Editor’s Choice Articles

Over the past decades, ferroelectric photovoltaic (FE-PV) systems, which use a homogenous ferroelectric material as a light-absorbing layer, have been studied using ferroelectric oxides. The PV activity of materials can be enhanced by adjusting the bandgap of materials, and it would have a large effect on the ferroelectric complex oxides. This phenomenon in epitaxial thin films of ferroelectric complex oxide, Bi_3.25La_0.75Ti₃O₁₂ (BLT), Fe- and Co-doped films were observed. Compared with undoped BLT, Co-(BLCT) doping and Fe and Co combined (BLFCT) doping resulted in the gradual reduction in the bandgap and efficient visible light absorption. The reduction in the bandgap to 11.4% and 18.1% smaller than the experimentally measured Eg of the bismuth titanate-based film using a simple Fe- and Co-doping method was performed, while maintaining ferroelectricity by analyzing the BLCT and BLFCT films based on polarization loops, and the temperature range of the out-of-plane lattice parameters and the photocurrent density of the BLFCT film was 32.2 times higher than that of the BLT film, which was caused by the decrease in the bandgap. This simple doping technique can be used to tune additional wide-bandgap complex oxides so that they can be used in photovoltaic energy conversion or optoelectronic devices. Full article

In this research, Böhler K340 cold work tool steel was subjected to three different heat treatment protocols, conventional heat treatment (CHT), shallow cryogenic treatment (SCT), and deep cryogenic treatment (DCT). The study compares the effect of SCT and DCT on the microstructure and consequently on the selected mechanical properties (micro- and macroscale hardness and impact toughness). The study shows no significant difference in macroscale hardness after the different heat treatments. However, the microhardness values indicate a slightly lower hardness in the case of SCT and DCT. Microstructure analysis with light (LM) and scanning electron microscopy (SEM) indicated a finer and more homogenous microstructure with smaller lath size and preferential orientation of the martensitic matrix in SCT and DCT samples compared to CHT. In addition, the uniform precipitation of more spherical and finer carbides is determined for both cryogenic treatments. Moreover, the precipitation of small dispersed secondary carbides is observed in SCT and DCT, whereas in the CHT counterparts, these carbide types were not detected. X-ray diffraction (XRD) and electron backscatter diffraction (EBSD) confirms that SCT and DCT are very effective in minimizing the amount of retained austenite down to 1.8 vol.% for SCT and even below 1 vol.% for the DCT variant. Full article

Aluminum thin films with thicknesses between approximately 10 and 60 nm have been deposited by evaporation and sputtering techniques. Layer characterization focused on reflectance, optical constants, and surface quality. Reflectance fits have been performed using a merger of three standard dispersion models, namely the Drude model, the Lorentzian oscillator model, and the beta-distributed oscillator model. A thickness dependence of the optical constants could be established in the investigated thickness range. Full article

Starting from solid-solutions (SS) of AlCoCrFeNi_x high-entropy alloys (HEAs) that have been produced with high purity constituent elements by vacuum arc remelting (VAR) method varying the nickel molar ratio x from 0.2 to 2.0, we investigated the synthesis of protective thin films of HEAs and high-entropy nitrides (HENs) with the aid of the pulsed laser deposition (PLD) system. The structure of all ten available bulk targets have been examined by means of X-Ray Diffraction (XRD), as well as their elemental composition by means of energy dispersion X-ray spectroscopy (EDS). Three targets with nickel molar composition x = 0.4, 1.2 and 2.0 corresponding to BCC, mixed BCC and FCC, and finally FCC structures were used for thin film depositions using a KrF excimer laser. The depositions were performed in residual low vacuum (10⁻⁷ mbar) and under N₂ (10⁻⁴ mbar) at room temperature (RT~25 °C) on Si and glass substrates. The deposited films’ structure was investigated using grazing incidence XRD, their surface morphology, thickness and elemental composition by scanning electron microscopy (SEM), EDS and X-ray photoelectron spectroscopy (XPS), respectively. A homemade four-point probe (4PP) set-up was applied to determine layers electrical resistance. Besides, a Nanoindentation (NI) was employed to test films’ mechanical properties. XRD results showed that all deposited films, regardless of the initial structure of targets, were a mixture of FCC and BCC structures. Additionally, the quantitative and qualitative EDS and XPS results showed that the elemental composition of films was rather close to that of the targets. The depositions under an N₂ atmosphere resulted in the inclusion of several percentage nitrogen atoms in a metallic nitride type compound into films, which may explain their higher electrical resistivity. The Young’s modulus, nanohardness and friction coefficient values showed that the deposited films present good mechanical properties and could be used as protective coatings to prevent damage in harsh environments. Full article

A new kind of low-carbon bainite steel with excellent strength and toughness was developed, serving as the bogie of the next-generation high-speed train. However, the softening of the heat-affected zone (HAZ) in laser-arc hybrid welding (LAHW) needs to be overcome. In this study, the effect of the cooling rate of the LAHW process on the microstructure and mechanical properties in the HAZ was explored via thermal simulation. The results showed that with increased cooling rate, the grain size increased, the content of lath martensite decreased, and the lath bainite gradually changed to a granular shape in the thermal simulation specimen. With the decrease in the cooling rate, i.e., with the increase of t_8/5, the strength–toughness matching of the material showed a downward trend. The thermal simulation specimen with a t_8/5 of 6~8 s had higher strength and good toughness, which can be considered a potential welding parameter reference. The content of martensitic austenite (M-A) constituents was the main factor that determined the strength and toughness of the joint. During the tensile test, the axial force caused the material to tighten, and the transverse stress as obvious in the part of the M-A constituents that are prone to microcracks and many defects, resulting in cracks, paths, and multi-component layers in the center. As a result, the thermal cycle specimens had mixed fracture characteristics. Full article

Pyroelectric energy harvesting is one of the more recent and promising solid-state approaches for directly converting time-dependent temperature fluctuations into electric energy. Conventional printing technologies can offer many advantages for the production of pyroelectric thin-film-based devices, such as low cost, low temperature, the use of flexible substrates and shaping at the same time as deposition. Nevertheless, some issues related to low printed thickness and film-forming microstructure control need to be addressed. In this exploratory study, the possibility of exploiting the highly attractive gravure printing process for the potential industrial manufacture of flexible polyvinylidene fluoride (PVDF) thin-film pyroelectric devices was investigated. By the use of corona pre-treatment of the printing substrate and low-temperature polar solvent evaporation, multilayer gravure-printed PVDF pyroelectric devices were successfully manufactured for the first time, achieving a maximum generated current of 0.1 nA at 2.5 K/s from a device with an active area of 1 cm². Considering the very low thermal inertia and performance scaling by the area expected for pyroelectric thin-film-based devices, combined with the upscaling potential of roll-to-roll gravure printing, our results provide new opportunities for on-demand, low-cost pyroelectric device manufacture and their integration in hybrid harvesters. Full article

