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Hydrogenated amorphous carbon (a-C:H) films have been grown from argon/methane gas mixtures by electron cyclotron resonance chemical vapour deposition (ECR-CVD) on silicon substrates. The effects of the application of a DC substrate bias on the structural, morphological and mechanical properties of the films have been explored by multiple analysis techniques such as infrared and micro-Raman spectroscopy,...
CdZnTe thin films of thickness 450–1400nm have been evaporated under vacuum onto unheated glass substrates, using a multilayer method. During film deposition, the two evaporation sources, separated by two glass cylinders, were maintained at temperatures of 720K for Zn and at 925–1200K for CdTe, respectively. After deposition, the samples were annealed in air up to 775K. The structural and optical...
We describe a detailed study of scanning electron microscopy (SEM) combined with energy dispersive spectroscopy (EDS) analysis to study composition and structure of 500nm thick polycrystalline GaN samples. The films have been deposited by cyclic-pulsed laser deposition (cyclic-PLD) with a Nd:YAG nanosecond pulsed laser at 1064nm. SEM pictures of the GaN layers revealed a structure composed of grains...
The DC abnormal-glow discharges with magnetic field assistance near the cathode targets are particularly useful in magnetron sputtering and are extensively used in industrial plasma processing applications [Thornton JA. J Vacuum Sci Technol 1978; 15(2): 171–177].In this work, an experimental study of the magnetic field influence on planar magnetron abnormal-glow discharges of argon on copper targets...
To achieve highly accurate controlled depositions a specially designed vapour source, for metals with low to medium melting temperature, was developed. A quartz crystal microbalance is fitted inside the evaporation chamber to provide real-time rate and thickness monitoring. A carefully planned geometry allows maintaining a small deposition area centred on the sample without compromising flow rate...
Titanium diboride (TiB 2 ) films are being investigated due to their promising uses not only in electronic devices but also for mechanical purposes. Its excellent corrosion resistance and chemical stability, as well as high hardness and wear resistance, makes TiB 2 particularly suitable for aluminium processing (e.g. extrusion, die-casting and machining). In the present work, TiB ...
In this work, three rubber-like materials (NBR 7201, NBR 9003 and HNBR 8001) with applications in the automotive industry were studied. Different atmospheric pressure plasma treatments were used to modify the surface properties of these materials in order to improve their tribological behaviour. Surface analyses of the samples by means of X-ray photoelectron spectroscopy (XPS) were performed in order...
In this work, an ultra-high vacuum reactive evaporation procedure has been tested and optimized for the growth of TiN thin films, throwing very good results both in composition of the TiN layers and secondary emission yield values and performance. Stoichiometry and composition are analyzed by means of X-ray photoemission spectroscopy which, together with the secondary electron emission measurements,...
In this work (Al,Ti) and (Al,Ti,N) films with composition gradient in depth starting either with pure Al or pure Ti were deposited on Si, glass and Au at room temperature in a DC magnetron discharge without bias. The plasma parameters, for both custom made cathodes, were determined and the process was real-time controlled to obtain in the plasma the necessary deposition changes in relative metal abundances...
In this work, a study on some optical properties of diamond-like carbon (DLC) films is presented. The DLC films have been deposited by DC discharge plasma-enhanced chemical vapor deposition (PECVD). The deposited layers have been characterized by spectrophotometry, ellipsometry and Fourier transform infrared spectroscopy (FTIR) analysis. The result shows that the C–Si ratio evolves with the DLC thickness...
In magnetrons the magnetic field confines partially the electron swarm in a trap near the cathode increasing sputtering yield and deposition rates. The magnetic field also decreases the ignition voltage even at relatively low pressures thus allowing sputtering at lower pressures. Under this conditions fewer collisions, less diffusion and less thermalization of the sputtered atoms occur during the...
We present in this work some experimental results obtained from nitriding AISI 304 stainless steel at different temperatures by means of RF/DC generated 10 15 m −3 density plasmas in the 1–4eV electron temperature range. The samples were biased up to −400V. Substrate temperatures have proved to be an influential factor in the diffusion of the ions impinging onto the material under...
In this study, tungsten oxide coatings with 13 and 75at% of oxygen were prepared by DC reactive magnetron sputtering from a pure W target in an Ar+O 2 atmosphere. The coating hardness (H) decreased with increasing oxygen content from 25 to 7.7GPa. The values of H/E ratio were 0.08 and 0.07 for W 87 O 13 and W 25 O 75 , respectively.The tribological measurements...
National Measurements Institutes calibrate vacuum pressure sensors a few gauges at a time in a time-consuming fashion, resulting in an accurate calibration with small uncertainty estimates. A manufacturer produces a comparatively large number of sensors a day which must be economically calibrated. Here, we investigate a procedure for rapid calibration of combination vacuum gauges while following as...
The most diffused leak detection method for the leak rates lower than 10 −2 mbarL/s that is based on the application of mass spectrometry with tracer gas (generally helium) is considered. A description is given of the metrological characterization of the mass spectrometer leak detectors (MSLD) for industrial applications since they represent the best choice for tightening tests having good...
Diamond-like carbon (DLC) is an adequate coating on a large variety of materials for tribological purposes, namely against iron alloys in automotive parts, bearings and forming tools. Herein, the tribological properties of DLC-stainless steel couples were assessed by unlubricated pin-on-disc experiments. Plasma enhanced chemical vapour deposition (PECVD) of DLC-Si or pure DLC coatings were performed,...
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