This study investigates the fabrication and characterization of binary Ti-Si and Ti-Al thin-film metallic glasses (TFMGs) deposited via electron beam evaporation on cp Ti and Si substrates. X-ray diffraction confirmed the amorphous structure of the Ti89Si11 and Ti55Al45 thin films. AFM revealed differences in surface roughness, with Ti89Si11 exhibiting a smoother surface (Ra = 0.9 nm) than Ti55Al45 (Ra = 1.6 nm), likely due to differences in atomic size mismatch, heat of mixing, and potential oxidation effects. Electrochemical tests in Hank’s solution demonstrated the superior corrosion resistance of Ti89Si11, which had the lowest icorr (0.123 µA/cm2) and widest passive region compared to Ti55Al45 and reference materials (cp Ti and SS316L). Mechanical properties revealed that both TFMGs exhibit higher indentation hardness and comparable reduced elastic modulus to cp Ti, with Ti55Al45 showing the highest hardness (5.93 ± 0.37 GPa). These findings highlight the potential of Ti-Si and Ti-Al TFMGs as high-performance materials for biomedical coatings.

In the analysis of nitrogen in Ti-based matrices by glow discharge emission spectroscopy (GDOES), the emission yield of the N I 149.262 nm line was found to depend on the sample composition, in particular, on the N/Ti ratio of the sample surface being sputtered. This was attributed to differences in the transport and redeposition of nitrogen in the GDOES discharge cell: if the surfaces surrounding the plasma consist largely of elemental Ti, the sticking coefficient of nitrogen on them is high and the number density of nitrogen in the volume of the plasma is reduced by adsorption on the walls more strongly than if these surfaces are partly or completely saturated with nitrogen. This leads to a decrease in emission yields of nitrogen lines and needs to be reflected in the analytical methodology. An analogous mechanism might be at play in the analysis of other gaseous elements as well.

Binary Ti-Si thin-film coatings, with compositions ranging from Ti97Si3 to Ti59Si41, were fabricated by simultaneous electron beam evaporation to evaluate their structural, electrochemical, and mechanical properties. Structural analysis revealed a composition-dependent transition from nanocrystalline alpha-Ti solid solutions to smooth, amorphous structures at silicon contents of 16 at.% and above. This amorphization drove a shift in wettability, increasing water contact angles from approximate to 67 degrees (hydrophilic cp-Ti) to approximate to 95 degrees (moderately hydrophobic) for high-Si films. Electrochemical tests in Hank's solution demonstrated significantly superior corrosion resistance for Ti-Si thin-film coatings; specifically, the high-Si amorphous coatings and the transitional Ti90Si10 coating exhibited corrosion current densities an order of magnitude lower than the cp-Ti substrate (i(corr) approximate to 0.02 vs. 0.22 & micro;A/cm(2)) and achieved exceptional passive layer resistance (R-b up to approximate to 18 M Omega.cm(2)) after 168 h immersion. Nanoindentation revealed higher hardness for all Ti-Si coatings compared to cp-Ti (4.4 GPa), peaking at similar to 8.4 GPa in the high-Si amorphous coatings (Ti68Si32, Ti59Si41). Notably, a minimum in both hardness and reduced elastic modulus occurred for the transitional Ti90Si10 coating. These findings highlight the potential of high-Si amorphous Ti-Si coatings and the transitional Ti90Si10 coating as protective surface layers for biomedical-relevant corrosive environments.

Glow discharge optical emission spectroscopy (GDOES) is a powerful and well-established method of elemental analysis of metals, coatings and surface-modified materials. This review contains essential information needed to establish and successfully run a GDOES laboratory and perform accurate, quantitative GDOES analyses. The basics of the methodology, instrumentation and analytical interpretation of experimental data are presented, and examples of typical depth profiling applications are given. Special attention is paid to application-specific calibrations, their assumptions and prerequisites. The calibration model of GDOES is special; besides the composition of calibration samples, their sputter rates (sputter factors) need to be accounted for. Typical analytical performance of GDOES is discussed (precision, accuracy), as well as the depth quantification in depth-profiling applications. Links to some other methods, complementary to GDOES, are mentioned, including the type and the character of analytical information each method can deliver.

