A major challenge for oriented diamond growth on metals is finding materials that combine a cubic structure with a lattice parameter matching that of diamond (aD = 0.357 nm), while also exhibiting low carbon affinity to prevent non-diamond growth or carbide formation. Copper is a promising substrate for the oriented growth of carbon allotropes. Alloying Cu with Ni forms an FCC solid solution that can achieve the ideal “diamond” lattice parameter. This study investigates oriented CVD diamond growth on NiCu thin films with varying compositions, establishing a correlation between alloy concentration and diamond quality. We demonstrate that a NiCu alloy with moderate Ni concentration (≈25 at.%) enables the production of high-quality diamond films with a Raman FWHM of 8 cm−1.

A major challenge for oriented diamond growth on metals is finding materials that combine a cubic structure with a lattice parameter matching that of diamond (aD = 0.357 nm), while also exhibiting low carbon affinity to prevent non-diamond growth or carbide formation. Copper is a promising substrate for the oriented growth of carbon allotropes. Alloying Cu with Ni forms an FCC solid solution that can achieve the ideal "diamond" lattice parameter. This study investigates oriented CVD diamond growth on Ni-Cu thin films with varying compositions, establishing a correlation between alloy concentration and diamond quality. We demonstrate that a Ni-Cu alloy with moderate Ni concentration (approximate to 25 at.%) enables the production of high-quality diamond films with a Raman FWHM of 8 cm- 1.

Ultrananocrystalline diamond films are conventionally described as diamond nanograins embedded in a sp(2)-rich amorphous carbon matrix. It was recently reported that as-deposited ultrananocrystalline diamond films consisted of dendrite-/nanofeather-like diamond aggregates embedded in a sp(2)-rich phase across the thickness. Here, we reveal that controlled oxidation at 725 degrees C selectively removes the intergranular sp(2) phase, exposing the hierarchical architecture throughout the film thickness. Cross-sectional scanning electron microscopy and depth-resolved Raman spectroscopy support that this morphology originates during growth via intense secondary nucleation and constrained lateral crystallite expansion. These results challenge the grain matrix model and provide a scalable route to anisotropic, high-surface-area diamond coatings.

Tribological performance of chemical vapor deposition (CVD) diamond coatings with different internal architectures-monolithic microcrystalline (M), nanocrystalline (N), bilayer (2L), and gradient structures (G4, G8, G12)-was evaluated under dry sliding against alumina. Gradient coatings with varied microcrystalline base thicknesses were prepared to clarify the influence of structural transitions on friction, wear, and adhesion. Coating architecture was found to play a decisive role in controlling tribological behavior. The gradient coating with the thickest microcrystalline base (G4) exhibited stable low friction and strong adhesion, whereas thinner gradients (G8, G12) and the bilayer (2L) showed unstable friction and higher wear, attributed to increased sp2 content and abrupt interfaces. The nanocrystalline coating demonstrated stable but higher friction, while the microcrystalline coating combined low wear with limited interfacial strength. Raman spectroscopy and post-test microscopy confirmed that the sp3/sp2 carbon phase balance and the presence of a continuous structural gradient govern crack propagation, debris formation, and friction stability. Overall, a graded architecture with a sufficiently thick microcrystalline base provides an effective design route for achieving mechanically robust, wear-resistant, and low-friction diamond coatings suitable for advanced tribological applications.

This study investigates an approach to enhancing the tribological properties of CVD diamond films by modifying their structure. The approach is based on periodic renucleation of the film during the synthesis process. A comparative analysis was conducted with films of a microcrystalline structure and a standard multilayer structure, consisting of alternating microcrystalline and nanocrystalline diamond layers. The results demonstrate that the periodically renucleated diamond film retains all the features of the multilayer structure, including low surface roughness of 311 nm, tensile residual stress of 2.8 GPa, low coefficient of friction of 0.08, and low wear rate of counter body of 2.19 x 10-6 mm3N- 1m- 1. Moreover, the periodically renucleated diamond film exhibits significantly improved wear resistance, with a 43 % lower wear rate compared to standard multilayer film.

One of the most promising applications of high entropy ceramics is their use as high temperature protective materials. Due to the additional entropic stabilization of the crystal structure, four- and five-element high entropy ceramics exhibit enhanced thermal and mechanical properties. For these applications, one of the most promising high entropy protective oxides are ZrO2- and HfO2-based protective HEOs. In this article, we study the HfO2–ZrO2–Y2O3–CeO2 equimolar system with the addition of MgO as a fifth component. We found that the HfZrCeY(Mg)O system maintains a single FCC crystalline structure up to the MgO concentration = 31.9 mol.%. Additionally, we determined that an addition of MgO at the close-to-equimolar HfZrCeY(Mg)O composition enhances the thermal properties of HEO, but reduces the mechanical properties such as hardness and resistance to crack formation. The minimum weight loss at the heating from RT up to 1450 °C was measured for the close-to-equimolar HfZrCeY(Mg)O composition at 18.4 mol.% MgO. The hardness of such composition was around 18 GPa. Due to the combination of these properties, the synthesized coating can be used as a protective material for high temperature applications, such as the protection of turbine parts.

