The relationship between surface morphology and crystal orientation in polycrystalline films is investigated using a quantitative experimental approach that analyzes hundreds of crystals and identifies thousands of facets. Four industry-relevant electroless copper deposits used for microvia filling in high-density interconnect printed circuit boards are examined. The reliability of copper-copper interlayer connections depends critically on the surface characteristics of the electroless copper layer prior to subsequent electrodeposition. Electroless copper films deposited from baths stabilized with sodium cyanide or 2,2 '-bipyridine, each prepared with and without nickel additives, are characterized. Surface topography measured by atomic force microscopy is correlated with crystal orientation data obtained by electron backscatter diffraction to identify the crystallographic facet types present at the surface. Deposits from cyanide-stabilized baths exhibit angular surface morphologies with smooth low-index {100} and {111} facets oriented parallel to the surface. Grains with a [110] orientation display increased roughness due to alternating {110} and {100} facets. In contrast, deposits from 2,2 '-bipyridine-sta-bilized baths show more gradual facet transitions and a broader distribution of facet types. Statistical analysis reveals distinct correlations between crystal orientation and surface facet combinations.

Bioactive glasses and glass-ceramics are widely investigated for bone regeneration due to their ability to bond to bone and stimulate osteogenesis. Achieving three-dimensional (3D) interconnected macroporosity remains critical for mimicking trabecular bone architecture and promoting cell infiltration and vascularization. In this work, we report the fabrication of 3D macroporous bismuth-doped bioceramic scaffolds based on a modified Bioglass 45S5 composition, prepared via a sol-gel route combined with electrophoretic deposition on polyurethane foam templates. As bismuth has already been reported to enhance radiopacity and to present antimicrobial activity, it was introduced (0-10 mol%) to explore its role as a functional dopant in macroporous bioceramic scaffolds.The resulting scaffolds exhibit fully interconnected macroporosity with mean pore diameters ranging from 366 to 553 mu m and mean strut thickness from 112 to 176 & micro;m. Structural and chemical characterization by SEM, XRD, FTIR, XPS, and ICP-MS reveals the coexistence of crystalline and amorphous phases and the presence of bismuth in mixed coordination environments, with a predominant Bi3+ oxidation state. In vitro bioactivity tests in simulated body fluid demonstrate that scaffolds containing low bismuth contents (<= 2.5 mol% Bi2O3) retain apatite-forming ability, whereas higher bismuth concentrations significantly inhibit hydroxyapatite formation. Cell viability assays confirm good cytocompatibility across all compositions. These results demonstrate that controlled bismuth incorporation supports the fabrication of multifunctional 3D bioceramic scaffolds and identify a compositional threshold beyond which bioactivity is compromised. This study provides design guidelines for bismuth-doped, bioactive scaffolds intended for bone tissue engineering applications.

The present study focuses on the synthesis and structural analysis of poly-epsilon-caproamide (PA6), produced through anionic polymerization of epsilon-caprolactam in bulk, utilizing mono and bifunctional activators. The research investigates the physical properties of PA6 synthesized under various polymerization conditions, aiming to understand how these conditions influence the polymer's behavior. The polymerization kinetics were monitored via dynamic rheology, offering insights into the progression of epsilon-caprolactam's conversion into PA6. Microstructural changes in the PA6 samples, including variations in the degree of crystallinity and the formation of alpha and gamma crystalline structures, were systematically studied. These transformations were dependent on both the type and concentration of the activator used, as well as the specific polymerization parameters applied. The interplay between these factors significantly impacted the resulting chemical and physical structure of the PA6 samples. In the latter part of the study, hybrid composites were fabricated by reinforcing poly-epsilon-caproamide with two distinct types of fiber fabrics by reactive processing, achieving a 25% weight fraction of reinforcement. Scanning electron microscopy (SEM) revealed excellent interfacial adhesion between the fibers and the polymer matrix, confirming the effectiveness of the fabrication process and the potential of these composites for advanced material applications.

Electron backscatter diffraction (EBSD) is used to determine the orientations of crystals on sample surfaces. In conjunction with the surface topography from atomic force microscopy (AFM), the facets of the crystals can be computed. Reconciling the coordinate systems of the EBSD and AFM measurements is a challenging and time-consuming process for rough polycrystal surfaces. This paper presents a novel method for importing EBSD data into the AFM coordinate system with minimal user input. This method proceeds by simulating EBSD band contrast images from the AFM topography. Then, a mapping between this simulated and the measured EBSD band contrast image is established by least-squares fitting. With this mapping, the EBSD data are projected onto the AFM coordinate system. In addition to automatic facet type determination, this enables a statistical analysis of the relation between the orientation and surface morphology of individual crystals on polycrystal surfaces. As an application example we analyze etched copper surfaces that are obtained in intermediate steps of the production of printed circuit boards (PCBs). Based on about 150 crystals, the analysis reveals a characteristic dependence of roughness and surface features such as ridges and etch hillocks on the crystal orientation.