Phosphorus-doped diamond (PDD) offers significant potential for innovative applications, yet traditional growth techniques face difficulties in achieving high levels of phosphorus incorporation. This study presents a novel growth process to enhance phosphorus incorporation into diamond layers through transient plasma conditions under CH4 gas pulsing. Unlike conventional approaches, heavily PDD layers ([P] similar to 3 x 10(20) atoms/cm(3)) are obtained at low phosphine concentrations by utilizing phosphorus contamination as the primary source of PH radicals. Time-resolved optical emission spectroscopy analysis reveals that, when the CH4 gas flow is turned off, the distinct relaxation dynamics of CH and PH radicals promote a non-equilibrium plasma state in which sufficient quantities of both radicals coexist. Additionally, the enhanced hydrogen etching process leads to the formation of faceted crystalline grains with reduced nucleation density and fewer non-diamond compounds. In contrast to the fine grains typically observed in conventional heavily PDD nanocrystalline layers, the phosphorus concentration exhibits a proportional trend with grain size, suggesting that phosphorus is primarily incorporated within the diamond grains rather than at grain boundaries. These findings pave the way for achieving heavily PDD layers with precise microstructural control, supporting the development of advanced devices.

A comprehensive treatment is presented of signal response in glow discharge emission spectroscopy as function of the analyte concentration and the sputter rate of the sample matrix. Deviations from linear response are expressed by 1/Gamma factors. Atomization, excitation, radiative transfer and self-absorption in the Grimm-type discharge is discussed. Experimental data on non-linear intensity response, line profiles of selected lines and some matrix effects are presented in the spectra of copper and zinc in the analysis of CuZnAl alloys and in the spectra of Fe, Ni, Cr. Plausible explanations of the findings are offered, based on the fundamentals of the discharge. Besides self-absorption, non-linear intensity response can also be caused by selective excitation processes due to heavy particle collisions, and even an apparent enhancement of some lines with a rising analyte concentration, a trend opposite to that caused by self-absorption. Charge transfer from argon ions to the atoms of some analyte elements is involved and other heavy particle reactions affecting the spectra, that may be occurring on the cathode surface or in its close vicinity. Similarities and differences with other analytical plasmas are discussed, including laser-induced breakdown spectroscopy.

Although heavily phosphorus-doped diamond (PDD) holds great potential for advanced device applications, incorporating phosphorus into diamond remains challenging with conventional growth methods. In this study, optical emission spectroscopy (OES) was used to correlate the emission intensity ratio of PH to CH radicals (IPH/ICH) with phosphorus concentration ([P]) in diamond layers synthesized under varying phosphine ([PH3]/[H2]) and methane ([CH4]/[H2]) concentrations using microwave plasma-enhanced chemical vapor deposition. OES results revealed a strong proportional relationship between IPH/ICH and [P] across different [PH3]/[CH4] ratios. However, beyond a maximum [P] of ∼7.0 × 1020 atoms/cm3, further increases in IPH/ICH did not lead to higher [P] with a significant reduction in phosphorus incorporation efficiency (η), consistent with the solubility limits of phosphorus in diamond. At lower [PH3]/[H2], [P] did not scale proportionally with [PH3]/[CH4], exhibiting nonlinear behavior due to phosphorus contamination (Pcont.) in the reaction chamber, which provided sufficient PHx radicals to grow heavily PDD without PH3 gas flow. By understanding plasma properties and their effects on [P], heavily PDD has been effectively achieved with enhancing [P] (up to 745%) and η (up to 143%) by alternating the dominant radical species in the plasma. Time-dependent control of precursor gas flow allowed modulation of IPH/ICH, improving control over phosphorus incorporation. This novel growth approach offers valuable insights for optimizing PDD synthesis, enabling more efficient phosphorus incorporation for electronic, electrochemical, and quantum applications.

In this research, the influence of the N+ ion implantation process on the microstructure of a biodegradable Zn0.8Mg-0.2Sr alloy was investigated using various experimental techniques. Microscopic analysis revealed that a fluence of 17 & sdot;1017 ions/cm2 resulted in the oversaturation of pure Zn and Mg2Zn11 surfaces, leading to the formation of nano/micro-porous layers up to 400 nm thick. The behavior of the Zn-0.8Mg-0.2Sr alloy was observed to be similar to that of the individual pure phases, albeit without the creation of open pore structures. A limited formation of MgO and Mg3N2 was observed on the alloy surface, although the overall surface presence of Mg significantly increased from 0.8 to 15 wt. %. This increase was caused by the decomposition of the Mg2Zn11 phase during the process and the subsequent diffusion of Mg toward the surface. The absence of Zn3N2 within the samples could be explained by the thermodynamic instability and low Zn-N affinity. Despite the absence of zinc nitride, GD-OES confirmed 10 at. % of nitrogen in the pure zinc, suggesting a possible accommodation of N atoms in the interstitial positions. This study points to the complex nature of the process and highlights other promising directions for future research.

