The size distribution curve clearly depict that the average size of the synthesized particles is 256 7 nm (Fig. ). FEG-SEM image of the as-developed quinary FeCoNiCuZn HEA shows equiaxed 8 grain structure, with a nearly-spherical shape (Fig. ). Additionally, bright-field TEM image 9 reveals that the particles are devoid of any clumping, individual metal clusters, or patches (Fig. ). The EDS elemental maps indicate that all the five elements in the HEA are uniformly 11 distributed across the entire sample, with no indications of phase segregation (Fig. ). The 12 homogenous distribution of the constituent elements at the atomic level is also confirmed through 13 high-angle annular dark-field (HAADF) scanning TEM (Fig. ). Further, high-resolution TEM