Finding the fivefold path: Crystals formed in nature or synthesized in a lab can have domains with different orientations that are called twins. Having five of these domains is relatively common, but how these fivefold twins form is still a mystery. Song et al. combined in situ transmission electron microscope observations with simulations to find two different pathways for forming fivefold twins in gold, platinum, and palladium nanoparticles. This combination provides a key insight into the twin-forming process, which might be exploited for developing nanoparticles suitable for a variety of applications. Science , this issue p. 40

Precipitates are crucial for crafting mechanically strong metallic materials. In this work, we report the dislocation cutting of B2 (ordered body-centered cubic) nanoprecipitates, typically considered nonshearable intermetallics, in a lightweight compositionally complex steel during cryogenic tensile loading. Shearing is enabled by the high strength level for dislocation glide within the austenitic matrix, attributed to the substantial strengthening from subnanoscale local chemical ordering zones and the pronounced solid solution strengthening from the multiprincipal elements in the matrix. This mechanism not only harnesses the intense strengthening and strain hardening provided by otherwise impenetrable brittle nanoprecipitates but also introduces ductility through their sequential shearing with ongoing deformation. Our steel thus showcases ultrahigh cryogenic tensile strength up to 2 gigapascal at a remarkable tensile elongation of 34%. This study reveals a new strategy for designing high-performance structural materials.

The discovery of an intrinsic ferromagnetic axion insulator MnB _i8 Te ₁₃ paves the way for quantized magnetoelectric effect.