Articles in 2022

Rare-earth hexaborides are of interest for their pressure-induced phase transformations, but further understanding is needed regarding their failure mechanisms. Here, nanoindentation of EuB₆ causes dislocation-mediated shear band formation, driven by the breaking of boron-boron bonds.

Theoretical studies have predicted a Kondo effect driven charge density wave order with two sublattices characterized by different single-ion Kondo temperatures. Here, X-ray photoemission spectroscopy provides evidence of a dual Kondo effect in the charge ordered phase of YbPd, elucidating the mechanism of its zero thermal expansion.

Metal halide to perovskite phase conversion is a facile approach for synthesizing high-quality perovskite semiconductors for optoelectronic applications. Here, these reactions are investigated at the nanoscale via in-situ x-ray scattering, revealing links between reaction kinetics, structure and composition.

Characterizing fission products in uranium dioxide nuclear fuel is important for predicting its long-term properties. Here, machine learning is used to mine microscopy images of precipitates and nanoscale gas bubbles in high-burn-up fuels, providing detailed structural insight of nanoscale fission products.

Topological insulator nanowires are interesting because, in the presence of superconductivity, they may host elusive Majorana fermions. Here, superconductivity in (Bi_1−xSb_x)₂Te₃ topological-insulator nanowires is realized by using palladium diffusion, providing a tunable platform for Majorana zero modes.

Hall effect measurements are often used to identify chiral spin textures in materials through the topological Hall effect, but similar Hall signals can arise due to sample inhomogeneity or experimental issues. Here, SrRuO3 is used as a model system to discuss the ambiguity in Hall signals, questioning the reliability of Hall effect measurements as evidence of chiral spin textures.

Mg-Li alloys are attractive for their low density, yet typically suffer from limited strength and rapid corrosion. Here, both these issues are addressed in a Mg-Li-Al alloy by friction stir processing followed by liquid CO₂ quenching, resulting in a durable microstructure.

α-Sn and SnGe alloys are a promising new class of quantum materials, but device integration requires they be grown on silicon. Here, germanium-doped α-Sn is grown on a native oxide on a silicon substrate via a reversed β-Sn to α-Sn phase transformation.

Lightsails accelerated by ground-based laser arrays are a candidate technology to send probes into deep space in a timeframe compatible with human life. Here, an optimization study identifies the most promising multilayer structures that maximize propulsion efficiency, thermal stability, and mechanical stiffness.

High-throughput materials discovery can reduce the time taken to identify high-performing materials. Here, compositionally-graded films are fabricated in a binary halide perovskite system, of interest for solar cells, and their stability investigated during artificial aging.

The BaSnO₃ perovskite is promising for electronic applications due to its transparency and high room-temperature mobility, but its effective masses, band gaps, and absorption edge are still controversial. Here, a combined theoretical and experimental study provides a consistent picture of its electronic structure and optical excitations.

In 2D materials devices, understanding interfacial reactions in the formation of metal contacts is important for tuning their properties. Here, electron microscopy reveals the formation of an intermetallic contact layer, characterized by an efficient edge-type charge transfer, when nickel, chromium, or titanium is deposited onto black-arsenic films.

Ultrafast low-energy electron diffraction allows the direct observation of atomic motions in structural transitions, but is accompanied by a strong photoinduced emission resulting in surface field effects. Here, these effects are quantified, enabling the isolation of the structural dynamics of interest.

Ptychography is an imaging technique based on algorithmic reconstruction of diffraction patterns that improves the spatial resolution of scanning transmission X-ray microscopy. Here, the possibility of ptychography at the carbon K-edge is demonstrated on carbon nanotube bundles, using a defocused beam to reduce radiation damage.

Proteins can be patterned in photoresponsive hydrogels by the application of light. Here, a two-photon lithography-based approach allows for the 3D patterning of proteins with micrometer precision, demonstrated for a photoinstructive hydrogel and relevant to a range of proteins.

Virus-like particles are promising for drug delivery systems and vaccine development, but controlling their size and morphology is challenging. Here, amino acid sequences are inserted into MS2 bacteriophage virus-like particles, with their size and shape being controlled by varying the insert used.

Chemical vapor deposition of diamond typically results in the faster growth of the (110) facet, but achieving large-area and high-quality surfaces is challenging and requires post-growth processing. Here, the authors present a systematic characterization of the structure and stability of oxygen-terminated diamond (110) surfaces.

The COVID-19 pandemic highlights the importance of tests for assessing antibody titer, such as for determining vaccine efficacy. Here, a fast-operating organic electrochemical transistor is shown to assess the cytopathic effect caused by the SARS CoV-2 virus on Vero E6 cells in real-time.