Phase Transition of Cubic Ice to Hexagonal Ice during Growth and Decomposition.

Ice, one of the most enigmatic materials on Earth, exhibits diverse polymorphism, with research mainly focusing on the most commonly observed phases: hexagonal ice (I), cubic ice (I), and stacking-disordered ice (I). While their formation or structural changes are crucial for advancements in cloud science, climate modeling, and cryogenic technology, the molecular mechanisms driving these phenomena remain unexplored. Herein, utilizing cryogenic transmission electron microscopy, we investigate the formation of ice at two different temperatures, demonstrating a size-dependent phase shift from I to I.

Layer-Controlled Growth of Single-Crystalline 2D BiOSe Film Driven by Interfacial Reconstruction.

As semiconductor scaling continues to reach sub-nanometer levels, two-dimensional (2D) semiconductors are emerging as a promising candidate for the post-silicon material. Among these alternatives, BiOSe has risen as an exceptionally promising 2D semiconductor thanks to its excellent electrical properties, attributed to its appropriate bandgap and small effective mass. However, unlike other 2D materials, growth of large-scale BiOSe films with precise layer control is still challenging due to its large surface energy caused by relatively strong interlayer electrostatic interactions.

Non-Equilibrium Sodiation Pathway of CuSbS.

Binary metal sulfides have been explored as sodium storage materials owing to their high theoretical capacity and high stable cyclability. Nevertheless, their relative high charge voltage and relatively low practical capacity make them less attractive as an anode material. To resolve the problem, addition of alloying elements is considerable.

Reducing Time to Discovery: Materials and Molecular Modeling, Imaging, Informatics, and Integration.

Multiscale and multimodal imaging of material structures and properties provides solid ground on which materials theory and design can flourish. Recently, KAIST announced 10 flagship research fields, which include KAIST Materials Revolution: Materials and Molecular Modeling, Imaging, Informatics and Integration (M3I3). The M3I3 initiative aims to reduce the time for the discovery, design and development of materials based on elucidating multiscale processing-structure-property relationship and materials hierarchy, which are to be quantified and understood through a combination of machine learning and scientific insights.

Graphene Liquid Cell Electron Microscopy of Initial Lithiation in CoO Nanoparticles.

As it governs the overall performance of lithium-ion batteries, understanding the reaction pathway of lithiation is highly desired. For CoO nanoparticles as anode material, here, we report an initial conversion reaction pathway during lithiation. Using graphene liquid cell electron microscopy (GLC-EM), we reveal a CoO phase of the initial conversion product as well as morphological dynamics during CoO lithiation.