| 1. |
- Abbasi, Mazhar Ali, et al.
(författare)
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Anions effect on the low temperature growth of ZnO nanostructures
- 2012
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Ingår i: Vacuum. - : Elsevier. - 0042-207X .- 1879-2715. ; 86:12, s. 1998-2001
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Tidskriftsartikel (refereegranskat)abstract
- Seed mediated aqueous chemical growth (ACG) route was used for the growth of ZnO nanostructures on Si substrate in four different growth mediums. The growth medium has shown to affect the morphology and the size of the different nanostructures. We observed that the medium containing zinc nitrate anions yields the nanorods, in a medium containing zinc acetate anions nano-candles are obtained. While in a medium containing zinc chloride anions ZnO nano-discs were obtained and in a medium containing zinc sulfate anions nano-flakes are achieved. Growth in these different mediums has also shown effect on the optical emission characteristics of the different ZnO nanostructures.
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| 2. |
- Alberdi, Alberto, et al.
(författare)
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Tribological behavior of nanocomposite coatings based on fullerene-like structures
- 2011
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Ingår i: Vacuum. - : Elsevier BV. - 0042-207X .- 1879-2715. ; 85:12, s. 1087-1092
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents a new group of nanocomposite coatings based on integrating inorganic fullerene-like material (IFLM) structures into conventional coating matrices. Such coatings have been developed within the scope of the European funded FOREMOST project (FP6-NMP3-CT-2005-515840). Regarding the synthesis of these nanocomposite coatings based on fullerene-like components, two alternative routes were explored: introducing preformed IFLMs into the coating deposition process or forming the fullerene-like components in situ during the coating deposition process. Both methods have been demonstrated to be technically feasible, depending on the nature of the coating matrix or the desired fullerene-like structure. These new materials allow some independent control of tribological properties usually known as antagonists (very high load bearing capacity with a very low friction coefficient). In the case of unidirectional movement, under dry conditions, the best coatings developed in FOREMOST displayed a coefficient of friction in air within the range 0.04-0.10, depending on the degree of humidity and the test conditions. Pure sliding laboratory tests indicate that for some industrial applications fullerene-like nanocomposite coatings can give significant reductions in wear and friction coefficient when compared to similar coatings without fullerene-like components. The lubrication mechanisms through which these fullerene-like structures improve friction and prevent wear are also discussed in this paper.
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| 3. |
- Andersson, Matilda, et al.
(författare)
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Deposition and characterization of magnetron sputtered amorphous Cr-C films
- 2012
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Ingår i: Vacuum. - : Elsevier BV. - 0042-207X .- 1879-2715. ; 86:9, s. 1408-1416
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Tidskriftsartikel (refereegranskat)abstract
- Thin films in the Cr-C system with carbon content of 25-85 at.% have been deposited using non-reactive DC magnetron sputtering from elemental targets. Analyses with X-ray diffraction and transmission electron microscopy confirm that the films are completely amorphous. Also, annealing experiment show that the films had not crystallized at 500 degrees C. Furthermore, X-ray spectroscopy and Raman spectroscopy show that the films consist of two phases, an amorphous CrCx phase and an amorphous carbon (a-C) phase. The presence of two amorphous phases is also supported by the electrochemical analysis, which shows that oxidation of both chromium and carbon contributes to the total current in the passive region. The relative amounts of these amorphous phases influence the film properties. Typically, lower carbon content with less a-C phase leads to harder films with higher Young's modulus and lower resistivity. The results also show that both films have lower currents in the passive region compared to the uncoated 316L steel substrate. Finally, our results were compared with literature data from both reactively and non-reactively sputtered chromium carbide films. The comparison reveals that non-reactive sputtering tend to favour the formation of amorphous films and also influence e.g. the sp(2)/sp(3) ratio of the a-C phase.
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| 4. |
- Azarov, A. Yu., et al.