The CrZrN/CrZrSiN multilayer coatings at a bilayer period range decreasing from 1.35 μm to 0.45 μm were synthesized on a Si (100) wafer and WC-6 wt.% Co substrate using a closed-field unbalanced magnetron sputter, and the thickness effects on the mechanical properties and thermal stability were investigated. The CrZrN/CrZrSiN multilayer coatings showed high hardness and elastic modulus in the ranges of 28 to 33 GPa and 255 to 265 GPa, respectively, and the friction coefficient showed the lowest value of 0.24 on the multilayer coating with a bilayer period of 0.54 μm. The bilayer periods affected the adhesion strength of the multilayer coatings. From the scratch test, the critical load (Lc2) steadily increased with the decreasing of the bilayer period, and the CrZrN/CrZrSiN multilayer coating with a bilayer period of 0.45 μm showed the highest critical load (Lc2) of 79 N. In the case of the annealing test, the bilayer periods affected the thermal stability of the multilayer coatings, and the CrZrN/CrZrSiN multilayer coatings with 0.54 μm showed a maximum hardness value of approximately 30 GPa up to 800 °C. Full article

The spectral emission data from the plasma glow of various sputtering targets containing indium oxide, zinc oxide, and tin oxide were obtained. The plasma was generated at various power and chamber pressures. These spectral data were then converted into two-dimensional arrays by implementing a basic array-reshaping technique and a more complex procedure utilizing an unsupervised deep-learning technique, known as the self-organizing-maps method. The two-dimensional images obtained from each single-emission spectrum of the plasma mimic an image that can then be used to train a convolutional neural network model capable of predicting certain plasma features, such as impurity levels in the sputtering target, working gas composition, plasma power, and chamber pressure during the machine operation. We show that our single-array-to-2D-array conversion technique, coupled with deep-learning techniques and computer vision, can achieve high predictive accuracy and can, therefore, be fundamental to the construction of a sputtering system’s digital twin. Full article

The anodising process parameters (voltage, temperature, and electrolyte) control the morphology and the chemical composition of the resulting anodic oxide film by altering the balance between oxide growth and oxide dissolution reactions. The porosity of the oxide film is reduced by the addition of tartaric acid to a sulfuric acid electrolyte, while anodising at elevated temperatures enhances oxide dissolution, leading to wider pores and rougher surfaces. No significant changes in the oxide chemical composition as a function of anodising parameters was found; in particular, no tartrate incorporation took place. The resistance of uncoated anodic oxide films against aggressive media and galvanic stress as a function of anodising parameters has been studied by electrochemical methods. Anodising in a mixed tartaric and sulfuric acid electrolyte improves the resistance of the anodic oxide against galvanic stress and aggressive media in comparison to sulfuric acid anodising processes. However, the corrosion protection performance of the anodic oxide films in combination with a corrosion-inhibitor loaded organic coating is not governed by the blank oxide properties but by the adhesion-enhancing morphological features formed during anodising at elevated temperatures at the oxide/coating interface. Full article

The correlations among microstructure, surface morphology, hardness, and elastic modulus of Bi₂Te₃ thin films deposited on c-plane sapphire substrates by pulsed laser deposition are investigated. X-ray diffraction (XRD) and transmission electron microscopy are used to characterize the microstructures of the Bi₂Te₃ thin films. The XRD analyses revealed that the Bi₂Te₃ thin films were highly (00l)-oriented and exhibited progressively improved crystallinity when the substrate temperature (T_S) increased. The hardness and elastic modulus of the Bi₂Te₃ thin films determined by nanoindentation operated with the continuous contact stiffness measurement (CSM) mode are both substantially larger than those reported for bulk samples, albeit both decrease monotonically with increasing crystallite size and follow the Hall—Petch relation closely. Moreover, the Berkovich nanoindentation-induced crack exhibited trans-granular cracking behaviors for all films investigated. The fracture toughness was significantly higher for films deposited at the lower T_S; meanwhile, the fracture energy was almost the same when the crystallite size was suppressed, which indicated a prominent role of grain boundary in governing the deformation characteristics of the present Bi₂Te₃ films. Full article

WSiN films were produced through hybrid pulse direct current/radio frequency magnetron co-sputtering and evaluated as diffusion barriers for Cu metallization. The Cu/WSiN/Si assemblies were annealed for 1 h in a vacuum at 500–900 °C. The structural stability and diffusion barrier performance of the WSiN films were explored through X-ray diffraction, Auger electron spectroscopy, and sheet resistance measurement. The results indicated that the Si content of WSiN films increased from 0 to 9 at.% as the power applied to the Si target was increased from 0 to 150 W. The as-deposited W₇₆N₂₄, W₆₈Si₀N₃₂, and W₆₃Si₄N₃₃ films formed a face-centered cubic W₂N phase, whereas the as-deposited W₅₉Si₉N₃₂ film was near-amorphous. The lattice constants of crystalline WSiN films decreased after annealing. The sheet resistance of crystalline WSiN films exhibited a sharp increase as they were annealed at 800 °C, accompanied by the formation of a Cu₃Si compound. The failure of the near-amorphous W₅₉Si₉N₃₂ barrier against Cu diffusion was observed when annealed at 900 °C. Full article

In this review, the operating principles of the nano-impact test technique are described, compared and contrasted to micro- and macro-scale impact tests. Impact fatigue mechanisms are discussed, and the impact behaviour of three different industrially relevant coating systems has been investigated in detail. The coating systems are (i) ultra-thin hard carbon films on silicon, (ii) DLC on hardened tool steel and (iii) nitrides on WC-Co. The influence of the mechanical properties of the substrate and the load-carrying capacity (H³/E²) of the coating, the use of the test to simulate erosion, studies modelling the nano- and micro-impact test and performing nano- and micro-impact tests at elevated temperature are also discussed. Full article

In this study, we investigated the characteristics of the n-type Ni/SiC ohmic contact using the laser annealing process on thin wafers. The electrical behavior of the ohmic contacts was tested in 4H-SiC JBS diode devices. As a result, a wafer thickness of 100 μm in the 4H-SiC JBS diode achieved a forward voltage of 1.33 V at 20 A with a laser annealing process using Ni silicide. Using a laser annealing process on a wafer thickness of 100 μm, an on-resistance decrease of almost 22% was demonstrated. Based on our experimental results, we suggest an alternative laser annealing fabrication scheme to obtain low on-resistance SiC power devices with thin structures after SiC grinding. Full article