In this work, we present experimental data on carbon nanotubes integration during diamond synthesis. Carbon nanotubes layers were preliminarily deposited on silicon and diamond substrates, after which the substrates were loaded into the HFCVD reactor for further growth of the diamond phase. The CVD process was held in an argon-free H2/CH4 working gas mixture without the use of a catalyst for carbon nanotubes growth. It is shown that in a wide range of studied working gas composition (CH4 concentration up to 28.6 vol.%) nanotubes etched from the substrate surface before the diamond growth process began.

A combination of two methods of chemical vapor deposition (CVD) of diamond films, microwave plasma–assisted (MW CVD) and hot filament (HF CVD), was used for the growth of 100 µm-thick polycrystalline diamond (PCD) layers on Si substrates. The bow of HF CVD and MW CVD films showed opposite convex\concave trends; thus, the combined material allowed reducing the overall bow by a factor of 2–3. Using MW CVD for the growth of the initial 25 µm-thick PCD layer allowed achieving much higher thermal conductivity of the combined 110 µm-thick film at 210 W/m·K in comparison to 130 W/m·K for the 93 µm-thick pure HF CVD film.

In this paper, we focus on the research of Al addition on Hf–Al–C film structure and oxidation resistance. It was found that obtained Hf–A–C films consist of a solid solution of Al in non-stoichiometric cubic HfC and have identical XRD patterns to bcc–HfC. Besides, the Al addition decreases the sample mass gain during oxidation in air at temperatures up to 800 °C. Mass gain for Hf–Al–C was 44.3 and 22.5% less, compared to pristine HfC, at 600 and 800 °C, respectively.

In this article we show the optical, mechanical and surface properties change depending on the Hf-Zr-Ce-Y-O thin film composition. Hf4Zr4CeY2O21 shows up to three times higher hardness compared to binary HfZrO4 oxide and up to 50% higher hardness compared to cubic ZrO2 and HfO2 due to the solid solution hardening effect. Equimolar film exhibit a high transmittance >85% and high hydrophobicity with the water contact angle ≈ 106°. Variation of the elemental composition in Hf-Zr-Ce-Y-O is allows to simultaneously tune mechanical and wetting properties for the optimum configuration depending on the application.

A planar solid oxide fuel cell (SOFC) was fabricated using a commercial Ni/yttria-stabilized zirconia (YSZ) anode support, an YSZ/gadolinium-doped ceria (GDC) thin-film electrolyte, and a composite cathode of La0.6Sr0.4Co0.2Fe0.8O3/Gd0.1Ce0.9O1.95 (LSCF/GDC). A small, three-cell, SOFC stack is assembled using 10 cm × 10 cm single cells, metallic interconnects, and glass-based sealing. The stack performance was examined at various fuel flow rates of H2 + N2 and air at a fixed temperature of 750 °C. The three-cell stack with a crossflow design produced peak power density of 0.216 W/cm2 or about 39 W total power at 750 °C.

Chemical vapor deposition (CVD) diamond is a prospective thin film material for cutting tools applications due to the extreme combination of hardness, chemical inertness, and thermal conductivity. However, the CVD diamond cutting ability of ferrous materials is strongly limited due to its extreme affinity to iron, cobalt, or nickel. The diamond⁻iron interaction and the diffusion behavior in this system are not well studied and are believed to be similar to the graphite⁻iron mechanism. In this article, we focus on the medium-temperature working range of 400⁻800 °C of a CVD diamond⁻Fe system and show that for these temperatures etching of diamond by Fe is not as strong as is generally accepted. The starting point of the diamond graphitization in contact with iron was found around 400 °C. Our results show that CVD diamond is applicable for the cutting of ferrous materials under medium-temperature conditions.

Given the exceptional characteristics of diamond films, they have become increasingly popular in the fields of medicine, microelectronics, and detector electronics. However, despite all the advantages, there are many technological problems that complicate their widespread application and impose limitations on diamond use in technological processes. In this study, we proposed a new technique for obtaining a complex topology of polycrystalline diamond coatings by selective seeding of the substrate by nucleation centers and subsequent surface treatment with reactive ion etching to reduce the number of parasitic particles. As a result, diamond films were obtained with a high particle concentration in the film region and high repeatability of the pattern. Moreover, parasitic particles influenced neutralization in areas where film coverage was not needed. The effect of the diamond nanoparticle concentration in a photoresist and the effect of reactive ion etching on the formation of a continuous film and the removal of parasitic nucleation centers were examined. The relative simplicity, low power consumption, and high efficiency of this method make it attractive for both industrial and scientific applications.

The effect of treatment by reactive ion etching in an argon atmosphere, and hydrogen plasma etching in a glow discharge plasma on the surface of the diamond films was investigated. Diamond films were deposited by the Chemical Vapor Deposition method on the hard alloy VK-8 substrates. The crystallites direction under the influence of argon ion beam processing was changed by 45 degrees from the original. The surface morphology becomes more developed (an average value of 20%) by etching in a glow discharge plasma in an atmosphere of hydrogen. Raman spectroscopy, Scanning Electron Microscope and Atomic Force Microscopy were used to determine the phase and microstructure composition of deposited films.

Preliminary high-intensity ion influence allows to one create an alloyed coating layer of tungsten carbide on the cutting coating of a hard-alloy wood-working tool. As a result the diamond coating formed from glow-discharge plasma does not have a preferred direction of growth, and mechanical stresses and adhesion strength of diamond coating increase. The edge wear of modified tools is noticeably decreased during the cutting of woody materials.