(författare)
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Structural damage in ZnO bombarded by heavy ions
- 2010
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Ingår i: Vacuum. - : Elsevier BV. - 0042-207X .- 1879-2715. ; 84:8, s. 1058-1061
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Tidskriftsartikel (refereegranskat)abstract
- The effect of implantation parameters on damage build-up in ZnO bombarded with Bi and Er ions is studied by Rutherford backscattering/channelling spectrometry. The results show that the damage accumulation behaviour in ZnO is different dramatically from that in other semiconductors. In particular, a variation of implantation parameters, such as collision cascade density, sample temperature and ion flux, has only a minor influence on the damage accumulation in the crystal bulk for the case of such heavy ions. Moreover, an intermediate damage peak, between the surface and bulk defect peaks, is observed for all the irradiation conditions studied. The cascade density affects the behaviour of this intermediate peak with increasing ion dose.
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| 5. |
- Baránková, Hana, et al.
(författare)
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Effect of the electrode material on the atmospheric plasma conversion of NO in air mixtures
- 2010
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Ingår i: Vacuum. - : Elsevier BV. - 0042-207X .- 1879-2715. ; 84:12, s. 1385-1388
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Tidskriftsartikel (refereegranskat)abstract
- Non-thermal atmospheric pressure plasma is widely used for conversion of hazardous gases. Results from different laboratories confirm importance of energy non-equilibrium in the plasma where dominant energy carriers are electrons and a dominant chemistry is based on formation and interactions of radicals. Because of rather high electric fields required for generation and sustaining of air discharges at atmospheric pressure many plasma systems were found rather to create a lot of NO instead of removing it. A widely supported way to clean NO and NO2 from air mixtures is a plasma assisted catalytic reduction where the cold plasma is combined with the solid-state catalyst. In an ideal case the plasma acts as an oxidation catalyst where an atomic oxygen from air oxidizes NO to NO2 and the solid-state catalysts are then capable to convert all NO2 to N-2 and O-2. In most cases it is also necessary to involve auxiliary gases, e.g., propylene, to make the process efficient enough. This work introduces an original cold plasma system based on atmospheric hollow cathodes generated by a nanopulse DC power with controllable voltage and pulse frequency. The system was optimized in both the geometry and the applied power. However, the material of electrodes was found to be the most important factor affecting the plasma performance and consequently the chemical kinetics. A 100% conversion of NO to NO2 was achieved with a graphite electrode, without using any auxiliary gas and without catalyst. Plasma performance and conversion efficiency are compared for several electrode materials.
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| 6. |
- Baránková, Hana, et al.
(författare)
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Optimization and performance of atmospheric Fused Hollow Cathodes
- 2013
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Ingår i: Vacuum. - : Elsevier BV. - 0042-207X .- 1879-2715. ; 87, s. 128-131
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Tidskriftsartikel (refereegranskat)abstract
- Experimental results on the atmospheric hollow cathode plasma generation and performance, using a special configuration with tunable wall separations, are presented. The influence of the gas and type of the power used for generation on the optimum size of the cathode slit is investigated. The experimental results are in agreement with the hollow cathode model. The plasma source/plasma reactor design is of utmost importance for control of plasma-chemical kinetics. An example of the atmospheric hollow cathode plasma application for the NOx conversion is given. The energy consumption and plasma characteristics are discussed.
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| 7. |
- Batool, S S, et al.
(författare)
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Silica nanofibers based impedance type humidity detector prepared on glass substrate
- 2013
-
Ingår i: Vacuum. - : Elsevier. - 0042-207X .- 1879-2715. ; 87, s. 1-6
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Tidskriftsartikel (refereegranskat)abstract
- Impedance type relative humidity detector is fabricated by depositing electrospun silica nanofibers on glass substrate. The silica nanofibers with an average diameter similar to 150 nm and length similar to 100 mu m were used. Thermogravimetric and differential scanning calorimetric analysis confirm that the accurate annealing temperature is 500 degrees C for complete removal of PVP. Humidity detecting devices were fabricated by defining titanium electrodes on top of the silica nanofibers. The performance of silica nanofibers humidity detectors was tested by AC electrical measurements at 40-90% relative humidity. The response and the recovery times were 5 s and 3 s, respectively, between 40% and 90% relative humidity. Contribution of dipoles, space charge polarization, relaxation of these dipoles and low frequency dispersion phenomenon were observed during impedance measurements.
