these, the present investigation is undertaken to explore the possibility of using nanocrystalline diamond (NCD) films in advanced automotive equipment. Accordingly NCD-films have been deposited using a modified hot-filament technique. Tribological behaviour of these films has been evaluated by means of a reciprocating model tribometer with different lubricant qualities. The worn surfaces were examined using scanning electron microscopy (SEM) and 3D white light confocal microscopy. The results show the influences of coating qualities and test conditions on the tribological response. Comparable friction coefficient can be found with high treated and low treated lubricants. These films exhibited negligible wear for the range of load tested. © 2009 Elsevier Ltd. All rights reserved.

Roy M.,Defence Metallurgical Research Laboratory | Ghodbane S.,BeSt coating GmbH | Koch T.,Vienna University of Technology | Steinmuller-Nethl D.,BeSt coating GmbH
Diamond and Related Materials | Year: 2011

The mechanical and frictional properties of hydrogen- and oxygen-terminated nanocrystalline diamond films (NCD) grown by hot-filament chemical vapor deposition (HFCVD) have been investigated in the present work. The structure and morphology of the NCD films have been characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and Raman-effect spectroscopy. In addition, X-ray photoelectron spectroscopy (XPS) and electron energy loss spectroscopy (EELS) have been used to investigate the surface chemical groups on the NCD surface. Mechanical and frictional properties are determined using atomic force microscopy (AFM), nano-indentation, nano-scratching and micro-tribometer. The friction behavior of these films in the load range of 25 to 200 mN under reciprocating sliding conditions, using steel counter-body material has been thoroughly studied. It is noted that these films are highly crystalline with nanometer size grains and contain a very high fraction of sp3 carbon bonds. They exhibit high hardness and high elastic modulus. The friction coefficient of the film is lower under unidirectional scratch with diamond indenter than the friction coefficient under low load reciprocating sliding against steel ball. Transfer of the film from the counter-body, oxidation of transfer film and mixing of transfer film with carbonaceous layer on the worn surfaces are responsible for such behavior. Although, the friction responses of H-terminated and O-terminated films are similar under unidirectional scratch with diamond indenter, the friction coefficient of O-terminated film is always higher than the friction coefficient of H-terminated film under reciprocating sliding condition against steel counter-body material. © 2011 Elsevier B.V.

Ghodbane S.,BeSt coating GmbH | Ghodbane S.,Institute Of Recherche Interdisciplinaire Iri | Ghodbane S.,CNRS Institute of Electronics, Microelectronics and Nanotechnology | Haensel T.,TU Ilmenau | And 9 more authors.
Langmuir | Year: 2010

This article reports on the use of high-resolution electron energy loss spectroscopy (HREELS) for the investigation of as-grown (hydrogen-terminated) and oxidized nanocrystalline diamond films (NCD) using chemical, physical, and electrochemical approaches. The results indicate that the nature and number of oxygen-related chemical groups generated on the NCD surface depend strongly on the oxidation process. A high concentration of C-O functions has been obtained on the NCD surface oxidized by rf (radio frequency) oxygen plasma, whereas the highest C - O/C-O ratio has been achieved by electrochemical oxidation. The NCD surface oxidized by rf plasma was totally free of C - O groups. Traces of surface hydroxyl groups (C-OH) have been detected upon annealing in air or through UV/ozone oxidation. © 2010 American Chemical Society.

Kloss F.R.,Innsbruck Medical University | Singh S.,Austrian Academy of Sciences | Hachl O.,Innsbruck Medical University | Rentenberger J.,Innsbruck Medical University | And 9 more authors.
Head and Neck | Year: 2013

Background Irradiation results in impaired bone healing. Thus, osteosynthesis procedures are afflicted with increased failure rates. To improve osseointegration bone morphogenetic protein-2 (BMP-2) immobilized on nanocrystalline diamond (NCD)-coated implant surfaces might be 1 solution. Methods By 4 weeks after irradiation of pig's mandible with a dose of 60 Gy a fracture was accomplished. Osteosynthesis was performed either with titanium osteosynthesis screws or NCD-coated screws with immobilized BMP-2. Nonirradiated animals served as control. After 1, 2, 4, and 8 weeks screws were evaluated histologically. Bone biopsies were gained to extract mesenchymal stem or precursor cells (MSCs). Results MSCs after irradiation demonstrated a behavior comparable to that of unirradiated cells. Consequently, immobilized BMP-2 resulted in an initial increased bone contact ratio (p =.014) but demonstrated no sustainable effect compared with osseointegration in nonirradiated bone (p =.08). Conclusion Immobilized BMP-2 demonstrates an osteoinductive effect in irradiated bone. MSCs as effector cells possess protective mechanisms to overcome the destructive effect of irradiation. © 2012 Wiley Periodicals, Inc.