Boron as thin film material is of relevance for use in modern micro- and nano-fabrication technology. In this research boron thin films are realized by a number of physical and chemical deposition methods, including magnetron sputtering, electron-beam evaporation, plasma enhanced chemical vapor deposition (CVD), thermal/non-plasma CVD, remote plasma CVD and atmospheric pressure CVD. Various physical, mechanical and chemical characteristics of these boron thin films are investigated, i.e., deposition rate, uniformity, roughness, stress, composition, defectivity and chemical resistance. Boron films realized by plasma enhanced chemical vapor deposition (PECVD) are found to be inert for conventional wet chemical etchants and have the lowest amount of defects, which makes this the best candidate to be integrated into the micro-fabrication processes. By varying the deposition parameters in the PECVD process, the influences of plasma power, pressure and precursor inflow on the deposition rate and intrinsic stress are further explored. Utilization of PECVD boron films as hard mask for wet etching is demonstrated by means of patterning followed by selective structuring of the silicon substrate, which shows that PECVD boron thin films can be successfully applied for micro-fabrication. Full article

This paper presents the influence of production parameters and analysis of ZrC coatings production on Monel^®400 substrate. The effects of laser beam power on the microstructure, chemical composition, corrosion resistance and on selected mechanical properties such as microhardness and wear resistance were investigated. The investigation consisted of the production of composite coatings using laser processing of pre-coatings made in paste form on a nickel based alloy (Monel^®400). In the studies, a diode laser with a rated power of 3 kW was used. The laser processing was carried out using a constant laser beam scanning speed of 3 m/min and three different laser beam powers: 350, 450, 550 W. It was found that it is possible to form composite coatings on a nickel-copper alloy substrate, where the matrix is made of nickel-copper based alloy from substrate and the reinforcing phase is ZrC. Investigation was carried out for single and multiple laser tracks. Based on the studies it was found that reinforcing phase content decreased as laser beam power increased. A similar relationship was found for all the other investigated properties such as microhardness, corrosion resistance, and wear resistance. As laser beam power increases, the microhardness of the Ni-Cu-based matrix decreases. However, is still greater than for the Monel^®400 substrate. It was found that the amount of hard carbide phases in the Ni-Cu-based matrix affects the corrosion and wear resistance of the coatings. Full article

Phase and domain structures in ferroelectric materials play a vital role in determining their dielectric and piezoelectric properties. Ferroelectric thin films with coexisting multiple domains or phases often have fascinating high sensitivity and ultrahigh physical properties. However, the control of the coexisting multiple domains is still challenging, thus necessitating the theoretical prediction. Here, we studied the phase coexistence and the domain morphology of PbTiO₃ epitaxial films by using a Landau–Devonshire phenomenological model and canonic statistical method. Results show that PbTiO₃ films can exist in multiple domain structures that can be diversified by the substrates with different misfit strains. Experimental results for PbTiO₃ epitaxial films on different substrates are in good accordance with the theoretical prediction, which shows an alternative way for further manipulation of the ferroelectric domain structures. Full article

Metal nanoparticles (NPs) are increasingly being used in many areas, e.g., industry, pharmacy, and biomedical engineering. NPs can be obtained through chemical and biological synthesis or using physical methods. AgNPs, AuNPs, CuNPs, FeNPs, MgNPs, SnO₂NPs, TiO₂NPs, and ZnONPs are the most commonly synthesized metal nanoparticles. Many of them have anti-microbial properties and documented activity supported by many tests against some species of pathogenic bacteria, viruses, and fungi. AgNPs, which are used for the production of commercial self-sterilizing packages, are one of the best-explored nanoparticles. Moreover, the EFSA has approved the use of small doses of silver nanoparticles (0.05 mg Ag·kg⁻¹) to food products. Recent studies have shown that metal NPs can be used for the production of coatings to prevent the spread of the SARS-CoV-2 virus, which has caused the global pandemic. Some nanoparticles (e.g., ZnONPs and MgONPs) have the Generally Recognized As Safe (GRAS) status, i.e., they are considered safe for consumption and can be used for the production of edible coatings, protecting food against spoilage. Promising results have been obtained in research on the use of more than one type of nanometals, which prevents the development of pathogen resistance through various mechanisms of inactivation thereof. Full article

High-entropy materials with tailorable properties are receiving increasing interest for energy applications. Among them, (disordered) rock-salt oxyfluorides hold promise as next-generation cathodes for use in secondary batteries. Here, we study the degradation behavior of a high-entropy oxyfluoride cathode material in lithium cells in situ via acoustic emission (AE) monitoring. The AE signals allow acoustic events to be correlated with different processes occurring during battery operation. The initial cycle proved to be the most acoustically active due to significant chemo-mechanical degradation and gas evolution, depending on the voltage window. Irrespective of the cutoff voltage on charge, the formation and propagation of cracks in the electrode was found to be the primary source of acoustic activity. Taken together, the findings help advance our understanding of the conditions that affect the cycling performance and provide a foundation for future investigations on the topic. Full article

We report the impact of oxygen (O₂) plasma time on an amorphous indium–gallium–zinc oxide (a-IGZO) thin-film surface that was carried out before TEOS deposition in order to optimize the performance of thin-film transistors (TFTs). TheO₂ plasma time of 60 s possessed the largest on/off current ratio of >10⁸, with a field-effect mobility (µ_FE) of 8.14 cm² V⁻¹ s⁻¹, and the lowest subthreshold swing (S.S.) of 0.395 V/decade, with a threshold voltage (V_th) of −0.14 V. However, increases in I_off and S.S. and decreases in the µ_FE were observed for the longer O₂ plasma time of 120 s. As the O₂ plasma time increased, the reduction in the carrier concentration in the IGZO channel layer may have resulted in an increase in V_th for the IGZO TFT devices. With an increase in the O₂ plasma time, the surface roughness of the IGZO channel layer was increased, the carbon content in the TEOS oxide film was reduced, and the film stoichiometry was improved. The SIMS depth profile results showed that the O/Si ratio of TEOS oxide for the sample with the O₂ plasma time of 60 s was 2.64, and its IGZO TFT device had the best electrical characteristics. In addition, in comparison to the IGZO TFT device without O₂ annealing, larger clockwise hysteresis in the transfer characteristics revealed that a greater number of electrons were trapped at the interface between TEOS oxide and the a-IGZO channel layer. However, hysteresis curves of the O₂-annealed IGZO TFTs with various O₂ plasma times were greatly reduced, meaning that the electron traps were reduced by O₂ annealing. Full article

High-entropy alloys (HEAs) are called also alloys without a main component or multiprincipal alloys. They consist of five, six or more components in more or less equal proportions and possess unique properties. Several dozens of thousands of publications have already been devoted to bulk HEAs, while HEA coatings are just beginning to develop. More than half of the works on the deposition of HEA coatings are devoted to laser cladding. In the laser cladding process, a mixture of powders on a substrate is melted in a focused laser beam, which sequentially scans the substrate. In the heated zone, the powder mixture melts. At the end of the crystallization process, a solidified polycrystal and a small amount of residual melt are found in the heated zone. It is possible that the grain boundaries (GBs) in the solidified polycrystal are incompletely or fully wetted by this liquid phase. In this way, the GB wetting with a melt determines the morphology and microstructure of HEAs coatings. This review analyzes GB wetting in single-phase HEAs, as well as in HEAs containing two or more phases. We analyze how the HEAs’ composition, laser scanning speed, laser beam power, external magnetic field or ultrasonic impact affect the microstructure and GB wetting. It is also shown how the microstructure and GB wetting change over the thickness of the rather thick as well as multilayer coatings deposited using a laser cladding. Full article