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| 8. |
- Beshkova, Milena, et al.
(författare)
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Sublimation epitaxy of 3C-SiC grown at Si- and C-rich conditions
- 2012
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Ingår i: Vacuum. - : Elsevier. - 0042-207X .- 1879-2715. ; 86:10, s. 1595-1599
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Tidskriftsartikel (refereegranskat)abstract
- 3C-SiC layers have been grown by using sublimation epitaxy at a source temperature of 2000 degrees C, under vacuum conditions (andlt;10(-5) mbar) on well oriented (on-axis) 6H-SiC (0001) substrates. Close space sublimation growth geometry has been used in a RF-heated furnace employing high-purity graphite crucible with a possibility to change the growth environment from Si vapor-rich to C vapor-rich. The optical microscopy in transmission mode reveals continuous 3C-domains for 3C-SiC with less than 0.4% 6H-inclusions for the layer grown at Si-rich conditions, and separate 3C-SiC domains for the layer grown at C-rich conditions. The type of 6H-inclusions for layers with continuous domain structure investigated by Atomic Force Microscopy (AFM) is discussed. 2Theta-omega scan shows 0006 and 111 peaks coming from the substrate and the layer, respectively with a higher intensity of the 111 peak for 3C-SiC grown at Si-rich conditions which is related with the continuous character of the 3C-SiC domains.
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| 9. |
- Greczynski, Grzegorz, et al.
(författare)
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Selection of metal ion irradiation for controlling Ti1-xAlxN alloy growth via hybrid HIPIMS/magnetron co-sputtering
- 2012
-
Ingår i: Vacuum. - : Elsevier. - 0042-207X .- 1879-2715. ; 86:8, s. 1036-1040
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate, for the first time, the growth of metastable single-phase NaCl-structure high-AlN-content Ti1-xAlxN alloys (x andlt;= 0.64) which simultaneously possess high hardness and low residual stress. The films are grown using a hybrid approach combining high-power pulsed magnetron (HPPMS/HIPIMS) and dc magnetron sputtering of opposing metal targets. With HIPIMS applied to the Al target, Aln+ ion irradiation (dominated by Aln+) of the growing film results in alloys 0.55 andlt;= x andlt;= 0.60 which exhibit hardness H similar to 30 GPa and low stress sigma = 0.2-0.7 GPa, tensile. In sharp contrast, films with corresponding AlN concentrations grown with HIPIMS applied to the Ti target, giving rise to Tin+ ion irradiation (with a significant Ti2+ component), are two-phase - cubic (Ti,Al)N and hexagonal AlN - with low hardness, H = 18-19 GPa, and high compressive stress ranging up to 2.7 GPa. Annealing alloys grown with HIPIMS applied to the Al target results in age hardening due to spinodal decomposition; the hardness of Ti0.41Al0.59N increases from 30 to 33 GPa following a 900 degrees C anneal.
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| 10. |
- Greczynski, Grzegorz, et al.