Depth profile analysis of a hydrogenated Ti-6Al-4V alloy by glow discharge optical emission spectroscopy (GDOES) is described. Besides the earlier reported 'hydrogen effects', causing changes in emission intensities of other elements if hydrogen is present, the analysis of hydrogen itself was found to be affected by the redistribution of hydrogen in the region adjacent to the analyzed spot, due to sample heating and the thereby increased hydrogen diffusivity. A simple model of heat transfer within the sample during the GDOES analysis is proposed and the surface temperature of the analyzed spot is estimated to be approximate to 365 degrees C, in the given experimental setup. In the analysis of hydrogen in a hydrogenated, 3D-printed Ti-6Al-4V alloy by GDOES, hydrogen diffuses from the depth due to sample heating, enters the plasma and affects the signal response. A model of heat conduction within the sample is presented.

The effect of titanium on the microstructure and properties of additively manufactured 1.2709 maraging steel is thoroughly studied in this work. For this purpose, a standardized alloy with 0.84wt. % Ti and a model alloy with 0.02wt. % of Ti were prepared by laser powder bed fusion. The microstructures and mechanical behaviour (tensile properties and hardness) of the alloys are described and compared here. It is shown that in contrast to the standardized alloy, the model alloy cracks along grain boundaries in a brittle manner. The effect of Ti is further completed by investigations of (i) an alloy with an addition of 0.7wt. % Ti prepared by laser powder bed fusion and (ii) a low-Ti alloy produced by conventional casting. It is unambiguously shown that the cracking is primarily caused by the interplay of steep temperature changes during laser powder bed fusion of the steel powder and of the low Ti content in the model alloy causing the absence of retained austenite at grain boundaries. Additionally, the tendency of grain boundaries to crack during additive manufacturing is shown to depend on the grain boundary character.

The challenge of doping synthetic diamond with phosphorus stems from the atomic size mismatch between phosphorus and carbon atoms, which previously hindered achieving high phosphorus doping levels. This limitation delayed the exploration of phosphorus-doped diamond (PDD) in electrochemical applications, where it holds potential as a novel and appealing electrode material because PDD uniquely combines diamond ' s exceptional properties with phosphorus atoms inducing n-type conductivity. In this study, heavily doped PDD electrodes were successfully developed using chemical vapour deposition, followed by comprehensive microstructural and electrochemical characterisations. The influence of phosphorus doping, manipulated via high phosphine gas concentration or time-dependant precursor gas flow control, on the PDD properties was thoroughly examined. PDD layers grown at higher phosphine concentrations demonstrated enhanced phosphorus incorporation, leading to a higher prevalence of fine nano-crystalline diamond grains and non-diamond carbon components, while also slowing the growth rate. Notably, a distinct PDD sample produced under dynamic gas flow with lower phosphine concentration revealed larger grain sizes, increased effective deposition rate, and improved phosphorus levels compared to its counterpart synthesized under static conditions. Cyclic voltammetry in a 1 mol L-1 KCl solution revealed a low double-layer capacitance ( <11 F cm(-2)) in all as-grown PDD electrodes. However, significant differences between the samples emerged during the experiments conducted with redox probes [Ru(NH3)(6)](3+/2+) and [Fe(CN)(6)](3-/4-). Particularly, higher phosphorus content promoted well-developed voltammograms, significantly reduced peak-to-peak separation values, faster electron transfer rates, and increased peak currents. Furthermore, the possibility of using heavily P-doped diamond electrodes for the detection of two organic analytes, dopamine and ascorbic acid, was successfully manifested. All in all, the asgrown, highly P-doped diamond electrodes proved their ability, first time ever, to record well-defined signals of both inorganic redox probes and complex organic compounds, unravelling their potential in electroanalysis and sensor development and broadening the scope of PDD utilisation.

Charge transfer reactions between argon ions and analyte atoms occur at a much higher rate in analytical glow discharges than in other similar plasmas, as follows from experimental Boltzmann plots of glow discharge emission spectra and the spectra generated by an inductively coupled plasma. A simple model of a Grimm-type discharge suggests that charge transfer-excited emission of the analyte elements comes largely from the cathode sheath, due to a high collision rate between the sputtered analyte atoms and argon ions accelerated in the cathode fall. The contribution to this radiation from the negative glow is several times lower. The mentioned enhancement of the charge transfer-excited emission in the cathode sheath is, however, not sufficiently high to explain the anomalously high rates of those charge transfer reactions relative to other plasmas. The different characteristics of emission from the cathode sheath and the negative glow also means that Boltzmann plots of glow discharge spectra cannot be interpreted in the conventional way. Further work is needed to explain the observed features of glow discharge excitation, as reflected in the emission spectra.

We have compared the total boron content and hole carrier concentration values obtained from various destructive and non-destructive quantification methods in boron doped nano-crystalline diamond films prepared over a range of doping levels, using microwave plasma enhanced chemical vapour deposition. Destructive secondary-ion mass spectrometry and relatively unreported glow discharge optical emission spectrometry were complemented by non-destructive Raman, spectroscopic ellipsometry and van der Pauw Hall measurements. Measurement techniques are discussed, including details of the glow discharge optical emission spectrometry technique; use of different laser powers and wavelengths, fitting parameters for Raman spectroscopy, and improved ellipsometry modelling. Finally, measured values are compared and discussed regarding their viability for estimation of total boron and electrically active boron in doped nano-crystalline diamond layers.

