Multidimensional thermally-induced transformation of nest-structured complex Au-Fe nanoalloys towards equilibrium

Abstract Bimetallic nanoparticles are often superior candidates for a wide range of technological and biomedical applications owing to their enhanced catalytic, optical, magnetic properties, which better than monometallic counterparts. Most properties strongly depend on chemical composition, crystallographic structure, phase distribution. However, little is known how crystal the nanoscale, transforms over time at elevated temperatures, even though this knowledge highly relevant in case used in, e.g., high-temperature catalysis. Au-Fe promising bimetallic system where low-cost Fe combined with catalytically active plasmonic Au. Here, we report situ temporal evolution crystalline ordering nanoparticles, obtained from modern laser ablation liquids synthesis. Our in-depth analysis, complemented by dedicated atomistic simulations, includes detailed structural characterization X-ray diffraction transmission electron microscopy as well atom probe tomography reveal elemental distributions down single resolution. We show that initially exhibit complex internal nested nanostructures compositions, distributions, size-depended microstrains. The temperature induces diffusion-controlled recrystallization merging, resulting formation face-centered-cubic ultrastructure contact body-centered cubic phase, demonstrates metastability these structures. Uncovering unique features could be attractive fundamental viewpoint they give further insights into nanoparticle mechanism under non-equilibrium conditions. Furthermore, evaluation structure changes upon heating potentially process utilization during