(författare)
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Time and energy resolved ion mass spectroscopy studies of the ion flux during high power pulsed magnetron sputtering of Cr in Ar and Ar/N-2 atmospheres
- 2010
-
Ingår i: VACUUM. - : Elsevier Science B.V., Amsterdam.. - 0042-207X. ; 84:9, s. 1159-1170
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Tidskriftsartikel (refereegranskat)abstract
- Mass spectroscopy was used to analyze the energy and composition of the ion flux during high power pulsed magnetron sputtering (HIPIMS/HPPMS) of a Cr target in an industrial deposition system. The ion energy distribution functions were recorded in the time-averaged and time-resolved mode for Ar+, Ar2+, Cr+, Cr2+, N-2(+) and N+ ions. In the metallic mode the dependence on pulse energy (equivalent of peak target current) was studied. In the case of reactive sputtering in an Ar/N-2 atmosphere, variations in ion flux composition were investigated for varying N-2-to-Ar flow ratio at constant pressure and HIPIMS power settings. The number of doubly charged Cr ions is found to increase linearly with increasing pulse energy. An intense flux of energetic N+ ions was observed during deposition in the reactive mode. The time evolution of ion flux composition is analyzed in detail and related to the film growth process. The ionization of working gas mixture is hampered during the most energetic phase of discharge by a high flux of sputter-ejected species entering the plasma, causing both gas rarefaction and quenching of the electron energy distribution function. It is suggested that the properties (composition and energy) of the ion flux incident on the substrate can be intentionally adjusted not only by varying the pulse energy (discharge peak current), but also by taking advantage of the observed time variations in the composition of ion flux.
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| 11. |
- Gudmundsson, Jon Tomas, 1965-
(författare)
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The high power impulse magnetron sputtering discharge as an ionized physical vapor deposition tool
- 2010
-
Ingår i: Vacuum. - : Elsevier. - 0042-207X .- 1879-2715. ; 84:12, s. 1360-1364
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Tidskriftsartikel (refereegranskat)abstract
- Various magnetron sputtering tools have been developed that provide a high degree of ionization of the sputtered vapor referred to as ionized physical vapor deposition (IPVD). The ions can be controlled with respect to energy and direction as they arrive to the growth surface which allows for increased control of film properties during growth. Here, the design parameters for IPVD systems are briefly reviewed. The first sputter based IPVD systems utilized a secondary plasma source between the target and the substrate in order to generate a highly ionized sputtered vapor. High power impulse magnetron sputtering (HiPIMS) is a recent sputtering technique that utilizes IPVD where a high density plasma is created by applying high power pulses at low frequency and low duty cycle to a magnetron sputtering device. A summary of the key experimental findings for the HiPIMS discharge is given. Measurements of the temporal and spatial behavior of the plasma parameters indicate electron density peak, that expands from the target with a fixed velocity. The discharge develops from an inert sputtering gas dominated to a sputtered vapor dominated during the pulse. The high electron density results in a high degree of ionization of the deposition material.
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| 12. |
- Hultman, Lars
(författare)
-
Editorial
- 2012
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Ingår i: Vacuum. - : Elsevier. - 0042-207X .- 1879-2715. ; 86:8, s. 1013-1013
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
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| 13. |
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| 14. |
- Katardjiev, Ilia, et al.
(författare)
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Recent developments in thin film electro-acoustic technology for biosensor applications
- 2012
-
Ingår i: Vacuum. - : Elsevier BV. - 0042-207X .- 1879-2715. ; 86:5, s. 520-531
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Forskningsöversikt (refereegranskat)abstract
- The article reviews recent developments of the thin film electro-acoustic (TEA) technology in view of the design and fabrication of micro-acoustic transducers for biosensor applications. The use of the TEA technology leads to transducer miniaturisation, compatibility with the IC technology, possibility for multiplexing, decrease in fabrication cost, reduction of consumables, mass fabrication, etc. Focus lies on the design, fabrication and evaluation of the transducer performance in liquid media as judged by electro-acoustic behaviour and ultimately by mass and viscosity resolution. The analysis draws the conclusion that the thickness excited quasi-shear thin film bulk acoustic resonator technology is far ahead in its development with regard to other alternative approaches in terms of both performance and level of maturity. Consequently, the main aspects of the quasi-shear thin film bulk acoustic resonator (FBAR) technology from film synthesis and fabrication through to performance evaluation and demonstration are reviewed in detail.
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| 15. |
- Liljeholm, Lina, et al.