The use of suitable secondary raw materials as fillers in progressive, protective agents primarily intended for horizontal concrete construction is very effective not only from the ecological but also from the economic point of view. The impact of using various types of waste glass as fillers on the mechanical parameters of epoxy coatings was experimentally verified. Assessing the dependency of the coating’s chemical resistance on the shape of the used filler’s particles was the main aim of the performed research. A solvent-free epoxy suitable for a chemically aggressive environment was selected for the experiment. These were epoxy coatings filled with a micro filler based on raw materials such as glass flakes and silica flour. Three tested formulations containing fillers with different particle shapes and characteristics were exposed to H₂SO₄, HCl, CH₂O₂ and NaOH at concentrations of 5% and 30% and evaluated after 60, 90 and 120 days. The chemical resistance assessment was carried out not only visually but also using a scanning electron microscope (SEM). Thanks to the use of the waste glass as a coating filler, tensile properties and hardness improved, and its use did not negatively affect the chemical resistance and adhesion of the epoxy coatings. It was found that the shape of the filler particles influences the resistance of the coating against a chemically aggressive environment. The epoxy coating containing pre-treated waste windshield glass (shards) showed even better properties than the reference coating. Full article

Real-time evaluation of materials’ mechanical response is crucial to further improve the performance of surfaces and coatings because the widely used post-processing evaluation techniques (e.g., fractography analysis) cannot provide deep insight into the deformation and damage mechanisms that occur and changes in coatings’ material corresponding to the dynamic thermomechanical loading conditions. The advanced in situ examination methods offer deep insight into mechanical behavior and material failure with remarkable range and resolution of length scales, microstructure, and loading conditions. This article presents a review on the in situ mechanical testing of coatings under tensile and bending examinations, highlighting the commonly used in situ monitoring techniques in coating testing and challenges related to such techniques. Full article

Active semiconductor layers of TiO₂ were synthesized via pulsed laser deposition in He, N₂, O₂, or Ar to manufacture DSSC structures. As-prepared nanostructured TiO₂ coatings grown on FTO were photosensitized by the natural absorption of the N719 (Ruthenium 535-bis TBA) dye to fabricate photovoltaic structures. TiO₂ photoanode nanostructures with increased adsorption areas of the photosensitizer (a combination with voluminous media) were grown under different deposition conditions. Systematic SEM, AFM, and XRD investigations were carried out to study the morphological and structural characteristics of the TiO₂ nanostructures. It was shown that the gas nature acts as a key parameter of the architecture and the overall performance of the deposited films. The best electro-optical performance was reached for photovoltaic structures based on TiO₂ coatings grown in He, as was demonstrated by the short-circuit current (Isc) of 5.40 mA, which corresponds to the higher recorded roughness (of 44 ± 2.9 nm RMS). The higher roughness is thus reflected in a more efficient and deeper penetration of the dye inside the nanostructured TiO₂ coatings. The photovoltaic conversion efficiency (η) was 1.18 and 2.32% for the DSSCs when the TiO₂ coatings were deposited in O₂ and He, respectively. The results point to a direct correlation between the electro-optical performance of the prepared PV cells, the morphology of the TiO₂ deposited layers, and the crystallinity features, respectively. Full article

The presence of defects like porosity and lack of fusion can negatively affect the properties of the materials manufactured by Selective Laser Melting (SLM). The optimization of the manufacturing conditions allows reducing the number of defects, but there is a limit for each manufacturing material and process. To expand the manufacturing envelope, a remelting after every layer of the SLM process has been used to manufacture Ti6Al4V alloy samples using an SLM with a CO₂ laser. The effect of this processing method on the microstructure, defects, hardness, and, especially, the corrosion properties was studied. It was concluded that the laser remelting strategy causes an increment of the α and β phases from the dissolution of metastable α’. This technique also provokes a decrease in the number of defects and a reduction of the hardness, which are also reduced with lower scanning speeds. On the other hand, all the corrosion tests show that a low scanning speed and the laser remelting strategy improve the corrosion resistance of the Ti6Al4V alloy since parameters like the Open Circuit Potential (OCP) and the Polarization Resistance (Rp) are nobler and the mass gain is lower. Full article

A simple and cost-efficient method to modify different surfaces in order to improve their bioactivity, corrosion and wear resistance proved to be sol-gel coatings. The silane layers have been shown to be effective in the protection of steel, aluminum or magnesium alloys and copper and copper alloys. Moreover, it has been found that the adding of different inorganic nanoparticles into silica films leads to increasing their performance regarding corrosion protection. In this study, we fabricated, a simple sol-gel method, transparent mono- and bi-layered hydrophobic coatings with simultaneous antibacterial, hydrophobic and anti-corrosive properties for the protection of metallic surfaces against the action of air pollutants or from biological attacks of pathogens. The first layer (the base) of the coating contains silver (Ag) or zinc oxide (ZnO) nanoparticles with an antibacterial effect. The second layer includes zinc oxide nanoparticles with flower-like morphology to increase the hydrophobicity of the coating and to improve corrosion-resistant properties. The second layer of the coating contains a fluorinated silica derivative, 1H,1H,2H,2H-perfluorooctyl triethoxysilane (PFOTES), which contributes to the hydrophobic properties of the final coating by means of its hydrophobic groups. The mono- and bi-layered coatings with micro/nano rough structures have been applied by brushing on various substrates, including metallic surfaces (copper, brass and mild steel) and glass (microscope slides). The as-prepared coatings showed improved hydrophobic properties (water CA > 90°) when compared with the untreated substrates while maintaining the transparent aspect. The corrosion resistance tests revealed significantly lower values of the corrosion rates recorded for all the protected metallic surfaces, with the lowest values being measured for the bi-layered coatings containing ZnO particles, both in the first and in the second layers of the coating. Considering the antibacterial activity, the most effective were the AOAg-II and AOZnO-II coatings, which exhibited the highest reduction of microbial growth. Full article

