Nanoscale Phase Engineering and Magnetic Property Enhancement in High-Entropy Alloy Nanoparticles by Continuous Microparticle Laser Fragmentation in Liquid
Year: 2026
Type: preprint
Abstract: High-entropy alloy nanoparticles (HEA NPs) offer compositional and structural tunability for applications, like water splitting, H2O2 production, or magnetocaloric technologies. Therefore, the interplay between composition, structure, and functionality is of significant interest for materials´ functionality optimization. Microparticle laser fragmentation in liquid flow (MP-LFL) is an emerging scalable method for nanoalloy production, but remains underexplored for HEA NPs. Here, we investigate CrFeCoNiX (X = Ga, Cu, Mo) HEA NPs fabricated by MP-LFL in ethanol and examine how compositional variations affect elemental homogeneity, size, phase structure, and magnetic properties. Microscopy, diffraction, size analysis, and magnetometry reveal particle sizes of 6-7 nm and pronounced differences in phase structures, ranging from single-phase fcc and biphasic fcc/bcc to amorphous structures, partially contrasting the initial feedstock microparticle structures. The low saturation magnetization (Ms, 310 K) of the as-synthesized superparamagnetic NPs increases strongly after in situ annealing by approximately 4-, 3-, or 24-fold for Ga-, Cu-, and Mo-containing NPs, respectively, coinciding with structural and elemental rearrangements. In contrast, the feedstock microparticles show no comparable increase, highlighting the role of the initial phase constitution in determining magnetic properties. Moreover, MP-LFL enables production of ~0.4 g h-1, with a record picosecond MP-LFL mass yield of ~60%, leaving room for further optimization and high throughput.
Source: ChemRxiv
Language: English
Topic: High Entropy Alloys Studies
Subfield: Mechanical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
Funder: Deutsche Forschungsgemeinschaft
Awards: G1605355240, TRR 270: HystereseDesign magnetischer Materialien für effiziente Energieumwandlung, Kolloidale „High Entropy Alloy (HEA)“ Nanopartikel durch kinetisch kontrollierte Laserablationssynthese in FlüssigkeitenBildungsmechanismus und deren Integration in zweiphasige KernSchaleMorphologien
OpenAlex ID: W7222715433