(författare)
-
Electrical characterization of wurtzite (Al,B)N thin films
- 2011
-
Ingår i: Vacuum. - : Elsevier. - 0042-207X .- 1879-2715. ; 86:4, s. 466-470
-
Tidskriftsartikel (refereegranskat)abstract
- Wurtzite aluminum nitride (w-AlN) thin films are of great interest for electro-acoustic applications and their material properties have in recent years been extensively studied. One way to tailor material properties is to vary the composition by adding other elements. Boron is an element that can take the place of aluminum in the crystal lattice of w-AlN. In the present study, polycrystalline w-(AI,B)N thin films were grown on p-Si(100) and Al/p-Si(100) substrates by pulsed DC reactive magnetron sputtering from a single Al/B target. MIS and MIM structures were fabricated to investigate the electrical properties of w-(AI,B)N thin films. Important dielectric thin film properties for microelectronics applications are the breakdown field, the permittivity (K) and leakage current through the film. The (AI,B)N thin film is found to have a dielectric strength of similar to 3 x 10(6) V cm(-1) and a kappa close to 12. The measured leakage current through the film is assumed to be mainly due to Frenkel-Poole emission with a trap energy at 0.71 eV below the conduction band edge.
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| 16. |
- Liljeholm, Lina, et al.
(författare)
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Reactive sputtering of SiO2–TiO2 thin film from composite Six/TiO2 targets
- 2010
-
Ingår i: Vacuum. - : Elsevier BV. - 0042-207X .- 1879-2715. ; 85:2, s. 317-321
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Tidskriftsartikel (refereegranskat)abstract
- Coatings of SiO2–TiO2 films are frequently used in a number of optical thin film applications. In this work we present results from depositing films with variable Si/Ti ratios prepared by reactive sputtering. The different Si/Ti ratios were obtained by varying the target composition of composite single targets. Compared to co-sputtering this facilitates process control and composition uniformity of the films. Varying the oxygen supply during sputter deposition can result in films ranging from metallic/substoichiometric to stoichiometric oxides. Transmittance spectra of the different films are presented and the optical constants are determined from these spectra. Furthermore, the deposition process, films structure and composition of the films are discussed. The study shows that by choosing the right composition and working in the proper oxygen flow range, it is possible to tune the refractive index.
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| 17. |
- Lloyd Spetz, Anita
(författare)
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Vacuum technology applied to solid state chemical sensors, processing, characterization and applications
- 2012
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Ingår i: Vacuum. - : Elsevier. - 0042-207X .- 1879-2715. ; 86:5, s. 488-494
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Tidskriftsartikel (refereegranskat)abstract
- This chapter will review several solid state chemical sensors with focus on the importance of ultra high vacuum, UHV, for the development of this area. Examples of sensors will be given where processing of sensors and sensing layers as well as characterization of chemical sensors takes place in UHV as well as examples of sensors for operation in UHV. Applications of chemical sensors both already commercialized and still on the research level will be given. Sensor technologies will span from metal oxide sensors, field effect transistor sensors to surface plasmon resonance, SPR, sensors and microcalorimeters. Examples of new challenging novel sensor approaches like sensors based on indirect SPR sensing and ultra sensitive graphene-based sensors for NO2 detection will also be given.
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| 18. |
- Malyshev, O. B., et al.
(författare)
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Ar beam induced desorption from different materials at TSL
- 2010
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Ingår i: Vacuum. - : Elsevier BV. - 0042-207X .- 1879-2715. ; 85:2, s. 338-343
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Tidskriftsartikel (refereegranskat)abstract
- This paper describes new experiments on the heavy ion desorption yield measurements with 5 MeV/u Ar8+ and summarizes all results of experiments with 5 MeV/u Ar8+ performed at The Svedberg Laboratory in Uppsala (Sweden). These results are important for the update and design of the FAIR facility at the GSI Helmholtz Centre for Heavy Ion Research in Darmstadt (Germany) where the required increase in beam intensity is limited by ion induced pressure instability. It was shown that lowest desorption yields can be achieved with gold coatings, whereas grazing incident loss increases the desorption yield by roughly an order of magnitude compared to perpendicular loss. The desorption yield of saturated NEG samples was measured to be higher compared to any non pumping samples. The desorption yield of copper can be lower and higher compared to stainless steel depending on cleaning procedure and sample history. Additionally the secondary electron and ion yield was measured to be a few tens of electrons and ions emitted per projectile impact in backward direction. Their influence on the desorption yield due to secondary effects was less than 5% compared to the primary desorption by the high energetic projectile. (C) 2010 Elsevier Ltd. All rights reserved.