The preparation of the implant site in guided surgery procedure takes place without irrigation, which could lead to increased friction of the drills with the formation and release of debris or metal particles. The presence of metal particles in the peri-implant tissue could represent a trigger for macrophage activity, bone resorption processes, and consequent implant loss. According to the guided surgical protocol, the study aimed to evaluate the presence of metal particles deposited during implant site preparation. Twenty-five adult porcine ribs from the same adult individual were chosen due to their trabecular bone structure, similar to facial bones. The samples were all 8 cm (length) × 3 cm (depth) × 2 cm (width) and were further subdivided to obtain 50 elements of 4 cm × 3 cm × 2 cm. Plexiglass was used to create structures such as surgical guides so that their function could be mimicked, and the guided implant site preparation sequence could be performed with them. The drill kit used in this study is a guided surgery drill kit characterized by high wear resistance, high yield strength, and good corrosion resistance. This same kit was used 50 times in this way to prepare 50 different implant sites and evaluated at different edges and number of preparation (T0-neutral edge, T1-1 full preparation, T2-10, T3-20, T4-30, T5-40, and T6-50) by SEM-EDX to assess the presence of any metal deposition. The presence of metal residues in the implant site increased according to the cycles of use of the drills. We have observed that in the first three groups, there is no presence of metals. This is evident in groups T3 and T4. Finally, the presence of metal residues becomes significant in the study’s last two groups of samples. The study highlighted how the lack of irrigation in the work site leads the deposition of metal particles and in addition to a reduction in the efficiency of the drills, resulting in less precise cutting, altering the shape of the prepared site, and, lastly, reducing the primary stability of the implants. Full article

The article presents the results of the laser alloying process of a ductile cast iron EN-GJS 350-22 surface with titanium powder in nitrogen atmosphere. The aim of this research was to test the influence of nitrogen atmosphere on the structure and properties of the ductile cast iron surface layer produced by a laser alloying process with titanium. The laser alloying process was conducted using a Rofin Sinar DL020 2 kW high-power diode laser (HPDDL) with rectangular focus and uniform power density distribution in the focus axis. The tests of the produced surface layers included macrostructure and microstructure observations, X-ray diffraction (XRD) analysis, energy-dispersive spectroscopy (EDS) on scanning electron microscope (SEM) and transmission electron microscope (TEM), Vickers hardness and solid particle erosion according to ASTM G76-04 standard. As a result of the laser alloying process in nitrogen atmosphere with titanium powder, the in situ metal matrix composite structure reinforced by TiCN particles was formed. The laser alloying process of ductile cast iron caused the increased hardness and erosion resistance of the surface. Full article

The placement of bone–level dental implants can lead to the detachment of particles in the surrounding tissues due to friction with the cortical bone. In this study, 60 bone–level dental implants were placed with the same design: 30 made of commercially pure grade 4 titanium and 30 made of Ti6Al4V alloy. These implants were placed in cow ribs following the company’s placement protocols. Particles detached from the dental implants were isolated and their size and specific surface area were characterized. The irregular morphology was observed by scanning electron microscopy. Ion release to the medium was determined at different immersion times in physiological medium. Cytocompatibility studies were performed with fibroblastic and osteoblastic cells. Gene expression and cytokine release were analysed to determine the action of inflammatory cells. Particle sizes of around 15 μM were obtained in both cases. The Ti6Al4V alloy particles showed significant levels of vanadium ion release and the cytocompatibility of these particles is lower than that of commercially pure titanium. Ti6Al4V alloy presents higher levels of inflammation markers (TNFα and Il–1β) compared to that of only titanium. Therefore, there is a trend that with the alloy there is a greater toxicity and a greater pro-inflammatory response. Full article

AlxMoNbTa (x = 0.5, 1.0 and 1.5) refractory high-entropy alloy (RHEAs) coatings were produced on Ti6Al4V by laser cladding. Ti₂AlNb as the second phase and the solid solutions with the body center cubic structure (BCC) as the matrix were synthesized in the coatings. The average microhardness of the coatings was increased with the increase in x, along with which the fracture toughness was decreased. Wear resistance of the coatings was investigated by the dry-sliding reciprocating wear tests at room temperature in air (Si₃N₄ as the counterparts, the 10 N load for 30 min, and the 3 mm/s sliding speed). The wear rate of the coatings was decreased with x enhanced from 0.5 (6.34 × 10⁻⁵ mm³/N·m) to 1.0 (5.90 × 10⁻⁵ mm³/N·m), then slightly increased with x enhanced to 1.5 (6.18 × 10⁻⁵ mm³/N·m). Oxidation resistance was evaluated by the high-temperature oxidation tests at 1000 °C in air for 120 h. The whole mass gain of the coatings showed a slight downward tendency (61.8 mg/cm² for x = 0.5, 57.8 mg/cm² for x = 1.0 and 56.3 mg/cm² for x = 1.5). The change in wear and oxidation mechanism with x was revealed in detail. Full article

We used sol-gel and spin-coating in the original configuration of a liquid deposition process to synthesize particularly thin ZnO films (<100 nm) with nano-granular morphology, high grain orientation and variable optical properties. The concentration of the zinc salt, the concentration of the chelating agent, the nature of the solvent and the substrate material have been identified as key parameters that determine the microstructure of the deposited layer and thus its final properties. The thorough and practical examination of the effects of the synthesis parameters evidenced a three-step growth mechanism for these ZnO thin films: (i) a reaction of precursors, (ii) a formation of nuclei, and (iii) a coalescence of nanoparticles under thermal annealing. The growth of these very thin films is thus conditioned by the interaction between the liquid phase and the substrate especially during the initial steps of the spin coating process. Such thin ZnO films with such nano-granular morphology may be of great interest in various applications, especially those requiring a large active surface area. Full article

Additive manufacturing (AM), for example, directed energy deposition (DED), may allow the processing of self-healing metal–matrix composites (SHMMCs). The sealing of cracks in these SHMMCs would be achieved via the melting of micro-encapsulated low melting point particulates (LMPPs), incorporated into the material during AM, by heat treatment of the part during service. Zn-Al alloys are good candidates to serve as LMPPs, for example, when the matrix of the MMC is made of an aluminum alloy. However, such powders should first be encapsulated by a thermal and diffusion barrier. Here, we propose a sol–gel process for encapsulation of a custom-made ZA-8 (Zn92Al8, wt.%) core powder in a ceramic alumina (Al₂O₃) shell. We first modify the surface of the ZA-8 powder with (12-phosphonododecyl)phosphonic acid (Di-PA) hydrophobic self-assembled monolayer (SAM) in order to prevent extensive hydrogen evolution and formation of non-uniform and porous oxide/hydroxide surface layers during the sol–gel process. Calcination for 1 h at 500 °C is found to be insufficient for complete boehmite-to-γ(Al₂O₃) phase transformation. Thermal stability tests in an air-atmosphere furnace at 600 °C for 1 h result in melting, distortion, and sintering into a brittle sponge (aggregate) of the as-atomized powder. In contrast, the core/shell powder is not sintered and preserves its spherical morphology, with no apparent “leaks” of the ZA-8 core alloy out of the ceramic encapsulation. Full article