Polycrystalline boron-doped diamond is a promising material for high-power aqueous electrochemical applications in bioanalytics, catalysis, and energy storage. The chemical vapor deposition (CVD) process of diamond formation and doping is totally diversified by using high kinetic energies of deuterium substituting habitually applied hydrogen. The high concentration of deuterium in plasma induces atomic arrangements and steric hindrance during synthesis reactions, which in consequence leads to a preferential (111) texture and more effective boron incorporation into the lattice, reaching a one order of magnitude higher density of charge carriers. This provides the surface reconstruction impacting surficial populations of CC dimers, CH, CO groups, and COOH termination along with enhanced kinetics of their abstraction, as revealed by high-resolution core-level spectroscopies. A series of local densities of states were computed, showing a rich set of highly occupied and localized surface states for samples deposited in deuterium, negating the connotations of band bending. The introduction of enhanced incorporation of boron into (111) facet of diamond leads to the manifestation of surface electronic states below the Fermi level and above the bulk valence band edge. This unique electronic band structure affects the charge transfer kinetics, electron affinity, and diffusion field geometry critical for efficient electrolysis, electrocatalysis, and photoelectrochemistry.

A new route of severe plastic deformation – the complex shearing of extruded tube (CSET) technique – was proposed recently. In this route, a tube is produced from a rod via extrusion combined with two passes of an equal channel angular pressing like processing and with mandrel rotation. In the present paper, we describe and discuss the changes in the microstructure of an aluminum single crystal processed by CSET with respect to grain refinement, orientation changes and dislocation distribution.

Boron- and phosphorus-doped diamond layers were analysed by glow discharge optical emission spectroscopy. A methodology for quantitative depth profiling of layers was developed, based on multi-matrix calibration with a calibration model assuming matrix-independent emission yields. Factors affecting accuracy and sensitivity of analysis are discussed. Analysis of boron with the B I line at 208.959 nm yielded a satisfactory performance. Analysis of phosphorus with the P I line at 178.284 nm in an argon glow discharge is affected by an argon-related interference, which can be avoided by using a neon discharge. The use of which leads to an eightfold improvement in the phosphorus detection limit. A light interference effect affecting the analysis in transparent layers is described, indicating that layers are transparent far into the ultraviolet region.

Charge transfer reactions between argon ions and analyte atoms occur at a much higher rate in analytical glow discharges than in other similar plasmas, as follows from experimental Boltzmann plots of glow discharge emission spectra and the spectra generated by an inductively coupled plasma. A simple model of a Grimm-type discharge suggests that charge transfer-excited emission of the analyte elements comes largely from the cathode sheath, due to a high collision rate between the sputtered analyte atoms and argon ions accelerated in the cathode fall. The contribution to this radiation from the negative glow is several times lower. The mentioned enhancement of the charge transfer-excited emission in the cathode sheath is, however, not sufficiently high to explain the anomalously high rates of those charge transfer reactions relative to other plasmas. The different characteristics of emission from the cathode sheath and the negative glow also means that Boltzmann plots of glow discharge spectra cannot be interpreted in the conventional way. Further work is needed to explain the observed features of glow discharge excitation, as reflected in the emission spectra.

In this work, phosphorus-doped polycrystalline diamond layers were grown using a new gas control process to increase the incorporation of phosphorus in diamond. Topographical characteristics and crystalline quality of the phosphorus-doped polycrystalline diamond layers grown on Si substrates were analyzed using Scanning Electron Microscopy (SEM) and Raman spectroscopy. The phosphorus concentration was determined using Glow-Discharge Optical Emission Spectroscopy (GDOES). Polycrystalline diamond layers have a good crystalline quality with a sp(3)/sp(2) carbon ration over 75%. The growth rate reaches up to 440 nm.h(-1), and the phosphorus concentration is well above 10(20) cm(-3). Novelty statement: This work reports on a new method for the production of phosphorus-doped polycrystalline diamond layers based on the pulsed injection of methane during the growth by microwave plasma enhanced chemical vapor deposition.

This note contains evidence that charge transfer from argon ions to neutral molybdenum atoms is a major excitation mechanism of the Mo II spectrum in an argon glow discharge.

The excitation of Ni I and Ni II emission spectra in an argon glow discharge was analyzed and compared with that of some other transition elements. Higher Ni I levels are enhanced compared to the trend corresponding to the Boltzmann distribution. Selective excitation of some Ni II levels was observed and attributed to the (Ar+-Ni-0) charge transfer reaction.