Here, the authors report a detailed method of growing LaAlGe, a nonmagnetic Weyl semimetal, thin film on silicon(100) substrates by molecular beam epitaxy and their structural and electrical characterizations. About 50-nm-thick LaAlGe films were deposited and annealed for 16 h in situ at a temperature of 793 K. As-grown high-quality films showed uniform surface topography and near ideal stoichiometry with a body-centered tetragonal crystal structure. Temperature-dependent longitudinal resistivity can be understood with dominant interband s–d electron–phonon scattering in the temperature range of 5–40 K. Hall measurements confirmed the semimetallic nature of the films with an electron-dominated charge carrier density of ~7.15 × 1021 cm−3 at 5 K.

β-Alanine and its derivatives are important starting materials for the preparation of peptides or compounds with biological activity. In this work, the authors are presenting a new approach for the synthesis of N-alkyl-β-amino acids and N-alkyl-β-amino esters using dendrimeric intermediates in a one-pot reaction, with friendly reaction conditions. Dendrimeric compounds, with a pentaerythritol core, were easy prepared and used to obtain the β-amino acid derivatives and β-amino esters with good yields. This paper presents the first reaction where dendrimers are used for synthesizing organic compounds. Spectroscopic characterization by 1H- and 13C-NMR of dendrimers and final products is also presented.

The lifetime of cyclically loaded devices is often limited by the fatigue resistance of their individual phases. An advanced method is presented for measuring the high-cycle fatigue behavior of materials at the micrometer scale using a nanoindenter. It is based on the cyclic deflection of focused ion beam-fabricated microcantilevers using the continuous stiffness method (CSM). In line with experimental data on bulk nanocrystalline copper, the specimens exhibit grain coarsening followed by the formation of extrusions and a fatigue strength exponent of −0.10. The method is suitable for characterizing single phases and individual components of further complex systems.

The remarkable progress in additive manufacturing has promoted the design of architected materials with mechanical properties that go beyond those of conventional solids. Their realization, however, leads to architectures with process-induced defects that can jeopardize mechanical and functional performance. In this work, we investigate experimentally and numerically as-manufactured defects in Ti–6Al–4V octet truss lattice materials fabricated with selective laser melting. Four sets of as-manufactured defects, including surface, microstructural, morphological, and material property imperfections, are characterized experimentally at given locations and orientations. Within the characterized defects, material property and morphological defects are quantified statistically using a combination of atomic force microscopy and micro–computed tomography to generate representative models that incorporate individual defects and their combination. The models are used to assess the sensitivity to as-manufactured defects. Then, the study is expanded by tuning defects amplitude to elucidate the role of the magnitude of as-designed defects on the mechanical properties of the lattice material.

Dissolution of oxides in aqueous solutions is fundamentally important for a range of applications and a critical process that determines the chemical durability of industrial ceramics, the performance of nuclear waste forms, and the chemical weathering of minerals. The thermodynamic equilibrium and kinetics of dissolution reactions are key to determining the rate at which oxides dissolve. The increase in collaborative research across disciplines in materials research necessitates a common background to tackle shared scientific problems across different fields. This review selectively examines the fundamentals of dissolution theories that have been developed in chemistry, geochemistry, and materials science, and assembles them into a single collective document for the broader materials science community. Applications of the theories are highlighted using examples from specific areas, but can be similarly applied to other areas. Challenges and future research needs for a predictive-level understanding are discussed in light of the current literature.

We here design and fabricate a new kind of copper matrix composites, where titanium carbide nanoparticles are in situ incorporated into and embedded within the copper matrix, by virtue of laser powder-bed-fusion (L-PBF) process. We made a multiscale examination on the microstructures of the additively manufactured samples, unraveling that there are many unusual microstructural features, including grain refinement, the existence of high-density dislocations, and supersaturation of titanium solute atoms in the as-printed metal matrix composites. These unique microstructural features are mainly interpreted by the intense thermal history and the rapid solidification nature of the L-PBF process. The resultant composites then integrate the most important four strengthening mechanisms in metals: grain boundary strengthening, dislocation strengthening, solid solution strengthening, and second-phase strengthening, rendering this new kind of copper matrix composites a remarkably high yield strength (~490 MPa) and large uniform elongation (~12%), surpassing many high-performance copper matrix composites and copper alloys.

In this study, uniaxial tensile loading simulations were performed on several single crystalline copper nanoporous (NP) structures with varying relative density (RD) via molecular dynamics simulations. From the results, two distinctive deformation patterns were observed: structures with a low RD went through coarsening, and structures with a high RD did not. During coarsening, dislocations are nucleated because of the high surface stress induced by the thin ligaments. These dislocations drive the merging of ligaments as well as nodes and lead to an increase in the differences between the size of nodes and ligaments. The disproportional nodes and ligaments result in a lowered strength. In addition, larger nodes provide more favorable circumstances for the formation of sessile dislocations, which hinder the movement of other propagating Shockley partials and result in strain hardening. Subsequently, lower RD structures offer anomalously high strain-hardening potential, whereas high RD structures show better strength but poor deformability. These results help us in better understanding the plastic behavior of NP structures as a function of their RD.

This work demonstrated the possibility to integrate electrochemical molecularly imprinted polymers (e-MIPs) on microelectrodes to detect organic pollutants. e-MIPs are a cross-linked polymer with specific target binding cavities with a redox tracer inside. e-MIPs were obtained by precipitation copolymerization of ferrocenylmethyl methacrylate as a functional monomer and a redox tracer with ethylene glycol dimethacrylate as a cross-linker and bisphenol A as a target molecule. FTIR and elemental analysis confirmed the presence of ferrocene inside the polymers. Nitrogen adsorption/desorption experiments and binding isotherms demonstrated the presence of binding cavities inside the e-MIP. The electrochemical properties of the e-MIP were characterized in organic/aqueous media before their patterned on microelectrode.

Localized deformation, including that by the deformation-induced shearing martensitic phase transformation, is responsible for hardening and embrittlement in irradiated face-centered cubic alloys. These localized deformation processes can have profound consequences on the mechanical integrity of common structural metals used in extreme radiation environments such as nuclear reactors. This article aims to review and understand exactly how irradiation affects the martensitic phase transformation in face-centered cubic alloys, with an emphasis on austenitic stainless steel, given its ubiquity in the archival literature. The influence of irradiation on stacking fault energy and subsequent implications on the phase transformation are discussed. Mechanisms by which irradiation-induced microstructures enhance the phase transformation are also described, including the surface energy contribution of irradiation-induced cavities (i.e., voids and bubbles) toward the critical martensite nucleation energy, and partial dislocation–cavity interactions. A deformation mechanism map illustrates how irradiation-induced cavities can modulate the martensitic transformation pathway.

Thermal barrier coating is a high-temperature protective technology widely used in industrial gas turbines. However, the failure of coating peeling because of the generation of thermally grown oxide (TGO) at the interface during service hinders its further application. In this study, Raman spectroscopy and wedge indentation are used to determine the TGO residual stress and the interface energy release rate, respectively. The effect of TGO on the interfacial fracture toughness during the growth process was discussed. Raman spectroscopy test results show that the residual stress of TGO is about 0.5 GPa. Wedge indentation test results illustrate that high-temperature heat treatment could accelerate the interface degradation of thermal barrier coatings. Stress analysis and test research demonstrate that the microcracks induced by compressive stress of TGO will propagate with increasing heating time, ending with failure of barrier coatings.