| 1. |
- Ali, Sharafat, 1976-, et al.
(författare)
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Synthesis and characterization of the mechanical and optical properties of Ca-Si-O-N thin films deposited by RF magnetron sputtering
- 2017
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Ingår i: Surface & Coatings Technology. - : Elsevier. - 0257-8972 .- 1879-3347. ; 315, s. 88-94
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Tidskriftsartikel (refereegranskat)abstract
- Ca-Si-O-N thin films were deposited on commercial soda-lime silicate float glass, silica wafers and sapphire substrates by RF magnetron co-sputtering from Ca and Si targets in an Ar/N-2/O-2 gas mixture. Chemical composition, surface morphology, hardness, reduced elastic modulus and optical properties of the films were investigated using X-ray photoelectron spectroscopy, scanning electron microscopy, nanoindentation, and spectroscopic ellipsometry. It was found that the composition of the films can be controlled by the Ca target power, predominantly, and by the reactive gas flow. Thin films in the Ca-Si-O-N system are composed of N and Ca contents up to 31 eq. % and 60 eq. %, respectively. The films thickness ranges from 600 to 3000 nm and increases with increasing Ca target power. The films surface roughness varied between 2 and 12 nm, and approximately decreases with increasing power of Ca target. The hardness (4-12 GPa) and reduced elastic modulus (65-145 GPa) of the films increase and decrease with the N and Ca contents respectively. The refractive index (1.56-1.82) is primarily dictated by the N content. The properties are compared with findings for bulk glasses in the Ca-Si-(Al)-O-N systems, and it is concluded that Ca-Si-O-N thin films have higher values of hardness, elastic modulus and refractive index than bulk glasses of similar composition. (C) 2017 Elsevier B.V. All rights reserved.
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| 2. |
- Ali, Sharafat, 1976-, et al.
(författare)
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Thin films in M-Si-O-N thin systems
- 2017
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Ingår i: 44th International Conference on Metallurgical Coating and Thin Films (ICMCTF), San Diego, CA, USA, 24-28 Apr 2017.
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Konferensbidrag (refereegranskat)
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| 3. |
- Aouadi, S, et al.
(författare)
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ICMCTF 2014 : Preface
- 2014
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Ingår i: Thin Solid Films. - : Elsevier. - 0040-6090 .- 1879-2731. ; 572, s. 1-1
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Tidskriftsartikel (refereegranskat)abstract
- The 41st International Conference on Metallurgical Coatings andThin Films (ICMCTF), sponsored by the Advanced Surface EngineeringDivision (ASED) of the American Vacuum Society (AVS), was heldfrom April 28 to May 2, 2014 in San Diego, California, USA.The week's technical program consisted of 37 technical sessions,which were organized into 13 symposia. The conference opened witha Plenary Lecture by Prof. Sybrand van der Zwaag, Materials Scienceand Engineering at the faculty of Aerospace Engineering at the TUDelft, The Netherlands, on “Self-healing Materials: an Alternative Approachto Create More Durable/Reliable Materials and Products”. TheExhibition Keynote Lecture was presented by Prof. Timothy P. Weihs,Department of Materials Science and Engineering at the Johns HopkinsUniversity, Baltimore, MD, USA, on “Driving Commercial Applicationsand Exploring Scientific Questions with Reactive Multilayer Foils”.During the conference week, a well subscribed poster session wasattended by a large and appreciative attendee audience. An expansivelarge two-day interactive industrial exhibition, with more than 50booths,was held inwhich companies displayed theirmost recent developmentsin vacuumscience and plasma-based deposition technologies.In addition to the technical symposia sessions, there were threefocused topical sessions, and six specialized short courses offered.Professor Jindrich Musil from the faculty of Applied Sciences atthe University of Bohemia, Plzeň, Czech Republic, was the recipientof the 2014 ASED R.F. Bunshah Annual Award; he presented the HonoraryLecture, “Advanced Hard Nanocomposite Coatings with UniqueProperties”. The award recognizes and honors Prof. Musil's seminalcontributions to the development of advanced nanocomposite coatingswith enhanced hardness, oxidation resistance, toughness, and crackresistance.The ASED Annual ICMCTF Graduate Student Awards werepresented to Shiyu Liu (Gold Medal), University of Cambridge, UK;Samantha K. Lawrence (Silver Medal), Purdue University, WestLafayette, IN, USA; and Trevor