Highlights

The Cr2+-based compounds, A2CrX4, where A = M+ (e.g., K+, Cs+, Rb+) or RNH3+ (e.g., MeNH3+) and X = Cl-, Br-, are an underexplored family of lead-free layered metal-halide perovskites. These compounds attracted a great deal of interest in the 1970s and 1980s after their "transparent ferromagnetism" was discovered, but they have received virtually no attention since, perhaps because they are extremely unstable in air. Further investigation into their chemistry and properties is warranted.

UW Chemical Engineering Prof. Lilo Pozzo’s ‘23/’24 Seed project aims to serve the materials community by advancing AI-driven experimentation and analysis for broad adoption and acceleration of materials research. Pozzo has engaged in highly collaborative projects to advance self-driving laboratory (SDL) technologies and to help others adopt them for their own workflows.

Wisconsin MRSEC researchers have leveraged the power of machine learning to tame the complexity of polycrystalline materials and predict their properties. They have developed a graph neural network approach that predicts materials properties with >98% accuracy 90,000 times faster than competing methods. They applied this model to predict magnetostriction, which quantifies the size change of a material induced by a magnetic field.

Researchers in the Wisconsin MRSEC have shown that depositing onto an alignment substrate creates better glass films that are anisotropic biaxially, meaning they are aligned in the plane of the substrate as well as out of plane. The in-plane orientation of the molecules affect how they interact with light and conduct electricity. In general, more alignment is better for applications ranging from flexible transistors to OLEDs to organic photovoltaics.

The UC San Diego team has achieved the assembly of checkerboard lattices from colloidal nanocrystals that harness the effects of multiple, coupled physical forces at disparate length scales (interfacial, interparticle, and intermolecular) and that do not rely on chemical binding. Colloidal Ag nanocubes were bi-functionalized with mixtures of hydrophilic and hydrophobic surface ligands and subsequently assembled at an air-water interface.

UC San Diego researchers developed and programmed cyanobacterial composite materials to remediate an organic dye pollutant. 

Optical properties of plasmonic ITO nanocrystal gels, assembled by thermoreversible cobalt terpyridine links, were tuned systematically based on the size and doping concentration of the nanocrystals and length of the custom ligand molecules. Correlation of optical shifts upon assembly with nanocrystal spacing deduced by small angle X-ray scattering was used to develop a universal structure-property relationship that was validated by large-scale optical simulations on gels made using Brownian dynamics simulations.

UT Austin researchers developed synthetic multi-arm poly(ethylene glycol) (PEG) hydrogels with three different dynamic covalent linking chemistries. They exhibit non-monotonic flow curves under steady shear, with shear thickening behavior that depends on the crosslinking bond exchange kinetics and polymer concentration.

This study by UT Austin researchers demonstrates the rich electronic structures in large-angle twisted bilayer WSe2 exemplified by the formation of multiple mini-gaps near the valence band maximum. By tuning the commensurability, the moiré material properties and functionalities can be precisely engineered.

UT Austin MRSEC researchers show that ferroelectric polar domains formed in a twisted hexagonal boron nitride (t-hBN) substrate can modulate light emission from an adjacent semiconductor monolayer. The abrupt change in electrostatic potential across the domains produces an in-plane electric field (E-field) and leads to a remarkably large exciton Stark shift in the adjacent MoSe2 monolayer, previously only observable in p-n junctions created by the advanced e-beam lithography tools. Both the spectrum and spatial pattern of the light emission of the monolayer are periodically modulated by the remote moire potential imposed by the t-hBN substrate.