Research articles

Vanadium dioxide is well known to display a metal-insulator transition, making it an attractive option for functional devices. Here, the growth of single crystal VO₂ microtube arrays is achieved via a thermal oxidation process that is faster and simpler than many existing fabrication technologies.

Paper is a ubiquitous material used in a range of applications, many of which expose it to fatigue loading. Here, a detailed study of the mechanical response of paper during high‐cycle fatigue loading is reported, with fiber fracture found to be a key degradation mechanism.

Strain engineering can enhance oxygen transport in cathodes in solid oxide fuel cells. Here, atomic scale imaging is used to probe local structures in tensile- and compressive-strained La_0.6Sr_0.4CoO_3-δ films, revealing higher oxygen vacancy concentration in tensile films, and vacancy ordering.

The pairing symmetry of superconducting Sr₂RuO₄ is debated, and analysis is complicated by difficulties in preparing high-quality thin films. Here, thin films of Sr₂RuO₄ are reproducibly grown by pulsed laser deposition with a Sr₃Ru₂O₇ single crystalline target, and the structural defect responsible for the suppression of the superconductivity on thin films has been identified.

Shock loading of materials alters the microstructure and considerably degrades mechanical performance. Here, shock loading of a nanocrystalline Cu–Ta alloy is found to induce minor changes to microstructure and mechanical performance, attributed to the annihilation of defects during deformation.

Organic materials are attractive for photovoltaic interfaces in bioelectronics, but are limited by adhesion in aqueous environments and responsiveness in the visible spectrum. Here, an organic interface is reported for neuronal stimulation in the near-infrared and tested on explanted mice retinas.

The nephrons in the kidney transport ions and organic molecules, but may not work effectively in patients with kidney disease. Here, a synthetic nephron is created, based on activated wafer electrodeionization, and shown to enable the transport of several physiologically relevant ions.

Coherent x-ray diffractive imaging is a powerful technique for determining strain on the nanometer scale. Here, it is used to image semiconducting GaAs_1-yN_y structures on a GaAs substrate and to measure strain, demonstrating its potential for studying highly strained interfaces in devices.

Improving the lifetime of organic light-emitting diodes requires that degradation processes are understood. Here it is demonstrated that magnetic field effects can be used as a non-destructive indicator of device degradation.

Rational design of photoelectrodes is a key requirement to boost conversion efficiency of photoelectrochemical redox flow cells. Here, band alignment design and surface coverage control are used to design single-photon photoelectrodes that achieve 9.4% solar-to-chemical conversion efficiency.

Superconductivity was recently observed in Nd_0.8Sr_0.2NiO₂ films. Here, superconductivity is found to be absent in bulk polycrystalline samples of Sr-doped NdNiO₂, raising questions regarding the origin of superconductivity in this material.

Controlling the microstructure of thin films is vital for tuning their properties. Here, machine learning is applied to obtain synthesis-composition-microstructure relationships in the form of structure zone diagrams for thin films, enabling microstructure prediction.

The ubiquitous Casimir interaction arises from electromagnetic fluctuations exchanged between objects. Here, by determining the optical conductivity components for type I and II Weyl semimetals, it is found that the Casimir interaction has strong similarities to metals, while the nontrivial topology plays a secondary role.

Uranium dioxide is commonly doped with chromium to improve its performance as a nuclear fuel. Here, with the aid of ab initio simulations and re-evaluation of experimental data, the oxidation state of chromium in the uranium dioxide lattice is identified as +2, not the widely believed +3.

Brick-and-mortar composite structures found in nature are known for their superior mechanical performance. Here, computational approaches are used to understand the key design features that control mechanical behavior, providing guidance for the design of improved composites.

Cu₂O is of great interest for its excitonic properties, yet challenges in its fabrication means that most experiments focus on naturally occurring samples. Here, scalable thermal oxidation is reported for the growth of Cu₂O with low-defect content, allowing the observation of Rydberg excitons.

Spider silk is well known for its high toughness. Here, a comprehensive study of the simultaneous effect of strain rate and humidity on toughness is reported, revealing that toughness is highest under mildly humid conditions and at high strain rates, similar conditions to those in nature.

Nano-scale coatings are important for controlling the functional behavior of surfaces. Here, a deposition process in liquid hydrocarbons is reported for metal oxides, in which a thin water coating on the substrate reacts with chemical precursors, forming a nano-scale layer.

The intrinsic flexibility of molecules opens the door to unusual physical properties. Now, a large thermal expansion coefficient of 980 ± 110 × 10⁻⁶ K⁻¹ is observed by scanning probe microscopy in a supramolecular network on a gold surface.

Controlling spatial conductivity in graphene is important for plasmonic devices, yet conductivity patterning typically changes the electromagnetic environment. Here, teraherz plasmons in graphene are confined to specific regions via a patterned zinc oxide gate, reducing electromagnetic coupling.