The primary objective of this study was to investigate and compare the surface topography of hard coatings deposited by three different physical vapor deposition methods (PVD): low-voltage electron beam evaporation, unbalanced magnetron sputtering and cathodic arc evaporation. In these deposition systems, various ion etching techniques were applied for substrate cleaning. The paper summarizes our experience and the expertise gained during many years of development of PVD hard coatings for the protection of tools and machine components. Surface topography was investigated using scanning electron microscopy (SEM), atomic force microscopy (AFM), scanning transmission electron microscopy (STEM) and 3D stylus profilometry. Observed similarities and differences among samples deposited by various deposition methods are discussed and correlated with substrate material selection, substrate pretreatment and deposition conditions. Large variations in the surface topography were observed between selected deposition techniques, both after ion etching and deposition processes. The main features and implications of surface cleaning by ion etching are discussed and the physical phenomena involved in this process are reviewed. During a given deposition run as well as from one run to another, a large spatial variation of etching rates was observed due to the difference in substrate geometry and batching configurations. Variations related to the specific substrate rotation (i.e., temporal variations in the etching and deposition) were also observed. The etching efficiency can be explained by the influence of different process parameters, such as substrate-to-source orientation and distance, shadowing and electric field effects. The surface roughness of PVD coatings mainly originates from growth defects (droplets, nodular defects, pinholes, craters, etc.). We briefly describe the causes of their formation. Full article

The present study aimed to produce bio-active packaging materials made of whey proteins (WPs) and essential oil (EO) extracted from Thymbra (Satureja capitata, L.), one of the most popular Palestinian wild plants. In this study, two different Thymbra leaves from Nablus and Qabatiya in Palestine were collected and analyzed for EOs by gas chromatography and mass spectrometry. Based on the analysis, two EOs, namely, TEO1 and TEO2, were extracted, and it was found that both samples primarily contain γ-terpinene and carvacrol, whereas p-cymene was detected only in TEO1. The antimicrobial activity of TEO1 and TEO2 was evaluated by microbroth microdilution assays against pathogenic bacteria and yeast. Based on the results, TEO1 exhibited potent antimicrobial activity against the test strains. Besides, TEO1 was chosen to functionalize WP-based films at different concentrations (0.1%, 0.4%, and 0.8% v/v of Film Forming Solutions). Film mechanical property investigation showed a marked reduction in the tensile strength and Young’s modulus at 0.8% TEO1. In contrast, its elongation at break value was significantly (p < 0.05) increased due to the plasticizing effect of the EO. Moreover, the film transparency was found to be significantly (p < 0.05) reduced by increasing TEO1 concentrations. Finally, microbiological investigations indicated that film antimicrobial activity against both gram-positive and gram-negative bacteria increased dose-dependently. The overall results open interesting perspectives for employing these films as preservative materials in food packaging. Full article

The restoration of paintings always involves the removal of darkened superficial layers, which are mainly due to dust deposition and aged varnishes. As cleaning is an irreversible and invasive treatment, physical methods (i.e., laser cleaning) instead of chemical ones are frequently suggested to reduce side effects on pictorial layers. Among the most employed laser systems, the free-running Er:YAG laser is considered very suitable for fine arts cleaning. This laser works at 2.94 μm, at which only –OH and –NH bonds in molecules are excited. This character can become a disadvantage when pigments with these functional groups are present. To understand the potential of the Er:YAG laser in such situations or in the presence of degradable pigments, the effectiveness of varnish removal from paintings prepared with egg yolk as the binder and cinnabar and lead white as the pigments were systematically investigated. Different cleaning conditions were used, and a hyperspectral sensor was innovatively used as a rapid, in situ and non-destructive technique to assess the effects of laser ablation, besides microscopic analysis. Though results obtained show all these pigments are sensitive to this laser radiation, satisfactory cleaning can be achieved without damaging the pictorial layer. The best cleaning conditions were 0.5 W of power (50 mJ and 10 Hz for energy and frequency), with 2-propanol as the wetting agent. Full article

Cu₃₀Al₇₀ and Ag₃₀Al₇₀ multilayer precursor films were prepared by magnetron sputtering, respectively. Then the nanoporous Cu/Ag multilayer composite films were successfully prepared by selecting the appropriate H₂SO₄ solution as the dealloying solution. It was found that the nanoporous structure was stable in the dealloying solution. The morphology and structure of nanoporous multilayer films are mainly related to the phase composition of precursors. The structure of nanoporous multilayers can be simply regarded as the superposition of single-layer structures. Our work shows that nanoporous multilayers can be well-prepared by magnetron sputtering combined with dealloying. Full article

Traditional refractory materials such as nickel-based superalloys have been gradually unable to meet the performance requirements of advanced materials. The Mo-Si-based alloy, as a new type of high temperature structural material, has entered the vision of researchers due to its charming high temperature performance characteristics. However, its easy oxidation and even “pesting oxidation” at medium temperatures limit its further applications. In order to solve this problem, researchers have conducted large numbers of experiments and made breakthrough achievements. Based on these research results, the effects of rare earth elements like La, Hf, Ce and Y on the microstructure and oxidation behavior of Mo-Si-based alloys were systematically reviewed in the current work. Meanwhile, this paper also provided an analysis about the strengthening mechanism of rare earth elements on the oxidation behavior for Mo-Si-based alloys after discussing the oxidation process. It is shown that adding rare earth elements, on the one hand, can optimize the microstructure of the alloy, thus promoting the rapid formation of protective SiO₂ scale. On the other hand, it can act as a diffusion barrier by producing stable rare earth oxides or additional protective films, which significantly enhances the oxidation resistance of the alloy. Furthermore, the research focus about the oxidation protection of Mo-Si-based alloys in the future was prospected to expand the application field. Full article

LiFePO₄ (LFPO)has great potential as the cathode material for lithium-ion batteries; it has a high theoretical capacity (170 m·A·h·g⁻¹), high safety, low toxicity and good economic benefits. However, low conductivity and a low diffusion rate inhibit its future development. To overcome these weaknesses, three-dimensional carbon-coated LiFePO₄ that incorporates a high capacity, superior conductivity and low volume expansion enables faster electron transport channels. The use of Cetyltrimethyl Ammonium Bromid (CTAB) modification only requires a simple water bath and sintering, without the need to add a carbon source in the LFPO synthesis process. In this way, the electrode shows excellent reversible capacity, as high as 159.8 m·A·h·g⁻¹ at 2 C, superior rate capability with 97.3 m·A·h·g⁻¹ at 5 C and good cycling ability, preserving ~84.2% capacity after 500 cycles. By increasing the ion transport rate and enhancing the structural stability of LFPO nanoparticles, the LFPO-positive electrode achieves excellent initial capacity and cycle life through cost-effective and easy-to-implement carbon coating. This simple three-dimensional carbon-coated LiFePO₄ provides a new and simple idea for obtaining comprehensive and high-performance electrode materials in the field of lithium cathode materials. Full article

