ESCOBAR-GALINDO , Ramón

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We examine here the depth resolution (interface width) in elemental analysis and depth profiling of complex layer systems of three ion-probing techniques, each of which has pros and cons: • Rutherford backscattering spectrometry (RBS); • secondary ion mass spectroscopy (SIMS); and, • glow-discharge optical emission spectroscopy (GDOES). RBS is...

The broadening effects found in the depth profiles of abrupt periodic multilayers obtained by Glow Discharge Optical Emission Spectroscopy (GDOES) have been modelled by assuming that the resulting absolute concentration profiles can be described by Gaussian functions of constant area (equal to that of the cross section of the individual layers)...

This paper describes an investigation into the migration and coalescence of equilibrium bubbles in helium implanted copper. Using computer simulation methods, the results indicate that when the swelling averaged over the implant depth approached 12%, the subsequent migration and coalescence leads to the unexpected formation of relatively...

The roughness induced during glow-discharge optical-emission spectroscopy (GDOES) measurements has been reported to cause a loss of resolution during GDOES depth-profiling analysis. In this paper, we undertake for the first time a study of the dynamics of the surface morphology of chromium and titanium thin films (designed in mono and...

In most of the industrial applications of multilayer coatings, a detailed knowledge of the interlayer structure and the interfaces is needed. In comparison with standard surface analysis techniques (SIMS, XPS, AES, etc.), depth profiling by radio-frequency glow discharge optical emission spectroscopy (rf-GDOES) provides rapid information, with...

AgDLC coatings were deposited by magnetron sputtering in order to evaluate: i) the Ag nanoparticle size distribution along the coatings thickness and ii) the silver stability in DLC coatings. Four different coatings were deposited, two AgDLC nanocomposite coatings containing 20 at.% of Ag, with thicknesses of 250 nm and 1000 nm, a 250 nm AgDLC...

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In depth profile analysis by radio-frequency glow discharge optical emission spectroscopy (rf-GDOES) techniques, the depth resolution mainly depends on the roughening induced during the sputtering and the resulting crater geometry. In this work we have tried to isolate the contributions of the different effects that degrade the depth resolution...

In this work, we have studied the improvement on the oxidation resistance of AlCrN-based coatings by adding a subsurface titanium nitride barrier layer. Since oxidation is interrelated with the inward diffusion of oxygen into the surface of AlxCr1−xN (x = 0.70) coatings and the outward diffusion of Cr to the surface, the oxidation behaviour of...

The crater shape effects in GDOES depth profiling of multilayer metal coatings, with an individual thickness layer >500 nm, studied in the foregoing paper, have been extended to the case of thinner layers (layer thickness <150 nm). The analysis of 10 bilayers of 70 nm chromium and 150 nm titanium showed an increased degradation of the...

Zirconium carbonitride coatings with silver nanoparticles were produced by DC unbalanced dual magnetron sputtering system, using two targets, Zr and Zr/Ag in an Ar, C2H2 and N2 atmosphere. Stainless steel 316L and silicon (100) substrates were used for electrochemical and structural characterization, respectively. Silver was found to be well...

Chromium nitride coatings have been deposited on silicon by magnetron sputtering in an Ar + N2 atmosphere at different bias substrate voltages. The poisoning effect has been studied monitoring the discharge voltage and total pressure. The chemical composition and crystalline structure have been analysed by Glow Discharge Optical Emission...

Two multilayer solar selective absorber coatings [Al/CrN0.95/Cr0.96Al0.04N1.08/Cr0.53Al0.47N1.12/Al2O3 (stack #1) and Cr0.96Al0.04N0.89/Cr0.62Al0.38N1.00/Cr0.53Al0.47N1.12/Al2O3 (stack #2)] were deposited on 316L steel by combining direct current (DC) and high power impulse magnetron sputtering (HiPIMS) technologies with the aim of increasing...

A systematic study for the optimization of the deposition process of ZnO thin films grown by dc magnetron sputtering at room temperature was carried out using different oxygen partial pressures and deposition times. We have established a correlation between the oxygen partial pressure, the chemical composition and the crystalline structure of...

Results of positron annihilation measurements on NaY pressed powders and deposited thin films using slow positron beam and conventional fast positron techniques are presented. In lifetime experiments using an external 22Na source an averaged long lifetime of 1.8 ns with a sum intensity of 27% was observed in pressed powders in the presence of...

A modified blister test has been developed based on helium ion implantation into selected areas of the metal substrate prior to the coating deposition. After a post-deposition thermal annealing, blisters are formed by agglomeration of the implanted gas at the ceramic–metal interface. This method can be used to control the pressure in the...

In this work, we report the successful growth of ZnO nanostructured films by oblique angle magnetron sputtering deposition (OAD) from a Zn target in a mixture gas of Ar/O2. The film microstructure and the surface morphology of the samples were explored by HRSEM. The crystalline structure and the composition were determined by XRD and RBS,...

Surface effects on (1 1 1) copper single crystal surfaces after 30 keV helium implantation up to 2.4 × 1016 ions cm−2 and subsequent annealing at 973 K have been studied using scanning electron and confocal microscopy. Since one aim of the work was to develop a method of studying the adhesion of surface coatings, the implantations were...

The aim of this study was to verify the possible physical and chemical changes that may occur on the surface of Ag–TiCN coatings after exposure to the culture media used in microbiological and cytotoxic assays, respectively tryptic soy broth (TSB) and Dulbecco's modified eagle's medium (DMEM). After sample immersion for 24 h in the media,...

ZnO is probably one of the most studied oxides since ZnO nanostructures are a very rich family of nanomaterials with a broad variety of technological applications. Although several chemical techniques offer the possibility to obtain such ZnO nanostructures, here we show that the controlled modification of the zinc surface by low-energy O2 +...

Surface modification by means of wear protective and antibacterial coatings represents, nowadays, a crucial challenge in the biomaterials field in order to enhance the lifetime of bio-devices. It is possible to tailor the properties of the material by using an appropriate combination of high wear resistance (e.g., nitride or carbide coatings)...

Quantitative GDOES studies in protective coating materials (oxides, nitrides, oxynitrides, etc.) are severely limited by the lack of certified standards containing known amounts of oxygen and/or nitrogen. In this work, we propose an alternative method for nitrogen quantification using as calibration samples, a series of deposited nitride...