Volume 23 Issue 1, January 2024

An essential part of developing organic mixed ionic–electronic conducting materials and organic electrochemical transistors is consistent and standardized reporting of the product of charge carrier mobility and volumetric capacitance, the μC* product. This Comment argues that unexpected changes in transistor channel resistance can overestimate this figure of merit, leading to a confusion of comparisons in the literature.

Frustrated by reproducibility in electrical measurements on ferroelectric films, Lane Martin, Jon-Paul Maria and Darrell Schlom discuss tactics to reliably synthesize ‘good’ ferroelectric samples, especially in the search for superior materials and device heterostructures.

Tae Hoon Lee and Zachary P. Smith argue that some of the most exciting materials that could be used for gas separations are metastable or crystalline, with properties that are altered by sample preparation and testing, but there are no widely accepted standards.

Kinetic trapping in supramolecular gels leads to varied morphologies and macroscopic properties. Emily R. Draper and Dave J. Adams discuss subtle experimental effects that can lead to reproducibility issues in these systems.

The materials modelling community is emerging as a champion for reproducible and reusable science. Aron Walsh discusses how FAIR databases, collaborative codes and transparent workflows are advancing this movement.

Joseph Heremans and Joshua Martin discuss the reproducibility of thermoelectric measurements and conclude that the uncertainty on the figure of merit zT is of the order of 15–20%.

Marc Legros, Frédéric Mompiou and Daniel Caillard discuss the different aspects that influence the reproducibility and reliability of characterizations performed using in situ mechanical tests in transmission electron microscopes.

Peng Wu, Tianyi Zhang, Jiadi Zhu, Tomás Palacios and Jing Kong discuss the reproducibility issues in the synthesis and device fabrication of two-dimensional transition metal dichalcogenides that need to be addressed to enable the lab-to-fab transition.

M. I. Eremets, V. S. Minkov, A. P. Drozdov and P. P. Kong discuss the substantial progress made in discovering and developing near-room-temperature superconductivity in hydrogen-rich materials. They focus on achieving reproducibility under the challenging experimental conditions of megabar pressures.

Incorporating additives that contain hydrogen-bonding nanochannels creates nanoconfined polymer gels that are highly stretchable, elastic and insensitive to notch propagation.

Using an electrochemical continuous flow cell, nitrogen reduction to ammonia is rigorously demonstrated through a calcium-mediated approach.

Elastic microphase separation controls the characteristic mesoscopic length scale of bulk bicontinuous materials.

An all-electric switch of the persistent electron swirl in a quantum anomalous Hall state enables researchers to flip the electronic chirality of this quantum state.

By forming a heterostructure interface, and by judicious choice of crystallographic orientation, piezoelectrics are developed that show expansion or contraction along all axes on application of an electric field.

An important but difficult separation, the removal of carbon monoxide from humid gas mixtures comprising oxygen, nitrogen and hydrocarbons, is addressed by exploiting Cu(I) coordination chemistry and framework flexibility.

A traditional physical-reservoir device has limited flexibility and cannot perform well across a range of computing tasks, owing to the fixed reservoir properties of the physical system. However, by exploiting the rich magnetic phase spaces of a single chiral magnet, reservoir properties can be reconfigured. This control enables on-demand optimization of computational performance across diverse machine-learning tasks.

Hybrid organic–inorganic perovskite materials have promise as the photovoltaic technology of the future. A method for spectroscopic optical control reveals how the structural dynamics and vibrations of a perovskite’s organic cations affect the electronic performance of working photovoltaic devices.

Oxidation can degrade the properties and functionality of three-dimensional bulk metallic glasses. However, the formation of percolating oxide networks in metallic glass nanotubes or nanosheets can induce interesting properties, such as a recoverable strain of 10–20% and elastic modulus of 20–30 GPa, which are rarely observed in their bulk counterparts.

Plastic deformation requires the propagation of a kinked profile along dislocations. It is shown that each kink acts as a set of travelling thermal spikes, favouring the nucleation of supplementary kinks and long dislocation jumps that are observed experimentally.

Oxidation normally deteriorates the mechanical properties of metals. But it is now shown that the formation of a percolating oxide network in metallic glass nanotubes can result in an unprecedented superelasticity of 14% at room temperature.

Thermally assisted spin–orbit torque is used to switch the edge current chirality in mesoscopic quantum anomalous Hall devices.

The authors demonstrate that the electrostatic potential originating on the surface of twisted bilayer and multilayer hexagonal boron nitride can be used to generate a moiré potential modulation on adjacent semiconductor layers, enabling the possibility of controlling the properties of this adjacent layer.

Employing a miniaturized spectrometer that combines a metasurface-based spectrometer array and a metalens, angle-resolved spectral imaging is achieved with a wavelength accuracy of 0.17 nm, spectral resolution of 0.40 nm and angular resolution of 4.88 × 10⁻³ rad for a spectrometer with a 4 × 4 μm² footprint.

Current physical neuromorphic computing faces critical challenges of how to reconfigure key physical dynamics of a system to adapt computational performance to match a diverse range of tasks. Here the authors present a task-adaptive approach to physical neuromorphic computing based on on-demand control of computing performance using various magnetic phases of chiral magnets.

Optically stimulated vibrational control for materials has the potential to improve the performance of optoelectronic devices. The vibrational control of FAPbBr₃ perovskite solar cells has been demonstrated, where the fast dynamics of coupling between cations and inorganic sublattice may suppress non-radiative recombinations in perovskites, leading to reduced voltage losses.

Piezoelectrics have longitudinal and transverse piezoelectric coefficients that are opposite in sign. Here, by tuning the interface inversion asymmetry in heterostructures, auxetic systems with positive longitudinal and transverse coefficients are realized, with expansion or contraction along all directions in an electric field.

The production of ammonia via the Haber–Bosch process is carbon-intensive and centralized, but electrochemical methods such as lithium-mediated processes in organic electrolytes could enable decentralized production using renewable energy. Calcium is now shown to mediate nitrogen reduction for ammonia synthesis.

Multi-metal and perovskite oxides are attractive as oxygen evolution electrocatalysts, and thus far the most promising candidates have emerged from experimental methodologies. Active-learning models supplemented by structural-characterization data and closed-loop experimentation can now identify a perovskite oxide with outstanding performance.

Chemical adsorption of CO on open metal sites enables separation from other gases but leads to selectivity and stability issues. Quasi-open metal sites in metal–organic frameworks are proposed here, which are accessible only by CO-induced structural transformation, enabling CO separation to 9N purity.

Production of bulk bicontinuous materials is limited by the ability to make uniform microarchitectures across large volumes. Here elastic microphase separation is used to fabricate bicontinuous materials with a homogeneous microstructure, with feature sizes tuned by the matrix stiffness.

Simultaneously highly elastic and deformable gels that maintain their mechanical properties have remained elusive. Here, using in situ polymerization confined within nanochannels, the authors prepare hysteresis-free gels insensitive to crack propagation.

Self-rectifying magnetoelectric metamaterials with nonlinear responses generate electrical pulse sequences that enable precisely timed remote neural stimulation and restoration of sensory motor responses in vivo.

Pro-regenerative biomaterials for the treatment of muscle injury induce the proliferation of a dendritic cell population associated with cross-presentation and self-tolerance, promoting a pro-regenerative immune environment to aid muscle wound healing.