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| 19. |
- Moreira, Milena, et al.
(författare)
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Aluminum scandium nitride thin-film bulk acoustic resonators for wide band applications
- 2011
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Ingår i: Vacuum. - : Elsevier BV. - 0042-207X .- 1879-2715. ; 86:1, s. 23-26
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Tidskriftsartikel (refereegranskat)abstract
- Piezoelectric c-textured Al(1-x)ScxN thin films, where the Sc relative concentration, x, varies in the range 0-0.15 have been studied in view of radio frequency (RF) electro-acoustic applications. Thin film bulk acoustic wave resonators (FBARs) employing these films were fabricated and characterized as a function of the Sc concentration for the first time. The measured electromechanical coupling is found to increase by as much as 100% in the above concentration range. The results from this work underline the potential of the c-textured Al(1-x)ScxN based FBARs for wide band RF applications.
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| 20. |
- Nsimama, P. D., et al.
(författare)
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Plasma emission monitoring (PEM) controlled DC reactive sputtered ZnO:Al thin films
- 2012
-
Ingår i: Vacuum. - : Elsevier BV. - 0042-207X .- 1879-2715. ; 86:12, s. 1939-1944
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Tidskriftsartikel (refereegranskat)abstract
- High deposition rate ZnO:Al films have been produced at room temperature by reactive DC sputtering using a plasma emission monitoring (PEM) control system. We have investigated the relationship between structural, optical and electrical properties of the ZnO:Al films. Crystal structures of the films have been studied by X-ray diffraction. Optimum ZnO:Al films, with 17-40 Omega/square sheet resistance range and transmittance approaching 88% in the visible region, exhibited a hexagonal ZnO structure with preferential (002) orientation and crystallite sizes of about 27 nm. Resistive transparent films displayed a more random orientation showing peaks at (100) and (102) orientations. Dark "metallic" films were shown to consist of mainly zinc. The optimal ZnO:Al film has been determined from a figure of merit based on power losses due to absorption and series resistance in the ZnO:Al films. It is highly transparent, with low resistance, pronounced (002) peak and large crystallite size. (C) 2012 Elsevier Ltd. All rights reserved.
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| 21. |
- Rech, S, et al.
(författare)
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Cold-spray deposition of Ti2AlC coatings
- 2013
-
Ingår i: Vacuum. - : Elsevier. - 0042-207X .- 1879-2715. ; 94, s. 69-73
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Tidskriftsartikel (refereegranskat)abstract
- Ti2AlC coatings have been fabricated by cold-spray deposition. The microstructure evolution as a function of basic spray parameters temperature and pressure onto AA6060 aluminium alloy and 1.0037 steel substrates has been studied. Adherent and dense 50–80 μm thick Ti2AlC coatings were deposited on soft AA6060 substrates under gas temperature and pressure of 600 °C and 3.4 MPa, respectively, whilst comparable results were obtained on harder 1.0037 steel by using higher temperature (800 °C) and pressure (3.9 MPa).
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| 22. |
- Sberveglieri, Giorgio, et al.
