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The complex nitrides of intermetallics based on titanium, aluminium and nickel are very promising materials for high-performance coatings. Samples of Ni 3 Al and TiAl 3 were prepared by the self-propagating high-temperature synthesis (SHS) of elemental powders in an argon atmosphere with subsequent pulsed-plasma ion nitriding. Results from the combustion synthesis of aluminides of...
Small angle X-ray scattering (SAXS) has been successfully applied for size and shape investigation of nanometer size features in different fields. With the rise of interest in nanoparticles in material science, the method is fully employed in research of wide variety of materials. Finally, the advance of thin films research with the structural features in nanometer range also shows great need for...
Monocrystalline epitaxial diamond layers were grown by microwave plasma CVD on (100) surfaces of high-temperature, high-pressure synthetic monocrystalline diamond bulk substrates. Electrical measurements were carried out using 2 and 4 point probes. Surface conductance was found to be in agreement with the boron doping level on as-grown layers. It is expected that the surface conductance is controlled...
The stability of commercially available yellow (Bayferrox 3920) and red (Bayferrox 140) micronized iron oxide pigments against highly aggressive treatment with oxygen plasma is examined. The red pigment microparticles with hematite crystal structure are stable, while the yellow pigment changes colour during the treatment. Structural analysis with powder X-ray diffraction and X-ray absorption methods,...
In the present investigation, a commercial plasma CVD system suited for the deposition of titanium nitride (TiN) was adapted for alumina deposition up to substrate temperatures of 800°C.The investigations clearly demonstrated that activating the process gas by plasma lowers the temperature needed for the formation of hard alumina coatings. The properties of the alumina coatings depend strongly on...
The present work describes a preliminary study of friction-induced surface reactions in ultra-high vacuum of H and D atoms adsorbed on stainless steel. Deuterium has been implanted in the sample by electrolysis of D 2 O. A pin with a ball end under controlled load produces the friction in alternating passes across the surface. A sample manipulator controls the normal and tangential loads of...
Tin (Sn) deposited on polycrystalline aluminium (Al) surfaces shows a Stranski–Krastanov growth mode which means that before Sn islands nucleate a thin Sn wetting layer is formed. If the wetting layer is removed from the Al surface by sputter cleaning in UHV it reforms by a solid state wetting process.The sources of the Sn atoms forming the wetting layer are the Sn islands, which are not removed from...
Dry sliding wear experiments at specific temperatures ranging from 20 to 500°C were conducted on CrCN coatings deposited onto steel substrates. The coatings were worn against 100Cr6 bearing steel balls, Si 3 N 4 and Al 2 O 3 balls, using a pin-on-disc sliding configuration at a contact load of 5N. Friction coefficient and coating wear rates were measured, and wear tracks...
The permeation/desorption of hydrogen and the reaction between oxygen and permeating/desorbing hydrogen from a polycrystalline palladium sample have been studied under ultra-high vacuum conditions. Furthermore, the effects of potassium on desorption and reaction has been investigated. Time-of-flight spectroscopy has been mainly used to determine the translational energy distribution of desorption...
Due to lack of long-range ordering, the density of amorphous silicon is lower than in its crystalline form. By hydrogenation of material, the density difference becomes larger. In order to study the effect quantitatively, a series of thin amorphous hydrogenated silicon films, with variation in hydrogen to silicon ratio from 6 to 31 at%, deposited by magnetron sputtering, was examined by UV–visible–IR...
The interaction of oxygen with a carbidized Mo(100) surface was investigated at different temperatures (300 K–1000K) with-angle resolved X-ray photoelectron spectroscopy. A carbide overlayer with a homogeneous Mo 2 C stoichiometry (down to the information depth of XPS) was produced by the high-temperature decomposition of C 2 H 4 on Mo(100).O 2 adsorbs dissociatively...
A series of Al/Cu/Fe multilayer films was deposited by sputtering elemental targets. Most of the tests were conducted on stainless steel and WC–Co hard metal substrates, some of them protected with a TiAlN coating. In order to ensure proper homogenization of the film, the samples were heat-treated in a tube furnace with argon flow. Different annealing patterns were tried with an emphasis on the dependence...
The ability of poly(ethylene oxide) (PEO) to form crystalline complexes with a variety of salts has provided a number of novel compounds in which to examine fundamental questions of structure, coordination and transport properties. In this work we study electrolyte from polymer–salt compounds based on ZnCl 2 . Polymer electrolyte (PEO) 8 ZnCl 2 has been prepared by the sol–gel...
We have developed a mercury-plated microelectrode array based on Indium Tin Oxide (ITO) films (600nm) prepared by rf reactive sputtering on a silicon substrate. Microelectrode behaviour of the disc arrays has been characterised by cyclic voltammetry (CV). Electroplating of mercury onto the ITO microelectrode array was carried out in a solution of Hg(NO 3 ) 2 and KNO 3 by applying...
Annealing effects in nano-sized gadolinium particles deposited on silicon substrates were studied with particular emphasis on the interface between the gadolinium particles and silicon substrate. Because of its sensitivity to such a buried structure, the specular X-ray reflectivity technique was employed in addition to analysis by in-plane X-ray diffraction and atomic-force microscopy. The samples...
Sputter deposited copper (Cu) coatings on plane glassy carbon (C) substrates serve as a model for the interface between Cu- and C-fibres in Cu–C metal matrix composites (MMCs). This interface is of crucial importance for the mechanical and thermal properties of copper carbon MMCs.If the Cu-coating is deposited on a nitrogen(N)-radiofrequency (RF)-plasma treated C-substrate at room temperature (RT),...
Fe 74 Si 11 B 14 Ni 1 soft-magnetic material was prepared as a powder using water atomisation. Using this method, powder particles of less than 45μm in diameter were obtained after sieving. In the as-water-atomised condition the powder particles were observed to be amorphous. Annealing resulted in the formation of a two-phase nanostructured morphology. The structure...
Discharge characteristics of magnetron cells with different geometry of the central cathode rod are presented. The cathode rod had one of the following cross-section shapes: circular, rectangular, square, star-like or 4-triangular. The discharge characteristics of the cells were measured systematically at different anode voltages between 1 and 8kV and pressures between 5×10 −9 and 1×10 ...
An overview of typical simple experiments, intended for didactic laboratory vacuum classes for undergraduate students majoring in Physics, Physics Engineering and Material Sciences, is presented. For all the experiments, the students perform actual measurements of characteristics of different vacuum components or material properties and compare the obtained results with the values tabulated in the...
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