Hardcastle (Bronze Medal), Universityof Leeds, UK.The electronic submission and handling of manuscripts via theElsevier Editorial System (EES), including the selection of reviewersand evaluation ofmanuscripts,were identical to the procedures appliedto manuscripts submitted as regular contributions for publication ininternational scientific journals. Following the tradition practiced since1987, the accepted manuscripts are published in the archival journalsSurface and Coatings Technology and Thin Solid Films. ICMCTF 2014proceedings are open-access to the participants for one year via theElsevier journals' web sites.The organization of this conference and the preparation of proceedingsvolumes would have been impossible without the tremendouseffort and dedication of many individuals, including the General Chair,Yip-Wah Chung, Northwestern University, USA, and the ProgramChair, Claus Rebholz, the University of Cyprus, the team of symposiaand session chairs that made possible the realization of an exciting technicalprogram. We especially thank all the authors and presenters fortheir contributions; we also thank the hundreds of reviewers for theirtimely submission of high quality reports. To our sponsors,we acknowledge,appreciate, and thank these companies for their most generousand continuing support.The 42nd International Conference on Metallurgical Coatings andThin Films (ICMCTF 2015) will be held in San Diego, California, April20–24, 2015, with Claus Rebholz, University of Cyprus, as the GeneralChair and Suneel Kodambaka, the University of California at Los Angeles, as the Program Chair.
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| 4. |
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| 5. |
- Broitman, Esteban, 1958-
(författare)
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A new method for in-situ measurement of nano-friction and nano-wear of thin films by using the Triboindenter TI-950
- 2014
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Ingår i: Nanobrucken 2014. - Saarbrucken, Germany : INM - Leibniz Institute for New Materials. ; , s. 24-
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The Triboindenter present many advantages for the measurement of friction and wear at the nanoscale. A reciprocating multi-cycle linear test can be programmed, from where it is possible to obtain simultaneously the friction force and wear rate from the lateral force and vertical displacement sensors, respectively. The friction values have high precision but the wear data is usually wrong in long duration tests because the drift rate is only measured just before the test start. Alternatively, one can program the SPM scanning mode of the instrument with a high load in order to produce the wear of the surface. At the end of the experiment, a squared hole is produced which can be measured using the SPM facility of the system. However, this wear experiment does not allow the simultaneous measurement of the friction coefficient.In this talk I will present a new methodology to measure in-situ the friction and wear of thin films using a Triboindenter TI-950 from Hysitron. I will show how the possible changes of drift rate during long-time tests can be overcome, obtaining simultaneous precise values of friction and wear rate as a function of time. I will discuss how the Triboimage® software can be adapted to this methodology in order to get realistic values of friction and wear. Finally I will show some results for soft (H < 1GPa) Pb films and very hard (H ~ 35 GPa) nitride coatings
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| 6. |
- Broitman, Esteban, 1958-, et al.
(författare)
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A Novel Oxide Characterization Method of Nickel Base Alloy 600 Used in Nuclear Plant Reactors
- 2013
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Konferensbidrag (refereegranskat)abstract
- The Alloy 600 is a polycrystalline nickel base alloy used in pressurized water reactors (PWR) of nuclear power plants. Long term exposure of the alloy to primary water of PWR generates an oxide film that strongly influences the stress corrosion cracking behavior of the alloy. Recently, it has been shown that the oxide film structure, composition and thickness depend on the dissolved hydrogen content in the primary water. In this work we have explored a novel approach which enables a high spatial resolution oxide thickness measurement by nanomechanical testing. Oxide films have been grown on Alloy 600 specimens exposed between 5000 and 35000 hours at 320-330°C with hydrogen levels in the range 5 to 25 mL H2/kg H2O. A Triboindenter TI-950 from Hysitron was used to measure the change of nanomechanical properties in polished cross-sections. The increase of hardness has been correlated to the presence of oxides.
