In Situ Visualization of Electron Beam-Driven High-Entropy Alloy Crystallization

Area of Science:

• Materials Science
• Nanotechnology
• Solid-state Chemistry

Background:

• Achieving uniform high-entropy alloy (HEA) nanoparticles via reduction-based synthesis is difficult due to elemental variations.
• Controlling elemental reduction, diffusion, and phase stability is crucial for HEA synthesis.

Purpose of the Study:

• To visualize and understand the electron beam-induced crystallization of amorphous high-entropy glycerolate (HE-glycerolate) films.
• To investigate the mechanism of forming single-phase face-centered cubic (fcc) HEA nanoparticles with controlled morphology.

Main Methods:

• In situ transmission electron microscopy (TEM) was used to observe the crystallization process.
• Amorphous HE-glycerolate films (Mg, Mn, Co, Ni, Zn) were subjected to electron beam irradiation.

Main Results:

• Electron beam irradiation induced crystallization via phase separation, radiolytic reduction, and atomic rearrangement.
• This process yielded single-phase fcc HEA nanoparticles with uniform cuboidal morphology and dominant {100} facets.
• The electron beam pathway provided finer control over composition and morphology than thermal annealing by limiting atomic mobility.

Conclusions:

• Electron beam-driven crystallization offers a novel, low-temperature route for synthesizing uniform HEA nanoparticles.
• Controlling atomic mobility is essential for achieving stable, compositionally homogeneous multielement solid solutions.
• The findings provide a foundation for designing scalable synthesis strategies for advanced HEA materials.