High Radiation Resistance in the Binary W-Ta System Through Small V Additions: A New Paradigm for Nuclear Fusion Materials.

Refractory High-Entropy Alloys (RHEAs) are promising candidates for structural materials in nuclear fusion reactors, where W-based alloys are currently leading. Fusion materials must withstand extreme conditions, including i) severe radiation damage from energetic neutrons, ii) embrittlement due to H and He ion implantation, and iii) exposure to high temperatures and thermal gradients. Recent RHEAs, such as WTaCrV and WTaCrVHf, have shown superior radiation tolerance and microstructural stability compared to pure W, but their multi-element compositions complicate bulk fabrication and limit practical use.

Heterogeneous Morphologies and Hardness of Co-Sputtered Thin Films of Concentrated Cu-Mo-W Alloys.

Heterogeneous microstructures in Cu-Mo-W alloy thin films formed by magnetron co-sputtering immiscible elements with concentrated compositions are characterized using scanning transmission electron microscopy (STEM) and nanoindentation. In this work, we modified the phase separated structure of a Cu-Mo immiscible system by adding W, which impedes surface diffusion during film growth. The heterogeneous microstructures in the Cu-Mo-W ternary system exhibited bicontinuous matrices and agglomerates composed of Mo(W)-rich phase.

Structural alignment of ZnO columns across multiple monolayer MoS layers as compliant substrates.

Understanding the behavior of materials in multi-dimensional architectures composed of atomically thin two-dimensional (2D) materials and three-dimensional (3D) materials has become mandatory for progress in materials preparation various epitaxy techniques, such as van der Waals and remote epitaxy methods. We investigated the growth behavior of ZnO on monolayer MoS as a model system to study the growth of a 3D material on a 2D material, which is beyond the scope of remote and van der Waals epitaxy. The study revealed column-to-column alignment and inversion of crystallinity, which can be explained by combinatorial epitaxy, grain alignment across an atomically sharp interface, and a compliant substrate.

Compositionally-Driven Formation Mechanism of Hierarchical Morphologies in Co-Deposited Immiscible Alloy Thin Films.

Co-deposited, immiscible alloy systems form hierarchical microstructures under specific deposition conditions that accentuate the difference in constituent element mobility. The mechanism leading to the formation of these unique hierarchical morphologies during the deposition process is difficult to identify, since the characterization of these microstructures is typically carried out post-deposition. We employ phase-field modeling to study the evolution of microstructures during deposition combined with microscopy characterization of experimentally deposited thin films to reveal the origin of the formation mechanism of hierarchical morphologies in co-deposited, immiscible alloy thin films.