Anhydrous mixtures of lithium acetate and sodium acetate were investigated by differential scanning calorimetry and X-ray powder diffraction. A tentative phase diagram is derived from these data. The Li1-xNaxCH3COO system has a eutectic for the NaCH3COO molar fraction of x approximate to 0.55. The relatively low eutectic melting point at 448 K (175 degree celsius) may make this composition an interesting molten salt solvent. Peritectic reactions correspond to phases with compositions near Li4Na(CH3COO)(5) and LiNa3(CH3COO)(4). On the Li-rich side of the eutectic, the system, prepared as a glass, can crystallized deliberately. This allows checking the data validity with the first law of thermodynamics. The stability range of the supercooled liquid increases with x up to Li0.55Na0.45CH3COO. For higher sodium concentrations, the samples remain mixtures of glass and crystalline phases, with the amount of the vitreous component decreasing linearly from x = 0.45 to x = 1. The fragility of the liquid state, highest for pure LiCH3COO, decreases by a factor of two over the range 0<x<0.2, and remains constant for higher

This study focuses on how catalyst concentration, activator concentration, and initial polymerization temperature impact in-situ anionic ring-opening polymerization (AROP) of omega-lauryllactam. Catalyst and activator roles are fulfilled by NaH and toluene-2,4-diisocyanate (TDI), respectively, with varying catalyst/activator ratios to assess the influence of a bifunctional activator on the polymerization process. The materials produced undergo a thorough analysis, with a specific emphasis on solidification time. The examination extends to scrutinizing how different concentrations of catalyst/activator and polymerization temperatures affect crucial physical and chemical parameters. The study identifies NaH-6 mol%/TDI-3 mol% as the optimal formulation for solidification among the three explored temperatures. Notably, at 180 and 200 degrees C, PA12 exhibits enhanced monomer conversion when a catalyst/activator ratio of 1.7 or 2 is applied. These findings underscore the significant impact of the catalyst/activator ratio and their individual concentrations on the polymer's final properties. This influence extends to factors such as crystallinity, polymer chain regularity, and dynamic mechanical properties. Additionally, the experimental conditions utilized for anionic polymerization are observed to shape the characteristics of PA12.

Bioglass 58S is a bioactive material that can be used to help bone regeneration. In this article we present the fabrication of macroporous 58S Bioglass scaffolds with 3D interconnected porosity, that were prepared by immersing a PMMA microsphere monolith into a 58S sol. The resulting composite samples were calcined leaving macroporous 58S BG scaffolds, which were characterized by SEM, DSC-TGA, XRD and FTIR spectroscopy. These were compared to 58S Bioglass powders prepared using the same sol and calcined under the same conditions. Apart from the presence of macropores, the main difference between the two types of Bioglass 58S samples was the presence of carbonate species in the samples prepared using the PMMA monolith. Finally, the bioactivity of the macroporous 58S scaffolds and 58S powders were evaluated using SBF and cell viability assays. The macroporous 58S scaffolds were found to greatly improve the cell viability compared to the 58S powders which could be attributed to the presence of carbonate species.

Abstract Steaming‐assisted conversion route, a new strategy, is first adapted for the synthesis of highly crystallized anatase TiO2 2D inverse opal (IO) monolayer films, and then to Nb‐doped TiO2 and W‐doped TiO2 2D IO monolayer films. Pure water, ammonia, or HCl solutions are used as a source of steaming vapor to convert dry films of amorphous TiO2 IO, NbCl5/TiO2, and WCl6/TiO2 composite IOs into anatase TiO2, Nb‐doped TiO2, and W‐doped TiO2 IO films. This new strategy renders possible the doping of metal ions within the framework of the anatase TiO2 IO films under low temperature and liquid‐free conditions. Further, the ordered array structure of the IO films is also effectively retained. The low steaming conversion temperature allows high dopant rates of homogeneously distributed heteroatoms, resulting in Nb doping as high as ≈34%. The thus prepared TiO2, Nb‐doped TiO2, and W‐doped TiO2 anatase IO films are successfully used as active electrodes in the fabrication of electrochromic devices.

To be able to regulate the anionic oxygen position in ferrites, an original compositing method is developed by introducing a porous p-type phase in the n-type matrix of ferrite spinel semiconductors. A result of this method is the synergetic effect of the enhanced mass and charge transport that impacted the morphology and anionic oxygen position within the MgFe2O4 structure. Our hypothesis is that fine tuning of the anionic oxygen position in ferrites allows us to regulate their physicochemical properties significantly, with the implications for diverse applications. The electron exchange interaction (J) between O-centered and octahedral- occupying iron (Fe)-centered orbitals affected both the electrical and magnetic properties of the matrix significantly, supporting our hypothesis. The three-dimensional variable range electron hopping is one such effect.

