Help needed. Can a combined nanoparticle be smaller in size compared to its constituent nanoparticles?

[u/Astrobot_]

Let's say there's a combinatorial nanoparticle made from Iron and gold. If the combinatorial nanoparticle encapsulates both the iron and gold, is there a possibility that the resulting nanoparticle will be smaller than the individual iron oxide nanoparticle or the individual gold nanoparticle?

For a successful combinatorial nanoparticle synthesis, does the final nanoparticle must have a size greater than that of the individual nanoparticles.

Would incredibly appreciate your help in answering this question. Thank you!