Ghodbane S.,CNRS Neel Institute | Ghodbane S.,BeSt coating GmbH | Ballutaud D.,French National Center for Scientific Research | Omnes F.,CNRS Neel Institute | Agnes C.,CNRS Neel Institute
Diamond and Related Materials | Year: 2010

In this work, we have used X-ray photoelectron spectroscopy (XPS) to investigate the nature of surface adsorbed species and their sensitivity to the boron concentration [B] in two sets of as-grown diamond films: homoepitaxial {111} and polycrystalline. These sets cover each one at least three of the four doping ranges: low doping (5 × 1016 < [B] < 1.5 × 1019 cm- 3), high doping (1.5 × 1019 < [B] < 3 × 1020 cm- 3), heavy doping (3 × 1020 < [B] < 2 × 1021 cm- 3), and phase separation ([B] > 2 × 1021 cm- 3). The results are compared to those we have previously obtained on {100} homoepitaxial films in the same doping ranges. A detailed description of both the nature and the relative concentrations of the main surface chemical species on every set of films is reported. Besides the usual CHx bonds on the diamond surface, the following oxygen-related groups: Ether (C-O-C), hydroxyl (C-OH, only on polycrystalline films), carbonyl (> C=O) and carboxyl (HO-C=O) have been found on the surface of grown diamond films, upon spontaneous oxidation under air (no oxidation treatment has been applied). The evolution of each surface chemical group according to the boron concentration in the films is. © 2010 Elsevier B.V. All rights reserved.

Neu E.,Saarland University | Arend C.,Saarland University | Gross E.,Saarland University | Guldner F.,Saarland University | And 10 more authors.
Applied Physics Letters | Year: 2011

We report on the production of nanodiamonds (NDs) with 70-80 nm size via bead assisted sonic disintegration (BASD) of a polycrystalline chemical vapor deposition film. The high crystalline quality NDs display intense narrowband (7 nm) room temperature luminescence at 738 nm from in situ incorporated silicon vacancy centers. We demonstrate bright, narrowband single photon emission with >100 000 cps. Due to the narrow fluorescence bandwidth as well as the near-infrared emission these NDs are also suitable as fluorescence labels with significantly enhanced performance for in vivo imaging. © 2011 American Institute of Physics.

Ghodbane S.,CNRS Neel Institute | Ghodbane S.,BeSt coating GmbH | Omnes F.,CNRS Neel Institute | Agnes C.,CNRS Neel Institute
Diamond and Related Materials | Year: 2010

In this work we use cathodoluminescence (CL) at liquid helium temperature to investigate the boron incorporation in {111}-homoepitaxial diamond films, grown outside the visible plasma ball by the Microwave plasma-assisted chemical vapor deposition (MPCVD) technique. The boron concentration of this set of films covers the whole possible doping range divided into four parts: Low doping (5 × 1016 < [B] < 1.5 × 1019 cm- 3), high doping (1.5 × 1019 < [B] < 3 × 1020 cm- 3), heavy doping (3 × 1020 < [B] < 2 × 1021 cm- 3), and phase separation range ([B] > 2 × 1021 cm- 3). The phase separation occurs for very high boron concentrations, between the diamond phase (sp3 carbon) and the other components of the layer, namely sp2 carbon and boron. A part of them is accumulated outside the diamond lattice. This detailed cathodoluminescence investigation of {111}-homoepitaxial diamond films has led to determining the doping range of the films and following the evolution of their crystalline quality when the boron concentration increases. In addition, a comparison between {111} and {100} films in the same doping ranges has been undertaken. © 2009 Elsevier B.V. All rights reserved.

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