Solid-state dewetting is the process by which thin solid films break up and retract on a substrate, forming nanostructures. While dewetting of single-crystalline films is understood as a surface-energy-driven process mediated by surface diffusion, polycrystalline films exhibit additional complexity due to the presence of grain boundaries. Most theoretical and computational studies have focused on single-crystalline dewetting. Here, we present the application of the grand-potential multi-phase-field model to the dewetting of thin polycrystalline films in three dimensions, reproducing the key phenomenology of this process. By considering isotropic interface/surface energy, we illustrate its consistency with predictions based on energetic arguments and the morphological evolution towards equilibrium. We also provide novel analytical criteria for the onset of three-dimensional dewetting, serving as fundamental theoretical benchmarks, and highlight the critical role of triple junctions. Moreover, we unveil the dewetting behavior of polycrystalline patches, extending the scenarios of their single-crystalline counterparts.

To enhance coercivity in high-performance Nd-Fe-B magnets, resource critical heavy rare earth elements Dy and Tb are used in the grain boundary diffusion process (GBDP). However, GBDP is limited to thin magnets, typically around 4 mm which restricts their applications. Here, we report a novel processing route by combining the GBDP process with a magnet stacking architecture using a < 10 μm thin low-melting multi-element Tb₁₀Pr₆₀Al₁₀Cu₁₀Ga₁₀ alloy which has now a dual function: it acts as a binder between the magnet segments and is at the same time an efficient source for core-shell formation on the individual crystallite level. This not only enables production of magnets with any thickness without losing performance, but also paves the way for resource efficiency using cheap and abundant light rare earth Cerium in hybrid magnets by strategically stacking different grades with tailored chemical compositions resulting in a unique macroscopic magnetic hardening.

The strength-ductility trade-off remains a critical challenge in additively manufactured stainless steels due to their process-induced microstructures. In this study, type 316 stainless steel (SS316) was fabricated via a novel metal additive manufacturing technique employing powder sheets (MAPS), demonstrating exceptional strength with considerable ductility. To elucidate the mechanisms underlying this performance, quasi-in-situ electron backscatter diffraction (EBSD) was employed to monitor the microstructural evolution and deformation behaviour of SS316 produced by MAPS in comparison with laser powder bed fusion (LPBF). LPBF exhibits extensive deformation twinning that facilitates broad strain accommodation with sustained hardening, whereas MAPS shows dense dislocation storage within cellular substructures, leading to pronounced strain hardening and superior strength. The limited twinning activation in MAPS constrains strain redistribution, localising plasticity along cellular subgrain boundaries. The interplay between dislocation-dominated hardening and twinning-limited plasticity provides MAPS-processed SS316 with enhanced mechanical performance and highlights the importance of processing strategy in tailoring deformation pathways.

The influence of pulsed nitrogen gas flow on microstructure and nitrogen-vacancy (NV) center formation was systematically investigated in polycrystalline diamond layers synthesized by microwave plasma chemical vapor deposition. Compared with static flow, gas pulsing enabled precise control of nitrogen-related radicals and induced a transition from microcrystalline to nanocrystalline diamond, accompanied by variations in residual stress and NV emission. Under optimized nitrogen flow, a bimodal structure emerged, comprising (001)-oriented, flake-like microcrystalline grains embedded in nanocrystalline diamond. Confocal optical analysis revealed that negatively charged NV (NV − ) centers were preferentially localized within highly crystalline grains, whereas neutral NV (NV 0 ) centers predominated at grain boundaries, forming spatially separated NV − -rich clusters. Relaxometry demonstrated that the longitudinal relaxation times of flake-like grains were comparable to those of high-quality single-crystal diamond. These findings demonstrate that pulsed nitrogen modulation provides an effective strategy for tailoring diamond microstructure and optimizing NV center formation, offering significant potential for quantum applications.