The distribution of facet types affects the functionality of the surfaces of polycrystalline films. However, we are not aware of a previously published convenient method to determine their distribution. This work describes and demonstrates a process to determine and map the Miller indexes (hkl) of crystal facets exposed at the surfaces of polycrystalline films. To find facet types in non-trivial cases, one must know the orientation of the crystal and the direction in which the facet is facing. The method presented here combines the crystal orientations obtained with electron backscatter diffraction with the topography of the same sample area measured with atomic force microscopy. A challenging step is to transfer the data from the two instruments into a common coordinate system. The sequence of steps in the data processing is presented, with methods to verify the results. The process is illustrated with the analysis of an etched copper clad laminate (CCL) and an electroless Cu film deposited on the CCL. This example relates to facet selection in electroless and galvanic plating processes in printed circuit board production, where an uncontrolled transition from epitaxial to non-epitaxial growth can lead to surfaces with unacceptable roughness.

Electroless Ni-P films (19, 13 and 6 at. % P), Ni95P4W1.1 and Ni91P5Mo4W0.4 deposits on Cu(Zn) substrates were annealed at temperatures up to 450 degrees C. Fracture toughness was evaluated by observing the level of cracking after indentation with a Vickers indenter. The films are mixtures of amorphous a-NiP, fcc-Ni and Ni3P, and their amounts vary with film composition and annealing temperature. The amounts of these phases, as well as film stress, crystallite sizes, preferred orientation and peak shapes were determined with X-ray diffraction (XRD). In the as-made state, all films are ductile and do not crack upon indentation. We show that embrittlement coincides with the transformation of a-NiP to Ni3P, and it is most severe for alloys with high phosphorus content. For Ni91P5Mo4W0.4, there is no Ni3P precipitation after annealing. Annealing increases the hardness of this deposit, and its fracture toughness remains high. Alloyed W and Mo are mostly dissolved in the fcc-Ni phase. Without Mo and W, the shape of fcc XRD peaks changes upon heating, whereas, in the Ni91P5Mo4W0.4, deposit constant peak shapes indicate a constant dislocation density. Independent of composition, film stress changes gradually with increasing annealing temperature from tensile to compressive due to differential thermal expansion of film and substrate.

A new strategy, the ‘alkaline steaming-assisted conversion route,’ has been developed to synthesize pure NiFe2O4 and CoFe2O4 nanoparticles by using ethylenediamine, together with ammonia, collectively as the alkaline steaming vapor.

We report the changes of atactic polystyrene (a-PS) upon annealing below the glass transition based on X-ray scattering, volume, and differential scanning calorimetry measurements of samples in the quenched and annealed states. Upon relaxation, an increase of the main diffuse diffraction peak and a decrease of the polymerization peak, typical for a-PS, are proportional to the enthalpy changes. The relaxation of enthalpy corresponds to a change of the fictive temperature by 6.1 K for annealing at 80 degrees C for 24 h. The changes of the fictive temperature derived from the X-ray structure factor are between 5.4 and 6.8 K, depending on the range of scattering vector. The relaxation signal has a zero crossing at low scattering angles. The volume of the samples, measured at ambient conditions, did not change upon relaxation. We attribute these observations to localized relaxation processes that involve a small number of phenyl groups.

A cyanide-stabilized electroless copper plating process with nickel as a stress-regulating additive was investigated. Small amounts of nickel or cyanide increase the deposition rate, while large amounts of cyanide decrease the deposition rate. The steady-state mixed potential shifts by – 0.23 V when about 0.05 at.% nickel is co-plated with copper. Cyanide by itself does not change the mixed potential. If nickel is also present, cyanide causes an anodic shift by + 0.09 V. Nickel changes the stress during deposition towards tensile, while cyanide changes it towards compressive. Both nickel and cyanide accelerate the transition to steady-state plating conditions.

The production of highly flexible printed circuit boards requires copper plating on roll annealed (RA) Cu foils with strong (001) crystallographic orientation, with electroless copper plating followed by galvanic copper plating. Concurrent epitaxial and polycrystalline crystal growth during galvanic plating has to be avoided because it leads to unacceptably rough sample surfaces, with polycrystalline regions protruding. Two electroless plating processes are compared in terms of their interaction with the subsequent galvanic plating step. Plating tests are carried out with RA substrates and (111), (011) and (001) copper single crystals. Crystallite orientation distributions are determined by measuring X-ray diffraction pole figures for the substrates, as well as the substrates with galvanic deposits, electroless deposits and combined electroless and galvanic deposits. One of the electroless processes creates Cu {111} planes parallel to the sample surface, thereby reliably disrupting epitaxy between the substrate surface and the growing galvanic film. Moderate constant stress in the electroless processes enables good mechanical adhesion to the substrate.