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| 7. |
- Broitman, Esteban, 1958-, et al.
(författare)
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Advanced Carbon-Based Coatings
- 2014. - 4
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Ingår i: Comprehensive Materials Processing. - : Elsevier. - 9780080966007 ; , s. 389-412
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Bokkapitel (refereegranskat)abstract
- This chapter focuses on the development of alloyed diamondlike coatings, in particular a new class of fullerene-like (FL) materials. We describe unique resilient FL compounds by self-organization of nano-curved sp2-hybridized carbon features, with tuned mechanical and surface energy properties. These unique resilient materials consist of bent and intersecting hexagonal basal planes, fabricated by the incorporation of odd-member rings. Cross-linking enables the material to extend the strength of the covalently 2D hexagonal graphene network into 3D. The microstructural properties of three types of coatings, which have the possibility to be applied on a large scale, are described: carbon nitride, phosphorous carbide, and carbon fluoride.
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| 8. |
- Broitman, Esteban, 1958-, et al.
(författare)
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Beschichtungsverfahren und Vorrichtung zum Beschichten
- 2007
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Patent (populärvet., debatt m.m.)abstract
- described are a method and an apparatus for coating bodies by means of Magnetron sputtering. The magnetron is the power over both a Pulsed power supply supplied, the peaks with very high Power density of the magnetron outputs, as well as a Power supply that has a constant power or a pulsed Power with comparatively low power densities to the magnetron emits.
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| 9. |
- Broitman, Esteban, 1958-, et al.
(författare)
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Comparative study on the properties of ZnO nanowires and nanocrystalline thin films
- 2012
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Ingår i: Surface & Coatings Technology. - : Elsevier. - 0257-8972 .- 1879-3347. ; 213, s. 59-64
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Tidskriftsartikel (refereegranskat)abstract
- The microstructural, morphological, optical and water-adsorption properties of nanocrystalline ZnO thin films and ZnO nanowires were studied and compared. The ZnO thin films were obtained by a sol–gel process, while the ZnO nanowires were electrochemically grown onto a ZnO sol–gel spin-coated seed layer. Thin films and nanowire samples were deposited onto crystalline quartz substrates covered by an Au electrode, able to be used in a quartz crystal microbalance. X-ray diffraction measurements reveal in both cases a typical diffraction pattern of ZnO wurtzite structure. Scanning electron microscopic images of nanowire samples show the presence of nanowires with hexagonal sections, with diameters ranging from 30 to 90 nm. Optical characterization reveals a bandgap energy of 3.29 eV for the nanowires and 3.35 eV for the thin films. A quartz crystal microbalance placed in a vacuum chamber was used to quantify the amount and kinetics of water adsorption onto the samples. Nanowire samples, which have higher surface areas than the thin films, adsorb significantly more water.
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| 10. |
- Broitman, Esteban, 1958-, et al.
(författare)
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Fullerene-like Carbon Nitride : A New Carbon-based Tribological Coating
- 2008. - 1
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Ingår i: Tribology of Diamond-Like Carbon Films. - Boston, MA : Springer. - 9780387302645 ; , s. 620-653
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Bokkapitel (refereegranskat)abstract
- In 1994, researchers at Linköping University discovered the fullerene-like allotrope of carbon nitride (FL-CNx) by using reactive magnetron sputtering in a nitrogen-containing atmosphere at rather low ion energy assistance. FL-CNx is a predominantly sp2-hybridized material with nitrogen structurally incorporated either substitutionally in a graphite sheet or in a pyridine-like manner, which initiates bending by formation of pentagons and cross-linking, respectively. The assumed nitrogen-induced cross-linkage between the sheets contributes considerably to the strength of FL-CNx by preventing interplanar slip. This results in an extremely fracture tough, elastic, and compliant material, which deforms by reversible bond rotation and bond angle deflection rather than slip and bond breaking.
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