Compared to aluminum nitride (AlN) with simple stoichiometry, lead zirconate titanate thin films (PZT) are the other promising candidate in advanced micro-electro-mechanical system (MEMS) devices due to their excellent piezoelectric and dielectric properties. The fabrication of PZT thin films with a large area is challenging but in urgent demand. Therefore, it is necessary to establish the relationships between synthesis parameters and specific properties. Compared to sol-gel and pulsed laser deposition techniques, this review highlights a magnetron sputtering technique owing to its high feasibility and controllability. In this review, we survey the microstructural characteristics of PZT thin films, as well as synthesis parameters (such as substrate, deposition temperature, gas atmosphere, and annealing temperature, etc.) and functional proper-ties (such as dielectric, piezoelectric, and ferroelectric, etc). The dependence of these influential factors is particularly emphasized in this review, which could provide experimental guidance for researchers to acquire PZT thin films with expected properties by a magnetron sputtering technique. Full article

Electromagnetic light from the Sun is the largest source, and the cleanest energy available to us; extensive efforts have been dedicated to developing science and engineering solutions in order to avoid the use of fossil fuels. Solar energy transforms photons into electricity via the photovoltaic effect, generating about 20 GW of energy in the USA in 2020, sufficient to power about 17 million households. However, sunlight is erratic, and technologies to store electric energy storage are unwieldy and relatively expensive. A better solution to store energy and to deliver this energy on demand is storage in chemical bonds: synthesizing fuels such as H₂, methane, ethanol, and other chemical species. In this review paper we focus on titania (TiO₂) nanotubes grown through electrochemical anodization and various modifications made to them to enhance conversion efficiency; these semiconductors will be used to implement the synthesis of H₂ through water splitting. This document reviews selected research efforts on TiO₂ that are ongoing in our group in the context of the current efforts worldwide. In addition, this manuscript is enriched by discussing the latest novelties in this field. Full article

Pectin is a biocompatible polysaccharide with intrinsic biological activity, which may exhibit different structures depending on its source or extraction method. The extraction of pectin from various industrial by-products presents itself as a green option for the valorization of agro-industrial residues by producing a high commercial value product. Pectin is susceptible to physical, chemical, and/or enzymatic changes. The numerous functional groups present in its structure can stimulate different functionalities, and certain modifications can enable pectin for countless applications in food, agriculture, drugs, and biomedicine. It is currently a trend to use pectin to produce edible coating to protect foodstuff, antimicrobial bio-based films, nanoparticles, healing agents, and cancer treatment. Advances in methodology, use of different sources of extraction, and knowledge about structural modification have significantly expanded the properties, yields, and applications of this polysaccharide. Recently, structurally modified pectin has shown better functional properties and bioactivities than the native one. In addition, pectin can be used in conjunction with a wide variety of biopolymers with differentiated properties and specific functionalities. In this context, this review presents the structural characteristics and properties of pectin and information on the modification of this polysaccharide, its respective applications, perspectives, and future challenges. Full article

There is an urgent need to increase the food supplies to fulfil the demands of future generations as the population of the world is expected to grow beyond 10 billion by 2050. An essential component for ensuring global food security is to reduce food losses during the post-harvest stage. Active edible coatings and films are a promising sustainable preservation technology for shelf-life extension of food products by hindering decay kinetics of minimally processed fruits and vegetables (F&V), by restricting the mass transfer of moisture, aroma, or gases and carrying an active compound, such as an antioxidant or antimicrobial. Active protein-based coatings and films have the potential to extend the shelf-life of food products by decreasing their respiration rates, as they exhibit an excellent gas barrier and good mechanical properties as compared to other biopolymeric packaging. Among protein-based biopolymers, casein and its derivatives as packaging films have been extensively studied due to their low cost, complete biodegradability, and availability. Currently, there is no review study focusing on caseinate-based active coating and film, thus, this review aims to give insights on the composition, rheology, structure, and properties of caseinate-based formulations by critically discussing the results presented in the literature. A methodological approach was followed to obtain relevant literature to discuss the influence of additives on the shelf-life of F&V. Furthermore, changes in secondary structure of casein were observed after incorporation of bioactive compounds (i.e., phenolic acids). Likewise, there is a need to explore chemical interactions among bioactive compounds and biopolymer material by using in silico and laboratory trials as food additives have shown to influence the physicochemical properties of film and shelf-life of food products. Full article

In recent years, nanostructures have improved the performance of solar cells and are regarded as the most promising microstructures. The optical properties of PEDOT:PSS/c-Ge hybrid solar cells (HSCs) based on the octagon germanium nanoparticles (O-GNPs) were numerically analyzed using the finite-difference time-domain (FDTD) method. The optimal structure of the hybrid solar cell is determined by changing the thickness of the organic layer and structural parameters of nanoparticles to enhance the optical absorption and eventually achieve high broadband absorption. By changing the structure parameter of O-GNPs, we studied its effect on solar cells. The optimization of geometric parameters is based on maximum absorption. The light absorption of our optimized HSCs is basically above 90% between 200 and 1500 nm. PEDOT:PSS is placed on top of O-GNPs to transmit the holes better, allowing O-GNPs to capture a lot of photons, to increase absorbance value properties in the AM1.5 solar spectral irradiated region. The transmittance is increased by adding poly-methyl methacrylate (PMMA). At the same time, the electrical characteristics of Ge solar cells were simulated by DEVICE, and short-circuit current (Jsc), open-circuit voltage (Voc), maximum power (Pmax), filling coefficient (FF) and photoelectric conversion efficiency (PCE) were obtained. According to the optimization results after adjusting the structural parameters, the maximum short-circuit current is 44.32 mA/cm²; PCE is 7.84 mW/cm²; FF is 69%. The results show that the O-GNPs have a good light trapping effect, and the structure design has great potential for the absorption of HSCs; it is believed that the conversion efficiency will be further improved through further research. Full article

In this thesis, Cu₂O nanochains were synthesized by thermal decomposition with copper formate-octylamine as the precursor, oleic acid and oleylamine as the catalyst stabilizer agent and paraffin as the solvent. The phase structure and micromorphology of Cu₂O nanochains were characterized by X-ray diffraction and transmission electron microscopy. The effect of reaction time and concentration of the precursor on the Cu₂O nanochains were discussed, and the formation mechanism of the Cu₂O nanochains was analyzed. The results show that Cu₂O nanochains were self-assembled by Cu₂O nanocrystals; with the extension of the reaction time, Cu₂O nanochains gradually become granular; increasing the concentration of the precursor will increase the entanglement degree of the nanochains. Oleic acid contributes to the formation of Cu₂O, and oleylamine plays a directional role in the formation of nanochains. On the basis of those phenomenon, a comparison of the Cu₂O nanochain-water nanofluids with that of a water-based liquid showed that after irradiating for 3000 s, the temperature of nanofluids reached 91.1 °C while the water was only 75.7 °C. This demonstrates the better performance of the Cu₂O nanochain-water nanofluid in the ability of light absorption, thermal conductivity and photothermal conversion. Full article