(författare)
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Synthesis and integration of tin oxide nanowires into an electronic nose
- 2012
-
Ingår i: Vacuum. - : Elsevier BV. - 0042-207X .- 1879-2715. ; 86:5, s. 532-535
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Tidskriftsartikel (refereegranskat)abstract
- Single crystal nanostructures of semiconducting tin oxides have been fabricated and characterized as sensing materials for implementation in an electronic nose. The nanowires exhibit exceptional crystalline quality and a very high length-to-width ratio, resulting in enhanced sensing capability as well as long-term material stability for prolonged operation. A sensing device based on SnO2 nanowires has been fabricated and comparatively tested in an array of chemical sensor with conventional thin film sensing device. Preliminary measurements ethanol/water mixtures demonstrate that nanowire-based sensors can be favourably implemented in the electronic nose and that they perform comparably with the conventional thin film layers.
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| 23. |
- Tynkova, A., et al.
(författare)
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Interdiffusion in Au(120 nm)/Ni(70 nm) thin films at the low-temperature annealing in the different atmospheres
- 2013
-
Ingår i: Vacuum. - : Elsevier BV. - 0042-207X .- 1879-2715. ; 87, s. 69-74
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Tidskriftsartikel (refereegranskat)abstract
- The development of the interdiffusion processes and the surface morphology changes in thin films of Au(120 nm)/Ni(70 nm) during annealing at 200 degrees C for 20 min in vacuum with different residual atmosphere pressures of 10(-3) and 10(-6) Pa and in an environment of hydrogen at a pressure of 5 x 10(2) Pa have been studied. Secondary ion mass spectrometry, Auger electron spectroscopy, X-ray diffraction, optical microscopy, atomic force microscopy and scanning electron microscopy were used. Surface microdefects that form in the films are related to the local oxidation of nickel and to the stress that arises due to interdiffusion. Defect formation and reactions at the surface are found to be controlling factors in the transport of nickel to the surface and in the observed morphology.
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| 24. |
- Vishnyakov, V, et al.
(författare)
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Ti3SiC2-formation during Ti–C–Si multilayer deposition by magnetron sputtering at 650 °C
- 2013
-
Ingår i: Vacuum. - : Elsevier. - 0042-207X .- 1879-2715. ; 93, s. 56-59
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Tidskriftsartikel (refereegranskat)abstract
- Titanium Silicon Carbide films were deposited from three separate magnetrons with elemental targets onto Si wafer substrates. The substrate was moved in a circular motion such that the substrate faces each magnetron in turn and only one atomic species (Ti, Si or C) is deposited at a time. This allows layer-by-layer film deposition. Material average composition was determined to Ti0.47Si0.14C0.39 by energy-dispersive X-ray spectroscopy. High-resolution transmission electron microscopy and Raman spectroscopy were used to gain insights into thin film atomic structure arrangements. Using this new deposition technique formation of Ti3SiC2 MAX phase was obtained at a deposition temperature of 650 °C, while at lower temperatures only silicides and carbides are formed. Significant sharpening of Raman E2g and Ag peaks associated with Ti3SiC2 formation was observed.
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| 25. |
- Yang, J.F., et al.
(författare)
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Effect of Si content on the microstructure and mechanical properties of Mo–Al–Si–N coatings
- 2012
-
Ingår i: Vacuum. - : Elsevier BV. - 0042-207X .- 1879-2715. ; 86:12, s. 2010-2013
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Tidskriftsartikel (refereegranskat)abstract
- Mo-Al (Al/(Mo+Al)=6.5%)-Si-N coatings with silicon content ranging from 0 to 17at.% were fabricated using d.c. reactive unbalanced magnetron sputtering technique in an Ar-N2 mixture. Surface morphology, element and phase composition, residual stress and nanohardness of these coatings were studied by scanned electrical microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), residual stress tester, and nanoindenter, respectively.Results exhibit that the residual stress built in the coating are compressive in nature ranging between 0.6 and 1.8 GPa. Nanohardness of Mo-Al-Si-N coatings increased at first and then decreased with silicon content, reaching a maximum value of 36 GPa at 8.3 at.% Si. The optimum hardness could be ascribed to higher compressive stress and nanocomposite structure where nanocrystallite Mo-Al-Si-N embedded in amorphous Si3N4 matrix.
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