Composite materials aimed at bone tissue engineering need to have suitable bioactivity in order to promote cell proliferation and adhesion. In this article, we study the potential of boronic acids to improve the bioactivity of chitosan-based composite materials. Samples were prepared using boronic acid functionalised chitosan and Bioglass 45S5. These composite materials, prepared by freeze-drying, exhibit 3D interconnected porosity. The materials were fully characterized using scanning electron microscopy (SEM), FT-IR and x-ray diffraction. Their bioactivity was assessed by immersion in simulated body fluid and cell cytotoxicity assays. Composite materials containing boronic acid show no toxicity for Mouse Sertoli (TM4), Human embryonic kidney 293 (Hek293) and Human bone marrow/stroma (HS-5) cells, as opposed to composites containing non-functionalised chitosan.

In this work anodic NiO electrochromism is investigated under two potential cycling modes: i) the response between coloration and bleaching in increasing potential steps (switching); ii) the stepwise modulation to coloration with increasing potential and back to bleaching (modulation). The films’ response is investigated by optical spectroscopy, colorimetry studies, Raman spectroscopy, XRD, cyclic voltammetry and chronoamperometry. Using the CIE (Commisson International de l’Éclairage) system of colorimetry the color stimuli of the films and the changes that take place upon reversible switching/modulation are recorded under various potentials. As shown by the CIE 1931 xy chromaticity coordinates, when NiO film is oxidized, a sharp decrease in luminance is observed. Optical measurements, performed as a function of applied potential, show excellent contrast between colored and bleached states. Up to now, for NiO, the coloration mechanism was considered as a surface phenomenon. Here, for the first time we show that upon ion insertion/extraction the lattice constant of NiO changes, proving that the EC coloration mechanism involves the unit cells in the bulk material. Furthermore, the fraction ratio of Li to Ni atoms (LiNi) is proposed. Considering the actual film fabrication conditions, the x value in LixNiO is found to be equal to 0.0046.

A combined experimental and simulation study is carried out to compare the properties of amorphous Ni100-xPx alloys obtained by electroless deposition and rapid melt-quenching. The onset of crystallization of experimental electroless deposited amorphous films is measured by differential scanning calorimetry experiments. Classical molecular dynamics simulations using Embedded Atom Model-based interactions are performed to obtain glassy Ni-P by melt-quenching the liquid with various quenching rates, as well as via low-energy chemical deposition to mimic experimental electroless deposition. It is shown that the deposited amorphous and glassy states display similar short-range order. The amorphous deposit corresponds to a glassy state obtained with a cooling rate of 10(9) K s(-1), indicating that deposition yields generally more relaxed amorphous structures. The appearance of phosphorus-enriched surface on the simulated deposited thin film, comparable to experimental observations, is discussed.

Hydrogen co-deposition in electroless copper is a cause of embrittlement, voids and blisters. Hydrogen release in the plating bath and its incorporation into the copper films were measured. The amount of hydrogen in the films was determined by monitoring its release over several days at ambient conditions. The mixed potential and the film stress were recorded during film deposition. Adding nickel ions in the plating bath lowers the mixed potential, and it reduces hydrogen incorporation from about 25 at.% to 0.01 at.%. However, the total amount of hydrogen generated per amount of plated copper remains unchanged. For films plated without nickel, the biaxial stress of the films and their hydrogen content are proportional with 3.2 +/- 0.3 MPa/at. % H.

Nanostructured feedstock material results in better surface protective coatings under high-temperature oxidation erosion environment. This research paper focuses on synthesizing ceramic-metallic (cermet) nanostructured Al2O3-Ni(Cr) feedstock particles using high-energy mechanical alloying (HE-MA) powder processing technology. The underscoring particle design objectives were twofold: (1) reduce the ceramic oxide grain size below 20 nm, and more pressingly (2) embed nano-scaled grains inside metal/alloy binder particles, hence the nanostructured cermet particles. The novelty of this research work lies in the successful embedment of nanostructured Al2O3 grains into the micron sized Ni(Cr) metallic binder matrix. In a SPEX mill with a milling speed of 1200 rpm along with variation in milling time following two separate material design compositions (design of experiments) it was possible to meet the stated objectives. Results show good conformance between the experimental and analytical data in terms of obtaining Al2O3 grain reinforced Ni(Cr) nanostructured particles with mean grain and particle sizes standing at 19 +/- 1.15 nm and 15 mu m +/- 4.6 mu m, respectively, after 12 h of milling. (C) 2018 Elsevier B.V. All rights reserved.