Rare earth-doped ceria thin films are currently thoroughly studied to be used in miniaturized solid oxide cells, memristive devices and gas sensors. The employment in such different application fields derives from the most remarkable property of this material, namely ionic conductivity, occurring through the mobility of oxygen ions above a certain threshold temperature. This feature is in turn limited by the association of defects, which hinders the movement of ions through the lattice. In addition to these issues, ionic conductivity in thin films is dominated by the presence of the film/substrate interface, where a strain can arise as a consequence of lattice mismatch. A tensile strain, in particular, when not released through the occurrence of dislocations, enhances ionic conduction through the reduction of activation energy. Within this complex framework, high pressure X-ray diffraction investigations performed on the bulk material are of great help in estimating the bulk modulus of the material, and hence its compressibility, namely its tolerance toward the application of a compressive/tensile stress. In this review, an overview is given about the correlation between structure and transport properties in rare earth-doped ceria films, and the role of high pressure X-ray diffraction studies in the selection of the most proper compositions for the design of thin films. Full article

A Plasma-Enhanced Chemical Vapor Deposition was chosen in order to deposit an organic thin film on polyethylene terephthalate monofilament to increase its adhesion with the rubber compound in a tire. The aim of the work is to find an alternative “green” method to the classical chemical dipping with Resorcinol Formaldehyde Latex: plasma treatments are environmentally friendly and easy to use. 2-isoprepenyl-2-oxazoline (2-iox) was employed as precursor and the treatments were performed in a vacuum system, both in a continuous regime and a pulsed regime. Initially, the coatings were deposited on polyethylene terephthalate sheets to study the wettability (by the measurement of contact angle) and the thickness (by profilometer) of the plasma polymer. The chemical characterization was investigated by Infrared and X-ray Photoelectron spectroscopies. Finally, the adhesion of the polyethylene terephthalate sheets was measured by Peel Test, using the coating as adhesive and as a pre-dip. The measurement of the peel force made it possible to optimize the plasma parameters that were applied on the monofilament. The adhesion was estimated by the measure of the extraction force and the evaluation of the coverage compared with those of the classical chemical treatment Resorcinol Formaldehyde Latex. Full article

Metamagnetic FeRh has been the focus of numerous studies for its highly unique antiferromagnetic (AF) to ferromagnetic (FM) metamagnetic transition. While this phase transition usually occurs above room temperature (often T_c > 400 K), both ion irradiation and strained epitaxial growth have been used to bring it to applicable temperatures. Nevertheless, cross sample variability is pervasive in these studies. Here we explore the optical and magnetic properties of 35 nm thick FeRh grown by magnetron sputter deposition simultaneously on two different single crystal substrates: epitaxially on MgO (001) and highly strained with large lattice mismatch on Al₂O₃ (1000). We then irradiate the epitaxial film with 5 keV N⁺ ions to introduce disorder (and to a lesser extent, modify chemical composition) without effecting the surface morphology. We find that the phase-transitional properties of both films are strikingly different due to the large lattice mismatch, despite being grown in tandem with nominally identical growth conditions including Fe/Rh stoichiometry, pressure, and temperature. We observe that N⁺ implantation lowers T_c by ~60 K, yielding a sample with nominally the same transition temperature as the non-epitaxial film on sapphire, yet with a significantly increased magnetic moment, a larger magnetization change and a more abrupt transition profile. We attribute these differences to the Volmer-Weber type growth mode induced by the sapphire substrate and the resulting rougher surface morphology. Full article

CH₃NH₃PbI₃ perovskite photovoltaic devices treated with a polysilane layer were fabricated and characterized. Decaphenylcyclopentasilane (DPPS) in chlorobenzene solution was deposited at the surface of the perovskite layer, and the resulting device was annealed at 140–260 °C. The photoconversion efficiencies of the DPPS-treated device remained high even after 255 days in ambient air. Raman scattering spectroscopy and ab initio molecular orbital calculations of DPPS suggested that it increased hole transport efficiency in the treated devices, which was confirmed from the high shunt resistances of the DPPS-treated devices. Full article

According to the old surface coating process of European and American furniture, the surface of modified poplar is first differentiated pre-treatment, and then the bottom color modification and material color modification are respectively applied to the modified poplar after the surface differentiation treatment. The visual physical quantity and physical and chemical properties were measured and compared with mahogany, which is commonly used in old furniture in Europe and America to explore the effect of colorants and coloring steps, as well as different surface pretreatments on the coloring effect. Finally, it is concluded that continuous coloring operations can narrow the difference in brightness and red color value in the coloring layer of modified poplar and mahogany. Continuous coloring operations increase the difference between the yellow-green color values of modified poplar and mahogany. Therefore, the coloring difference between modified poplar and mahogany was affected by the colorant and coloring steps. Through color accumulation, the gap between the two in the target color coloring effect can be reduced, thereby reducing the difference between the coloring effect of modified poplar and mahogany. Full article

The study and the restoration of a polychrome limestone statue representing the Virgin with the Child, from Palazzo Madama in Turin (NW Italy) offered interesting conservation issue related to the polychromy on stone. To preserve the pictorial layers, it was necessary to re-establish the cohesion among the different polychrome layers (original and repainted) and the adhesion between polychrome film and the stone substrate. Particular attention was paid to the choice of intervention materials, selected through a preliminary survey of the scientific literature, and then verified by laboratory tests (tape test, colorimetric test, and permeability test). The most suitable product should to be able to penetrate porosity, to consolidate the layers, to make the pictorial film adhere with the stone surface, and to avoid changes in the colour and in the permeability. The material chosen also had to ensure compatibility with the cleaning method that could only take place after the consolidation of the pictorial layers due to the problematic state of preservation. A range of products, characterised by their small particle size and low viscosity, was tested, and a micro-acrylic resin was selected and successfully applied on the polychromy of the sculpture. Full article

Thick NiTi shape memory alloy coatings (300–500 µm) were produced on graphite and AISI 304 substrates by radio frequency inductively-coupled plasma spray technology (RF-ICP) from feedstock NiTi powders. Their microstructure as well as chemical and phase composition were characterized and a methodology for the characterization of functional shape memory properties of the thick coatings was developed. The coatings exhibited cubic to monoclinic martensitic transformation and shape memory effect. The presented results prove that NiTi coatings with functional thermomechanical properties can be easily produced on structural materials by RF-ICP. Further optimization will be needed to prepare NiTi coatings with better microstructural and chemical homogeneity. Full article